SUB-BASIN EVALUATION
Strategic Environmental Assessment of the
Hydropower Sector in Myanmar
© International Finance Corporation 2017. All rights reserved.
2121 Pennsylvania Avenue, N.W.
Washington, D.C. 20433
Internet: www.ifc.org
The material in this work is copyrighted. Copying and/or transmitting portions or all of this work without
permission may be a violation of applicable law. IFC encourages dissemination of its work and will
normally grant permission to reproduce portions of the work promptly, and when the reproduction is for
educational and non-commercial purposes, without a fee, subject to such attributions and notices as we
may reasonably require.
IFC does not guarantee the accuracy, reliability or completeness of the content included in this work, or for
the conclusions or judgments described herein, and accepts no responsibility or liability for any omissions
or errors (including, without limitation, typographical errors and technical errors) in the content
whatsoever or for reliance thereon. The boundaries, colors, denominations, and other information shown
on any map in this work do not imply any judgment on the part of The World Bank concerning the legal
status of any territory or the endorsement or acceptance of such boundaries. The findings, interpretations,
and conclusions expressed in this study do not necessarily reflect the views of the Executive Directors of
The World Bank or the governments they represent.
The contents of this work are intended for general informational purposes only and are not intended to
constitute legal, securities, or investment advice, an opinion regarding the appropriateness of any
investment, or a solicitation of any type. IFC or its affiliates may have an investment in, provide other
advice or services to, or otherwise have a financial interest in, certain of the companies and parties.
All other queries on rights and licenses, including subsidiary rights, should be addressed to IFC’s
Corporate Relations Department, 2121 Pennsylvania Avenue, N.W., Washington, D.C. 20433.
International Finance Corporation is an international organization established by Articles of Agreement
among its member countries, and a member of the World Bank Group. All names, logos and trademarks
are the property of IFC and you may not use any of such materials for any purpose without the express
written consent of IFC. Additionally, “International Finance Corporation” and “IFC” are registered
trademarks of IFC and are protected under international law.
Cover photo credit: Tessa Bunney 2017
ACKNOWLEDGEMENTS
The Strategic Environmental Assessment (SEA) for the Hydropower Sector in Myanmar would not
have been possible without the leadership of the Ministry of Natural Resources and Environmental
Conservation (MONREC) and Ministry of Electricity and Energy (MOEE), with support from the
Australian government. Myanmar government focal points for this study including Daw Thandar
Hlaing, U Htoo Aung Zaw, U Nay Lin Soe and U Sein Aung Min played a critical role at all stages of
the SEA process. U Hla Maung Thein, Daw Mi Khaing, U Tint Lwin Oo and Dr. San Oo guided the
work of the SEA and focal points. These individuals provided technical inputs and facilitated working
relations.
International Centre for Environmental Management (ICEM) and Myanmar Institute for Integrated
Development (MIID) prepared the SEA with IFC. ICEM’s technical team included Jeremy Carew-
Reid, Rory Hunter, Edvard Baardsen, Jens Grue Sjørslev, John Sawdon, Kyaw Moe Aung, Lina Sein
Myint, Lois Koehnken, Lwin Wai, Mai Ky Vinh, Peter-John Meynell, Rick Gregory, Stephen Gray,
Vuong Thu Huong, Win Myint, Yan Min Aung, and Yinn Mar Swe Hlaing.
The IFC team guiding the SEA included Kate Lazarus, Pablo Cardinale, Matt Corbett, Naung San Lin
and Tiffany Noeske. Vikram Kumar, IFC Country Manager for Myanmar provided valuable inputs.
We also recognize the ongoing support of IFC’s Environmental and Social Governance Department
and Infrastructure Department, as well as the feedback and collaboration received from colleagues at
The World Bank.
We are grateful to the dedicated civil society organizations, NGOs, SEA Advisory and Expert
Groups, and the Hydropower Developers’ Working Group for contributing to this study and working
to advance sustainability in Myanmar’s hydropower sector.
ABBREVIATIONS
CIA Cumulative impact assessment
Cn loss of nutrients and organic matter
Cs Salinization
ESIA Environmental and social impact assessment
EST Estimated
FFI Fauna & Flora International
GIS Geographic information system
GoM Government of Myanmar
HDWG Hydropower Developers’ Working Group
HPP Hydropower project
IFC International Finance Corporation
IWMI Integrated Water Management Institute
KBA Key biodiversity areas
KIO Kachin Independence Army, Kachin Independence Organization
km kilometer
KNU Karen National Union
MIID Myanmar Institute for Integrated Development
MIMU Myanmar Information Management Unit
MOEE Ministry of Electricity and Energy
MONREC Ministry of Natural Resources and Environmental Conservation
MW Megawatt
NR Natural resources
PA Protected area
PRC People’s Republic of China
SAZ Self-administered Zone
SB Sub-basin
SDF Sustainable Development Framework
SEA Strategic Environmental Assessment
SEP Stakeholder Engagement Plan
SN Soil renewal
WCS Wildlife Conservation Society
Wd Terrain deformation/mass movement
WWF World Wildlife Fund for Nature
i
TABLE OF CONTENTS
ABBREVIATIONS ...................................................................................................................... I
TABLE OF CONTENTS ............................................................................................................ II
LIST OF FIGURES ................................................................................................................... III
LIST OF TABLES ..................................................................................................................... III
1 INTRODUCTION .......................................................................................................... 4
1.1 Evaluation Criteria ..................................................................................................... 5
1.2 Sub-basin Evaluation Summary Sheets ................................................................. 7
1.3 Information Limitations ............................................................................................ 7
2 METHODOLOGY ......................................................................................................... 9
2.1 Geomorphology and Sediment Transport ....................................................................... 9
2.2 Aquatic Ecology and Fisheries...................................................................................... 15
2.3 Terrestrial Biodiversity ................................................................................................. 22
2.4 Social and Livelihoods .................................................................................................. 25
2.5 Peace and Conflict ........................................................................................................ 27
3 NATIONAL MAPS AND SUMMARY TABLES ......................................................... 30
3.1 Summary ....................................................................................................................... 30
4 SUB-BASIN EVALUATION SUMMARY SHEETS .................................................... 37
4.1 Ayeyarwady Basin ........................................................................................................ 37
4.2 Chindwin Basin ............................................................................................................. 95
4.3 Bago and Myit Mo Hka Basin .................................................................................... 119
4.4 Bilin Basin .................................................................................................................. 122
4.5 Sittaung Basin ............................................................................................................. 125
4.6 Mekong Basin ............................................................................................................. 134
4.7 Thanlwin Basin ........................................................................................................... 146
4.8 Tanintharyi Coastal Basins ......................................................................................... 179
4.9 Rakhine Coastal Basins............................................................................................... 188
4.10 Surma-Meghna Basin.................................................................................................. 211
REFERENCES ....................................................................................................................... 215
ii
LIST OF FIGURES
Figure 1.1: Myanmar sub-basin .............................................................................................................. 5
Figure 2.1: Soil degradation for Myanmar showing widespread loss of topsoil..................................... 9
Figure 2.2: Strahler Order 4+ rivers considered as a special case for “connectivity” ........................... 12
Figure 2.3: Geomorphic land classes based on geology and slope ....................................................... 13
Figure 2.4: Catchment areas and average annual flow rates of the major river basins in Myanmar used
to derive catchment runoff .................................................................................................................... 14
Figure 2.5: Key biodiversity areas and intact forests in the Sittaung sub-basins .................................. 25
Figure 3.1: Geomorphology baseline value ratings .............................................................................. 31
Figure 3.2: Aquatic ecology and fisheries baseline value ratings ......................................................... 32
Figure 3.3: Terrestrial biodiversity basely ............................................................................................ 33
Figure 3.4: Social and livelihoods baseline value ratings ..................................................................... 34
Figure 3.5: Conflict baseline value ratings ........................................................................................... 35
LIST OF TABLES
Table 1.1: Indicators used to evaluate each theme .................................................................................. 6
Table 1.2: Sub-basin evaluation sheet format and data sources sub-basin evaluation ............................ 7
Table 2.1: Summary of geomorphology and sediment transport parameters, input information, and
rationale for inclusion in the analysis ................................................................................................... 10
Table 2.2: Characteristics of sub-basins with existing or under-construction hydropower projects and
connectivity adjustment factor .............................................................................................................. 11
Table 2.3: Weightings for determining sediment production potential ................................................ 13
Table 2.4: Combined classes and total length of river reaches in Myanmar (Source: Lehner &
Dallaire, 2014)...................................................................................................................................... 15
Table 2.5: Scores for KBA classification.............................................................................................. 17
Table 2.6: Scores for confluence type and buffer size (km) ................................................................ 17
Table 2.7: Scores for presence of threatened fish and other aquatic organisms ................................... 17
Table 2.8: Scores for values of upstream forest cover .......................................................................... 18
Table 2.9: Agricultural intensity index ................................................................................................. 19
Table 2.10: Mining intensity index ....................................................................................................... 19
Table 2.11: Scores for urban population centers, river size, and length of downstream influence ....... 19
Table 2.12: Rural population density .................................................................................................... 20
Table 2.13: Road density ...................................................................................................................... 20
Table 2.14: Dam types and influence.................................................................................................... 20
Table 2.15: Biodiversity value ratings for the Sittaung sub-basins ...................................................... 24
iii
1 INTRODUCTION
An evaluation of baseline environmental and social conditions in Myanmar’s eight drainage basins
including the Ayeyarwady, Thanlwin, Mekong, Myit Mo Hka and Bago, Sittaung, Bilin, Tanintharyi,
and Rakhine was undertaken to provide an overview of the types, extent and value (importance) of
natural and social resources potentially affected by medium and large scale (≥10 MW capacity)
hydropower development. The country-wide evaluation provides information on features that enable
whole-of-basin hydropower planning and GIS layers that provide an overview of basin conditions.
To analyze variable conditions and different features across entire basins1, six of the eight basins were
divided into discrete sub-basins. The two smallest basins, Bago and Bilin, were analysed as single
drainage areas. Sub-basins were selected as the primary spatial unit for analysis within each basin in
the SEA because:
• they are discrete natural drainage units directly affected by medium/large scale hydropower
development, with impacts on river flows, water quality, geomorphology, aquatic habitat,
and biodiversity occurring within this area;
• this level of detail aligns with the main intended use of the Sustainable Development
Framework (SDF) for early project screening prior to successively more detailed planning in
cumulative impact assessments (CIAs) and project environmental and social impact
assessments (ESIAs); and
• more detailed analysis at the watershed level within a sub-basin was not possible given
current information limitations.
A total of 58 sub-basins were delineated throughout Myanmar (Figure 1.1). This mosaic of natural
drainage areas enables analysis and management planning at the two most important system levels:
basin and sub-basin. Analysis down to the watershed level was not possible given current information
limitations (i.e. some layers of data provide finer level information but not all layers are this detailed).
As more detailed information is obtained, natural and social resources analysis will be added,
completing a multi-scale approach to hydropower planning.2
Sub-basins were identified using HydroSHED3 levels. Most sub-basins (43) were selecting using
HydroSHED level 6 boundaries. Some Level 6 HydroSHEDs were divided into Level 7, 8 or 9
drainage areas, especially where large hydropower projects or cascades exist or are planned. Some
Level 7, 8 and 9 drainage areas were combined to create sub-basin areas of a suitable size for strategic
analysis.
Fifty-two sub-basins drain directly into the basin mainstem river / major tributary or sea, with the
remaining six sub-basins each draining into a downstream sub-basin before discharging into the
mainstem / major tributary. Six sub-basins that discharge into another sub-basin were delineated as
being separate from the downstream sub-basin due to their large size or distinct features (e.g.
significant existing HPPs). These sub-basins are: Naw Chaung Hka discharging into the Nmae Hka;
Upper Myitnge discharging into the Lower Myitnge; Myittha discharging into the Manipur;
Balachaung discharging into the Nam Pawn; and Paung Luang and Bawagata both discharging into
1
Definitions of important terms:
River basin - an area of land from which all surface runoff flows through a sequence of streams, rivers and,
possibly, lakes into the sea at a single river mouth, estuary, or delta.
Coastal basin – a collection of sub-basins along the coastal belt, many of which drain directly into the sea in
numerous places rather than via a single discharge point.
Sub-basin – a discrete drainage area within large river basin.
Watershed - a discrete drainage area within a sub-basin.
2
G. Pegram, Y. Li, T. Le. Quesne, R. Speed, J. Li, and F. Shen. 2013. River Basin Planning: Principles,
procedures and approaches for strategic basin planning. Paris, UNESCO.
4
the Sittuang Other. Accordingly, the connectivity of these six sub-basins with the free-flowing
mainstem or the sea is dependent upon what occurs within the downstream sub-basin.
Figure 1.1: Myanmar sub-basin
1.1 Evaluation Criteria
Baseline information and spatial data were compiled to evaluate the existing conditions and trends.
Only key biophysical and socio-economic ‘values’ were analysed, relating to those features likely to
be significantly impacted by hydropower development, as well as the status of armed conflict.
5
Information and data sources included published information, spatial data and expert opinion.
Existing GIS layers were utilized where available and reliable (e.g. forest cover).
An overview description of each sub-basin was developed covering major biophysical features, socio-
economic features, local administration, and the status of hydropower development. Environmental
and social scores were assigned to each of five strategic themes for each sub-basin:
1. Geomorphology and sediment
2. Aquatic ecology and fisheries
3. Terrestrial biodiversity
4. Social and livelihoods
5. Conflict
For each theme a set of evaluation criteria or indicators were identified to best provide an indication
of the relative value of that theme. Indicators were generally selected where reliable and uniform data
was available country-wide. Each indicator was scored on a relative scale then used to calculate the
overall theme rating for each sub-basin. The five themes in each sub-basin received a rating of
between 1 to 5, with 1 indicating a Low value and 5 a Very High value. The methodology applied for
baseline evaluation is described detail in Section 2.
Table 1.1: Indicators used to evaluate each theme
Theme Indicator
• River connectivity and delta and coastline stability
Geomorphology
• Potential sediment production
• Flow input
Aquatic ecology and Ecologically value rating:
fisheries • River reach rarity
• Presence of endemic species
• Key Biodiversity Areas (KBAs), Ramsar sites, and important wetlands
• Confluences
• Karst geology
• Presence of threatened fish and aquatic organisms
Human pressure rating:
• Deforestation
• Agriculture and mining intensity
• Urban and rural population
• Road infrastructure
• Hydropower and irrigation dams4
• Key Biodiversity Areas %
Terrestrial
biodiversity • Intact forest %
• Presence of endangered ecoregions
• Social vulnerability = % of female-headed households (Census 2014)
Social and
livelihoods • Dependence on natural resources (NR) = the mean % of “Own Account
Workers as % of work force” in townships within sub -basins (Census 2014)
• Poverty = % of households that own a television (Census 2014)
• Presence and status of ethnic armed groups
Peace and conflict
• Historical population displacement
• Conflict incidents 2012-2017
4
The impact of existing hydropower and irrigation reservoirs was considered for sub-basins with existing HPPs.
6
1.2 Sub-basin Evaluation Summary Sheets
An evaluation sheet was prepared for each sub-basin summarizing the main environmental and social
conditions relating to hydropower development and the status of armed conflict in each sub-basin.
Table 1.2: Sub-basin evaluation sheet format and data sources sub-basin evaluation
Sub-basin:
Basin:
Overview Size, location, topography and map
Area (km2): GIS measurement
Average rainfall:
Physical
Average sub-basin outflow:
Minimum outflow:
Population: Estimated using Census 2014 data and village tract population
Ethnic diversity: Myanmar Information Management Unit 2015 – data on
ethnolinguistic groups
Economic activities:
Socio-economic
Mining: Mining disturbance data (Eco-Dev/ALARM, 2016)
Land use: Land Use (LU)/Land Cover (LC) (IWMI, 2015)
Navigable waterways: Official waterways for freight and passenger transport as
defined by the Ministry of Transport and Communication (ADB, 2016)
States/Regions: GIS analysis
Administration
Major town(s): As above
Hydropower Numbers of existing, planned, under-construction hydropower projects sourced
development from HPP database prepared in consultation with MOEE
Sub-basin evaluation
Aquatic ecology and fisheries Rating 1-5
Geomorphology and sediment Rating 1-5
Terrestrial biodiversity Rating 1-5
Social, livelihoods, and significant sites Rating 1-5
Conflict Rating 1-5
A summary of the sub-basin evaluation results, including national maps and summary tables for each
theme, is presented in Section 3.
1.3 Information Limitations
Sub-basin baseline data was limited in many key areas, including river hydrology and
geomorphology, riverine ecosystems and aquatic species, and socio-economic conditions. In the
7
absence of detailed information, indicative or proxy information was used to assess some features, or
the information was not evaluated. Specific information limitations for each discipline are described
in Section 2.
The sustainable development framework will be periodically revised as key information becomes
available. In the short to medium term more detailed information and data will be obtained through a
combination of studies that are underway or planned. This includes studies and data collection
identified in the SEA as being essential to implement effective hydropower planning, the monitoring
of operational hydropower projects by GoM and private developers, and feasibility studies and impact
assessments undertaken by hydropower developers.
Key studies that will help to inform the first revision of the SDF include the Ayeyarwady Integrated
River Basin Management Project (AIRBM) being undertaken by the National Water Resources
Committee with support from The World Bank, and a number of research projects supported by the
Water, Land and Ecosystems (WLE) Initiative of the Consultative Group for International
Agricultural Research (CGIAR).
8
2 METHODOLOGY
2.1 Geomorphology and Sediment Transport
This analysis aims to describe the large-scale characteristics of sub-basins contributing to the
geomorphic functioning of river systems at the sub-basin and basin levels. River geomorphology is
largely controlled by water and sediment inputs as well as how they are transported downstream to the
delta and the sea. This approach assumes that if the sediment and water inputs and pathways in a river
have not been altered, then its geomorphology will remain intact. This analysis does not focus on
small-scale, reach-level geomorphic attributes, which are incorporated into the aquatic ecology
analysis using “rare and unique river reaches” as an input parameter.
This analysis also does not consider local land-use changes that can affect sediment and water inputs
despite their importance. There are two reasons for this: firstly, these impacts can change from years
to decades, but the impact of hydropower on the geomorphology of river systems needs to be
considered on time scales of decades to centuries. Local land-use changes, such as mining increasing
sediment input, water extraction for irrigation reducing flood peaks, or river improvements for
navigation altering channel geometry, are likely to experience significant changes over centuries and
are difficult to project into the future.
Secondly, most of Myanmar has been affected by soil loss due to land degradation (Figure 2.1), but
there is insufficient information about the relative magnitude of impacts on the sub-basins to
incorporate this into the analysis. The adopted methodology assumes that steeper and wetter areas,
whether degraded or not, will contribute more sediment as compared to lower-sloped and drier areas.
For each sub-basin, three large-scale parameters are assessed: 1) connectivity, 2) sediment production
potential, and 3) flow input. The parameters, the input information used for evaluating the parameters,
and the rationale for inclusion in the analysis are summarized in Table 2.1.
Figure 2.1: Soil degradation for Myanmar showing widespread loss of topsoil
Other degradation classes are:
Cn = Loss of nutrients and organic matter
Cs = Salinization
SN = Soil renewal
Wd = Terrain deformation/mass movement
9
A score of 1 to 5 was assigned to the three indicators for each sub-basin and together, they make up
the final sub-basin rating. For each indicator, 5 denotes the highest 20% of the basins with respect to
sensitivity to change or value, indicating that a sub-basin is functioning at or close to its natural state,
while 1 is assigned to the lowest 20% of the sub-basins. A low value indicates that a sub-basin is
already being modified with respect to the parameter. Details of how scores were derived for each
indicator are presented in the following sections.
Table 2.1: Summary of geomorphology and sediment transport parameters, input information, and
rationale for inclusion in the analysis
Indicators Input parameters Rationale
1. River • Strahler order5 River systems are maintained by the production and
connectivity/ • Area of sub-basin transport of sediment from the headwaters of rivers to
delta and the sea. Delta and coastline stability are dependent on
• Position of sub-basin with
coastline the delivery of material from river systems.
respect to the coast
stability Dams reduce the connectivity of rivers, prevent the
• Size and distribution of passage of sediment, or alter the flow regime of rivers,
existing dams thereby fundamentally altering geomorphic processes.
2. Potential • Distribution of the Potential sediment production is a measure of how
sediment geomorphic land units much sediment a sub-basin is likely to generate. It is
production identified within sub-basins dependent on geology and slope, and altered by land-
use changes.
Areas generating coarse grained sand and gravel
provide the materials that maintain channel, delta, and
coastline stability. Areas generating fine-grained
material provide transport for nutrients to flood plains
and underpin coastal productivity.
3. Flow input • Rainfall/runoff The unregulated flow of water through river systems
• Sub-basin area transports sediment, shapes river channels and
establishes the seasonal timing of processes that control
• Position of sub-basin with
ecological functioning (e.g. flood pulse, dry season,
respect to the coast
floods, etc.).
2.1.1 Connectivity
Connectivity scores were calculated based on the highest Strahler Order present in the sub-basin, the
sub-basin area, and the presence of existing hydropower projects. For the analysis, the sub-basin areas
were ranked by percentile to provide their relative difference while eliminating the order of magnitude
difference among them. The percentile value was multiplied by the Strahler Order and then assigned a
value of 1-5 based on percentile rankings (e.g. 1st -20th percentile = 1, 21st-39th percentile = 2, etc.).
This initial scoring was modified based on the presence of existing or under-construction hydropower
projects within the sub-basins. Sub-basins with existing projects are shown in Table 2.2 and the
connectivity scores were modified based on the following criteria:
• No modification if <5% of the sub-basin is located upstream of hydropower projects
• Score reduced by 1 if >5% but <90% of the sub-basin is located upstream of hydropower
projects
• Score reduced by 1 if the connectivity of the sub-basin is reduced due to hydropower projects
in a downstream sub-basin (only applied to the Upper Myitnge sub-basin)
• Score reduced by 2 if >90% of the sub-basin is located upstream of hydropower projects.
5
Strahler Order is a measure of the complexity of river systems based on the number of tributaries feeding into
a river reach. Small headwater streams have a Strahler Order of 1, and the joining of two Strahler Order 1
tributaries creates a Strahler Order 2 river reach, as shown in the diagram (Strahler, 1952, 1957). The joining of
a higher order (e.g. 3) with a lower order (e.g. 2) does not increase the Strahler Order downstream.
10
Totals that resulted in negative values, or zero, were scored as 1.
Table 2.2: Characteristics of sub-basins with existing or under-construction hydropower projects and
connectivity adjustment factor
Approx. % of
Number of Max. Strahler Connectivity
SB # Sub-basin (SB) catchment upstream
HPPs in SB Order adjustment factor
HPPs
3 Lower Myitnge 2 4 >90 -2
4 Ma Gyi Chaung 1 2 80 -1
5 Mali Creek 1 1 40 -1
6 Dapein 1 3 >90 -2
9 Mone Chaung 3 2 80 -1
10 Mu 1 3 50 -1
12 Nmae Hka 1 3 <5 0
13 Shweli 2 3 >90 -2
16 Upper Myitnge 0 3 0 -1*
17 Zawgyi/Myogyi 4 4 60 -1
21 Bago 1 2 10 -1
46 Myittha 1 3 20 -1
52 Nam Lwe 1 3 >90 -2
64 Thatay 1 1 >90 -2
72 Other Sittaung 6 3 30 -1
73 Paung Laung 3 2 90 -2
91 Balachaung 4 2 >90 -2
96 Nam Teng 2 3 40 0
* The Upper Myitnge sub-basin does not have any hydropower projects, but connectivity is affected by the
projects in the Lower Myitnge sub-basin.
In the connectivity assessment, the mainstem of the Ayeyarwady, Chindwin, and Thanlwin with
Strahler Order 4 or greater were excluded from the analysis and treated as unique units. These
mainstem reaches (Figure 2.2) play a critical role in providing pathways for sediment, water, fish, and
other aquatic organisms to move through the system and were assigned a ranking of 5 in the
vulnerability analysis. Sub-basins containing the mainstem reaches were assigned the highest Strahler
Order present in the sub-basin excluding the mainstem and evaluated as described above.
In the Lower Myitnge and Manipur sub-basins, there are rivers with a Strahler Order of 4 but are not
mainstems of the Ayeyarwady, Chindwin, or Thanlwin. They were not considered as a special case
and were included in the connectivity indicator scoring along with all other sub-basins.
11
Figure 2.2: Strahler Order 4+ rivers considered as a special case for “connectivity”
2.1.2 Potential Sediment Input
The potential sediment input score was calculated based on the distribution of geomorphic land units
– determined from the physical attributes of the landscape – in each sub-basin. Figure 2.3 shows the
distribution of these geomorphic classes in each sub-basin with examples.
Each land class was assigned a weighting based on its estimated relative sediment production
potential as summarized in Table 2.3. Steeply sloping areas on hard rock were given the highest value
due to their potential to produce sand and gravel, which are critical for river-channel stability and
habitat maintenance.
12
Each sub-basin’s score was calculated by multiplying the weighting by the percentage of each of its
geomorphic land class present. The percentile ranking of these scores was used to assign final scores
of 1 to 5, similar to the method applied to the other indicators. The potential sediment input scores for
the Shweli, Dapein, and Upper Thanlwin were adjusted by +1 to account for the large catchment areas
and high sediment input potential associated with the catchments located outside of Myanmar.
Figure 2.3: Geomorphic land classes based on geology and slope
Table 2.3: Weightings for determining sediment production potential
Geomorphic class Sediment production potential weighting
Slopes >10° and hard rock geology 5 - High potential to produce sand and gravel
Slopes >10° and intermediate hardness 4 - Good potential to produce sand and gravel, silt, and clay
geology
Slope <10° and hard geology 3 - Moderate potential to produce sand and gravel
Slope 3-10° and soft geology 2 - Low potential for sand and gravel; high potential for silt and clay
Slopes <3° and elevation >30 m 1 - Very low input of “new” sediment; areas of re-working
Slope <3° and elevation <30 m 0 - Generally areas of deposition and re-working
2.1.3 Flow Input
The flow input indicator was calculated based on the water volume input from each sub-basin using
the following calculation:
Area of SB X average rainfall in SB X runoff coefficient = water volume Input
The runoff coefficient was estimated using the information in Figure 2.4 with the results for each
catchment shown in the table below.
13
Figure 2.4: Catchment areas and average annual flow rates of the major river basins in Myanmar used to
derive catchment runoff
Basin Runoff coeff.
Upper Aye 0.83
Lower Aye 0.54
Chindwin 0.73
Bago 0.80
Sittaung 0.80
Rakhine 0.77
Thanlwin 0.72
Tanintharyi 0.98
Mekong 0.57
The resultant water volumes were ranked by percentile similarly to the other indicators (e.g. 1st-20th
percentiles = “1”, 21st-39th percentiles = “2”, etc.).
For sub-basins containing a mainstem reach, only the inflow from the sub-basin area was considered.
The importance of the through-flow of water in the mainstem reach was recognized and accounted for
in the connectivity score.
2.1.4 Final Sub-basin Ratings
The final sub-basin ratings for geomorphology were determined by adding the three indicator scores
and normalizing the total to a range of 1 to 5. Scores that were <0.5 were assigned a final score of 1.
14
2.2 Aquatic Ecology and Fisheries
Sub-basin evaluation of aquatic ecology and fisheries involved: i) identifying the ecological values of
river sub-basins and ii) analyzing existing human pressures on each river reach.
The ecological value of river sub-basins in Myanmar was calculated based on combining multiple
GIS layers to determine the ecological sensitivity of river reaches within each sub-basin. The analysis
process is described below, completed with the calculations for estimating the ecological value. A
supplementary process for describing human pressures on each river reach and sub-basin is also
described.
2.2.1 Ecologically Sensitive River Reaches
The analysis was based on World Wildlife Fund for Nature’s (WWF’s) River Reach Classification for
the Greater Mekong Region (2014). The basic spatial unit of this classification is “river reach,” a
linear unit representing a stretch of river between two consecutive confluences. Lehner and Allaire’s
classification applied a range of hydrological, physio-climatological, and geomorphological
classifications to the river reaches. In addition, this analysis applied a set of geospatial variables
linked to the ecological sensitivity of the river reaches of the Ayeyarwady and Thanlwin basins to
create an overall measure, classifying river reaches as having low, medium, high, or very high
ecological sensitivity.
Another set of geospatial variables related to negative human pressures was applied to the river
reaches of the Ayeyarwady and Thanlwin to develop a combined score. Those river reaches with
scores below a defined threshold were classified as having low, medium, high, or very high human
pressure.
2.2.2 Ecological Sensitivity
2.2.2.1 River Reach Rarity
Lehner and Dallaire’s (2014) combined classes refer to an aggregate of hydrological, physio-
climatological, and geomorphological classifications. The total length of the river reaches within each
of Lehner and Dallaire’s (2014) Combined classes was calculated for the basins. The Combined class
is an aggregate of a range of hydrological, physio-climatological and geomorphological
classifications. The total length of the river reaches within each of the different river sizes (Mainstem,
Large, and Medium, Small rivers and headwater streams) was also calculated for the basins. The
percentage of the total length of each river size occupied by each of the Combined classes was then
calculated. This percentage was used to score each reach for rarity, so that reaches occupying 0-5% of
their river size were given a rarity score of 4, reaches occupying 5-10% were given a score of 3,
reaches occupying 10-20% were given a score of 2 and the remainder, occupying 20-71%, were the
most common Combined classes, and were given a score of 1. Mainstem reaches were given an
automatic score of 5 to reflect their importance. The rarest river reaches - with combined class reaches
in 0-5% of their constituent Simple Hydrological class - were given a rarity score of 4; those in 5-10%
received a score of 3; those in 10-20% received a score of 2; the remainder 20-71% - the most
common - were given a score of 1.
Table 2.4: Combined classes and total length of river reaches in Myanmar (Source: Lehner & Dallaire,
2014)
Sum Percentage
Rarity
Combined class description reach length simple
score
(km) hydrological
Large river, in dry broadleaf forest region, with floodplains 0.63 0.01 4
Medium river, in dry broadleaf forest region, with low gradient 18.74 0.09 4
Large river, in mangrove region 8.50 0.12 4
Large river, in montane region, with low gradient 12.16 0.17 4
Medium river, in montane region, with high gradient 145.32 0.73 4
15
Sum Percentage
Rarity
Combined class description reach length simple
score
(km) hydrological
Large river, in moist broadleaf forest region at high elevation,
56.07 0.78 4
with low gradient
Medium river, in mangrove region 185.76 0.93 4
Medium river, in moist broadleaf forest region at low elevation,
245.39 1.23 4
with high gradient
Large river, in dry broadleaf forest region, with floodplains and
108.99 1.52 4
sediment
Medium river, in moist broadleaf forest region at high elevation,
325.86 1.64 4
with high gradient
Medium river, in karst within montane region 347.02 1.74 4
Medium river, in moist broadleaf forest region at high elevation,
363.43 1.83 4
with floodplains
Medium river, in coniferous region, with high gradient 422.47 2.12 4
Large river, in moist broadleaf forest region at high elevation,
169.94 2.37 4
with floodplains
Main stem, meandering channel with alluvium 112.68 2.39 4
Medium river, in dry broadleaf forest region, with floodplains 493.92 2.48 4
Large river, in moist broadleaf forest region at low elevation,
204.91 2.86 4
with floodplains and sediment
Large river, in karst region at high elevation 206.21 2.88 4
Large river, in karst within montane region 251.70 3.51 4
Large river, in moist broadleaf forest region at high elevation,
353.20 4.93 4
with sediment
Medium river, in coniferous region, with low gradient 1,172.14 5.89 3
Medium river, in montane region, with low gradient 1,239.07 6.23 3
Large river, in large delta region 448.08 6.25 3
Medium river, in large delta region 1,284.07 6.45 3
Main stem, large delta 304.58 6.47 3
Medium river, in moist broadleaf forest region at high elevation,
1,305.72 6.56 3
with low gradient
Large river, in moist broadleaf forest region at low elevation,
506.75 7.07 3
with low gradient
Medium river, in karst region at high elevation 1,436.37 7.22 3
Large river, in moist broadleaf forest region at low elevation,
634.06 8.85 3
with sediment
Large river, in coniferous region, with low gradient 1,033.71 14.42 2
Medium river, in karst region at low elevation 2,980.58 14.98 2
Medium river, in moist broadleaf forest region at low elevation,
3,215.01 16.16 2
with floodplains
Main stem, anastomose channel 959.36 20.38 1
Large river, in moist broadleaf forest region at low elevation,
1,585.62 22.12 1
with floodplains
Large river, in karst region at low elevation 1,587.79 22.15 1
Medium river, in moist broadleaf forest region at low elevation,
4,719.35 23.72 1
with low gradient
16
Sum Percentage
Rarity
Combined class description reach length simple
score
(km) hydrological
Main stem, rock-cut river channel 3,330.83 70.76 1
2.2.2.2 Endemic Areas
Polygons delineating the presence of endemic species were determined based on literature, e.g.
(Allen, 2010), and consultation with organizations such as FFI and Wildlife Conservation Society
(WCS). River reaches intersecting these areas were given a score of 3.
2.2.2.3 Key Biodiversity Areas, Ramsar sites, and important wetland areas
Polygons delineating KBAs were obtained from the World Database of Key Biodiversity Areas.
Additional KBAs were identified during a workshop held in June 2017 as an important activity of the
SEA. Expert reviews further classified these areas as terrestrial only, terrestrial or river, aquatic birds,
or fully riverine wetland. Areas recognized as globally important, e.g. Ramsar sites, World Heritage
sites, or part of the 2004 Wetland Inventory, were given the highest scores. River reaches intersecting
these areas were scored as follows:
Table 2.5: Scores for KBA classification
KBA classification Score
Recognized as globally important 5
Fully riverine wetland 4
Aquatic birds 3
Terrestrial on river 2
Terrestrial only 1
2.2.2.4 Confluences
Confluences are recognized areas mixing water and migration routes, often with important habitat
features. They can be both ecologically and culturally significant. River confluence points were
identified by reviewing the reach classification dataset. Buffer zones of varying sizes were applied to
each point to create an expert defined area of influence. River reaches intersecting these areas of
influence were given the following scores in Table 2.6.
Table 2.6: Scores for confluence type and buffer size (km)
Confluence type Buffer size Score
Large river confluence with large river 10 km 2
Large river confluence with main stem 20 km 3
2.2.2.5 Karst Geology
River reaches classified as flowing through Karst landscape by Lehner and Dallaire 2014 were given
a score of 3.
2.2.2.6 Presence of Threatened Fish and Other Aquatic Organisms
The predicted presence of critically endangered, endangered, and vulnerable species of fish and other
aquatic organisms in each sub-basin was taken from the IBAT/Redlist Freshwater Assessment. River
reaches within those sub-basins were scored as follows:
Table 2.7: Scores for presence of threatened fish and other aquatic organisms
Reach intersects with a basin polygon where the Vulnerable Endangered Critically
presence of Red List fish species (sp.) has been indicated fish fish endangered fish
Score 3 4 5
17
Reach intersects with a basin polygon where the Vulnerable Endangered Critically
presence of Red List fish species (sp.) has been indicated fish fish endangered fish
Vulnerable Endangered Critically
Reach intersects with a basin polygon where the
aquatic sp. aquatic sp. endangered aquatic
presence of Red List species (not fish) has been indicated
(not fish) (not fish) sp. (not fish)
Score 3 4 5
2.2.2.7 Combined Ecological Sensitivity Scoring
A combined ecological sensitivity score was then calculated for each river reach, with a range of +1 to
+23:
• Reaches with a score of less than or equal to 4 were classified as low sensitivity.
• Reaches with a score between +4 and +9 were classified as medium sensitivity.
• Reaches with a score between +9 and +13 were classified as high sensitivity.
• Reaches with a score greater than +13 were classified as very high sensitivity.
2.2.2.8 Developing an Ecological Value for the Sub-basins
The ecological sensitivity scores of all river reaches within a sub-basin were then combined to derive
a total ecological value for each sub-basin. The combination was done by weighting the length of
each river reach with its ecological sensitivity score and dividing by the total length of river reaches in
that sub-basin. These values were then normalized on a scale of 1-5, where 1 indicates a basin with
very low ecological value and 5 with the highest ecological value.
For sub-basins containing a mainstem reach, only the inflow from the sub-basin area was considered.
The ecological value of the mainstem portions was excised from the calculations of sub-basins
through which the mainstems of Ayeyarwady, Chindwin and Thanlwin are flowing. The ecological
value thus reflects only the tributaries flowing into the mainstems in these sub-basins.
2.2.3 Human Pressures
Human pressures are an indicator of the state of river health. The higher the pressures from different
human activities, the more likely the river quality and character will suffer.
2.2.3.1 Deforestation
Lehner and Dallaire’s (2014) river-reach classification included a measure, derived from the Global
Land Cover 2000 project, of the percentage of the upstream watershed covered with forest. A low
percentage was considered a valid proxy for deforestation. The following scores were applied to river
reaches depending on the value of upstream forest cover (Table 2.8).
Table 2.8: Scores for values of upstream forest cover
Deforestation Upstream forest cover Score
Low 40-60% -1
Medium 20-40% -2
High 0-20% -3
2.2.3.2 Agriculture and Mining
Experts assessed the impact of agriculture and mining by applying scores to each HydroBASINS level
6 sub-basin. HydroBASINS is a global database with a series of polygon layers that depict watershed
boundaries and sub-basin delineations. The database provides consistently sized and hierarchically
nested sub-basins, following the topological concept of the Pfafstetter coding system. This allows for
analysis of issues such as upstream and downstream connectivity. River reaches intersecting the sub-
18
basins were given a score of between -1 and -5 for both the impact of mining and agriculture based on
the expert assessment.
Agricultural intensity was calculated from the area of agricultural land within each sub-basin, factored
by the area of double and triple cropping. Land-use data has been taken from an Integrated Water
Management Institute (IWMI) database. The index calculation took the percentage of cultivated area
in the sub-basin and multiplied this by the percentage of agricultural land that was double- or triple-
cropped. This was then multiplied by 1,000, yielding index ranges from 0 to over 3,000. Each river
reach in the sub-basin was then given a score as shown in Table 2.9.
Table 2.9: Agricultural intensity index
Agricultural intensity index ranges Score
0 – 25 1
25-250 2
250-750 3
750 – 3,000 4
>3,000 5
Mining intensity was calculated from the mining area dataset from Myanmar Information
Management Unit (MIMU). This dataset was overlaid on the hydro basins level 6; then the mining
intensity index was calculated by dividing the area of mines in hectares divided by the area of each
hydro basin in square kilometres multiplied by 1,000, yielding a range of indices between 0 and
25,000. The river reaches in each sub-basin were then scored as shown in Table 2.10.
Table 2.10: Mining intensity index
Mining intensity Index ranges Score
0 – 25 1
25 – 250 2
250 – 2500 3
2,500 - 10,000 4
>10,000 5
2.2.3.3 Urban Population Centers
The locations and populations of major urban areas in Myanmar were obtained from MIMU. Areas of
influence were then delineated downstream of the population centers; the size of an area was
dependent on the size of the population center and the size of the river affected by the population
center. River reaches intersecting the area of influence from a population center were given a negative
score depending on the size of the population centre. See below table for details of the sizes of areas
of influence and scoring (Table 2.11).
Table 2.11: Scores for urban population centers, river size, and length of downstream influence
Urban population centers River size Length of downstream influence Score
> 1 million people Mainstem river 50 km -5
> 1 million people Large river 75 km -5
> 1 million people Medium river 100 km -5
100,000 - 1 million people Mainstem river 25 km -4
100,000 - 1 million people Large river 50 km -4
100,000 - 1 million people Medium river 100 km -4
19
Urban population centers River size Length of downstream influence Score
100,000 - 1 million people Small river 125 km -4
10,000 - 100,000 people Mainstem river 10 km -3
10,000 - 100,000 people Large river 25 km -3
10,000 - 100,000 people Medium river 50 km -3
10,000 - 100,000 people Small river 100 km -3
2.2.3.4 Rural Population Density
The rural population density was used as a measure of pressure from rural populations on the aquatic
natural resources. The data came from WWF’s River Reach Classification for the Greater Mekong
Region (Lehner and Dallaire 2014), which incorporated a field of population density above each river
reach (Table 2.12).
Table 2.12: Rural population density
Rural population density Number of people per sq km above each river reach
> 25 and > 50 and > 100 and
Reach has a rural population score of <= 25 > 500
<= 50 <= 100 <= 500
River reach score 0 -1 -2 -3 -4
2.2.3.5 Road Infrastructure Density
The road infrastructure overlay was obtained from MIMU. This was correlated with the sub-basins
and the density of road infrastructure calculated by the area of each sub-basin. The estimated road
density indices for all river reaches in each sub-basin are shown in Table 2.13.
Table 2.13: Road density
Road density Length of road per area of sub-basin (km/sq km)
Reach intersects with a basin
0.0-0.025 0.025-0.05 0.05-0.075 0.075-0.1 0.1-0.224
polygon with a road index
River reach score 0 -1 -2 -3 -4
2.2.3.6 Dams Downstream
The HPP database generated by the SEA was used to determine the location of hydropower and
irrigation dams as well as the areas of influence for each dam. These areas stretched downstream from
each dam up to the next confluence with a river reach with a higher hydrological class. River reaches
intersecting a dam area of influence were given the scores shown below in Table 2.14.
Table 2.14: Dam types and influence
Dam type Score
Irrigation -3
Hydro >100 MW -4
Hydro <100 MW -3
Hydro <50 MW -2
2.2.3.7 Reservoirs
The extent of dam reservoirs was ascertained from the Global Surface Water database. River reaches
intersecting a dam reservoir (irrigation or hydropower) were given a score of -5.
2.2.3.8 Combined Human Pressure Index
A combined pressure score was then calculated for each river reach with scores ranging from -1 to
20
-24.
• Reaches with a score between -1 and -5 were classified as very low pressure.
• Reaches with a score between -5 and -10 were classified as low pressure.
• Reaches with a score between -10 and -15 were classified as medium pressure.
• Reaches with a score between -15 and -20 were classified as high pressure.
• Reaches with a score between -20 and -24 were classified as very high pressure.
2.2.3.9 Developing a Human Pressure Index for the Sub-basins
The human pressure scores on all river reaches within a sub-basin were combined to derive a human
pressure index for each sub-basin. The combination was done by weighting the length of each river
reach with its human pressure score and dividing it by the total length of river reaches in that sub-
basin. These values were then normalized on a scale of 1-5, where 1 indicates a basin with very low
human pressure and 5 with the highest pressure. This analysis was used to describe the trends in each
sub-basin’s aquatic environment.
21
2.3 Terrestrial Biodiversity
In considering terrestrial biodiversity, the SEA identifies areas of biodiversity value countrywide and
then grades all regions according to criteria that reflect biodiversity importance. This process provides
a national comparative analysis that represents the attributes of Myanmar’s biodiversity without being
too computationally demanding.
Myanmar is a recognized biodiversity hotspot, supporting a very high number of species unique to the
region and of global importance. Yet, information on Myanmar’s biodiversity is patchy with large
areas of the country unsurveyed. For example, in 2014, 26 species of plants and animals were newly
described for Myanmar. Since then, there has been a steady stream of discoveries as the level of effort
and investment increased; big gaps, however, remain. Therefore, a national biodiversity assessment
needs to use forms of aggregated information, proxies, and expert judgment to achieve a
comprehensive and reliable picture.
2.3.1 Assessment Parameters
The assessment used four main parameters or criteria for identifying areas of biodiversity value: key
biodiversity areas (KBA), protected areas (PA), intact forests, and ecoregions. Each parameter reflects
a complex mix of biodiversity ingredients such as species, ecosystems, and genetic resources; each is
a combination of field-based information, spatial interpretation, and expert judgment and experience.
Together, they provide a rich and reasonably accurate strategic picture of the nature, extent, and
location of remaining biodiversity in the country.
The analysis was conducted at two geographic levels for the 14 river basins nationwide and the 58
sub-basins.
2.3.2 Key Biodiversity Areas
The KBA designation is a new tool for identifying areas of remaining important biodiversity. Using
globally standardized criteria and thresholds, KBAs are identified across the country and represent the
most important sites for biodiversity conservation worldwide. They provide a vital habitat for
threatened plant and animal species in terrestrial, freshwater, and marine ecosystems.
Sites qualify as global KBAs if they meet one or more of 11 criteria clustered into five categories:
threatened biodiversity, geographically restricted biodiversity, ecological integrity, biological
processes, and irreplaceability. They are an “umbrella” designation, usually covering existing
protected areas, Important Bird Areas, Important Plant Areas, and Important Sites for Freshwater
Biodiversity.
The identification of KBAs is an evolving tool to help countries fill critical gaps in their national
system of protected areas and to support development planning and environmental assessment so that
negative impacts on biodiversity can be avoided.
In Myanmar, KBAs have no legal standing as an official form of land tenure except where they
overlap with formally established protected areas. They cover many different forms of land tenure,
ownership, and use, making their effective management to maintain and enhance biodiversity an all-
of-government responsibility.
A preliminary KBA listing for Myanmar was considered at a January 2012 stakeholder workshop
convened by the Wildlife Conservation Society, resulting in the identification of 132 KBAs. To
update this initial KBA database, the SEA convened a second two-day working session of
government agencies, international conservation organizations, local nongovernmental organizations,
the private sector, and academia in July 2017. The KBA boundaries were defined based on field
research, GIS analysis, expert knowledge, and participatory mapping. As a result, KBAs now cover
close to 41% of the country including 182 sites; boundaries will continue to be adjusted and refined
based on further biodiversity surveys and collective expert knowledge and experience. This
assessment of biodiversity values uses the updated KBA database.
22
2.3.3 Protected Areas
In Myanmar, the national protected area (PA) system covers almost 6% of the country, including
national parks, wildlife reserves and sanctuaries, forest parks, and nature reserves. PA boundaries are
officially defined under national legislation. PAs are the mainstay of biodiversity conservation and
associated products and services in the country.
While some KBAs and PAs overlap, the KBA network is more extensive and representative of
remaining biodiversity values in Myanmar. The establishment of PAs in Myanmar reflects historical
links with forest administration, hunting, and recreational uses; it is not a systematic process based on
relative biodiversity importance and values. But the SEA decided to include PAs in this biodiversity
assessment because their establishment over the past 10 years has been shaped by conservation
priorities such as the tiger reserve in the Northern Ayeyarwady basin.
2.3.4 Intact Forests
The assumption underlying the use of intact forests as a proxy for biodiversity is that they provide
greater species biodiversity, productivity of goods, variety and integrity of services, and connectivity
attributes and processes than degraded forests. Intact forests are an unbroken expanse of natural
ecosystems showing no sign of significant human activity and large enough to maintain all native
biodiversity, including viable populations of wide-ranging species. The lower their exposure to
humans, the greater the ability of ecosystems to support their natural biological diversity and
ecological processes as well as absorb and recover from disturbance (resistance and resilience).
Two important sources of data were used in analyzing forests of Myanmar: the Myanmar Forest
Cover Change (2002-2014) study and Hansen et al. (2013). Data from the Myanmar Forest Cover
Change study were used to create cover maps of intact forests (greater than 80% canopy cover),
degraded forests (between 10% and 80% canopy cover), and plantation and non-forests (less than
10% canopy cover), as well as graphs and tables of intact forests, degraded forests, degraded regions,
and changed forest cover.
Plots of annual cumulative loss of forests by basin, where forest loss was determined for open and
medium-closed canopy cover, and intact forests, were derived from Hansen et al. (2013). The canopy
cover metrics adopted for these plots were based on those from the Myanmar Global Forest Resources
Assessment 2015, and the Myanmar Forest Cover Change (2002-2014) study. The term “open forest”
refers to forest with greater than 10% and less than or equal to 40% canopy cover; “medium-closed
forest” has a canopy cover of more than 40%; and “intact forest” has greater than 80% canopy cover.
The term “medium-closed” rather than “closed” (as defined in the Myanmar Forest Resources
Assessment) is used as the latter better describes the three categories of canopy cover presented in this
study: open, medium-closed, and intact forest. More details on the methodology adopted for forest
analysis is given in Chapter 3.
2.3.5 Ecoregions
Myanmar is represented by 14 ecoregions, which describe the original assemblage of plants, animals,
climate, and geomorphological characteristics in the country. Each ecoregion is a large area of land
containing a geographically distinct mix of species, natural communities, and environmental
conditions. Ecoregions are areas where ecosystems (and the type, quality, and quantity of
environmental resources) are similar.
They are identified by analyzing the patterns and composition of biotic and abiotic phenomena that
affect or reflect differences in ecosystem quality and integrity. These phenomena include geology,
landforms, soils, vegetation, climate, land use, wildlife, and hydrology. The relative importance of
each characteristic varies from one ecological region to another. In this assessment, the key attribute
that needs to be kept in mind is that ecoregions represent what was there, not necessarily what
remains. When combined with one or more of the other parameters, ecoregions are an important
source of information on the relative value of biodiversity found in KBAs, PAs, and intact forests.
23
2.3.6 Biodiversity Sub-basin Evaluation
The four parameters were used in two ways to define areas of biodiversity value in Myanmar. As
overarching proxies for biodiversity, KBAs and intact forests were combined to make up a
biodiversity index that identified areas of value within each river basin and ranked river sub-basins
from very low to very high value. PAs and ecoregions were then applied to ensure certain important
areas were not overlooked in the index because they were relatively small or their values were not
properly recognized and described.
First, KBAs and intact forests were overlaid on river basins and the total percentage coverage of each
parameter calculated. That index provided a measure of current biodiversity status. Also, annual
cumulative forest losses from 2002 to 2014 for each basin were graphed for i) open forests, ii)
medium-closed forests, and iii) intact forests. The analysis of cumulative forest loss allowed for the
definition of trends in biodiversity.
Second, biodiversity index ratings were calculated for the 58 sub-basins as follows (Table 2.15):
• % KBAs (1 to 5 score)
• % intact forests (1 to 5 score)
• Add scores and average
• Results in a rating from very low to very high value (i.e. five sub-basin categories)
The 1 to 5 scores were given based on equally distributed percentiles, with each score representing
20% of the total range. The percentile ranges were defined by the highest value among each sub-
basin, which was 99% for KBAs and 85% for intact forests.
The method is illustrated in Figure 2.5 and Table 2.15 for the three Sittaung sub-basins.
Table 2.15: Biodiversity value ratings for the Sittaung sub-basins
Main basin Sittaung
Sub-basin Paung Laung Bawagata Other Sittaung
Total area (km2) 4,986.0 1,229.2 28,698.3
Number of HPPs 4 1 6
2
Area (km ) 0.0 0.0 212.2
PA
% 0.0 0.0 0.7
Area (km2) 1,045.2 86.2 2,418.4
Intact
forests % 21.0 7.0 8.4
Score 2 1 1
2
Area (km ) 3,668.4 412.7 9,905.1
KBA % 73.6 33.6 34.5
Score 4 2 2
Sub-basin score 3 2 2
Third, critically endangered ecoregions and PAs were mapped to identify sub-basins or small pockets
of biodiversity of global importance that were not captured in the KBA and intact forest index. For
example, the Irrawaddy Dry Forest ecoregion is critically endangered, but due to its small stature,
relatively low forest canopy cover (around 60%), and remaining small vestiges, it was not picked up
by the index. Identifying the location of the dry forest and small PA or KBA pockets coinciding with
the ecoregion gave the sub-basin a gold star of exceptional value, even though it might not be ranked
highly using just the biodiversity index. A gold star means that the sub-basin warrants special care
and safeguards when any development is considered.
24
Figure 2.5: Key biodiversity areas and intact forests in the Sittaung sub-basins
2.4 Social and Livelihoods
2.4.1 Summary of Criteria in Calculating Overall Theme Score
The criteria for the selection of indicators were as follows:
• Indicator’s relevance for hydropower development
25
• Availability of nationwide quality-checked data
• Transparency – for stakeholders to be able to provide inputs
• Simplicity – for replicability and integration into the overall score
Three indicators were selected for the following three aspects of social vulnerability:
1. Social vulnerability = % of female-headed households (Census 2014)
Female-headed households are assumed to be more vulnerable to social change as they often have
only one head of family and fewer income earners than male-headed households, which often
have at least two.
2. Dependence on natural resources = mean % of “own account workers as % of workforce”
in townships within sub-basins (Census 2014)
This category includes independent, self-employed people (farmers, fishers, handicraftsmen, etc.)
who are assumed to be more vulnerable to potential hydropower impacts such as relocation and
changes in land and water access.
3. Poverty = % of households owning a television (Census 2014)
This indicator for general poverty level was selected several regression analysis runs on the only
available rural poverty data from 2010. The data were by State/Region/Division and were placed
as the independent variable, while Census 2014 data on township percentages of households
having various house materials (bamboo, wood, concrete, etc.), drinking water source, ownership
to various assets (car, truck, motorbike, mobile phone, etc.) were placed as dependent variables.
None of the tested Census 2014 variables had a significant statistical correlation with the poverty
data from 2010 (at PValue < 0.005). The percentage of households owning a TV was the only
indicator that had a significant correlation with the 2010 poverty data and was therefore selected
as the poverty indicator.
The index was constructed as follows:
Allocation of townships to sub-basins were based on township area centroids (their mid-point),
thereby transforming polygons to points so that township and sub-basin boundaries would not
overlap. The steps for constructing the vulnerability rating were:
1. Census 2014 percentages of households with various characteristics by township were
averaged by sub-basin.
2. The 10th percentile of the average percentages were calculated and given a score from 1 to 10,
1 being the lowest score in terms of social vulnerability.
3. The scores from the three indicators were added and the 20th percentile for these values were
calculated. Each percentile was given a score between 1 and 5. This is the total social
vulnerability rating presented here.
26
2.5 Peace and Conflict
This methodology for sub-basin and sustainability analysis links hydropower development to the
presence and likelihood of conflict by sub-basin and hydropower project, respectively. Armed conflict
is a constraint to hydropower development; in instances where the precursors of armed conflict are
present, hydropower development can potentially exacerbate conflict. Critically, this methodology
does not consider how hydropower is developed. The “legacy model” of hydropower development, as
described in the conflict baseline of the hydropower SEA, has been a driver of conflict. The final SEA
report will consider approaches where hydropower development can mitigate conflict risks and
potentially address some of Myanmar’s underlying conflict drivers.
Key issues
1. Political disputes over governance and territory
2. Issues related to equality and human rights
3. Patterns of violence associated with contested territory
Each trend had at least one indicator for the vulnerability analysis. Data for each indicator were
normalized from their raw form and scaled 1-5. Indicators were combined to produce evaluation
vulnerability ratings scaling from very low (light green) to very high (dark green).
For the sustainability analysis, each of the three indicators were applied to specific projects, using a 1-
3 scale. Only proposed (not existing) projects were assessed. Indicators were combined, giving each
project an impact score ranging from 3 (low) to 9 (high).
2.5.1 Sub-basin Evaluation
Indicator Criteria Methodology Results
1. Presence and status of The presence of armed groups in sub- The presence and status of armed
armed groups basins was scaled from 1-5: groups are intrinsically linked to
(disagreement over historical and contemporary disputes
governance and territory) 1: No armed group presence or no over governance and territory.
armed group with constitutional
territory (accommodated claims); They pose differing conflict risks
3: Tolerated claims (ceasefires); depending on the nature (or absence) of
5: Hostile claims to territory political agreements between the armed
(conflict). groups and the state.
These measures were averaged when
the composition of armed group
presence within sub-basins was
mixed.
Data were sourced from the Asia
Foundation.
2. Historical population A five-point scale for historical Historical population displacement is a
displacement population was based on the proxy measure for a variety of equality
(proxy indicator for following categories: and rights issues that can complicate
equality and rights issues) hydropower development and act as a
0.5 weighting 1: 0-29 conflict driver (e.g. land tenure issues,
2: 30-499 relatively limited access to
3: 500-1,999 services/weaker social contract,
4: 2,000-10,000 relatively high human rights abuses,
5: 10,000 + etc.).
Data and scaling were sourced and Populations displaced by conflict are
adapted from the United Nations significantly more likely to have
Office for the Coordination of experienced human rights abuses.
Humanitarian Affairs.
27
Indicator Criteria Methodology Results
3a. Conflict incidents A logarithmic scale was used based Armed conflict in sub-basins poses a
2012-2016 on the average number of conflict challenge to hydropower development
(patterns of violence incidents per year for each sub-basin. and is associated with potential delays
associated with contested The accuracy of this scale has been or scrapping of such projects. Armed
territory) compared against the Heidelberg conflict is a significant risk – a potential
Institute for International Conflict show stopover – and may need to be
Research (HIIK) 2012-2016 global considered differently compared to
conflict barometer results. vulnerability ratings of other themes.
1: 0 conflict incident Hydropower development also poses a
2: 1 conflict incident risk to initiate or exacerbate conflict in
3: 2-3 conflict incidents areas where territories are contested,
4: 4-9 conflict incidents same as under the first indicator.
5: 10+ conflict incidents
Data were sourced from the
Myanmar Peace Monitor
(www.mmpeacemonitor.org)
3b. Estimated battle deaths The estimated numbers were Both historical and contemporary
1989-2015 normalized to the HIIK conflict conflict data were included to make
(patterns of violence intensity rating (country/year) on a conclusions more robust. More
associated with contested scale of 1-5: importantly, the decision to include
territory) 1: 25> historical conflict data is because even
0.5 weighting 2: 25-49 in peaceful areas, the potential for
3: 50-199 violence remains as Myanmar has yet
4: 200-499 to reach sustainable political
5: 500+ agreements to end its armed
insurgencies. Historical instances have
Data were sourced from the Uppsala shown repeatedly that the country’s
Conflict Data Program, which peaceful areas under ceasefires can turn
estimated battlefield deaths based on violent abruptly, which will have
media, academic, and civil society significant implications for hydropower
reporting. development in those areas. Also,
hydropower development, if
mismanaged, can be damaging for the
political process that aims to move
beyond ceasefires to reach permanent
political agreements.
2.5.2 National Map of Conflict Sub-basin Evaluation
Fewer than half of the sub-basins (45%) received “very low” or “low” conflict vulnerability ratings.
Ten sub-basins (17%) were rated “medium,” 19 (33%) were “high,” and three (5%) were “very high.”
The very high ratings in Myanmar’s west were a result of the high incidence of intercommunal
conflicts and displacement in Rakhine State between 2012 and 2016. Most sub-basins in or across
Ayerwaddy, Yangon, Bago, Magwe, Mandalay, and Saigang regions were rated “low” or “very low,”
given the relative absence of armed group activity, population displacement, or armed violence in
these areas.
28
Most sub-basins in Kachin and northern Shan states had “high” or “very high” conflict vulnerability
ratings due to the presence of multiple armed groups and frequent conflict and population
displacement between 2012 and 2016. Sub-basins in southern and eastern Shan states, as well as
Kayin and Kayah states, and the Tanintharyi region, were rated as “medium” or “high” because of the
presence of multiple armed groups, high historical conflict, and high historical displacement, even
though many of these areas are currently
under ceasefires. The Thanlwin (especially),
Rakhine, and parts of the Ayeyarwady basin
(middle) returned the highest conflict
vulnerability ratings.
Sub-basin Vulnerabilities in Myanmar
20
18
16
14
12
10
8
6
4
2
0
Very low Low Meduim High Very
high
29
3 NATIONAL MAPS AND SUMMARY TABLES
3.1 Summary
The baseline ratings (1-5) for each of the five themes were overlaid on national maps to show the
biophysical, socio-economic, and conflict values in the 58 sub-basins.
The geomorphology, aquatic ecology and fisheries, and terrestrial biodiversity baseline values were
grouped as biophysical ratings. Thirty-three sub-basins have high (4) or very high (5) ratings.
Social and livelihoods and conflict were treated as separate themes for analysis. For social and
livelihoods, four sub-basins are rated very high and 15 sub-basins have high ratings. Conflict was
categorized as “yes” (rating 4-5) or “no” (rating 1-3). Six sub-basins have very high conflict ratings
and 15 have high ratings.
Table 3.1 provides a summary of the sub-basin ratings for each theme. The ratings will serve as a
guide to areas that require focused protection in terms of management and investment and identify
areas that can be further developed under strict conditions.
30
Figure 3.1: Geomorphology baseline value ratings
31
Figure 3.2: Aquatic ecology and fisheries baseline value ratings
32
Figure 3.3: Terrestrial biodiversity basely
33
Figure 3.4: Social and livelihoods baseline value ratings
34
Figure 3.5: Conflict baseline value ratings
35
Table 3.1: Baseline value ratings for all themes
36
4 SUB-BASIN EVALUATION SUMMARY SHEETS
4.1 Ayeyarwady Basin
4.1.1 Mali Hka
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
5 5 5 5 4
Overview
Sub-basin size = relatively large
Location = Kachin state, northern
Myanmar, bordering northwestern
India
Topography:
% cover of
Type
sub-basin
Slopes 3-10
14%
soft rock
Slopes>10
65%
hard rock
Slopes>10
21%
intermed rock
Area: 23,287 km2
Physical Average rainfall: 2,524 mm
Average sub-basin outflow: 2,693.3 m3/s
Population: 74,211
Ethnic diversity: Assamese, Kachins (Singpho), Khun, Lisu, Nua, and
Shan
Socio-economic Economic activities:
+ Mining area: 8.9 km2 (covers 0.04% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (0%), Agriculture-Rainfed-Single (0.6%)
37
States/Regions: Kachin
Administration Major town/s: Nagmung, Putao, and Sumprabum
Existing: 0
Under construction: 0
Hydropower development Planned: 1 (Laza – 1,900 MW)
Identified potential site: 0
Geomorphology and sediment Rating 5
Sub-basin size: very large (88th percentile)
• Headwater sub-basin of the Ayeyarwady straddling Myanmar’s
eastern, older crystalline strata and the younger, softer rocks in the
west.
• The catchment is steep, receives high rates of rainfall, and is likely to
provide high volumes of sand into the Ayeyarwady.
• The catchment has low levels of development; although alluvial mining
along river banks causes local disturbances, analysis suggests that
geomorphic processes are intact in the sub-basin.
Aquatic ecology and fisheries Ecological Value Score 5
Human Pressures score 1
• Mali Hka has a very high ecological value representing the
importance of the headwaters of the Ayeyarwady.
• There is a high proportion of rare river reaches – about
30% of the reach lengths and about 60% of karst limestone
river reaches in the sub-basin.
• It is recognized as an area of high endemism for fish, as
shown by recent surveys carried out around Putao. Long
distance migratory species such as Anguilla bengalensis
reach this sub-basin.
• Confluence with Nmae Hka at Myitsone is very important
ecologically and culturally
• The basin has a very low human pressure score indicating
good river health, with low loss of forest cover, small
population density and little agriculture, mining and roads
• No Hydropower dams at present, though Laza HPP is
proposed
Terrestrial biodiversity Rating 5
38
Intact forest cover = 70%
KBA = >90%
• One of the most biodiverse sub-
basins and a habitat for numerous
endemic fish species, tigers, threatened
birds, dolphins, and various other species.
• Has several wildlife sanctuaries,
including Kponkanrazi, Hukaung Valley,
and Bumhpabum.
• Among only six out of 58 sub-
basins to receive a biodiversity rating of
5.
Social, livelihoods, and significant sites Rating 5
• “Own account workers” (livelihood dependent on agriculture/NR) = 27% of the workforce
• Female-headed households = 22% of total households on average
• Avg. % of households owning a TV = 26%
• Ethnic minority groups = Assamese, Kachins (Singpho), Khun, Lisu, Nua, and Shan
• Sub-basin vulnerability rating = 5
Conflict Rating 4
• Armed group presence: KIO in <50% of the sub-basin
• Est. battle deaths (1989-2015) = 70
• Media-reported armed conflict incidents (2012-2016) = 14
• Historical conflict-related displaced people (est.) = 2,140
39
4.1.2 Naw Chang Hka
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
2 4 5 2 3
Overview
Sub-basin size = small
Location = Kachin state, northeastern
Myanmar, bordering China
Topography:
% cover of
Type
sub-basin
Slopes 3-10
1%
soft rock
Slopes>10
99%
hard rock
Area: 2,401 km2
Physical Average rainfall: 1,540 mm
Average sub-basin outflow: 86 m3/s
Population: 20,039
Ethnic diversity: Chinese (Han), Kachins (Singpho), Lisu, Shan, and Yi
(incl. Chila, Pupiao, and Lolo)
Socio-economic Economic activities:
+ Mining area: 0.5 km2 (covers 0.1% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (0%), Agriculture-Rainfed-Single (0.2%)
40
States/Regions: Kachin
Administration Major town/s:
Existing: 0
Under construction: 0
Hydropower development Planned: 4 (Gaw Lan – 120 MW, Hkankawn – 140 MW, Lawngdin – 600
MW, Tongxinqiao – 340 MW)
Identified potential site: 0
Geomorphology and sediment Rating 2 (5)
Sub-basin size: small (18th percentile)
• This sub-basin catchment has been extracted from the high-scoring
Nmae Hka (geomorphology rating = 5) as it is targeted for
hydropower development.
• The headwaters of this very small, steep sub-basin with high rainfall
extend into China, but it remains undeveloped and well forested.
• Its small size and low Strahler Order river result in its low
geomorphology rating.
• If this area were included in the Nmae Hka, it would not alter the
geomorphic rating of 5 for the larger sub-basin.
Aquatic ecology and fisheries Ecological value rating 3
Human pressure rating 1
• A small tributary of the N’Mae Hka with a mean
annual flow estimated at 86 m3/sec and a
minimum flow of 17 m3/sec.
• A high elevation sub-basin with a fast-flowing
river containing many rocks, rapids, and white
water.
• Has a high ecological value with six different
river reach types of which 4 are very rare,
including a medium river, in moist broadleaf
forest region at high elevation, with low gradient
and a medium river in karst region at high
elevation.
• The headwaters of the Ayeyarwady near the
Chinese border are likely to be important for
endemic species; the upper part of its catchment
lies within the Nmae Hka KBA and the Fen-
shui-Ling valley.
• Human pressures are low, so the river health
status is likely to be good, although there is an
open-cast mine in the hills near the watershed
with the Shweli sub-basin.
• A cascade of four HPPs has been proposed,
namely Gaw Lan, Hkankawn, Lawngdin, and
Tongxingiao.
Terrestrial biodiversity Rating 5
41
Intact forest cover = >60%
KBA = 99%, a habitat for >20 endemic
species including the red panda and snap-
nose monkey
Critically endangered ecoregion = 39%,
contained significant swaths of the Nujiang
Langcang Gorge alpine conifer and mixed
forests ecoregion
• Among very few sub-basins that
receive both a biodiversity rating of 5 and a
red star to signify the importance of
protecting this region
Social, livelihoods, and significant sites Rating 2
• “Own account workers” (livelihood dependent on agriculture/NR) = 26% of the workforce
• Female-headed households = 19% of total households on average
• Avg. % of households owning a TV = 43%
• Ethnic minority groups = Karen, Kayah, and Shan
• Sub-basin vulnerability rating = 2
Conflict Rating 3
• Armed group presence: armed groups in some of the sub-basin
• Est. battle deaths (1989-2015) = 0
• Media-reported armed conflict incidents (2012-2016) = 1
• Historical conflict-related displaced people (est.) = 2,190
• Small sub-basin likely underestimates vulnerability
42
4.1.3 Nmae Hka
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
5 4 5 3 4
Overview
Sub-basin size = large
Location = Kachin state, northeastern
Myanmar, bordering China
Topography:
% cover of sub-
Type
basin
Slopes 3-10
1%
soft rock
Slopes>10
99%
hard rock
Area: 17,501 km2
Physical Average rainfall: 1,540 mm
Average sub-basin outflow: 1383.3 m3/s
Population: 25,296
Ethnic diversity: Chinese (Han), Kachins (Singpho), Khun, Lisu, Nua, and
Tibetans (incl. Hsifan and Chiajung)
Socio-economic Economic activities:
+ Mining area: 10.5 km2 (covers 0.06% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (0.1%), Agriculture-Rainfed-Single (0.2%)
States/Regions: Kachin
Administration Major town/s: Chipwi, Hkawbude, Tsawlaw
Existing: 1 (Chipwi Nge – 99 MW)
Planned: 8 (Chipwi – 3,400 MW, Dum Ban – 130MW, Khaunglanphu – 2,700
Hydropower development
MW, Myitsone – 6,000MW, Nam Li – 165 MW, Pisa – 2,000 MW, Renan –
1,200 MW, and Wutsok – 1,800 MW)
43
Under construction: 0
Identified potential site: 0
Geomorphology and sediment Rating 5
Sub-basin size: large (75th percentile; high Strahler Order & high rainfall)
• Situated in the headwaters of the Ayeyarwady, the sub-basin is
elevated; the river is steep and transports sand- to boulder-sized
sediment.
• The Chipwi sub-catchment is highly developed for mining and
forestry, which likely contributes an altered sediment load to the
catchment; the catchment is unregulated except for one HPP that
regulates <5% of the sub-basin catchment.
• The sub-basin scores highly for all geomorphic indicators resulting
in a final rating of “5.”
• The assessment excludes the Naw Chang Hka sub-basin, which is
evaluated independently; even if included, it would not have altered
the final geomorphology rating of the Nmae Hka basin.
Aquatic ecology and fisheries Ecological value rating 4
Human pressure rating 1
• The Nmae Hka has a high ecological value because of the importance of the Ayeyarwady
headwaters.
• Nearly 80% of the Nmae Hka’s river reaches are rare, with the longest type being large river, in
coniferous region, with low gradient; its tributaries mainly have reaches of medium river, in
coniferous region, with high gradient.
• Has a different river network shape compared to Mali Hka but is similar to the Upper Thanlwin –
with a long narrow mainstem, short tributaries on the left bank, and very little karst reaches (only
9%).
• Recognized area for endemics and important terrestrial KBAs in river valley.
• Confluence with the Mali Hka at the Myitsone is very important ecologically and culturally.
• Pressures are still relatively low, though gold mining is a potential threat to river health, and one HPP
is under construction – Chipwe Nge (99 MW) on the Chipwe Hka tributary.
Terrestrial biodiversity Rating 5
44
Intact forest cover = >70%
KBA = >90%
• A habitat for more than 20 endemic
species including the red panda and snap-
nose monkey
Protected area = >27%
• Includes the Hkakaborazi National
Park and the Hponkanrazi Wildlife
Sanctuary
Critically endangered ecoregions = 20% of
the Nujiang Langcang Gorge alpine conifer
and mixed forests ecoregion
• One of the only sub-basins that
receives both a top biodiversity rating of 5
and a red star to signify the importance of
protecting this region.
Social, livelihoods, and significant sites Rating 3
• “Own account workers” (livelihood dependent on agriculture/NR) = 25% of the workforce
• Female-headed households = 16% of total households on average
• Avg. % of households owning a TV = 16%
• Ethnic minority groups = Kachins (Singpho), Khun, Lisu, Nua, and Tibetans (incl. Hsifan and
Chiajung)
• Sub-basin vulnerability rating = 3
Conflict Rating 4
• Armed group presence: influential in much of the sub-basin, including both opposed to and
supportive of the Myanmar army (medium)
• Est. battle deaths (1989-2015) = 6
• Media-reported armed conflict incidents (2012-2016) = 11
• Historical conflict-related displaced people (est.) = 13,053
45
4.1.4 Namtabak
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
3 3 2 N/A 5
Overview
Sub-basin size = smallest in the country
Location = Kachin state, northeastern
Myanmar, bordering China
Topography:
% cover of
Type
sub-basin
Slopes 3-10
39%
soft rock
Slopes<3
55%
Elev>30m
Slopes>10
6%
hard rock
Area: 718 km2
Physical Average rainfall: 1,910 mm
Average sub-basin outflow: 115.7 m3/s
Population: N/A
Ethnic diversity: Kachins (Singpho), Khamti, Lhao Vo, and Zaiwa
Economic activities:
Socio-economic + Mining area: 0.3 km2 (covers 0.04% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (0.1%), Agriculture-Rainfed-Single (7.3%),
Irrigated-Single (0.1%), Irrigated-Double (1.6%), Irrigated-Triple (0.1%)
States/Regions: Kachin
Administration Major town/s:
46
Existing: 0
Under construction: 0
Hydropower development Planned: 2 (Nam Tabak I – 141 MW, Nam Tabak II – 144 MW)
Identified potential site: 0
Geomorphology and sediment Rating 1
Sub-basin size: smallest in the analysis (low Strahler Order 2)
• Has similar characteristics as Mali Creek as it drains the western flanks
of the Shan plateau.
• Its headwaters extend into China where two cascade hydropower
schemes have been developed on its major tributaries.
• Within Myanmar, the river is largely undeveloped and forested.
• The low geomorphic rating reflects its small size, low Strahler Order,
and upstream regulation, including de-watered areas leading to
relatively low connectivity and input of water ratings.
Aquatic ecology and fisheries Ecological value rating 3
Human pressure rating 2
• A small tributary on the east
bank of the Ayeyarwady, 110 km
downstream from the Mali Hka
and N‘Mae Hka confluence.
• The mean annual flow at the
confluence with the mainstem is
112 m3/sec.
• It has 114 km of large- and
medium-sized river reaches,
mainly in moist broadleaf forest
region at low elevation, with low
gradient. Four of the six river
reach types found in the sub-
basin are rare, making up 61% of
the river reach lengths. There is
no karst limestone.
• The Myitkyina-Nandebad-Talawgyi KBA – listed as data-deficient – covers the lower reaches of the
basin. There is some pressure on river health from mining and agriculture, but rural populations are
quite low.
• Two hydropower dams are proposed on this tributary.
Terrestrial biodiversity Rating 2
47
Intact forest cover = 34%
KBA = 19%
• The Myitkyina-Nandebad-
Talawgyi KBA
Protected areas = 0%
Critically endangered ecoregions = 0%
Social, livelihoods, and significant sites Rating N/A
Ethnic minority groups = Kachins (Singpho), Khamti, Lhao Vo, and Zaiwa
Conflict Rating 4
• Armed group presence: KIO in much of the sub-basin, including areas under KIO control
• Est. battle deaths (1989-2015) = 1
• Media-reported armed conflict incidents (2012-2016) = 4
• Historical conflict-related displaced people (est.) = 3,936
48
4.1.5 Mali Creek
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
1 3 2 N/A 3
Overview
Sub-basin size = second-smallest in
Myanmar
Location = Kachin state, northern
Myanmar, bordering China
Topography:
% cover of
Type
sub-basin
Slopes 3-10
59%
soft rock
Slopes>10
41%
hard rock
Area: 719 km2
Physical Average rainfall: 1,828 mm
Average sub-basin outflow: 51.5 m3/s
Population: N/A
Ethnic diversity: Singpho, Lhao Vo, and Khamti
Economic activities:
Socio-economic + Mining area: 0.2 km2 (covers 0.03% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (0.2%), Agriculture-Rainfed-Single (5.2%),
Irrigated-Single (0.1%), Irrigated-Double (1.9%)
States/Regions: Kachin
Administration Major town/s: Nil
49
Existing: 1 (Mali – 11 MW)
Under construction: 0
Hydropower Planned: 0
development Identified potential site: 0
Geomorphology and sediment Rating 1
Sub-basin size: very small (2nd percentile; low order rivers)
• Drains the western edge of the Shan plateau and discharges to the
Upper Ayeyarwady.
• The HPP development has disrupted the connectivity of the sub-basin,
trapped sediment, regulated the flow, and resulted in a >5 km reach of
the river being de-watered.
• Its small size, combined with its highly regulated nature, contributes to
the resultant low geomorphic rating.
Aquatic ecology and fisheries Ecological value rating 3
Human pressure rating 2
• A very small sub-basin on the east bank of the Ayeyarwady; the confluence is immediately
downstream of the Namtamphak with a mean annual flow of 52 m3/sec.
• It has 52 km of two river reach types: medium river, in moist broadleaf forest region at low elevation,
with both low and high gradient; the second type is rare with 6 km of it.
• Similar to the Namtamphak, the lower reaches lie within the Myitkyina-Nandebad-Talawgyi KBA.
• There is a small run-of-river hydropower plant in the upper reaches, with a 1 km reservoir and very
low impact rating on aquatic ecology.
Terrestrial biodiversity Rating 2
50
Intact forest cover = 33%
KBA = 9%
Protected area = 0%
Critically endangered ecoregions = 0%
Social, livelihoods, and significant sites Rating N/A
Ethnic minority groups = Kachins (Singpho), Lhao Vo, and Khamti
Conflict Rating 3
• Armed group presence: Kachin Independence Army (KIO) in much of the sub-basin, including areas
under KIO control
• Est. battle deaths (1989-2015) = 3
• Media-reported armed conflict incidents (2012-2016) = 4
• Historical conflict-related displaced people (est.) = 4,003
• NB: small sub-basin and degree of KIO control (vs. contestation) likely underestimates vulnerability
51
4.1.6 Dapein
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
1 3 2 2 4
Overview
Sub-basin size = relatively small
Location = Kachin state, northeastern
Myanmar
Topography:
% cover of
Type
sub-basin
Slopes 3-10
5%
soft rock
Slopes<3
28%
Elev>30m
Slopes>10
67%
hard rock
Area: 1,235 km2
Physical Average rainfall: 1,686 mm
Average sub-basin outflow: 372.8 m3/s
Population: 62,914
Ethnic diversity: Kachins (Singpho) and Shan
Economic activities:
Socio-economic + Mining area: No
+ Navigable waterways: None
+ Land use: Plantation (1.0%), Agriculture-Rainfed-Single (6.8%),
Flood Plain-Single (0.7%), Flood Plain-Double (0.3%), Irrigated-Double (5.5%)
52
States/Regions: Kachin
Administration Major town/s: Bhamo
Existing: 1 (Dapein 1 – 240 MW)
Under construction: 0
Hydropower Planned: 1 (Dapein 2 – 140 MW)
development Identified potential site: 0
Geomorphology and sediment Rating 1
Sub-basin size: small (10th percentile)
• The Dapein River rises in China, where it has been substantially
developed for hydropower.
• Drains the western rim of the Shan Plateau flowing through the
foothills and large depositional area before joining the Ayeyarwady
near Bhamo.
• Its high degree of regulation (>90% of catchment is upstream of
existing HPP) and extensive de-watered river reaches have disrupted
the connectivity of the river, reduced sediment passage, and altered
the flow regime, resulting in a low overall rating.
Aquatic ecology and fisheries Ecological value rating 3
Human pressure rating 3
• The Dapein river has a relatively small sub-basin flowing in from China on the east bank of the
Ayeyarwady. The flows at the
confluence are about 370 m3/sec.
• It has 62 km of river reach
(levels 2 and 3) with nine river
reach types of which six are rare
(76% of the lengths). The type
with the longest sections is large
river, in moist broadleaf forest
region at low elevation, with
floodplains and sediment. It does
not flow through karst limestone.
• The 96 inns KBA covers the
lower part of the sub-basin.
• The main human pressures on
the river include the cascade of
dams in China and the Dapein 1 HPP (240 MW) built about 50 km upstream of the confluence with
the Ayeyarwady.
Terrestrial biodiversity Rating 2
53
Intact forest cover = 40%
KBA = 30%
• An
important habitat for the endangered
Irrawaddy dolphin and several other
species of fish.
Social, livelihoods, and significant sites Rating 2
• “Own account workers” (livelihood dependent on agriculture/NR) = 23% of the workforce
• Female-headed households = 32% of total households on average
• Avg. % of households owning a TV = 60%
• Ethnic minority groups = Kachins (Singpho) and Shan
• Sub-basin vulnerability rating = 2
Conflict Rating 4
• Armed group presence: KIO in much of the sub-basin, including areas under KIO control
• Est. battle deaths (1989-2015) = 1
• Media-reported armed conflict incidents (2012-2016) = 7
• Historical conflict-related displaced people (est.) = 9,785
• Casualties appear to account for 2011 conflict close to Dapein HPP, and could underestimate
vulnerability
54
4.1.7 Shweli
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
3 2 2 5 4
Overview
Sub-basin size = medium
Location = Kachin and Shan states,
eastern Myanmar, bordering China
Topography:
% cover of
Type
sub-basin
Slopes 3-10
10%
Hard rock
Slopes 3-10 soft
23%
rock
Slopes<3
21%
Elev>30m
Slopes>10 hard
46%
rock
Area: 13,141 km2
Physical Average rainfall: 1,533 mm
Average sub-basin outflow: 1,020.2 m3/s
Population: 328,567
Ethnic diversity: Kachins (Singpho), Palaung, and Shan
Economic activities:
Socio-economic + Mining area: 16.2 km2 (covers 0.12% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (0.2%), Agriculture-Rainfed-Single (5.4%),
Irrigated-Double (1.2%), Irrigated-Triple (0.1%)
States/Regions: Kachin, Mandalay, Sagaing, and Shan
Administration Major town/s: Mongmit and Mabein
55
Existing: 1 (Shweli 1 – 600 MW)
Under construction: 1 (Shweli 3 – 1,050 MW)
Hydropower development Planned: 2 (Nam Paw – 20 MW, Shweli 2 – 520 MW)
Identified potential site: 0
Geomorphology and sediment Rating 3
Sub-basin size: large (63rd percentile; high Strahler Order)
• Drains the western Shan plateau and foothills before flowing through
an alluvial plain and joining the Ayeyarwady.
• Heavily developed with extensive mining and agriculture activities as
well as existing hydropower projects in China and Myanmar.
• The lower reaches of the river have shown geomorphic response to
the flow and sediment changes with substantial straightening of the
main channel upstream of the confluence since the 1980s.
• The sub-basin has large water and sediment inflows as well as a high
Strahler Order, but a high level of regulation reduced its final
geomorphic rating.
Aquatic ecology and fisheries Ecological value rating 2
Human pressure rating 3
• The Shweli River rises in China; after
flowing in a southwest direction, it takes
a turn to the north before its confluence
with the Ayeyarwady about 380 kms
downstream from the Myitsone.
• Its mean annual flow is 1,018 m3/sec
and minimum flow is estimated at 207
m3/sec at the confluence.
• With 750 kilometers within China and
Myanmar, it has 17 river reach types of
which 10 are rare, representing about
44% of the length. About 47% of its
river reach length flows through
limestone karst.
• The sub-basin is not remarkable for
endemic or threatened aquatic species,
and there are no aquatic KBAs.
• The Shweli River has been extensively modified and regulated by at least eight HPPs in cascade in
China. In Myanmar, there is one existing HPP (Shweli 1 – 600 MW) and one under construction
(Shweli 3 – 1,050 MW). Shweli 3 is lowest in the sub-basin but is considered to have the highest
impact, especially on connectivity; with a much longer reservoir (65 km), it will flood a larger length
of rare river reaches. A third HPP, Shweli 2, is proposed between Shweli 1 and 3.
Terrestrial biodiversity Rating 2
56
Intact forest cover = 19%
KBA = 22%
• A habitat for the endangered
Irrawaddy dolphin and a breeding ground
for other important fish species.
Protected area = 1.5%; the Shwe U
Daung Wildlife Sanctuary
Critically endangered ecoregion = 6%;
the Irrawaddy dry forest ecoregion prior
to human intervention
Social, livelihoods, and significant sites Rating 5
• “Own account workers” (livelihood dependent on agriculture/NR) = 29% of the workforce
• Female-headed households = 27% of total households on average
• Avg. % of households owning a TV = 50%
• Ethnic minority groups = Kachins (Singpho), Palaung, and Shan
• Sub-basin vulnerability rating = 5
Conflict Rating 4
• Armed group presence: Multiple armed groups in much of the sub-basin, actively contesting territory
with the Myanmar Army (very high)
• Est. battle deaths (1989-2015) = 40
• Media-reported armed conflict incidents (2012-2016) = 178
• Historical conflict-related displaced people (est.) = 7,108
• Conflict in this sub-basin has been extremely high (more than 10 incidents 2012-2016), thus
vulnerability is likely underestimated
57
4.1.8 Ma Gyi Chaung
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
2 2 2 2 3
Overview
Sub-basin size = relatively small
Location = Shan state in the heart of
Myanmar
Topography:
% cover of sub-
Type
basin
Slopes 3-10
14.7%
Hard rock
Slopes 3-10
8.8%
soft rock
Slopes<3
0.5%
Elev>30m
Slopes>10
75.9%
hard rock
Area: 4,341 km2
Physical Average rainfall: 1,802 mm
Average sub-basin outflow: 166.7 m3/s
Population: 167,149
Ethnic diversity: Palaung, Shan
Economic activities:
+ Mining area: 9 km2 (covers 0.21% of sub-basin)
Socio-economic
+ Navigable waterways: None
+ Land use: Plantation (0%), Agriculture-Rainfed-Single (5.8%),
Flood Plain-Double (0.1%), Irrigated-Double (2.5%), Irrigated-Triple (0.1%)
States/Regions: Mandalay, Shan
Administration Major town/s: Mogoko, Monglon
Hydropower Existing: 1 (Sedawgyi – 25 MW)
58
development Planned: 1 (Sedawgyi upper – 64 MW)
Under construction: 0
Identified potential site: 0
Geomorphology and sediment Rating 2
Sub-basin size: small (28th percentile)
• Drains the western escarpment of the Shan plateau, including the
southern area of the Moguk mining districts.
• The Sedawgyi hydropower and irrigation project is in the lower
reaches, about 30 km upstream of the confluence with the
Ayeyarwady.
• The project is effective at capturing sediment – satellite images show
sediment-laden water entering the impoundment, with “clear” water
being discharged.
• The impoundment has a long residence time (~30 days) and the dam
has substantially altered the geomorphic functioning of the river
system and its relationship with the Ayeyarwady.
Aquatic ecology and fisheries Ecological value rating 2
Human pressure rating 4
• This relatively
small river basin
and tributary on the
left bank of the
Ayeyarwady has a
mean annual flow
of 162 m3/sec and a
minimum flow
estimated at 23
m3/sec.
• It has five river
reach types, of
which two are rare
(14%). However,
94% of the river
flows through karst
limestone.
• It has no KBAs and
is not noted for
endemic or
threatened species.
• The upper reaches
flow through
forested hills. In the
lower reaches, the
Sedawgyi HPP (25
MW) is a combined irrigation and hydropower dam located about 40 km upstream from the
confluence with the Ayeyarwady. Its reservoir extends for 16.5 km upstream and it provides a
moderate degree of regulation of the flows.
• A second Sedawgyi dam upstream (65 MW) is proposed about 50 km upstream from the Sedwagyi
reservoir.
• The lower reaches down to the confluence with the mainstem are more intensively cultivated. There
is moderate pressure from mining activities and river health is expected to be poor.
Terrestrial biodiversity Rating 2
59
Intact forest cover = 23%
KBA = 3%
• A habitat for the endangered
Irrawaddy dolphin and a breeding ground
for freshwater fish.
Social, livelihoods, and significant sites Rating 2
• “Own account workers” (livelihood dependent on agriculture/NR) = 25% of the workforce
• Female-headed households = 28% of total households on average
• Avg. % of households owning a TV = 64%
• Ethnic minority groups = Palaung and Shan
• Sub-basin vulnerability rating = 2
Conflict Rating 3
• Armed group presence = in about 50% of the sub-basin
• Est. battle deaths (1989-2015) = 0
• Media-reported armed conflict incidents (2012-2016) = 19
• Historical conflict-related displaced people (est.) = 0
60
4.1.9 Myitnge Upper
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
5 2 1 4 4
Overview
Sub-basin size = large
Location = Shan state, eastern
Myanmar
Topography:
% cover of
Type
sub-basin
Slopes 3-10
49%
Hard rock
Slopes 3-10 soft
2%
rock
Slopes<3
3%
Elev>30m
Slopes>10 hard
46%
rock
Area: 22,447 km2
Physical Average rainfall: 1,628 mm
Average sub-basin: outflow: 207.45 m3/s
Population: 718,996
Ethnic diversity: Kachins (Singpho), Karen, Palaung, Shan, and Wa (Kawa)
Economic activities:
Socio-economic + Mining area: 17.1 km2 (covers 0.08% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (0.4%), Agriculture-Rainfed-Single (16.3%),
Irrigated-Single (0.1%), Irrigated-Double (0.6%)
States/Regions: Shan
Administration Major town/s: Kyaukme, Lashio, and Namtu
61
Existing: 0
Under construction: 0
Hydropower development Planned: 3 (Nam Tu – 100 MW, Nam Lang – 210 MW, Nam Hsim – 30 MW)
Identified potential site: 0
Geomorphology and sediment Rating 5
Sub-basin size: very large (86th percentile; high Strahler Order, high rainfall)
• Drains the steeply sloping Shan Plateau; no regulated rivers in the
sub-basin and the high Strahler Order tributaries retain good
connectivity.
• The river discharge enters the Lower Myitnge sub-basin in which the
mainstem is regulated for big-scale HPPs with large impoundments.
Although the Upper Myitnge’s connectivity score was reduced due
to this downstream regulation, its geomorphic rating remains a 5 due
to the high values of other input indicators.
• This sub-basin is considered to have very high internal geomorphic
functioning despite its greatly compromised connectivity with the
Ayeyarwady. This is considered when evaluating potential planned
HPPs.
Aquatic ecology and fisheries Ecological value rating 2
Human pressure rating 3
• Covers the headwaters of the Myitnge consisting of three
branches – Nam Hsim and Nam Tu to the north and Nam
Lang from the south.
• The combined flow of the three branches is 417 m3/sec
with an estimated minimum flow of 85 m3/sec (Nam Tu =
205 m3/sec, Nam Lang = 143 m3/sec).
• Has five different river reach types, two of which are rare,
making up 25% of the total reach length; 85% of the river
reaches flow through karst limestone.
• No riverine KBAs and no endemic or threatened fish
species.
• Has relatively low agricultural intensity and mining, but
significant parts of the forest have been cleared for upland
cultivation; the rural population density in these areas is
quite high.
Terrestrial biodiversity Rating 1
62
Intact forest cover = 8%
KBA = 1%; home to an endemic species
of gecko and several cave-dwelling
invertebrates
Social, livelihoods, and significant sites Rating 4
• “Own account workers” (livelihood dependent on agriculture/NR) = 30% of the workforce
• Female-headed households = 26% of total households on average
• Avg. % of households owning a TV = 57%
• Ethnic minority groups = Kachins (Singpho), Karen, Palaung, Shan, and Wa (Kawa)
• Sub-basin vulnerability rating = 4
Conflict Rating 5
• Armed group presence: Multiple armed groups influential in much of the sub-basin, actively
contesting territory with the Myanmar Army
• Est. battle deaths (1989-2015) = 63
• Media-reported armed conflict incidents (2012-2016) = 366
• Historical conflict-related displaced people (est.) = 4,374
• Conflict in this sub-basin has been extremely high (more than 10 incidents 2012-2016), thus
vulnerability is likely underestimated.
63
4.1.10 Myitnge Lower
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
2 2 1 1 2
Overview
Sub-basin size = medium
Location: Spanning multiple states
in the center of the country
Topography:
% cover of
Type
sub-basin
Slopes 3-10
54%
Hard rock
Slopes<3
13%
Elev>30m
Slopes>10
32%
hard rock
Area: 8,070 km2
Physical Average rainfall: 1,496 mm
Average sub-basin outflow: 526.4 m3/s
Population: 1,221,902
Ethnic diversity: Palaung, Shan
Economic activities:
Socio-economic + Mining area: 10.4 km2 (covers 0.13% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (0%), Agriculture-Rain-fed-Single (23%),
Irrigated-Single (0.1%), Irrigated-Double (4.9%), Irrigated-Triple (0.6%)
64
States/Regions: Mandalay and Shan
Administration Major town: Pyin-Oo-Lwin
Existing: 1 (Yeywa – 790 MW)
Under construction: 1 (Yeywa upper – 280 MW)
Hydropower development Planned: 2 (Deedoke – 66 MW, Yeywa middle – 700 MW)
Identified potential site: 0
Geomorphology and sediment Rating 2
Sub-basin size: moderate (44th percentile; Strahler Order 4)
• A very large and complex river system – the Lower Myitnge drains a
steeply sloping predominantly “hard rock” area and likely generates
large volumes of sand and gravel.
• The connectivity, sediment delivery, and flow pattern of the Lower
Myitnge has been disrupted through the Yeywa (operating) and Upper
Yeywa (under construction) HPPs.
• These projects include large storages effective at trapping sediment and
allow large-scale alterations of the flow regime.
Aquatic ecology and fisheries Ecological value rating 2
Human pressure rating 4
• Joins the Ayeyarwady mainstem just downstream of Mandalay; shortly before this confluence, the
sub-basin is joined by the Zawgyi and Panlaung Chaung rivers. At the confluence with the mainstem,
the flow is 724 m3/sec and estimated minimum flow is 149 m3/sec, of which 73% comes from the
Myitnge river.
• The sub-basin has seven river reach types; two of them are rare but cover only 5% of the river reach
lengths. However, 62% of the river reaches flow through karst – mostly as large rivers at low
elevation.
• Human pressures from agriculture and mining are moderate. Had one riverine KBA – Mehon or
Doke-hta Waddy river; it was important for turtles but has since been inundated by the Yeywa HPP.
• The Yeywa HPP (790 MW) is located about 100 km upstream from the confluence with the
mainstem and the reservoir extends for 75 km upstream. It has had a significant impact on the aquatic
ecology, water quality, water flows, and degree of regulation, as a result of the loss of connectivity
between the mainstem and the rare river reaches in the Upper Myitnge.
• The Upper Yeywa HPP
(290 MW) is under
construction and is
expected to have a more
moderate impact on the
river ecology, especially as
connectivity with the
mainstem was already lost
with the first dam. A third
dam is planned between
the two Middle Yeywa so
that the lengths of
impounded reservoir will
extend for 200 km above
the Yeywa HPP. A run-of-
river re-regulating dam at
Deedoke, 20 km
downstream of Yeywa is
also planned.
65
Terrestrial biodiversity Rating 1
Intact forest cover = 11%
KBA = 17%
• A habitat for the Irrawaddy
dolphin, several species of freshwater fish,
and several species of threatened water
birds; the Pyin Oo Lwin bird sanctuary
makes up about 1% of the sub-basin.
Protected area = 0%
Critically endangered ecoregions = 0%
Social, livelihoods, and significant sites Rating 1
• “Own account workers” (livelihood dependent on agriculture/NR) = 23% of the workforce
• Female-headed households = 26% of total households on average
• Avg. % of households owning a TV = 60%
• Ethnic minority groups = Palaung and Shan
• Sub-basin vulnerability rating = 1
Conflict Rating 2
• Armed group presence = small, borders Danu Self-administered Zone (Danu SAZ)
• Est. battle deaths (1989-2015) = 17
• Media-reported armed conflict incidents (2012-2016) = 10
• Historical conflict-related displaced people (est.) = 0
66
4.1.11 Zawgyi/Myogyi
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
3 2 1 4 2
Overview
Sub-basin size = medium
Location = Shan state, central
Myanmar
Topography:
% cover of sub-
Type
basin
Slopes 3-
10 Hard 30%
rock
Slopes 3-
10 soft 1%
rock
Slopes<3
48%
Elev>30m
Slopes>10
21%
hard rock
Area: 16,327 km2
Physical Average rainfall: 1,185 mm
Average sub-basin outflow: 195.2 m3/s
Population: 2,099,186
Ethnic diversity: Karen and Shan
Economic activities:
Socio-economic + Mining area: 88.2 km2 (covers 0.54% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (0%), Agriculture-Rainfed-Single (44.2%),
Rainfed-Double (0.1%), Irrigated-Double (5%), Irrigated-Triple (0.5%)
States/Regions: Magway, Mandalay, and Sagaing
Administration
Major town/s: Meiktila and Pyawbwe
67
Existing: 4 (Kinda – 56 MW, Myogyi – 30 MW, Zawgyi I – 18 MW, Zawgyi
II – 12 MW)
Hydropower development Under construction: 0
Planned: 0
Identified potential site: 0
Geomorphology and sediment Rating 3
Sub-basin size = large (72nd percentile)
• Third sub-basin in the Myitnge occupying the western portion of the
large catchment.
• The headwaters of one major tributary extend into the steeply sloping
flanks of the Shan plateau, while the other main tributary is confined
to low-lying central basin.
• The steeper headwater area has been developed for hydropower with
four HPPs established.
• The regulated flow and low-lying areas with lower rainfall and
sediment input result in the geomorphic rating of 3.
Aquatic ecology and fisheries Ecological value rating 2
Human pressure rating 5
• The Zawgyi and Panlaung Chaung rivers
join the Myitnge just before the
confluence with the Ayeyarwady
mainstem.
• The mean annual flows of the two rivers
are 195 m3/sec with a minimum flow
estimated at 39 m3/sec.
• They have seven different river reach
types of which three are rare, making up
10% of the total reach length. The river
reach type of the Panlaung Chaung is
medium river, in moist broadleaf forest
region at low elevation, with floodplains.
The Zawgyi River is more diverse and its
reach types include medium rivers in karst
at low elevation and at high elevation in
the upper reaches.
• The Panlaung Pyadalin Cave Wildlife
Sanctuary, located in one of the branches
of the Panlaung Chaung near the Kinda
dam, is a limestone cave with Neolithic cave paintings. The lower Doke-hta Wady watershed forest
has also been identified as a KBA on the Zawgyi river.
• Has more than 20 irrigation reservoirs (pink dots) in the western part of the sub-basin, with medium
agricultural intensity and high mining activities.
• The sub-basin has four existing combined hydropower and irrigation reservoirs: Kinda (56 MW, 14.5
km length reservoir, >9 months of storage capacity); Myogi (30 MW, 10 km reservoir, high degree
of regulation); Zawgyi II (12 MW, 8 km reservoir, 5 months storage, and high degree of regulation);
and Zawgyi I (18 MW), a diversion dam with 2 km de-watered zone and no storage.
Terrestrial biodiversity Rating 1
68
Intact forest cover = 4%
KBA = 20%, a habitat for threatened
water birds and several species of
cave invertebrates
Protected areas = 2%, the
Minzontaung and Panlaung Pyadalin
Cave wildlife sanctuaries
Critically endangered ecoregions =
19%, the Irrawaddy dry forest that
has been affected by infrastructure
development and forest degradation
Social, livelihoods, and significant sites Rating 4
• “Own account workers” (livelihood dependent on agriculture/NR) = 25% of the workforce
• Female-headed households = 24% of total households on average
• Avg. % of households owning a TV = 43%
• Ethnic minority groups = Karen and Shan
• Sub-basin vulnerability rating = 4
Conflict Rating 2
• Armed group presence: Danu SAZ covers <50% of the sub-basin
• Est. battle deaths (1989-2015) = 5
• Media-reported armed conflict incidents (2012-2016) = 0
• Historical conflict-related displaced people (est.) = 3,187
69
4.1.12 Tributary with Indawgyi Lake Catchment
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
3 4 3 1 4
Overview
Sub-basin size = medium
Location = Tributary with the Indawgwi
Lake catchment, Kachin State, western
Myanmar
Topography:
% cover of
Type
sub-basin
Slopes 3-10
85%
soft rock
Slopes<3
8%
Elev>30m
Slopes>10
7%
intermed rock
Area: 9,357 km2
Physical Average rainfall: 2,280 mm
Average sub-basin outflow: 814.5 m3/s
Population: 673,608
Ethnic diversity: Kachins (Singpho) and Shan
Economic activities:
Socio-economic + Mining area: 11 km2 (covers 0.12% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (0%), Agriculture-Rainfed-Single (8.2%),
Irrigated-Single (0.1%), Irrigated-Double (3.5%)
States/Regions: Kachin and Sagaing
Administration Major town/s: Mogaung, Kamaing, Mohnyin, and Hopin
70
Existing: 0
Under construction: 0
Hydropower development Planned: 0
Identified potential site: 0
Geomorphology and sediment Rating 3
Sub-basin size: medium (53rd percentile)
• The Indawgyi Lake is in a tectonically active fault-controlled sub-
basin within the northern Ayeyarwady basin; the lake connects to
the mainstem Ayeyarwady via an outlet in the north and a highly
meandering river.
• The lake experiences high levels of sedimentation from Land use,
including mining activities.
• This sub-basin hosts important ecological habitats. Although its
geomorphic relevance on a basin scale is considered moderate, it has
high value in a local context.
Aquatic ecology and fisheries Ecological value rating 4
Human pressure rating 2
• This tributary with the Indawgyi Lake
catchment is large and complex, with its
confluence on right bank of the
Ayeyarwady about 155 km downstream
from the Myitsone. The mean annual
flow is estimated at 814 m3/sec with a
minimum flow of about 100 m3/sec.
• It has five different river reaches, none of
which are rare, but with over 50%
flowing through karst limestone.
• The basin consists of three main valleys
separated by hill ridges, one flowing from
the north and two from the south. In the
southwest valley lies the Indawgyi Lake,
with wet grasslands surrounding it.
• The lake is a Ramsar site and globally
important wetland area. It is also a
wildlife sanctuary recognized for its
waterbird populations and fish diversity.
It is an area of high endemism for fish
and other aquatic organisms.
• Human pressures are increasing, with the
valleys extensively cultivated; only the
hillsides remain forested. About 30,000
people live around the lake, and much of
the surrounding grasslands have been converted to cultivating wet rice.
• Gold mining activity in the Indawgyi Lake catchment is beginning to cause serious contamination in
the lake.
Terrestrial biodiversity Rating 3
71
Intact forest cover = 41%
KBA = 49%
• An important habitat for
several endangered species of fish and
freshwater turtles
Protected areas = 26%
• Three wildlife sanctuaries:
Pidaung, Indawgyi, and Hukaung
Valley
Social, livelihoods, and significant sites Rating 1
• “Own account workers” (livelihood dependent on agriculture/NR) = 25% of the workforce
• Female-headed households = 25% of total households on average
• Avg. % of households owning a TV = 66%
• Ethnic minority groups = Kachins (Singpho) and Shan
• Sub-basin vulnerability rating = 1
Conflict Rating 4
• Armed group presence: Multiple armed groups influential in much of the sub-basin, actively
contesting territory with the Myanmar Army
• Est. battle deaths (1989-2015) = 30
• Media-reported armed conflict incidents (2012-2016) = 41
• Historical conflict-related displaced people (est.) = 2,771
72
4.1.13 Ayeyarwady Upper
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
3 2 2 4 5
Overview
Sub-basin size = large
Location = Kachin and Shan states,
northeastern Myanmar, bordering China
Topography:
% cover of sub-
Type
basin
Slopes 3-10
6%
Hard rock
Slopes 3-10 soft
61%
rock
Slopes<3
26%
Elev>30m
Slopes>10 hard
7%
rock
Area: 17,939 km2
Physical Average rainfall: 1,716 mm
Average sub-basin outflow: 6,245.1 m3/s
Population: 894,488
Ethnic diversity: Kachins (Singpho) and Shan
Economic activities:
+ Mining area: 9.3 km2 (covers 0.05% of sub-basin)
Socio-economic
+ Navigable waterways: 301.2 km
+ Land use: Plantation (0.2%), Agriculture-Rainfed-Single (8.9%),
Flood Plain-Single (0.2%), Flood Plain-Double (0.6%), Irrigated-Single
(0.2%), Irrigated-Double (3.4%), Irrigated-Triple (0.1%)
States/Regions: Kachin, Sagaing, and Shan
Administration Major town/s: Katha, Mansi, and Myitkyina
73
Existing: 0
Under construction: 0
Hydropower development Planned: 0
Identified potential site: 0
Geomorphology and sediment Rating 3
Sub-basin size: large (79th percentile; Strahler Order 1 & 2)
• A large catchment comprising numerous small Strahler Order 1 and
2 watersheds that report directly to the mainstem.
• Contains large, flat-lying areas associated with the floodplains
around Bhamo and cuts through hills to enter the Sagaing fault zone
at the southern extents.
• Inflows to the sub-basin include the large unregulated flow from the
Mali Hka and Nmae Hka, and the regulated flows of the Mali Creek,
Dapein and Shweli rivers.
• The moderate geomorphology rating is linked to the low Strahler
Order and low sediment contribution from the basin.
• NOTE: This rating does not apply to the mainstem Ayeyarwady,
which is considered a special unit with a geomorphic value of 5.
Aquatic ecology and fisheries Ecological value rating 2
Human pressure rating 2
• The Ayeyarwady Upper starts at the confluence with the
Mali Hka and N’Mae Hka extending to the confluence
with the Shweli River.
• The mainstem consists of rock-cut river channel and
anastomose channel, neither of which are rare, but it is a
critical migratory route for fish to the Ayeyarwady
headwaters
• The tributaries flowing into the mainstem have a low
ecological value because they are quite small and not
very diverse. There are 11 river reach types of which six
are rare, making up about 29% of all the river reaches in
the sub-basin; 37% of the river reaches run through karst
limestone, especially the tributaries on the right bank.
• The mainstem flows through several recognized riverine
and wetland KBAs, including the Ayeyarwady sections,
Myintkyina to Sinbo, Bhamo and Shwegyu sections, 96
Inns, and Nam Sam Chaung.
• Human pressure rating is low, with some mining and little agriculture activity, low population
density, and few roads. The river health status is expected to be good.
• Note: The Ecological Value
rating is for the tributaries only, not
for mainstem reaches
74
Terrestrial biodiversity Rating 2
Intact forest cover = 21%
KBA = 31%; a habitat for aquatic flora and fauna
including the endangered Irrawaddy dolphin and several
endemic species of fish.
Protected area = 0.5%; the Pidaung Wildlife Sanctuary
Critically endangered ecoregion = >5%; the Irrawaddy dry
forest before human influence was introduced to the
ecoregion
Social, livelihoods, and significant sites Rating 4
• “Own account workers” (livelihood dependent on agriculture/NR) = 29% of the workforce
• Female-headed households = 30% of total households on average
• Avg. % of households owning a TV = 60%
• Ethnic minority groups = Kachins (Singpho) and Shan
• Sub-basin vulnerability rating = 4
Conflict Rating 5
• Armed group presence: High influence in much of the sub-basin, including areas under KIO control
• Est. battle deaths (1989-2015) = 64
• Media-reported armed conflict incidents (2012-2016) = 110
• Historical conflict-related displaced people (est.) = 48,027
75
4.1.14 Ayeyarwady Middle
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
2 1 2 2 1
Overview
Sub-basin size = large
Location = spanning several states in
the center of Myanmar
Topography:
% cover of sub-
Type
basin
Slopes 3-10
45%
soft rock
Slopes<3
55%
Elev>30m
Area: 17,940 km2
Physical Average rainfall: 1,163 mm
Average sub-basin outflow: 9,378.6 m3/s
Population: 3,344,726
Ethnic diversity: Kachins (Singpho), Lisu, and Shan
Economic activities:
+ Mining area: 35.1 km2 (covers 0.2% of sub-basin)
Socio-economic
+ Navigable waterways: 374 km
+ Land use: Plantation (0%), Agriculture-Rainfed-Single (32.3%), Flood
Plain-Single (0.8%), Flood Plain-Double (0.3%), Irrigated-Single (0.3%),
Irrigated- Double (4.2%), Irrigated-Triple (0.5%)
States/Regions: Kachin, Magway, Mandalay, Sagaing, and Shan
Administration Major town/s: Banmauk, Mandalay, Myingyan, Nabar, and Sagaing
76
Existing: 0
Under construction: 0
Hydropower development Planned: 0
Identified potential site: 0
Geomorphology and sediment Rating 2
Sub-basin size: large (81st percentile; maximum Strahler Order 2)
• The low-order tributaries are attributable to the narrow nature of the
sub-basin, which is largely fault controlled, as the Ayeyarwady
occupies the Sagaing fault zone through this area.
• Once out of the fault zone, the Ayeyarwady “spills” into a broad
alluvial plain, accounting for the large percentage of flat-lying
area in the basin.
• The rating of “2” is attributable to the low Strahler Order inputs,
combined with low potential sediment input.
• NOTE: This rating pertains only to the tributaries draining into the
Ayeyarwady and does not apply to the mainstem, which is
considered a special unit with a geomorphic value of 5.
Aquatic ecology and fisheries Ecological value rating 1
Human pressure rating 3
• The Ayeyarwady
Middle is a long
stretch of 386 km
from the Upper
Ayeyarwady
mainstem down to the
confluence with the
Chindwin.
• The mainstem
initially flows for 64
km through an
anastomosing channel
(code 10020)
consisting of several
channels enclosing
floodplains, with
oxbow lakes and islands. It then flows through a very straight rock-cut gorge (code 10010) between
Takaung and Kyaukmyaung before passing through another anastomosing channel that follows a
broad, open course through the central dry zone where large areas consist of alluvial flats. From
Mandalay, the river makes an abrupt westward turn before curving southwest to unite with the
Chindwin River.
• The mainstem is joined on the left bank above Mandalay by the Ma Gyi Chaung River (with the
Sedwagyi HPP) and below Mandalay by the Myitnge River (with the Yeywa HPP). On the right
bank, the Mu River joins about 100 km upstream from the Chindwin confluence.
• The other tributaries flowing into the Ayeyarwady Middle mainstem are very small and mainly in the
northern section (right hand diagram). There are only three river reach types all of which are
common. By themselves, they have a Very Low Ecological Value.
• The mean annual flow at the top end of this sub-basin is 6,254 m3/sec and before the Chindwin
confluence is 9,379 m3/sec.
• The mainstem is a critical migratory pathway for fish and key for the overall connectivity of the
river. The entire stretch upstream of Mandalay is important for the Irrawaddy dolphin and turtles with
recognized riverine KBAs in the Shwegyu and Singu sections and the Irrawaddy dolphin protected
area.
• Human pressures from agriculture are generally moderate above Mandalay, but these increase below
77
Mandalay where there are at least 10 irrigation reservoirs in the sub-basin. Mining pressures are also
moderate.
• Lower parts of the Ayeyarwady Middle mainstem are increasingly polluted especially through
runoff, sewage, and industrial waste waters from major urban areas such as Mandalay and Sagaing.
Navigation intensity also increases below Mandalay.
• Note: The Ecological Value rating is for the tributaries only, not for mainstem reaches
Terrestrial biodiversity Rating 2
Intact forest cover = 9%
KBA = 29% incl. dry zone wetlands that
are habitat for the endangered Irrawaddy
dolphin and threatened water birds
Critically endangered ecoregion = 22%;
Irrawaddy dry forest
The Minwuntaung and Shwe U Daung
Wildlife Sanctuaries, though small (<1%),
are also in this sub-basin.
Social, livelihoods, and significant sites Rating 2
• “Own account workers” (livelihood dependent on agriculture/NR) = 23% of the workforce
• Female-headed households = 26% of total households on average
• Avg. % of households owning a TV = 59%
• Ethnic minority groups = Kachins (Singpho), Lisu, and Shan
• Sub-basin vulnerability rating = 2
Conflict Rating 1
• Armed group presence: None or low
• Est. battle deaths (1989-2015) = 5
• Media-reported armed conflict incidents (2012-2016) = 1
• Historical conflict-related displaced people (est.) = 23
78
4.1.15 Ayeyarwady Lower
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
4 2 2 4 1
Overview
Sub-basin size = second-largest
spanning multiple states
Location = in eastern and central
Myanmar
Topography:
% cover of
Type
sub-basin
Slopes 3-10
28%
soft rock
Slopes<3
67%
Elev>30m
Slopes>10
intermed 5%
rock
Physical Area: 37,114 km2
Average rainfall: 875 mm
Average sub-basin outflow: 15,418.2 m3/s
79
Population: 3,563,016
Ethnic diversity: Chini, Karen
Economic activities:
+ Mining area: 17.6 km2 (covers 0.05% of sub-basin)
Socio-economic + Navigable waterways: 319 km
+ Land use: Plantation (0%), Agriculture-Rainfed-Single (43.6%), Flood Plain-
Single (0.2%), Flood Plain-Double (0.2%), Irrigated-Single (0.2%), Irrigated-
Double (1.2%), Irrigated-Triple (0.4%)
States/Regions: Bago, Chin, Magway, Mandalay, Nay Pyi Taw, Rakhine, and
Sagaing
Administration
Major town/s: Bagan Nyaung Oo, Kyaukpadaung, Magway, Myayde, Pakokku,
Pauk, and Taungdwingyi
Existing: 0
Under Construction: 0
Hydropower Planned: 0
development Identified potential site: 0
Geomorphology and sediment Rating 4
Sub-basin size: very large (98th percentile; Strahler Order 3 rivers)
• Encompasses low-lying areas of the Central Dry Belt, with some
tributaries extending into the Arakan range.
• These hills likely contribute pulses of sediment during intense
rainfall events.
• Contains the most downstream bedrock sections that exert control
on the course of the mainstem Ayeyarwady before the river enters
the alluvial delta.
• NOTE: This score pertains only to the tributaries draining into the
Ayeyarwady and does not apply to the mainstem, which is
considered a special unit with a geomorphic value of 5.
Aquatic ecology and fisheries Ecological value rating 2
Human pressure rating 3
80
• Contains the mainstem from the
confluence with the Chindwin to
that with the Man Chaung. The
mainstem reaches are 338 km of
anastomose channel – multiple
channels enclosing floodplains and
islands. Several tributaries enter on
the right bank (of which the Mone
Chaung and Man Chaung are
described separately) and one enters
on the left bank.
• There are seven river reaches of
which three are rare, making up
28.5% of the reach lengths. There
are no karst reaches. The
predominant reach types in the
tributaries are medium river, in
moist broadleaf forest region at low
elevation, with low gradient and
with floodplains. The main rare
reach type is medium river, in dry
broadleaf forest region, with
floodplains.
• The Ayeyarwady mainstem is an
important route for migratory fish
species, especially for the Hilsa.
There are spawning areas for the
Hilsa and several other species near
Magway and Pakokku.
• Human pressures on the river include pollution from urban wastes and increasing agricultural
intensity affecting water quality as the mainstem is an important navigation route. There are over 40
irrigation reservoirs constructed in this sub-basin, especially to the east of the mainstem.
• Note: The Ecological Value rating is for the tributaries only, not for mainstem reaches
Terrestrial biodiversity Rating 2
81
Intact forest cover = 3%
KBA = 23%
Protected area = 0%
Critically endangered ecoregion = 51% of
the sub-basin used to comprise the
Irrawaddy dry forest ecoregion, for which it
will receive a red star, signifying the need
to protect the remaining dry forest
Social, livelihoods, and significant sites Rating 4
• “Own account workers” (livelihood dependent on agriculture/NR) = 23% of the workforce
• Female-headed households = 25% of total households on average
• Avg. % of households owning a TV = 36%
• Ethnic minority groups = Chini and Karen
Conflict Rating 1
• Armed group presence = none to low
• Est. battle deaths (1989-2015) = 4
• Media-reported armed conflict incidents (2012-2016) = 0
• Historical conflict-related displaced people (est.) = 15
82
4.1.16 Delta
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
4 2 2 1 1
Overview
Sub-basin size = largest in
Myanmar
Location = Spanning several
states encompassing much of
the southern region
Topography:
% cover of
Type
sub-basin
Slopes 3-
10 soft 17%
rock
Slopes<3
65%
Elev<30m
Slopes<3
16%
Elev>30m
Slopes>10
intermed 2%
rock
Area: 53,084 km2
Physical Average rainfall: 2,236 mm
Average sub-basin outflow: 17,086.2 m3/s
Population: 11,815,891
Ethnic diversity: Chini, Karen
Socio-economic
Economic activities:
+ Mining area: 2.4 km2
83
+ Navigable waterways: 7,885.3 km
+ Land use: Plantation (1.0%), Agriculture-Rainfed-Single (6.8%), Flood Plain-
Single (0.7%), Flood Plain-Double (0.3%), Irrigated-Double (5.5%)
States/Regions: Ayeyarwady, Bago, Magway, Rakhine
Administration Major town/s: Bogale, Hinthada, Letpadan, Minhla, Pantanaw, Pathein, Pyay,
Yangon
Existing: 0
Under construction: 0
Hydropower Planned: 0
development Identified potential site: 0
Geomorphology and sediment Rating 4
Sub-basin size: largest in the analysis including numerous small tributaries
• Predominantly flat-lying area of sediment storage and reworking,
with gently sloping low hills in the west.
• High score due to a large inflow of water and high connectivity
within the tributaries, even without considering the mainstem.
• NOTE: This score pertains only to the tributaries draining into the
Ayeyarwady and does not apply to the mainstem, which is
considered a special unit with a geomorphic value of 5.
Aquatic ecology and fisheries Ecological value rating 2
Human pressure rating 4
• The Ayeyarwady Delta is the final sub-basin where the river breaks up into about 6 distributary
channels before reaching the sea. It is tidal and increasingly saline towards the sea.
• The mean annual flow at the point where the
distributary channels start is about 16,000 m3/sec,
with a minimum flow of 2,288 m3/sec
• The delta consists of 11 different river reach
types of which 6 are rare. The first 116 km of the
mainstem are in an anastomose channel,
thereafter for 305 km the mainstem river reach
type is characterized as flowing through the large
delta. River reaches in the smaller channels in
reaches above the main delta are the common
Medium river, in moist broadleaf forest region at
low elevation, with floodplains. Towards the
bottom end nearest the sea, the medium river
reaches flow through mangrove areas. There is a
small area of karst in the north-west part of the
delta sub-basin.
• The delta supports an important estuarine and
coastal fishery, with mangrove areas which are
important for fish and crustacean breeding. The
migration routes for Hilsa and eel from the sea
up the mainstem channels are very important.
The main spawning area for Hilsa is around
Hinthada and other distributary channels in the
delta.
• Myanmar’s most recent Ramsar site at
Meinmahla Kyun is a mangrove area in the delta
• The human pressures are largely driven by the intensity of agriculture, with double and even triple
cropping in many parts of the delta. The rural population density is high and there are many large
towns throughout the delta, contributing domestic and industrial wastes and urban runoff. Cutting of
84
mangroves has contributed to degradation of the delta ecosystem.
• Note: The Ecological Value rating is for the tributaries only, not for mainstem reaches
Terrestrial biodiversity Rating 2
Intact forest cover = 4%
KBA = 52%
Protected area = 0.3%
Critically endangered ecoregions =
Irrawaddy dry forests (4.2%), Irrawaddy
freshwater swamp forests (26%), and
coast mangrove forests (17%), but these
areas have been reduced to small pockets
due to population pressure, agricultural
encroachment, and forest clearing
• Despite its low biodiversity
value rating of 2, this sub-basin receives
a red star for the urgent need to safeguard
what remains of its critically endangered
ecoregions.
Social, livelihoods, and significant sites Rating 1
• “Own account workers” (livelihood dependent on agriculture/NR) = 18% of the workforce
• Female-headed households = 22% of total households on average
• Avg. % of households owning a TV = 54%
• Ethnic minority groups = Chini and Karen
Conflict Rating 1
• Armed group presence = none to very low
• Est. battle deaths (1989-2015) = 17
• Media-reported armed conflict incidents (2012-2016) = 1
• Historical conflict-related displaced people (est.) = 0
85
4.1.17 Mu
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
3 1 1 5 1
Overview
Sub-basin size = relatively large
Location = Mandalay and Sagaing
regions
Topography:
% cover of
Type
sub-basin
Slopes 3-10
0%
Hard rock
Slopes 3-10 soft
33%
rock
Slopes<3
67%
Elev>30m
Area: 19,708 km2
Physical Average rainfall: 1,260 mm
Average sub-basin outflow: 375.5 m3/s
Population: 1,953,363
Ethnic diversity: Lisu and Shan
Economic activities:
+ Mining area: 33.7 km2 (covers 0.17% of sub-basin)
Socio-economic
+ Navigable waterways: None
+ Land use: Plantation (0%), Agriculture-Rainfed-Single (32.6%),
Flood Plain-Double (0.1%), Irrigated-Single (0.8), Irrigated-Double (8.4%),
Irrigated-Triple (0.2%)
86
States/Regions: Mandalay and Sagaing
Administration Major town/s: Pinlebu, Shwe Bo, and Wetlet
Existing: 1 (Thapanzeik – 30 MW)
Under construction: 0
Hydropower development Planned: 0
Identified potential site: 0
Geomorphology and sediment Rating 3
Sub-basin size: very large (82nd percentile)
• Drains low undulating hills with a broad valley floor, with similar
attributes to the Middle Ayeyarwady mainstem.
• Regulated by a large hydropower and irrigation project in the upper
catchment, and the entire catchment has been highly developed for
agriculture.
• The impoundment has a potential residence time of ~170 days,
suggesting the flow regime can be highly altered relative to natural
flow patterns. The geomorphic rating is attributable to the large
volume of water derived from the catchment, its high Strahler Order
offset by the reduction in connectivity, sediment transport, and flow
patterns attributable to the regulation.
Aquatic ecology and fisheries Ecological value rating 1
Human pressure rating 5
• Flows from the north to south parallel to the Ayeyarwady
mainstem between the confluences of the Myitnge and Chindwin
rivers.
• Mean annual flows before the confluence are 373 m3/sec with a
minimum flow of 44 m3/sec. At the confluence, total flows in the
Ayeyarwady are 9,418 m3/sec.
• Has three different river reach types: All of which are common,
predominantly large and medium rivers, in moist broadleaf forest
region at low elevation, with floodplains.
• Generally flat except in the upper catchment where the hills have
been largely deforested and in the lower parts where the land is
intensely cultivated.
• Has a very large combined irrigation and hydropower reservoir
of Thapanzeik (30 MW) downstream, covering an area of 397
km2 and a length of 42 km. The reservoir has a storage capacity
of nearly six months, with a very high degree of flow regulation
at the dam site.
Terrestrial biodiversity Rating 1
87
Intact forest cover = 12%
KBA = 2%
Protected area = 1%
• The Chatthin Wildlife Sanctuary
is home to several species of deer.
Critically endangered ecoregion = 0.5%
Social, livelihoods, and significant sites Rating 5
• “Own account workers” (livelihood dependent on agriculture/NR) = 27% of the workforce
• Female-headed households = 25% of total households on average
• Avg. % of households owning a TV = 38%
• Ethnic minority groups = Lisu and Shan
• Sub-basin vulnerability rating = 5
Conflict Rating 1
• Armed group presence: None or low
• Est. battle deaths (1989-2015) = 13
• Media-reported armed conflict incidents (2012-2016) = 0
• Historical conflict-related displaced people (est.) = 0
88
4.1.18 Mone Chaung
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
1 1 2 4 1
Overview
Sub-basin size = relatively small
Location = Chin and Rakhine states,
western Myanmar
Topography:
% cover of
Type
sub-basin
Slopes 3-10
20%
soft rock
Slopes<3
13%
Elev>30m
Slopes>10
67%
intermed rock
Area: 5,974 km2
Physical Average rainfall: 1,694 mm
Average sub-basin outflow: 136.8 m3/s
Population: 232,711
Ethnic diversity: Chini
Economic activities:
Socio-economic + Mining area: No
+ Navigable waterways: None
+ Land use: Plantation (0%), Agriculture-Rainfed-Single (6%),
Irrigated-Double (1.5%), Irrigated-Triple (0.1%)
States/Regions: Chin, Magway, and Rakhine
Administration Major town/s: Sidoktaya
89
Existing: 2 (Kyee Ohn Kyee Wa – 74 MW, Mone Chaung – 75 MW)
Under construction: 1 (Upper Buywa – 150 MW)
Hydropower development Planned: 1 (Buywa – 42 MW)
Identified potential site: 0
Geomorphology and sediment Rating 1 (4)
Sub-basin size: small (35th percentile; maximum Strahler Order 2)
• Drains the eastern flanks of the Western Ranges, extending into the
low-lying central basin.
• A cascade of three HPP developed on the mainstem of the tributary;
each has a large impoundment – the most downstream project has
potential water retention times of >50 days.
• The river’s highly regulated nature disrupts its connectivity, sediment
regime, and flow patterns, resulting in a low rating.
Aquatic ecology and fisheries Ecological value rating 1
Human pressure rating 4
• The Mone Chaung is a small
tributary joining the right bank of
the Ayeyarwady Lower just
upstream of Magway. The mean
annual flows at the confluence are
137 m3/sec with minimum flows
estimate at 13 m3/sec
• It contains 6 river reach types of
which 3 are rare, covering 27% of
the reach lengths. Most of the
reaches are Large and Medium
rivers in moist broadleaf forest
region at low elevation, with
floodplains or at low gradient. The
principal rare river reach type is
Large river, in dry broadleaf forest
region, with floodplains and sediment, reflecting the vegetation type in the Dry Zone.
• The river is not a noted area for endemic or threatened fish or other aquatic species, and there are no
riverine KBAs in the sub-basin
• The principal human pressure upon aquatic ecology are the cascade of two existing HPPs – Kee Ohn
Kee Wa (74 MW) with a 30-km reservoir and 45-day storage capacity, and an assessed medium
impact upon aquatic ecology, and Mone Chaung HPP (75 MW) with a 20-km reservoir, and 76-day
storage capacity. There are also two irrigation weirs downstream of the Kee Ohn Kee Wa dam, so the
whole river is already significantly regulated – 32.5%.
• An additional HPP Buywa is under construction, and a fourth Upper Buywa is planned. Buywa HPP
(42 MW) will have a 38 km2 reservoir and is likely to increase the degree of regulation to about 36%
in the river. With all four dams in place the Mone Chaung will be one of the most regulated, and
reservoir inundated rivers in Myanmar.
Terrestrial biodiversity Rating 2
90
Intact forest cover = 26%
KBA = 10%
• The region encompasses
important habitats for many species
including tigers, leopards, bears, and
more.
Protected areas = 2
• The Shwesettaw Wildlife
Sanctuary and the Natmataung National
Park make up 7% of the sub-basin
Critically endangered ecoregions = 3%
• Irrawaddy dry forest ecoregion
Social, livelihoods, and significant sites Rating 4
• “Own account workers” (livelihood dependent on agriculture/NR) = 25% of the workforce
• Female-headed households = 21% of total households on average
• Avg. % of households owning a TV = 26%
• Ethnic minority groups = Chini
• Sub-basin vulnerability rating = 4
Conflict Rating 1
• Armed group presence: None or low
• Est. battle deaths (1989-2015) = 0
• Media-reported armed conflict incidents (2012-2016) = 0
• Historical conflict-related displaced people (est.) = 4
91
4.1.19 Mindon
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
1 2 2 4 1
Overview
Sub-basin size = relatively small
Location = Rakhine state, western
Myanmar
Topography:
% cover of
Type
sub-basin
Slopes 3-10
54%
soft rock
Slopes<3
15%
Elev>30m
Slopes>10
31%
intermed rock
Area: 4,445 km2
Physical Average rainfall: 1,385 mm
Average sub-basin outflow: 173.6 m3/s
Population: 20,039
Ethnic diversity: Chini
Economic activities:
+ Mining area: No
Socio-economic
+ Navigable waterways: None
+ Land use: Plantation (0%), Agriculture-Rainfed-Single (7.2%), Rainfed-
Double (0.1%), Irrigated-Single (0.4), Irrigated-Triple (0.5%)
States/Regions: Magway and Rakhine
Administration Major town/s: Mindon
92
Existing: 0
Under construction: 0
Hydropower development Planned: 0
Identified potential site: 1 (Mindon – 18 MW)
Geomorphology and sediment Rating (4)
Sub-basin size: small (30th percentile; Strahler Order 2 tributary)
• Drains the steep western ranges before flowing through an area of
alluvial fill and reworking; situated in the Ayeyarwady Lower sub-basin.
• Its low geomorphology rating is attributable to its small size and low
Strahler Order.
• If the Mindon HPP was considered as part of the Ayeyarwady Lower
sub-basin, it still would not diminish the geomorphology rating of this
larger unit, i.e. 4.
Aquatic ecology and fisheries Ecological value rating 2
Human pressure rating 3
• The Man Chaung sub-basin is the next
tributary in the right bank of the
Ayeyarwady Lower below Mone
Chaung. It contains six river reach types,
but only one is rare, making up 2% of
the river reach lengths. However, it has
the only karst river reach in the Lower
Ayeyarwady, with about 45% of its
reach lengths being large and medium
rivers in karst region at low elevation.
• The mean annual flows at the confluence
with the Ayeyarwady are 172 m3/sec
with minimum flows estimated at 11
m3/sec.
• No aquatic endemic or threatened
species and only one mainly terrestrial
KBA, the Man Chaung watershed.
• Human pressures generally relate to increasing agricultural intensity and rural population density.
• Mindon HPP (18 MW) is the only hydropower project proposed for this sub-basin.
Terrestrial biodiversity Rating 2
93
Intact forest cover = 13%
KBA = 49%, home to several
endangered species of birds and
threatened animals including the white-
handed gibbon
Social, livelihoods, and significant sites Rating 4
• “Own account workers” (livelihood dependent on agriculture/NR) = 35% of the workforce
• Female-headed households = 18% of total households on average
• Avg. % of households owning a TV = 37%
• Ethnic minority groups = Chini
• Sub-basin vulnerability rating = 4
Conflict Rating 1
• Armed group presence: none or low
• Est. battle deaths (1989-2015) = 0
• Media-reported armed conflict incidents (2012-2016) = 0
• Historical conflict-related displaced people (est.) = 0
94
4.2 Chindwin Basin
4.2.1 Chindwin Headwaters 1
Baseline value ratings
Aquatic Terrestrial
Geomorphology Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
3 4 5 1 2
Overview
Sub-basin size = medium
Location = Kachin State adjacent to
Myanmar’s northern border, which it
shares with India
Topography:
% cover of
Type
sub-basin
Slopes 3-10
6%
soft rock
Slopes<3
7%
Elev>30m
Slopes>10
87%
intermed rock
Area: 5,977 km2
Physical Average rainfall: 2,957 mm
Average sub-basin outflow: 256.8 m3/s
Population: 51,980
Ethnic diversity: Kachins (Singpho) and Nagas (Ao, Sema, Lhota, Rengma,
etc.)
Socio-economic Economic activities:
+ Mining area: No
+ Navigable waterways: None
+ Land use: Plantation (0%), Agriculture-Irrigated-Double (0.2%)
States/Regions: Kachin and Sagaing
Administration Major town/s: Nanyun and Pansaung
95
Existing: 0
Under construction: 0
Hydropower development Planned: 0
Identified potential site: 1 (Ta Rung Hka – 150 MW)
Geomorphology and sediment Rating 3
Sub-basin size: small (37th percentile; Strahler Order 2)
• Steep, structurally controlled sub-basin in the headwaters of the
Chindwin with narrow valleys.
• Lies within steep erosive strata, receives high rainfall, and potentially
provides a large sediment input to the Chindwin.
• The moderate geomorphology rating is attributable to its small size
and low Strahler Order.
Aquatic ecology and fisheries Ecological value rating 4
Human pressure rating 1
• Consists of several branches of relatively
consistent river reach diversity with eight
river reach types, six of which are rare.
The predominant reach type is large
rivers in moist broadleaf forest region at
low elevation, with sediment. The upper
river reaches are mainly medium rivers in
moist broadleaf forest region at low
elevation, with low gradient, but there are
also medium rivers in coniferous region,
with both low and high gradient, in the
highest reaches. There is no karst
limestone.
• The mean annual flows are 564 m3/sec
with a minimum flow of 72 m3/sec.
• Most of the sub-basin lies within the
Hukaung Valley Wildlife Sanctuary and KBA, which is important for water birds as well as
terrestrial biodiversity. The Chindwin headwaters are recognized as important for endemic fish
species.
• Human pressures are very low; forest cover has remained quite high with low population density and
little agriculture and mining activities. These factors contribute to its high ecological value.
Terrestrial biodiversity Rating 5
96
Intact forest cover = 85%
KBA = 100%; the whole sub-basin falls
within a KBA essential for tigers and
several species of birds
Protected areas = 93%; the Hukaung Valley
Wildlife Sanctuary is among six out of 58
sub-basins receiving the highest
biodiversity value rating
Social, livelihoods, and significant sites Rating 1
• “Own account workers” (livelihood dependent on agriculture/NR) = 22% of the workforce
• Female-headed households = 13% of total households on average
• Avg. % of households owning a TV = 4%
• Ethnic minority groups = Kachins (Singpho) and Nagas (Ao, Sema, Lhota, Rengma, etc.)
• Sub-basin vulnerability rating = 1
Conflict Rating 2
• Armed group presence: Naga SAZ and KIO active in parts of the sub-basin
• Est. battle deaths (1989-2015) = 1
• Media-reported armed conflict incidents (2012-2016) = 0
• Historical conflict-related displaced people (est.) = 0
97
4.2.2 Chindwin Headwaters 2
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
2 5 5 2 3
Overview
Sub-basin size = medium
Location = immediately south of
Chindwin Headwaters 1, northern
Myanmar
Topography:
% cover of sub-
Type
basin
Slopes 3-
10 soft 27%
rock
Slopes<3
28%
Elev>30m
Slopes>10
intermed 45%
rock
Area: 7,813 km2
Physical Average rainfall: 3,018 mm
Average sub-basin outflow: 669.6 m3/s
Population: 60,019
Ethnic diversity: Kachins (Singpho) and Khun
Economic activities:
Socio-economic
+ Mining area: 26.7 km2 (covers 0.34% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (0%), Agriculture-Irrigated-Double (0.2%)
States/Regions: Kachin and Sagaing
Administration Major town/s: Tanai
98
Existing: 0
Under construction: 0
Hydropower Planned: 0
development Identified potential site: 2 (Ta Nai Hka – 15 MW, Tawog Hka – 50 MW)
Geomorphology and sediment Rating 2
Sub-basin size: medium (40th percentile; Strahler Order 3)
• The eastern headwater drains a large area of steep erodible strata.
• Contains a large, low-lying flat central valley where sediment is
stored and the river meanders.
• The river has a Strahler Order of 3 but not much of its catchment area
is likely to be a source of sediment. The small sub-basin size and low
sediment input contribute to its low geomorphology rating.
• No existing HPP.
Aquatic ecology and fisheries Ecological value rating 5
Human pressure rating 1
• About half of its river reaches run through karst
limestone at low and high elevation, especially in
the upper part, similar to the Mali Hka sub-basin;
its lower river reaches tend to be similar to the
Headwaters 1 sub-basin, predominantly large
rivers in moist broadleaf forest region at low
elevation, with sediment.
• Has eight river reach types, four of which are rare,
making up 8% of the river reaches.
• The mean annual flow before the confluence of the
two headwater rivers is 670 m3/sec, with a
minimum flow of 65 m3/sec. After the confluence,
the mean annual flow is 1,232 m3/sec, i.e. in the
Tanai River.
• Recognized as important endemic areas for fish
and other aquatic flora and fauna.
• The upper eastern part lies within the Bumphabum
KBA, which is recognized for water birds; the
Hukaung Valley Wildlife Sanctuary and the
Hukaung extension KBA also cover a large part of
the sub-basin. The Tanai River, a fully riverine
KBA, extends from the lower lying part of the
river reaches beyond the confluence with the
Chindwin headwater 1 sub-basin.
• Human pressure in the sub-basin is very low, with
extensive high forest cover, low rural population,
and low agricultural intensity. Mining activity is
developing and may affect river health in the
future.
Terrestrial biodiversity Rating 5
99
Intact forest cover = 72%
KBA = 99%; critical habitat for tigers,
leopards, elephants, and several species of
birds
Protected areas = 73%; Contains the Hukaung
Valley, the Hponkanrazi, and the
Bumhpabum wildlife sanctuaries
• Among six out of 58 sub-basins that
received a biodiversity value rating of 5
Social, livelihoods, and significant sites Rating 2
• “Own account workers” (livelihood dependent on agriculture/NR) = 35% of the workforce
• Female-headed households = 17% of total households on average
• Avg. % of households owning a TV = 52%
• Ethnic minority groups = Kachins (Singpho) and Khun
• Sub-basin vulnerability rating = 2
Conflict Rating 3
• Armed group presence: KIO active in much of the sub-basin
• Est. battle deaths (1989-2015) = 5
• Media-reported armed conflict incidents (2012-2016) = 5
• Historical conflict-related displaced people (est.) = 134
100
4.2.3 Chindwin Upper
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
5 3 4 4 2
Overview
Sub-basin size = 7th largest
Location = Kachin state, northern
Myanmar, bordering India
Topography:
% cover of
Type
sub-basin
Slopes 3-10
34%
soft rock
Slopes<3
8%
Elev>30m
Slopes>10
58%
intermed rock
Area: 23,314 km2
Physical Average rainfall: 2,539 mm
Average sub-basin outflow: 3,401.6 m3/s
Population: 112,506
Ethnic diversity: Kachins (Singpho), Nagas (Ao, Sema, Lhota, Rengma, etc.),
and Shan
Economic activities:
Socio-economic
+ Mining area: 76.5 km2 (covers 0.33% of sub-basin)
+ Navigable waterways: 184.5 km
+ Land use: Plantation (0.1%), Agriculture-Rainfed-Single (0.6%),
Irrigated-Double (0.2%)
States/Regions: Kachin and Sagaing
Administration Major town/s: Hkamti, Homalin, Lahe, and Layshi
101
Existing: 0
Under construction: 0
Hydropower development Planned: 1 (Tamanthi – 1,200 MW)
Identified potential site: 0
Geomorphology and sediment Rating 5
Sub-basin size: very large (89th percentile; complex Strahler Order 3 rivers)
• Receives high rainfall and drains the erodible, steeply sloping Western
Ranges.
• The sub-basin is well forested with low levels of development and no
existing HPPs.
• The geomorphology rating of 5 reflects its large size, complex rivers,
and high flow and sediment input.
• NOTE: This rating pertains only to the tributaries draining into the
Chindwin and does not apply to the mainstem Chindwin, which is
considered a special unit with a geomorphic value of 5.
Aquatic ecology and fisheries Ecological value rating 3
Human pressure rating 1
• The large sub-basin has a 390-km mainstem (over 1,000 m3/sec) flowing through rock-cut river
channel. It contains 11 different river reach types, seven of which are rare, covering 29% of the reach
lengths, but there is no karst limestone reaches.
• The mean annual flow at the start is 1,232 m3/sec and increases to 3,402 m3/sec, with a minimum
flow of 336 m3/sec at the end.
• The mainstem is an important fish migratory route, while the western tributaries in the Chin hills are
recognized for endemic fish species. The tributary flowing in from Nagaland in India hosts
threatened turtle species.
• The upper sub-basin lies within the Hukaung Valley Wildlife Sanctuary; downstream of this lies the
Htamunthi Wildlife Sanctuary, which follows the Chindwin Valley. Both are important habitats for
water birds and turtles.
• Human pressures are generally very low, except some forest clearance and significant mining activity
along the river valley. The river health status is considered good.
• A proposed hydropower dam at Tamanthi has been postponed.
• Note: Ecological value rating based upon tributaries only, not mainstem reaches
Terrestrial biodiversity Rating 4
102
Intact forest cover = 73%
KBA = 73%; a habitat for several endemic
species including Burmese-roofed turtles and
Burmese peacocks
Protected areas = 30%; include the Hukaung
Valley and the Htamanthi wildlife sanctuaries
Social, livelihoods, and significant sites Rating 4
• “Own account workers” (livelihood dependent on agriculture/NR) = 26% of the workforce
• Female-headed households = 18% of total households on average
• Avg. % of households owning a TV = 21%
• Ethnic minority groups = Kachins (Singpho), Nagas (Ao, Sema, Lhota, Rengma, etc.), and Shan
• Sub-basin vulnerability rating = 4
Conflict Rating 2
• Armed group presence: Some areas occupied by Naga SAZ and others influenced by KIO
• Est. battle deaths (1989-2015) = 2
• Media-reported armed conflict incidents (2012-2016) = 2
• Historical conflict-related displaced people (est.) = 266
103
4.2.4 Chindwin Middle
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
4 3 3 4 1
Baseline Value Ratings
Sub-basin size = Large
Location = Sagaing region,
northwestern Myanmar, bordering
India
Topography:
% cover of
Type
sub-basin
Slopes 3-10
86%
soft rock
Slopes<3
11%
Elev>30m
Slopes>10
intermed 3%
rock
Area: 14,376 km2
Physical Average rainfall: 1,898 mm
Average sub-basin outflow: 4,606.5 m3/s
Population: 278,877
Ethnic diversity: Chini and Shan
Economic activities:
+ Mining area: 33.3 km2 (covers 0.23% of sub-basin)
Socio-economic
+ Navigable waterways: 221.8 km
+ Land use: Plantation (0%), Agriculture-Rainfed-Single (6.7%), Flood
Plain-Single (0.1%), Flood Plain-Double (0.3%), Irrigated-Single (0.2%),
Irrigated- Double (1.4%), Irrigated-Triple (0.1%)
104
States/Regions: Chin and Sagaing
Administration Major town/s: Kalewa, Mawlaik, and Phaungbyin
Existing: 0
Under construction: 0
Hydropower development Planned: 0
Identified potential site: 0
Geomorphology and sediment Rating 4
Sub-basin size: large (68th percentile; Strahler Order 3 tributaries)
• Most of the basin is underlain by the Western Ranges and is likely to
contribute high sediment loads during periods of intensive rainfall;
structurally controlled river network that drains into the Chindwin
mainstem.
• No hydropower developments in the sub-basin or upstream.
• The sub-basin is largely forested with some agriculture in the lower
flat areas, resulting in its high geomorphic rating.
• NOTE: This rating does not apply to the mainstem Chindwin, which
is considered a special unit with a geomorphic value of 5.
Aquatic ecology and fisheries Ecological value rating 3
Human pressure rating 2
• Extends from the confluence with the Uyu
River to that with the Manipur river. The mean
annual flows after these two points are 4,099
m3/sec and 5,837 m3/sec.
• The mainstem has 280 km of rock-cut river
channel; the tributaries have five other river
reach types, two of which are rare covering only
3% of the reach lengths. The characteristic river
reach types are large and medium rivers in
moist broadleaf forest region at low elevation,
with floodplains, and medium river in moist
broadleaf forest region at low elevation, with
low gradient; all of them are common.
• A small part of the catchment in the hills marks
the border with India.
• The mainstem is an important fish migratory
route and the western tributaries lie within an
area recognized for endemic fish species. The
Chindwin Middle – together with the associated
wetlands in the upstream floodplains – is now a
newly recognized riverine KBA.
• Human pressures are generally low despite
some agricultural and alluvial gold mining
activities in the floodplains.
• Note: Ecological value rating based upon
tributaries only, not mainstem reaches
Terrestrial biodiversity Rating 3
105
Intact forest cover = 30%
KBA = nearly 48%, including wetlands
important for fish migration and several species
of mammals such as gibbons, serows, and
elephants
Critically endangered ecoregion = 4%; the
Irrawaddy dry forest
Social, livelihoods, and significant sites Rating 4
• “Own account workers” (livelihood dependent on agriculture/NR) = 27% of the workforce
• Female-headed households = 23% of total households on average
• Avg. % of households owning a TV = 42%
• Ethnic minority groups = Chini and Shan
• Sub-basin vulnerability rating = 4
Conflict Rating 1
• Armed group presence: None or low
• Est. battle deaths (1989-2015) = 0
• Media-reported armed conflict incidents (2012-2016) = 1
• Historical conflict-related displaced people (est.) = 0
106
4.2.5 Chindwin Lower
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
2 1 1 5 2
Overview
Sub-basin size = relatively large
Location = spans multiple states in
western Myanmar
Topography:
% cover of sub-
Type
basin
Slopes 3-
10 soft 34%
rock
Slopes<3
66%
Elev>30m
Area: 16,621 km2
Physical Average rainfall: 1,113 mm
Average sub-basin outflow: 5,563.9 m3/s
Population: 3,563,016
Ethnic diversity: Burmese
Economic activities:
+ Mining area: 40.6 km2 (covers 0.24% of sub-basin)
Socio-economic
+ Navigable waterways: 261 km
+ Land use: Plantation (0%), Agriculture-Rainfed-Single (38.7%), Flood
Plain-Single (0.1%), Flood Plain-Double (0.2%), Irrigated-Single (0.3),
Irrigated-Double (2%), Irrigated-Triple (0.5%)
107
States/Regions: Magway, Mandalay, and Sagaing
Administration Major town/s: Budalin and Monywa
Existing: 0
Under construction: 0
Hydropower development Planned: 0
Identified potential site: 0
Geomorphology and sediment Rating 2
th
Sub-basin size: large (74 percentile; low Strahler Order rivers)
• Numerous rivers flow directly to the Chindwin mainstem; sediment
deposition has resulted in a broad, flat central valley through which
the mainstem flows and re-works sediments.
• Low sediment inputs and a low connectivity score due to the low-
order tributaries in the sub-basin contribute to its geomorphology
rating of 2.
• No existing hydropower plants.
• NOTE: This rating does not apply to the mainstem Chindwin, which
is considered a special unit with a geomorphic value of 5.
Aquatic ecology and fisheries Ecological value rating 1
Human pressure rating 3
• A relatively flat sub-basin with the Chindwin
mainstem consisting predominantly of 236 km of
rock-cut river channel that changes to an
anastomosing channel about 82 km before the
Ayeyarwady confluence.
• Several small tributaries enter from the right bank,
consisting of medium rivers in moist broadleaf
forest region at low elevation, with low gradient
and with floodplains.
• The mean annual flow before the confluence with
the Ayeyarwady is 5,664 m3/sec, increasing the
Ayeyarwady’s downstream flow to 15,053 m3/sec.
The minimum flows are estimated at 538 m3/sec.
• The mainstem is recognized as an important
migratory route for fish with the presence of some
threatened fish species. There are no riverine
KBAs.
• Human pressures come from increasing
agricultural intensity, as reflected by the 13
irrigation reservoirs and weirs in the lower part of
the sub-basin. Mining intensity is moderate.
• Note: Ecological value rating based upon
tributaries only, not mainstem reaches
Terrestrial biodiversity Rating 1
108
Intact forest cover = 13%
KBA = 14%; a habitat for gibbons,
serows, and elephants
Protected areas = 9%; contains the
Alaungdaw Kathapa National Park
Critically endangered ecoregion = 8%;
the Irrawaddy dry forest
Social, livelihoods, and significant sites Rating 5
• “Own account workers” (livelihood dependent on agriculture/NR) = 25% of the workforce
• Female-headed households = 26% of total households on average
• Avg. % of households owning a TV = 35%
• Ethnic minority groups = None
• Sub-basin vulnerability rating = 5
Conflict Rating 1
• Armed group presence: none or low
• Est. battle deaths (1989-2015) = 1
• Media-reported armed conflict incidents (2012-2016) = 0
• Historical conflict-related displaced people (est.) = 0
109
4.2.6 Uyu
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
3 1 4 2 3
Overview
Sub-basin size = medium
Location = Kachin state, northern
Myanmar
Topography:
% cover of
Type
sub-basin
Slopes 3-10 soft
78%
rock
Slopes<3
18%
Elev>30m
Slopes>10
4%
intermed rock
Area: 11,440 km2
Physical Average rainfall: 2,187 mm
Average sub-basin outflow: 699.1 m3/s
Population: 370,874
Ethnic diversity: Kachins (Singpho), Lisu, Nagss (Ao, Sma, Lhota, Rengma,
etc.)
Economic activities:
Socio-economic + Mining area: 317.3 km2 (covers 2.77% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (0%), Agriculture-Rainfed-Single (3.5%),
Flood Plain-Double (0.1%), Irrigated-Single (0.1%), Irrigated-Double (0.6%),
Irrigated-Triple (0.1%)
110
States/Regions: Kachin and Sagaing
Administration Major town/s: Hpakan
Existing: 0
Under construction: 0
Hydropower development Planned: 0
Identified potential site: 1 (U Yu Chaung – 12 MW)
Geomorphology and sediment Rating 3
Sub-basin size: large (60th percentile; Strahler Order 3)
• A relatively flat catchment with no existing HPPs drains the eastern
side of the Upper Ayeyarwady, resulting in a high connectivity score.
• The sub-basin originally has a low sediment input score, but mining
activity has disturbed large areas of the catchment and the natural
conditions have been greatly altered.
• This catchment has a geomorphology rating of 3 because land use is
not considered, but the extensive mining and disturbance should be
recognized and a rating of 2 is probably more appropriate.
Aquatic ecology and fisheries Ecological value rating 1
Human pressure rating 2
• A major tributary of the Chindwin flowing
in from the northeast; it has five river reach
types, two of which are rare, making up
only 7% of total reach lengths. The
predominant type is large river in moist
broadleaf forest region at low elevation,
with floodplains. The upper reaches are
characterized as medium rivers in moist
broadleaf forest region at low elevation,
with low gradient.
• The mean annual flow is 697 m3/sec, with a
minimum flow of 31.8 m3/sec, showing a
much wider variability than many of the
other rivers. The ratio of its mean annual
flow/minimum flow is about 20 compared
to 10 in other rivers.
• While not noted for endemic or threatened
species, the Uyu River was originally
identified as a KBA because of water birds. However, intensive alluvial gold mining activity in the
floodplains has destroyed much of the aquatic habitat and contaminated the waters with high
sediments and mining waste. The river health is now considered very low.
Terrestrial biodiversity Rating 4
111
Intact forest cover = 59%
KBA = 60%; a habitat for several mammals
including gibbons, serows, tigers, and
elephants.
Protected areas = 1% including the Indawgyi,
the Hukaung Valley, and the Htamanthi
wildlife sanctuaries
Social, livelihoods, and significant sites Rating 2
• “Own account workers” (livelihood dependent on agriculture/NR) = 23% of the workforce
• Female-headed households = 25% of total households on average
• Avg. % of households owning a TV = 57%
• Ethnic minority groups = Kachins (Singpho), Lahu, Lisu, Nagas (Ao, Sema, Lhota, Rengma, etc.),
and Shan
• Sub-basin vulnerability rating = 2
Conflict Rating 3
• Armed group presence: Small areas influenced by KIO
• Est. battle deaths (1989-2015) = 15
• Media-reported armed conflict incidents (2012-2016) = 34
• Historical conflict-related displaced people (est.) = 1,415
• The very high level of recent conflict suggests that the sub-basin’s vulnerability may be
underestimated.
112
4.2.7 Manipur
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
4 4 2 2 2
Overview
Sub-basin size = medium
Location = Chin State, western Myanmar
Topography:
% cover of sub-
Type
basin
Slopes 3-
10 soft 14%
rock
Slopes<3
3%
Elev>30m
Slopes>10
intermed 83%
rock
Area: 8,972 km2
Physical Average rainfall: 1,803 mm
Average sub-basin outflow: 208.6 m3/s
Population: 516,151
Ethnic diversity: Chini
Economic activities:
Socio-economic
+ Mining area: 6.9 km2 (covers 0.08 % of sub-basin)
+ Land use: Plantation (0.2%), Agriculture-Rainfed-Single (5.3%),
Irrigated -Double (2.7%)
States/Regions: Chin and Sagaing
Administration Major town/s: Hakha and Kalay
113
Existing: 0
Under construction: 0
Hydropower development Planned: 1 (Manipur – 380 MW)
Identified potential site: 0
Geomorphology and sediment Rating 4
Sub-basin size: medium (51st percentile; Strahler Order 4)
• Located in the western ranges underlain by erodible rock with high
rainfall; the mainstem tributary has a Strahler Order of 4, one of a few
tributaries in Myanmar with this characteristic.
• The Manipur is situated downstream of the Myittha sub-basin, which
contains one HPP. When the two are considered together, the
catchment area upstream of the hydropower plant is only about 10%
and is unlikely to exert a strong influence on the Manipur.
• The high Strahler Order, high flow, and high sediment input result in a
geomorphology rating of 4.
Aquatic ecology and fisheries Ecological value rating 4
Human pressure rating 4
• Flowing in from the Indian state of the same name,
the river takes an eastward turn and then flows
northwards again until it joins the Chindwin
mainstem at Kalewa.
• Contains 12 different river reach types, seven of
which are rare, making up 23% of the reach
lengths. About 39% of the river reaches (in the
upper and north-south parts) flow through karst
limestone, while the lower reaches before meeting
the Chindwin are generally large river in moist
broadleaf forest region at low elevation, with
floodplains.
• The mean annual flows at the confluence with the
Chindwin are 782 m3/sec, with a minimum flow of
88 m3/sec.
• The upper river is recognized as a new riverine
KBA and the sub-basin is also recognized for
endemic and threatened fish species as well as
other aquatic organisms.
• Human pressures include the regulation and
potential pollution from India with its high
population, intensive agriculture, and a
hydropower plant.
• In Myanmar, the upper reaches generally have
good forest cover and low agriculture intensity.
Agricultural and mining activities increase in the
lower valley. Kale is a large town posing some
industrial pollution on the river.
• The proposed Manipur HPP would be located
above where the river flows out of the limestone
hills into its floodplain and turns northwards.
Terrestrial biodiversity Rating 2
114
Intact forest cover = 34%
KBA = 29%, with endemic fish species
threatened by potential HPPs likely to disrupt
natural breeding and migration patterns
Social, livelihoods, and significant sites Rating 2
• “Own account workers” (livelihood dependent on agriculture/NR) = 1 6% of the workforce
• Female-headed households = 25% of total households on average
• Avg. % of households owning a TV = 36%
• Ethnic minority groups = Chini
• Sub-basin vulnerability rating = 2
Conflict Rating 2
• Armed group presence: The Chin National Front (CNF) ceasefire, active in <50% of the sub-basin
• Est. battle deaths (1989-2015) = 5
• Media-reported armed conflict incidents (2012-2016) = 1
• Historical conflict-related displaced people (est.) = 0
115
4.2.8 Myittha
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
2 1 2 2 1
Overview
Sub-basin size = medium
Location = Chin state, western
Myanmar
Topography:
% cover of
Type
sub-basin
Slopes 3-10
56%
soft rock
Slopes<3
2%
Elev>30m
Slopes>10
42%
intermed rock
Area: 8,644 km2
Physical Average rainfall: 1,542 mm
Average sub-basin outflow: 208.6 m3/s
Population: 230,513
Ethnic diversity: Chini
Economic activities:
Socio-economic + Mining area: 11.6 km2 (covers 0.13% of sub-basin)
+ Navigable waterways: None
+Land use: Plantation (0%), Agriculture-Rainfed-Single (12%),
Irrigated-Double (1.2%)
116
States/Regions: Chin, Magway, and Sagaing
Administration Major town/s: Gangaw and Tilin
Existing: 1 (Myittha – 40 MW)
Under construction: 0
Hydropower development Planned: 0
Identified potential site: 0
Geomorphology and sediment Rating 2
Sub-basin size: medium (47th percentile; Strahler Order 3 river)
• Situated in the Western Ranges and drains both steep and shallow
sloping areas of erodible strada.
• A newly commissioned HPP in the catchment has a large reservoir
and regulates around 20% of the sub-basin area, suggesting it has the
potential to alter flow regimes on scales of weeks to months.
• The overall geomorphology rating is 2 but is very close to the cut off
for 3.
Aquatic ecology and fisheries Ecological value rating 1
Human pressure rating 2
• A relatively small sub-basin that flows from south
to north to join the Manipur River. It has four river
reach types, none of which are rare and
predominated by the common large river in moist
broadleaf forest region at low elevation, with
floodplains. In the upper reaches, it has medium
river in moist broadleaf forest region at low
elevation, with low gradient and with floodplains.
Karst river reaches make up about 15% of the
reach lengths.
• The mean annual flow is estimated at 207 m3/sec
with a minimum flow of 20 m3/sec.
• Not an area of endemic or threatened fish species
and no aquatic KBAs.
• Human pressures are generally low despite
moderate mining activity. Agricultural activities
are restricted to the lowland river valley and
floodplains.
• The Myittha HPP has been constructed recently
with a relatively low impact on the aquatic
ecology. The 12 km2 reservoir is small but has a
45-day retention time and a high degree of
regulation at the dam site. Since the flow is small,
this degree of regulation is minimized by the
confluence with the Manipur River.
Terrestrial biodiversity Rating 2
117
Intact forest cover = 31%
KBA = 2%
Protected areas = 1.5%; the
Alaungdaw Kathapa and Matmataung
national parks, which house several
mammal species including elephants,
tigers, leopards, and bears
Social, livelihoods, and significant sites Rating 2
• “Own account workers” (livelihood dependent on agriculture/NR) = 22% of the workforce
• Female-headed households = 24% of total households on average
• Avg. % of households owning a TV = 42%
• Ethnic minority groups = Chini
• Sub-basin vulnerability rating = 2
Conflict Rating 1
• Armed group presence: None or low
• Est. battle deaths (1989-2015) = 0
• Media-reported armed conflict incidents (2012-2016) = 0
• Historical conflict-related displaced people (est.) = 0
118
4.3 Bago and Myit Mo Hka Basin
4.3.1 Bago
Baseline value ratings
Geomorphology Aquatic ecology Terrestrial Social &
Conflict
& sediment & fisheries biodiversity livelihoods
2 1 2 1 1
Overview
Sub-basin size = small
Location = Coastal sub-basin in southern
Myanmar, draining directly into the
Andaman Sea; covers most of Yangon
Topography:
% cover of
Type
sub-basin
Slopes 3-10
15%
soft rock
Slopes<3
64%
Elev<30m
Slopes<3
21%
Elev>30m
Area: 10,261 km2
Physical Average rainfall: 3,151 mm
Average sub-basin outflow: 328.4 m3/s
Population: 4,610,213
Ethnic diversity: Karen
Economic activities:
+ Mining area: 0.1 km2
Socio-economic
+ Navigable waterways: None
+ Land Use: Plantation (0.1%), Agriculture-Rainfed-Single (3.2%), Flood Plain-
Single (0.4%), Irrigated-Single (14.3%), Irrigated-Double (12.8%), Irrigated-
Triple (15.3%)
119
States/Regions: Bago and Yangon
Major town/s: Bago, Dagon Myothit (East), Dagon Myothit (North), Dagon
Myothit (Seikkan), Dagon Myothit (South), Dawbon, Hlegu, Htaukkyant, Kawa,
Administration
Kayan, Kyauktan, Mingalartaungnyunt, North Okkalapa, Pazundaung, South
Okkalapa, Tadar, Tamwe, Thaketa, Thanatpin, Thanlyin, Thingangyun, and
Thongwa
Existing: 1 (Zangtu)
Hydropower Under construction: 0
development Planned: 0
Identified potential site: 0
Geomorphology and sediment Rating 2
Sub-basin size: medium (58th percentile)
• Drains the southern Bago Hills and flows directly to the sea via a
broad floodplain and delta.
• One multi-use HPP with a large retention capacity and the potential
to alter flows monthly or seasonally.
• The small sub-basin area, low Strahler Order (2), and regulated flow
result in a relatively low geomorphic rating.
• Despite this rating, rivers flowing directly into the sea have an
important geomorphic function in maintaining coastlines and deltas.
Aquatic ecology and fisheries Ecological value rating 1
Human pressure rating 4
• Contains six river reach types, including
four rare types covering 23% of total reach
length. Predominant types are large and
medium rivers in the moist broadleaf
forest region at low elevation, with
floodplains. Reaches near the sea occur in
large delta and mangrove areas.
• The mean annual flow down the Bago is
328 m3/sec with a minimum flow of 25
m3/sec.
• Endemic fish species are found in Upper
Bago Yoma. The Hilsa migrate up the
Bago and some threatened fish species
occur there.
• Terrestrial KBAs in Central Bago Yoma
and North Zarmayi Elephant Range
• Human pressures include a high
population density and intensive
agriculture with at least 15 irrigation
reservoirs and weirs.
• The existing HPP, Zaungtu (20 MW), has
a high impact on aquatic ecology,
especially water quality and flows. The
18.5 km-long reservoir has a 61-day
residence time and a 17% degree of
regulation at the dam site.
Terrestrial biodiversity Rating 2
120
Intact forest cover = 2%
KBA = 40%, home to wild elephants
Protected area = 0%
Critically endangered ecoregions = 24%;
the Irrawaddy freshwater swamp forests
(12%) and coast mangrove forests (12%),
diminished by dredging, logging, and
hunting
Social, livelihoods, and significant sites Rating 1
• “Own account workers” (livelihood dependent on agriculture/NR) = 15% of the workforce
• Female-headed households = 26% of total households on average
• Avg. % of households owning a TV = 74%
• Ethnic minority groups = Karen
• Sub-basin vulnerability rating = 1
Conflict Rating 1
• Armed group presence: none or low
• Est. battle deaths (1989-2015) = 23
• Media-reported armed conflict incidents (2012-2016) = 0
• Historical conflict-related displaced people (est.) = 0
121
4.4 Bilin Basin
4.4.1 Bilin
Baseline value ratings
Geomorphology Aquatic ecology Terrestrial Social &
Conflict
& sediment & fisheries biodiversity livelihoods
2 1 2 4 3
Overview
Sub-basin size = relatively small
Location = Kayin State, eastern
Myanmar
Topography:
% cover of sub-
Type
basin
Slopes 3-10
49%
soft rock
Slopes<3
16%
Elev<30m
Slopes>10
35%
hard rock
Area: 3,056 km2
Physical Average rainfall: 3,138 mm
Average sub-basin outflow: 179m3/s
Population: 216,160
Ethnic diversity: Karen and Kayah
Economic activities:
Socio-economic + Mining area: 4 km2 (covers 0.13% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (0%), Agriculture-Rainfed-Single (1.1%), Irrigated-
Single (1.4%), Irrigated-Double (3.4%), Irrigated-Triple (0.3%)
122
States/Regions: Bago, Mon, and Kayin
Administration Major town/s: Bilin
Existing: 0
Hydropower Under construction: 0
development Planned: 1 (Bilin – 280 MW)
Identified potential site: 0
Geomorphology and sediment Rating 2
Sub-basin size: small (23rd percentile; Strahler Order 3)
• Drains the foothills of the Shan Plateau and discharges to the sea via a
narrow coastal plain and delta.
• The hillsides are vegetated, but the valley floor has been highly altered
through mining and agriculture; these changes would have an impact
on the geomorphic processes of the sub-basin.
• No existing HPPs, high rainfall, and a river Strahler Order of 3
contribute to its final geomorphology rating.
Aquatic ecology and fisheries Ecological value rating 1
Human pressure rating 4
• Lying between the Sittaung and the Thanlwin, the sub-basin contains
seven river reach types, but only one of them is rare, covering less
than 1% of the river reaches. The predominant reach types are large
and medium rivers in moist broadleaf forest region at low elevation,
with low gradient and floodplains; only a very small amount of karst
exists in the lower end of the sub-basin.
• The mean annual flow at the mouth of the Bilin is 177 m3/sec with a
minimum flow of 9 m3/sec.
• The river has no endemic species but discharges into the Gulf of
Mottama, a very productive and diverse coastal ecosystem with
important water birds (a potential Ramsar site).
• Human pressures include high population density, mining, and
intensive agriculture.
• One HPP is proposed for Bilin.
123
Terrestrial biodiversity Rating 2
Intact forest cover = 15%
KBA = >40%; a diverse range of species
including elephants, tigers, endemic fish,
tortoises, and more
Protected area = 2%; the Kelatha and
Kyaikhtiyoe wildlife sanctuaries for
several bird species
Critically endangered ecoregions = 0%
Social, livelihoods, and significant sites Rating 4
• “Own account workers” (livelihood dependent on agriculture/NR) = 17% of the workforce
• Female-headed households = 32% of total households on average
• Avg. % of households owning a TV = 39%
• Ethnic minority groups = Karen and Kayah
• Sub-basin vulnerability rating = 4
Conflict Rating 3
• Armed group presence: tolerated in some of the sub-basin, Karen National Union (KNU) ceasefire
• Est. battle deaths (1989-2015) = 17
• Media-reported armed conflict incidents (2012-2016) = 0
• Historical conflict-related displaced people (est.) = 10,933
124
4.5 Sittaung Basin
4.5.1 Paung Laung
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
2 2 3 1 2
Overview
Paung Laung is a medium-sized sub-
basin that falls within the Kayah,
Kayin, and Shan states in the center of
Myanmar.
Area: 4,986 km2
Average rainfall: 1,269 mm
Average sub-basin outflow: 95 m3/s
Topography:
% cover of sub-
Type
basin
Slopes 3-10
4%
Hard rock
Slopes 3-10
4%
soft rock
Slopes<3
0%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10
92%
hard rock
Slopes>10
0%
intermed rock
Population: 594,705
Ethnic diversity: Karen, Kayah, Shan
Economic activities:
Socio-economic + Mining area: 2.7 km2 (covers 0.05% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (0.1%); Agriculture-Rainfed-Single (1.1%),
Irrigated-Single (0.3%), Irrigated-Triple (1.6%)
States/Regions: Kayah, Kayin, Mandalay, Nay Pyi Taw, Shan
Administrative: Major town/s: Zay Yar Thi Ri
125
Existing: 3 (Nancho – 40 MW, Paung Laung (lower) – 280 MW, Paung
Laung (upper) – 140 MW)
Status of hydropower Under Construction: 0
development Planned: 1 (Paung Laung (middle) – 100 MW)
Identified potential site: 0
Geomorphology and sediment Rating 2
• The small (32nd) Paung Laung sub-basin is a tributary of the Sittuang
with its catchment extending up the western side of the Shan Plateau;
• It receives high rainfall and has the potential for high sediment input,
but the sub-basin has been developed for hydropower;
• The hydropower development results in the regulation of flow from
over 90% of the sub-basin, with two of the schemes having large
impoundments with long potential residence times (~30 days) that
could significantly alter the flow regime of the sub-basin;
• These factors result in a low geomorphology rating.
Aquatic ecology and fisheries Ecological Value rating 2
Human Pressure rating 3
• The Paunglaung sub-basin lies in the
headwaters of the Sittaung basin. It contains 3
river reach types, of which 1 is rare. The
predominant river reach types are Medium
river, in moist broadleaf forest region at low
elevation, with low gradient and with
floodplains. There is no karst in the medium
sized river reaches, but there is karst limestone
in the headwaters of the Paunlaung, including
a long underground river in the hills to the
east.
• The mean annual flow from the sub-basin
contributing to the Sittaung is 95 m3/sec with a
minimum flow of 18 m3/sec.
• This part of the Sittaung basin has recorded a
high diversity of molluscs, and the Paunlaung
catchment KBA is important for limestone
caves and invertebrates.
• The main pressures on the Paunlaung sub-
basin are the three existing hydropower
projects Paunlaung Upper, Paunlaung Lower
and Nancho. The Upper Paunlaung HPP (140
MW) has a high impact upon aquatic ecology,
with a reservoir of 50 km, 121 days storage
time and a 46 % degree of regulation at the
dam site. Lower Paunlaung HPP (280 MW)
with a 16-km reservoir and 32-day storage
time, and 12% degree of regulation at the dam
site. With large drawdowns and high
proportion of dead storage, they both carry
higher risks of poor water quality. Nancho HPP is on a smaller branch of the Paunlaung, (40 MW)
with a reservoir of 3 km and only 2 days storage.
Terrestrial Biodiversity Rating 3
126
The Paung Laung sub-basin contains
significant regions of KBA (74%) and
modest intact forest (21%) cover. The
KBA in the sub-basin is a habitat for
pangolins and other small mammals
along with bird species such as the
green peafowl.
Social, livelihoods, and significant sites Rating 1
In the Paung Laung sub-basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 26% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 18% of the households on average. The average percentage of
HHs owning a TV, as a proxy for poverty levels, is 58%. The ethnic minority groups in the sub-basin are
Karen, Kayah and Shan. On this basis, the sub-basin vulnerability rating is 1.
Conflict Rating 2
• Non- ceasefire armed group (KNPP) and Pa-O SAZ in half of sub-basin (medium)
• Zero estimated battle deaths 1989-2015 (very low)
• Zero 2012-2016 media-reported armed conflict incidents (very low)
• 1744 estimated historical conflict-related displaced people (medium)
127
4.5.2 Bawgata
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
1 2 2 4 3
Overview
Bawgata is one of the smaller sub-
basins and is located in the Bago
Region in the eastern part of
Myanmar.
Area: 1,229 km2
Average rainfall: 2,806 mm
Average sub-basin outflow: 54 m3/s
Topography:
% cover of
Type
sub-basin
Slopes 3-10
0%
Hard rock
Slopes 3-10
55%
soft rock
Slopes<3
0%
Elev<30m
Slopes<3
32%
Elev>30m
Slopes>10
13%
hard rock
Slopes>10
0%
intermed rock
Population: 892,747
Ethnic diversity: Karen
Economic activities:
Socio-economic + Mining area: 0.02 km2
+ Navigable waterways: None
+ Land use: Plantation (0%); Agriculture-Rainfed-Single (6.1%), Irrigated-
Single (3.0%), Irrigated – Double (1.5%), Irrigated-Triple (1.4%)
States/Regions: Bago
Administrative: State
Major town/s: Kyaukkyi
128
Existing: 0
Under Construction: 0
Status of hydropower Planned: 1 (Bawgata – 160 MW)
development Identified potential site: 0
Geomorphology and sediment Rating 1 (4)
• The very small Bawgata sub-basin (9th percentile) is a Strahler Order 2
tributary of the Sittaung River;
• The river drains the western flank of the Shan plateau before flowing
through a wide alluvial plain to the confluence with the Sittuang;
• The sub-basin receives high rainfall and has a high runoff, but due to its
small size, low order river and generally limited areas of sediment
input, the sub-basin has a low geomorphology rating.
Aquatic ecology and fisheries Ecological Value rating 2
Human Pressure rating 2
• The Bawgata is very small tributary on the east bank of
the Sittaung, just above the similarly small tributary with
the Shwegyin dam. There are three river reach types,
none of which are rare in this sub-basin. The predominant
river reach type is Medium river, in moist broadleaf forest
region at low elevation, with floodplains.
• The mean annual flows at the confluence with the
Sittaung 54 m3/sec with a minimum flow of 4.5 m3/sec
• There are no riverine KBAs in the sub-basin, though in
the southern headwaters of this sub-basin there is the
terrestrial Shwe Kyin and Bawgada watershed KBA
• There are no special aquatic biodiversity features in this
sub-basin
• Human pressures are generally low and the forest cover in
the watershed is still good.
• A hydropower dam, Bawgata, is proposed for the sub-
basin
Terrestrial Biodiversity Rating 2
129
The Bawgata sub-basin does not contain
any critically endangered ecoregions or
protected areas. It contains relatively
little intact forest (7%), but over one-
third of the sub-basin is composed of
KBA dedicated to a diverse range of
species including elephants, tigers,
endemic fish, tortoises, and more.
Social, livelihoods, and significant sites Rating 4
In the Bawgata sub-basin’s Townships, own account workers indicating livelihood dependence on agriculture
and natural resources comprise on average 19% of the workforce. Female-headed households, which indicate
social vulnerability accounts for 34% of the households on average. The average percentage of HHs owning a
TV, as a proxy for poverty levels, is 31%. The ethnic minority groups in the sub-basin are Karen. On this
basis, the sub-basin vulnerability rating is 4.
Conflict Rating 3
• Most of the sub-basin controlled by ceasefire armed group, KNU (medium)
• Nine estimated battle deaths 1989-2015 (very low)
• Two 2012-2016 media-reported armed conflict incidents (low)
• 16767 estimated historical conflict-related displaced people (medium)
130
4.5.3 Sittaung Other
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
4 2 2 1 3
Overview
Other Sittaung is the 4th largest sub-basin
and spans several states in the southern
region of the main body of Myanmar. It
outlets to the Andaman Sea.
Area: 28,698 km2
Average rainfall: 2,081 mm
Average sub-basin outflow: 1232.1 m3/s
Topography:
% cover of sub-
Type
basin
Slopes 3-10
2%
Hard rock
Slopes 3-10
45%
soft rock
Slopes<3
12%
Elev<30m
Slopes<3
28%
Elev>30m
Slopes>10
12%
hard rock
Slopes>10
0%
intermed rock
Population: 3,088,695
Ethnic diversity: Chini, Karen, Kayah
Economic activities:
+ Mining area: 31.6 km2 (covers 0.11% of sub-basin)
Socio-economic
+ Navigable waterways: None
+ Land use: Plantation (0%); Agriculture-Rainfed-Single (12.4%),
Flood Plain-Single (0.1%), Irrigated-Single (3.3%), Irrigated – Double
(5.8%), Irrigated-Triple (5.3%)
States/Regions: Bago, Kayah, Kayin, Magway, Mandalay, Mon, Naypyitaw,
Administrative: Shan
Major town/s: Daik, Lewe, NAY PYI TAW, Pyinmana, Pyu, Taungoo
131
Existing: 6 (Kabaung – 30 MW, Kun Chaung – 60 MW, Phyu Chaung – 40
MW, Shwegyin – 75 MW, Thauk Ye Khat 2 – 120 MW, Yenwe – 25 MW)
Status of hydropower Under Construction: 0
development Planned: 0
Identified potential site: 1 (Thauk Ye Khat 1 – 75 MW)
Geomorphology and sediment Rating 4
• The very large (95th percentile) Sittaung sub-basin hosts a range of
land types, draining the steep, hard Shan Plateau in the east, and the
lower Bagan hills in the west, with a broad alluvial valley in between;
• The sub-basin delivers water and sediment directly to the sea,
maintaining the coastal fringe;
• It is modified by the presence of 6 hydropower projects on low order
headwater tributaries. Collectively < 30 of the sub-basin area lies
upstream of the hydropower projects;
• The hydropower projects are considered to alter the geomorphic
functioning of the sub-basin to some degree, but the large water
inflow, complex drainage systems and high percentage of the basin
that is not regulated contribute to a high overall geomorphology rating of 4.
Aquatic ecology and fisheries Ecological Value rating 3
Human Pressure rating 4
• The other Sittaung sub-basin consists of the whole of the
Sittaung basin, except for the Paunlaung and Bawgata sub-
basins. The Sittaung river flows through a straight wide valley
running from north to south between two well-forested ridges
- the Bago and Paunlaung Yomas. It discharges into the sea in
the Gulf of Mottama.
• The sub-basin contains 6 river reach types of which 3 are rare.
The predominant river reach types are Large and medium
rivers, in moist broadleaf forest region at low elevation, with
floodplains and at low gradient.
• The mean annual flow of the Sittaung river at the point of
discharge is 1,233 m3/sec with a minimum flow of 141 m3/sec
• The river contains no rare species of fish, but recent surveys
indicate a high mollusc diversity and the Bago Yoma has been
identified as an area where fish endemism is high.
• Several KBAs have been identified in the sub-basin, including
Yay Thoe reservoir an irrigation reservoir where rare
freshwater mussels have been found, a KBA along the
mainstem of the Sittaung considered important for its
connectivity with the Gulf of Mottama, the Central Bago
Yoma, and Moyingyi wetlands, one of Myanmar’s 3 Ramsar
sites. These important assets raise the ecological value of the
sub-basin, which would be lower as a result of the few rare
river reaches
• The human pressures in the sub-basin are high due to high
rural population density and the intensity of agriculture in the
valleys. There are over 30 irrigation reservoirs and weirs in the sub-basin especially in the upper part
of the catchment.
• In addition to 3 hydropower dams on the Paunlaung, there are 6 large hydropower projects on
tributaries leading into the Sittaung – Kabaung (30 MW), Kun Chaung (60 MW), Phyu Chaung (40
MW), Shwegyin (75 MW), Thauk Ye Khat 2 (120 MW), and Yenwe (25 MW). These have had
significant impact upon the aquatic ecology of the both the tributaries and of the Sittaung mainstem,
especially in terms of Degree of flow regulation and risks to water quality.
132
Terrestrial Biodiversity Rating 2
The Other Sittaung sub-basin contains
35% KBA and 9% intact forest.
Similarly to other large sub-basins,
there are numerous KBAs that provide
habitats for various species of birds,
mammals, and aquatic flora and fauna
including the fresh water mussel and
the fresh water bivalve. In the past
approximately 5% of the sub-basin was
composed of the critically endangered
Irrawaddy dry forest ecoregion as well.
Social, livelihoods, and significant sites Rating 1
In the Sittaung Other sub-basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 18% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 24% of the households on average. The average percentage of
HHs owning a TV, as a proxy for poverty levels, is 45%. The ethnic minority groups in the sub-basin are
Chini, Karens and Kayah. On this basis, the sub-basin vulnerability rating is 1.
Conflict Rating 3
• Ceasefire armed group (KNU) influential in small parts of the sub-basin (low)
• 211 estimated battle deaths 1989-2015 (high)
• One 2012-2016 media-reported armed conflict incidents (low)
• 41628 estimated historical conflict-related displaced people (very high)
133
4.6 Mekong Basin
4.6.1 Nam Lwe
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
3 2 2 1 2
Overview
Nam Lwe is a medium-sized sub-
basin located in the Shan state in the
eastern part of Myanmar and shares a
border with China.
Area: 9,364 km2
Average rainfall: 1,381 mm
Average sub-basin outflow: 297.8
m3/s
Topography:
% cover of
Type
sub-basin
Slopes 3-10
3%
Hard rock
Slopes 3-10
3%
soft rock
Slopes<3
0%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10
94%
hard rock
Slopes>10
0%
intermed rock
Population: 366,861
Ethnic diversity: Hani (Akha, Uni, Xapho, Cosung, Cote, Khape), Kachins
(Singpho), Lahu, Pulang (Puman), Shan
Socio-economic Economic activities:
+ Mining area: 2.4 km2 (covers 0.03% of sub-basin)
+ Navigable waterways: None
+ Land use: N/A
States/Regions: Shan
Administrative: Major town/s: Mong Hpen, Ho Tawng, Mong Pawk, Mong Kar, Mongkhet,
Mongyang, Mongpauk, Mongla, Kengtung, Mongyu
134
Existing: 1 (Mongwa – 66 MW)
Under Construction: 0
Status of hydropower Planned: 4 (He Kou – 138 MW, Keng Tong – 170 MW, Keng Yang – 70
development MW, Suo Lwe – 240 MW)
Identified potential site: 0
Geomorphology and sediment Rating 3
• Nam Lwe is a medium sized sub-basin (54th percentile) in Mekong
basin, with a Strahler Order 3 mainstem;
• The catchment drains steep hard rock mountains and is well vegetated
with little development, except for a recently commissioned
hydropower project located in the lower catchment;
• Rainfall is low compared to other parts of Myanmar, and these features
combine to produce a geomorphology rating of 3, reflecting a reduction
due to the loss of connectivity associated with the dam.
Aquatic ecology and fisheries Ecological Value rating 2
Human Pressure rating 3
• The Nam Lwe is the
northernmost tributary of the
Mekong in Myanmar, running
along the Chinese border. It has
10 river reach types, 5 of which
are rare covering 54% of the
reach lengths in the sub-basin
and 7% of reaches running
through karst region. The
predominant reach types are
Large river, in moist broadleaf
forest region at low elevation,
with sediment and the rare
Medium river, in moist
broadleaf forest region at high
elevation, with low gradient.
• The mean annual flows at the confluence with the Mekong are 297 m3/sec with a minimum of 43
m3/sec.
• It has some threatened fish species noted in the lower part of the sub-basin, and would be an
important tributary of the Mekong for spawning fish movements and a KBA has been identified
associated with this.
• Human pressures are medium, but with low population density and low agricultural intensity and
mining activity. There is an existing hydropower dam Mongwa (66 MW) of relatively low impact,
but blocking the fish migration route 81 km from the confluence with the Mekong.
• Four other hydropower projects are planned for the Nam Lwe - He Kou (138 MW), Keng Tong (170
MW), Keng Yang (70 MW), and Suo Lwe (240 MW).
Terrestrial Biodiversity Rating 2
135
The Nam Lwe sub-basin contains
modest KBA (18%) and intact forest
(22%) cover. The KBA in this sub-basin
is another trans-boundary corridor that
supports mammal and fish migration
from China. The Loimwe protected area
composes around 0.5% of sub-basin area
as well.
Social, livelihoods, and significant sites Rating 1
In the Nam Lwe sub-basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 27% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 12% of the households on average. The average percentage of
HHs owning a TV, as a proxy for poverty levels, is 54%. The ethnic minority groups in the sub-basin are
Hani (Akha, Uni, Xapho, Cosung, Cote, Khape), Kachins (Singpho), Lahu, Pulang (Puman), Shan. On this
basis, the sub-basin vulnerability rating is 1.
Conflict Rating 2
• Ceasefire armed group (RCSS) active in more than half of this sub-basin (medium)
• 12 estimated battle deaths 1989-2015 (low)
• Two 2012-2016 media-reported armed conflict incidents (medium)
• Zero estimated historical conflict-related displaced people (very low)
136
4.6.2 Nam Hkoke
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
2 5 2 2 3
Overview
Nam Hkoke is a relatively small sub-
basin located in the Shan state in the
eastern part of Myanmar and shares a
border with Thailand.
Area: 3,411 km2
Average rainfall: 1,368 mm
Average sub-basin outflow: 49.6 m3/s
Topography:
% cover of
Type
sub-basin
Slopes 3-10
4%
Hard rock
Slopes 3-10
4%
soft rock
Slopes<3
0%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10
92%
hard rock
Slopes>10
0%
intermed rock
Population: 104,649
Ethnic diversity: Kachins (Singpho), Lao, Shan, Yao
Economic activities:
Socio-economic
+ Mining area: No
+ Navigable waterways: None
+ Land use: N/A
States/Regions: Shan
Administrative: Major town/s: Monghsat, Mongkhoke
137
Existing: 0
Under Construction: 0
Status of hydropower Planned: 1 (Mong Hsat – 30 MW)
development Identified potential site: 1 (Nam Hkok – 30 MW)
Geomorphology and sediment Rating 2 (4)
• The Nam Hkoke sub-basin is a small (24th percentile), low order
Strahler tributary of the Mekong;
• Similar to the other Mekong sub-basins it has a high potential input
score sediment;
• The final rating for this sub-basin is relatively low due to its small
catchment size. It has been identified as a sub-basin because it is
targeted for future hydropower development
Aquatic ecology and fisheries Ecological Value rating 5
Human Pressure rating 1
• The Nam Hkoke sub-basin in Myanmar contains the headwaters of the
Nam Mae Kok which is an important tributary of the Mekong in
Thailand. It is thus a transboundary river. In Myanmar, the river consists
of 128 km of medium sized river with 4 river reach types, one of which
is rare, making up 26% of the reach lengths. Over 50% of the river
reaches flow through a karst region at low elevation.
• The mean annual flow at the point where it crosses the border into
Thailand is 50 m3/sec with a 7.4 m3/sec minimum flow
• The high Ecological Value rating registered is largely due to the
presence of endangered fish species and critically endangered aquatic
plants and insects that have been found in the Nam Mae Kok in Thailand
and are assumed to occur in the Nam Hkoke in Myanmar.
• Human pressures are very low on this sub-basin, especially as it is in a
border area.
• Two hydropower dams are proposed on the Nam Hkoke, the Nam Hkok
(30 MW) and the Mong Hsat (30 MW).
Terrestrial Biodiversity Rating 2
138
Nam Hkoke contains notable KBA (50%) and
modest intact forest (19%) cover. The KBA in the
sub-basin includes the Golden Triangle Area and
the Namsam Mountain Region, which are habitats
for aquatic plant species, vulnerable species of
dragon flies, and other aquatic species such as
turtles.
Social, livelihoods, and significant sites Rating 2
In the Nam Hkoke sub-basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 27% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 12% of the households on average. The average percentage of
HHs owning a TV, as a proxy for poverty levels, is 43%. The ethnic minority groups in the sub-basin are
Karen. On this basis, the sub-basin vulnerability rating is 2.
Conflict Rating 3
• Multiple armed groups active in much of the sub-basin, with ceasefires and closer relationships with
the Myanmar army (medium)
• Nine estimated battle deaths 1989-2015 (very low)
• One 2012-2016 media-reported armed conflict incidents (low)
• 18722 estimated historical conflict-related displaced people (very high)
139
4.6.3 Nam Lin
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
1 2 2 1 1
Overview
Nam Lin is a small sub-basin located in
the Shan state in the eastern part of
Myanmar and shares a border with
Laos.
Area: 2,638 km2
Average rainfall: 1,408 mm
Average sub-basin outflow: 46.1 m3/s
Topography:
% cover of
Type
sub-basin
Slopes 3-10
15%
Hard rock
Slopes 3-10 soft
15%
rock
Slopes<3
0%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10 hard
70%
rock
Slopes>10
0%
intermed rock
Population: 207,869
Ethnic diversity: Hani (Akha, Uni, Xapho, Cosung, Cote, Khape), Lahu, Lao,
Shan, Yao, Yuan
Socio-economic Economic activities:
+ Mining area: 4.8 km2 (covers 0.18 % of sub-basin)
+ Navigable waterways: None
+ Land use: N/A
States/Regions: Shan
Administrative: Major town/s: Tarlay, Monghpyak
140
Existing: 0
Status of hydropower Under Construction: 0
development Planned: 1 (Nam Lin – 36 MW)
Identified potential site: 0
Geomorphology and sediment Rating 1 (4)
• The Nam Lin is a very small (19th percentile) sub-basin with a low
Strahler Order tributary of the Mekong River. These characteristics
combine for a low Connectivity value;
• It drains steep, hard rock areas and has the potential to produce
sizeable sediment loads of sands and gravel, but rainfall is relatively
low resulting in low flow input indicator Rating;
• The relatively low connectivity value and low flow input result in a
low overall geomorphology rating despite a high potential sediment
score;
• The sub-basin is included in the analysis as it is targeted for future
hydropower development;
Aquatic ecology and fisheries Ecological Value rating 2
Human Pressure rating 2
• Nam Lin is a very small tributary of the
Mekong. It contains 3 river reach types,
none of which are rare, and with a very
small proportion of karst reaches. The
two predominant types are Medium
river, in moist broadleaf forest region at
low elevation, with low gradient and
with floodplains.
• The mean annual flow at the confluence
with the Mekong is 45 m3/sec with a
minimum flow of 7 m3/sec.
• The sub-basin does not contain
outstanding ecological features and
though some threatened fish species may
be present.
• Human pressures are low, with low population density, low agriculture intensity and low mining
activity.
• One hydropower project is planned near the confluence with the Mekong – the Nam Lin HPP (36
MW)
Terrestrial Biodiversity Rating 2
141
The Nam Lin sub-basin contains little
KBA (4%) and modest intact forest
(21%) cover. The KBA in the sub-
basin includes the Mekong fresh water
corridor that supports fish migration
from species that travel between
country boundaries into Laos and
China.
Social, livelihoods, and significant sites Rating 1
In the Nam Lin sub-basin’s Townships, own account workers indicating livelihood dependence on agriculture
and natural resources comprise on average 28% of the workforce. Female-headed households, which indicate
social vulnerability accounts for 19% of the households on average. The average percentage of HHs owning a
TV, as a proxy for poverty levels, is 61%. The ethnic minority groups in the sub-basin are Hani (Akha, Uni,
Xapho, Cosung, Cote, Khape), Lahu, Lao, Shan, Yao and Yuang. On this basis, the sub-basin vulnerability
rating is 1.
Conflict Rating 1
• Ceasefire and non-ceasefire armed groups active in less than half of this sub-basin (low)
• 7 estimated battle deaths 1989-2015 (very low)
• Zero 2012-2016 media-reported armed conflict incidents (very low)
• Zero estimated historical conflict-related displaced people (very low)
142
4.6.4 Mekong Other
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
4 5 2 1 4
Overview
Other Mekong is a medium-sized
sub-basin located in the Shan state in
the eastern-most region of Myanmar
and shares a border with China, Laos,
and Thailand.
Area: 6,534 km2
Average rainfall: 1,531 mm
Average sub-basin outflow: 32.2 m3/s
Topography:
% cover of
Type
sub-basin
Slopes 3-10
12%
Hard rock
Slopes 3-10
12%
soft rock
Slopes<3
0%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10
76%
hard rock
Slopes>10
0%
intermed rock
Population: 79,890
Ethnic diversity: Hani (Akha, Uni, Xapho, Cosung, Cote, Khape, Lahu, Shan
Economic activities:
Socio-economic + Mining area: 7.2 km2 (covers 0.11% of sub-basin)
+ Navigable waterways: None
+ Land use: N/A
States/Regions: Shan
Administrative: Major town/s: Mong Yawng
143
Existing: 0
Under Construction: 0
Status of hydropower Planned: 0
development Identified potential site: 0
Geomorphology and sediment Rating 4
• The Mekong Other sub-basin consists of three distinct watersheds
along the Mekong River with multiple Strahler Order 2
tributaries. Collectively they form a small sub-basin (38th
percentile);
• There are no dams in the catchments which drain steeply sloping
hard rocks;
• The high connectivity rating and potential sediment input ratings
results in a geomorphology rating of 4, even though rainfall is
lower than in other basins;
• This analysis does not consider the mainstem Mekong River
which flows along the southern boundary of this sub-basin.
Aquatic ecology and fisheries Ecological Value rating 5
Human Pressure rating 3
• The Mekong Other sub-basin is
effectively the Mekong mainstem
along the Myanmar border from
China to the Golden Triangle. It
consists of 287 km of mainstem
rock cut river channel. It contains 7
other river reach types of which 3
are rare, making up 13 % of the
river reach lengths with only 4%
flowing in karst regions. The
predominant river reaches are
Medium river, in moist broadleaf
forest region at low elevation, with
low gradient and with floodplains.
• The mean annual flow in the
Mekong at the start of the sub basin
is 2,005 m3/sec with a minimum
flow of 357 m3/sec, and at the end
of the sub-basin the mean annual
flow is 2665 m3/sec
• The Ecological values of this sub-
basin is rated as very high, because
of the importance of migratory species of fish and the presence of some critically endangered and
endangered fish species.
• The length of the Mekong mainstem has also been recognized as a riverine KBA.
• Human pressures are medium, because despite there being very low population density along the
Mekong, with little agriculture and mining pressure, there are 8 large hydropower plants upstream in
China with very significant regulation of seasonal and daily flows. There is also significant
commercial navigation on this stretch of the Mekong between China and Chiang Saen.
• Note: The Ecological Value rating is for the tributaries only, not for mainstem reaches
Terrestrial Biodiversity Rating 2
144
Mekong Other sub-basin contains
almost 40% KBA and 12% intact
forest. The KBA in this sub-basin is an
important habitat for small mammals
and a trans-boundary corridor between
China, Laos, Thailand, and Myanmar.
Almost 2% of the sub-basin is made up
of the Parsar protected area as well.
Social, livelihoods, and significant sites Rating 1
In the Mekong Other sub-basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 37% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 10% of the households on average. The average percentage of
HHs owning a TV, as a proxy for poverty levels, is 68%. The ethnic minority groups in the sub-basin are
Hani (Akha, Uni, Xapho, Cosung, Cote, Khape), Lahu and Shan. On this basis, the sub-basin vulnerability
rating is 1.
Conflict Rating 4
• Multiple armed groups active in much of the sub-basin (high)
• 32 estimated battle deaths 1989-2015 (low)
• Four 2012-2016 media-reported armed conflict incidents (high)
• 3868 estimated historical conflict-related displaced people (high)
145
4.7 Thanlwin Basin
4.7.1 Nam Ma
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
3 2 1 N/A 2
Overview
Nam Ma is one of the smaller sub-
basins, located in the Shan state in the
northeastern region of Myanmar that
shares a border with China.
Area: 3,425 km2
Average rainfall: 1,406 mm
Average sub-basin outflow: 78.9 m3/s
Topography:
% cover of sub-
Type
basin
Slopes 3-10
0%
Hard rock
Slopes 3-10
0%
soft rock
Slopes<3
0%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10
100%
hard rock
Slopes>10
intermed 0%
rock
Population: 24,479
Ethnic diversity: Wa, Parauk, Shan
Economic activities:
Socio-economic + Mining area: 0.5 km2 (covers 0.01% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (6%); Agriculture-Rainfed-Single (6.9%),
States/Regions: Shan Major town/s: Mongmao, Hsawng Hpa, Hkun Mar,
Administrative: Yawng Lin, Pangwaun, Lin Haw, Man Tun
146
Existing: 0
Status of hydropower Under Construction: 0
development Planned: 1 (Mantong – 225 MW)
Identified potential site: 0
Geomorphology and sediment Rating 3
• Nam Ma is a small sub-basin (26th percentile) situated within the Shan
Plateau with a Strahler Order 2 mainstem;
• It receives relatively low rainfall and its small size and low Strahler
contribute to low connectivity and flow input indicator scores, even
though there are no hydropower projects in the sub-basins;
• It has a high sediment potential owing to its catchment being located
completely within the mountainous Shan Plateau;
• Extensive deforestation has occurred within the basin and there are
sediment deposits evident at the confluence of the Thanlwin in satellite
images. Current land use practices are not included in this analysis.
Aquatic ecology and fisheries Ecological Value rating 2
Human Pressure rating 2
• The Nam Ma is a small left bank
tributary of the Upper Thanlwin. It
contains 2 river reach types, 1 of
which is rare covering 25% of the
reach lengths. The predominant
type is Medium river, in moist
broadleaf forest region at low
elevation, with low gradient, with a
substantial length of moist
broadleaf forest region at high
elevation.
• The mean annual flows at the
confluence with the Thanlwin is 78 m3/sec with a minimum flow of 11 m3/sec.
• There are no outstanding aquatic ecological features and no KBAs in this sub basin
• Human pressures are also low, with low rural population density, agricultural intensity and mining
activity.
• One hydropower project is planned the Mantong HPP (225 MW)
Terrestrial Biodiversity Rating 1
147
The Nam Ma sub-basin contains no KBA and
modest intact forest (16%) cover. With no
protected areas or critically endangered
ecoregions, it is a not a particularly notable
region from a biodiversity standpoint and is
given a rating of 1.
Social, livelihoods, and significant sites Rating N/A
The ethnic minority groups in the sub-basin are Wa, Parauk and Shan
Conflict Rating 2
• Sub-basin is in Wa SAD (medium)
• Four estimated battle deaths 1989-2015 (very low)
• Zero 2012-2016 media-reported armed conflict incidents (very low)
• Zero estimated historical conflict-related displaced people (very low)
148
4.7.2 Nam Hka
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
4 2 2 2 2
Overview
Nam Hka is a medium-sized sub-basin
located in the Shan state in the eastern
part of Myanmar and shares a border
with China.
Area: 8,074 km2
Average rainfall: 1,356 mm
Average sub-basin outflow: 202 m3/s
Topography:
% cover of sub-
Type
basin
Slopes 3-10
0%
Hard rock
Slopes 3-10
0%
soft rock
Slopes<3
0%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10
100%
hard rock
Slopes>10
0%
intermed rock
Population: 19,732
Ethnic diversity: Shan, Wa (Kawa)
Economic activities:
Socio-economic + Mining area: 1.3 km2 (covers 0.02% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (2.6%); Agriculture-Rainfed-Single (6%),
Irrigated – Double (0.1%)
States/Regions: Shan
Administrative: Major town/s: Mong Ping, Pang Yang
149
Existing: 0
Under Construction: 0
Status of hydropower Planned: 1 (Nam Hka – 210 MW)
development Identified potential site: 0
Geomorphology and sediment Rating 4
• The Nam Hka is a medium size sub-basin (46th percentile) that lies
next to the Upper and Middle Thanlwin sub-basins and has been
separated out due to its potential hydropower development;
• The Nam Hka is a Strahler Order 3 river, which has high sediment
input potential owing to its location within the steep Shan Plateau
• It receives relatively low rainfall compared to other sub-basins in
Myanmar, but is unregulated and maintains good connectivity.
Aquatic ecology and fisheries Ecological Value rating 2
Human Pressure rating 2
• The Nam Hka is a small left bank tributary of the
Upper Thanlwin. It contains 4 river reach types, 1
of which is rare covering less than 1% of the
reach lengths. The predominant types are Large
river, in moist broadleaf forest region at low
elevation, with sediment and Medium river, in
moist broadleaf forest region at low elevation,
with low gradient, with a substantial length of
moist broadleaf forest region at high elevation.
There are no karst reaches.
• The mean annual flows at the confluence with the
Thanlwin is 202 m3/sec with a minimum flow of
25 m3/sec.
• There are no outstanding aquatic ecological
features and no KBAs in this sub basin
• Human pressures are also low, with low rural
population density, agricultural intensity and
mining activity.
• One hydropower project is planned the Nam Hka
(210 MW)
Terrestrial Biodiversity Rating 2
150
The Nam Hka sub-basin contains modest
KBA (21%) and intact forest (19%) cover.
The KBA in the sub-basin is a habitat for
the big-headed turtle and the impressed
tortoise.
Social, livelihoods, and significant sites Rating 2
In the Nam Hka sub-basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 25% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 10% of the households on average. The average percentage of
HHs owning a TV, as a proxy for poverty levels, is 22%. The ethnic minority groups in the sub-basin are
Kachins (Singpho), Lao, Shan and Yao. On this basis, the sub-basin vulnerability rating is 2.
Conflict Rating 2
• Approximately half of the sub-basin is UWSA territory and Wa SAZ (medium)
• Zero estimated battle deaths 1989-2015 (very low)
• Two 2012-2016 media-reported armed conflict incidents (medium)
• Zero estimated historical conflict-related displaced people (very low)
151
4.7.3 Nam Teng
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
1 2 2 4 4
Overview
Nam Teng is a medium-sized sub-basin
located in the Kayah and Shan states in
the eastern region of Myanmar.
Area: 15,386 km2
Average rainfall: 1,475 mm
Average sub-basin outflow: 334.7 m3/s
Topography:
% cover of sub-
Type
basin
Slopes 3-10
76%
Hard rock
Slopes 3-10
0%
soft rock
Slopes<3
0%
Elev<30m
Slopes<3
2%
Elev>30m
Slopes>10
22%
hard rock
Slopes>10
0%
intermed rock
Population: 339,258
Ethnic diversity: Karen, Kayah, Shan, Wa (Kawa)
Economic activities:
Socio-economic + Mining area: 4.1 km2 (covers 0.03% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (0.4%); Agriculture-Rainfed-Single (17.4%),
Irrigated – Double (0.2%)
States/Regions: Kayah, Shan
Administrative: Major town/s: Langkho, Mawkmai
152
Existing: 1 (Keng Tawng – 54 MW)
Under Construction: 1 (Keng Tawng upper – 51 MW)
Status of hydropower Planned: 0
development Identified potential site: 0
Geomorphology and sediment Rating 3
• Nam Teng is a large (70th percentile), high Strahler Order (3) sub-basin
that predominantly drains the high, undulating area of the Shan Plateau
before flowing south into steeper terrain;
• There are two hydropower projects in the catchment that regulate about
40% of the catchment, and have water storage potential of 1 – 2 weeks
which lowers the connectivity of the sub-basin;
• The sub-basin has moderate rainfall and sediment input potential,
resulting in an overall medium geomorphology rating.
Aquatic ecology and fisheries Ecological Value rating 2
Human Pressure rating 3
• The Nam Teng is a large tributary of the Thanlwin,
entering on the right bank, 160 km above the Nam
Pawn confluence. Its river reaches are diverse with
11 types of which 6 are rare, making up about 57%
of the reach type lengths. Over 70% of these reach
types lie in karst regions, both large and medium at
low and high elevation. Of the common reach types,
Large and Medium river, in moist broadleaf forest
region at low elevation, with low gradient are found.
• The mean annual flows at the confluence are 333
m3/sec with minimum flows at 60 m3/sec
• The sub-basin is not reported to have endemic or
threatened species of fish, but with the high
proportion of karst reaches, this may be due to
absence of relevant surveys.
• There is one KBA in the Nam San valley in the upper
part of the sub-basin.
• Human pressures on the aquatic ecology are medium,
with moderate rural populations and cultivation in
the valleys, and some shifting cultivation and loss of
forest cover in the hillsides.
• There is one hydropower plant existing Keng Tawng
(54 MW) and one under construction Keng Tawng
upper (51 MW) Both are considered to have a
relatively low impact upon the aquatic ecology, the
existing dam with a small length of dewatered river
reach between dam and power station and the upper
dam having a reservoir of 11 km.
Terrestrial Biodiversity Rating 2
153
The Nam Teng sub-basin contains
moderate KBA (23%) and little intact
forest (2%) cover. The KBA in the sub-
basin is a habitat for several endemic
species including the soft-shell turtle and
various fish species.
Social, livelihoods, and significant sites Rating 4
In the Nam Teng sub-basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 35% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 21% of the households on average. The average percentage of
HHs owning a TV, as a proxy for poverty levels, is 44%. The ethnic minority groups in the sub-basin are
Karen, Kayah, Shan and Wa (Kawa). On this basis, the sub-basin vulnerability rating is 4.
Conflict Rating 5
• Multiple armed groups influential in much of the sub-basin (high)
• 151 estimated battle deaths 1989-2015 (high)
• 21 2012-2016 media-reported armed conflict incidents (very high)
• 29,977 estimated historical conflict-related displaced people (very high)
154
4.7.4 Nam Pawn
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
5 3 1 4 4
Overview
Nam Pawn is a medium-sized sub-basin
located in the Kayah, Kayin, and Shan
states in the central region of Myanmar.
Area: 11,572 km2
Average rainfall: 1,446 mm
Average sub-basin outflow: 402.3 m3/s
Topography:
% cover of sub-
Type
basin
Slopes 3-10
39%
Hard rock
Slopes 3-10
1%
soft rock
Slopes<3
0%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10
60%
hard rock
Slopes>10
0%
intermed rock
Population: 435,364
Ethnic diversity: Karen, Kayah, Shan
Economic activities:
+ Mining area: 11.6 km2 (covers 0.13% of sub-basin)
Socio-economic + Navigable waterways: None
+ Land use: Plantation (0.7%); Agriculture-Rainfed-Single (21.8%),
Rainfed-Double (0.5%), Irrigated-Single (0.3), Irrigated – Double (0.4%)
States/Regions: Kayah, Kayin, Shan
Administrative: Major town/s: Loilen
155
Existing: 0
Under Construction: 0
Status of hydropower Planned: 5 (Hawkham (upper) – 180 MW, Hpak Nam – 105 MW, Hpi Hseng
development – 45 MW, Nam Pawn (lower) – 105 MW, Nam Pawn (upper) – 150 MW)
Identified potential site: 0
Geomorphology and sediment Rating 5
• The large (61st percentile) Nam Pawn sub-basin includes both
undulating and steeply sloping areas of the Shan Plateau;
• Maximum Strahler Order is 3, and inflows include the regulated
flow from the Baluchaung sub-catchment which joins the Nam
Pawn in the middle of the sub-basin;
• Rainfall is moderate, and connectivity is considered high due to the
large basin size, high Strahler Order, and lack of any hydropower
developments (does not consider regulation of Baluchaung);
• Potential sediment input is high resulting in an overall
geomorphology rating of 5.
Aquatic ecology and fisheries Ecological Value rating 3
Human Pressure rating 3
• The Nam Pawn is a long tributary of the Thanlwin lying between the Balachaung and the Thanlwin
mainstem. The sub-basin consists of two parts, the lower watershed after the confluence with the
Balachaung down to the Thanlwin, and the upper watershed above the Balachaung confluence, where
the river splits into two main branches that extend for a further 200 km.
• The Nam Pawn sub-basin contains 9 river reach types of which 4 are rare, making up 55% of the
reach type lengths. 65% of the reach types lie in karst regions. In the lower watershed, the
predominant reach types are Large and medium rivers, in moist broadleaf forest region at low
elevation, at low gradient and with floodplains, but before the confluence with the Balachaung, the
rivers in karst regions start and continue up both branches of the upper watershed. At the very top of
both branches the river starts as Medium river, in moist broadleaf forest region at high elevation,
with low gradient.
• The mean annual flows of the Nam Pawn at the confluence with the Thanlwin is 400 m3/sec with a
minimum flow of 70 m3/sec.
• The sub-basin is not within a recognized area of endemism but threatened species of fish are found in
the sub-basin. There are two terrestrial KBAs in the upper parts of the watershed.
156
• Human pressures are medium with low agricultural intensity, medium mining activity, and loss of
forest cover.
• 5 hydropower projects are planned in the upper watershed of this sub-basin - Hawkham (upper), Nam
Pawn (lower), Nam Pawn (upper), Hpak Nam, Hpi Hseng.
Terrestrial Biodiversity Rating 1
The Nam Pawn sub-basin contains moderate
KBA (20%) and little intact forest (6%)
cover. The KBA in the sub-basin is a habitat
for endemic species of geckos and other cave
species, including several invertebrates. The
Taunggyi Bird Sanctuary makes up around
0.5% of the sub-basin.
Social, livelihoods, and significant sites Rating 4
In the Nam Pawn sub-basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 33% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 23% of the households on average. The average percentage of
HHs owning a TV, as a proxy for poverty levels, is 50%. The ethnic minority groups in the sub-basin are
Karen, Kayah and Shan. On this basis, the sub-basin vulnerability rating is 4.
Conflict Rating 4
• Multiple Pa’O and Shan armed groups and Pa’O SAZ (high)
• 34 estimated battle deaths 1989-2015 (low)
• Eight 2012-2016 media-reported armed conflict incidents (high)
• 19,900 estimated historical conflict-related displaced people (very high)
157
4.7.5 Baluchaung
Baseline value ratings
Geomorphology Aquatic ecology Terrestrial Social and
Conflict
and sediment and fisheries Biodiversity livelihoods
2 5 2 2 3
Overview
Baluchaung is a medium-sized sub-basin
located in the Kayah and Shan states in
the center of the country.
Area: 7,837 km2
Average rainfall: 1,493 mm
Average sub-basin outflow: 151.6 m3/s
Topography:
% cover of sub-
Type
basin
Slopes 3-10
72%
Hard rock
Slopes 3-10 soft
0%
rock
Slopes<3
0%
Elev<30m
Slopes<3
9%
Elev>30m
Slopes>10 hard
20%
rock
Slopes>10
0%
intermed rock
Population: 892,747
Ethnic diversity: Karen, Kayah, Shan
Economic activities:
+ Mining area: 6.1 km2 (covers 0.08% of sub-basin)
Socio-economic
+ Navigable waterways: None
+ Land use: Plantation (1.7%); Agriculture-Rainfed-Single (39.9%), Rainfed-
Double (0.7%), Irrigated-Single (0.2%), Irrigated – Double (2.7%), Irrigated-
Triple (0.3%)
States/Regions: Kayah, Mandalay, Shan
Administrative: Major town/s: Kalaw, Loikaw, Taunggyi
158
Existing: 3 (Baluchaung 1 – 28 MW, Baluchaung 2 – 168 MW, Baluchaung 3-
52 MW)
Status of hydropower Under Construction: 1 (Baluchaung upper – 30 MW)
development Planned: 0
Identified potential site: 0
Geomorphology and sediment Rating 2
• The Baluchaung sub-basin is a medium (42nd percentile) sized
catchment that drains the undulating Shan Plateau;
• IT receives moderate rainfall, and has a moderate sediment supply
potential;
• The connectivity of the river is altered by the presence of a
hydropower cascade in the lower catchment another hydropower
project in the headwaters. Flow in the river is also altered due to the
operation of the Moby Dam for irrigation and regulating flows to the
Baluchaung cascade;
• The cascade diverts water out of the river resulting in extended
dewatered reaches that disrupt the connectivity of the system.
Aquatic ecology and fisheries Ecological Value rating 5
Human Pressure rating 5
• The Baluchaung river flows into the Nam Pawn, a
west bank tributary of the Thanlwin. The sub-basin
has very high ecological value due to the unique
feature of Inle Lake which lies in the top part of the
sub-basin. It has 8 river reach types, all of which are
rare, and over 60% of which lie in karst limestone
areas. In the upper part of the sub-basin, the
predominant reaches are medium rivers in karst at
high elevation and montane. After Inle Lake it flows
through Medium river, in moist broadleaf forest
region at high elevation, with low gradient and with
floodplains. In the central part of the sub-basin the
Moby irrigation dam has created another large lake
downstream of Inle Lake. Towards the end of the sub-
basin the river again flows through karst at high
elevation.
• At its confluence with the Nam Pawn the mean
annual flow in the Baluchaung river is 151 m3/sec
with a minimum flow of 30 m3/sec
• Inle Lake is recognized as having a unique
biodiversity of fish and molluscs, with many endemic
species, probably because of its high karst location.
• The Baluchaung sub-basin is under high human
pressure, with a combination of moderate mining and
agricultural intensity, high rural population density
and use of Inle Lake for tourism and fisheries, and increasing water pollution.
• There are three run-of river hydropower projects driven by the storage capacity of the Moby dam at
the bottom end of the sub-basin – Baluchaung 1 (28 MW), Baluchaung 2 (168 MW) and Baluchaung
3 (52 MW). These three dams in cascade have eliminated any connectivity between the Baluchaung
and the rest of the Thanlwin system. Together they have created a 22-km dewatered stretch of the
river between the dams and the power houses.
• A fourth hydropower project is under construction, Baluchaung upper (30 MW) which would have a
reservoir of 10 km and 3 km dewatered zone. It is located on an upper branch of the Baluchaung
opposite to Inle Lake.
159
Terrestrial Biodiversity Rating 2
Over 20% of the Baluchaung sub-basin is
composed of KBA that is home to several
endemic and endangered species of birds,
including the Giant Nuthatch. A small
portion of the sub-basin (7%) is classified
as a protected area (Taunggyi Bird
Sanctuary and Inlay Wetland Wildlife
Sanctuary) as well to support the
endangered species. However, with less
than 2% intact forest present in the sub-
basin, it receives a biodiversity rating of 2.
Social, livelihoods, and significant sites Rating 2
In the Baluchaung sub-basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 28% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 23% of the households on average. The average percentage of
HHs owning a TV, as a proxy for poverty levels, is 59%. The ethnic minority groups in the sub-basin are
Karen, Kayah and Shan. On this basis, the sub-basin vulnerability rating is 2.
Conflict Rating 3
• Less than half of the sub-basin is influenced by armed groups including the KNPP and the Pa’O SAZ
(medium)
• Nine estimated battle deaths 1989-2015 (low)
• Two 2012-2016 media-reported armed conflict incidents (low)
• 7220 estimated historical conflict-related displaced people (very high)
*Baluchaung 3 HPP discharges water into the Nam Pawn River.
160
4.7.6 Yunzalin
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
2 4 3 N/A 3
Overview
Yunzalin is a relatively small sub-basin
that falls within the Kayah and Kayin
states in the southern region of the main
body of Myanmar.
Area: 3,036 km2
Average rainfall: 1,709 mm
Average sub-basin outflow: 128.6 m3/s
Topography:
% cover of sub-
Type
basin
Slopes 3-10
0%
Hard rock
Slopes 3-10
25%
soft rock
Slopes<3
0%
Elev<30m
Slopes<3
2%
Elev>30m
Slopes>10
72%
hard rock
Slopes>10
0%
intermed rock
Population: 8,076
Ethnic diversity: Chin (Asho)
Economic activities:
Socio-economic + Mining area: No
+ Navigable waterways: None
+ Land use: Plantation (0.1%); Agriculture-Rainfed-Single (2.3%),
Irrigated-Single (0.6%), Irrigated – Double (0.2%)
States/Regions: Bago, Kayah, Kayin, Mon
Administrative: Major town/s: Hpapun
Existing: 0
Under Construction: 0
Status of hydropower Planned: 0
development Identified potential site: 1 (Yunzalin – 100 MW)
161
Geomorphology and sediment Rating 2 (3)
• The Yunzalin is a small (21st percentile), narrow basin situated between
the Bilin and Thanlwin basins that flows directly to the sea;
• It is not presently developed for hydropower but has moderate rainfall
and low Strahler Order (2) limiting its Inflow and Connectivity scores;
• The sub-basin has high sediment production potential, and provides
sediment input directly to the coastal zone;
• Similar to other small sub-basins identified for potential hydropower
development its geomorphic rating would likely increase if it were
included in one of the larger neighbouring basins.
Aquatic ecology and fisheries Ecological Value rating 4
Human Pressure rating 2
• The Yunzalin sub-basin is a small tributary of the
Lower Thanlwin, flowing north to south parallel to
the Thanlwin. It contains 10 river reach types of
which 5 are rare, covering 24.5% of the reach
lengths. The commonest reaches are Large and
medium river, in moist broadleaf forest region at
low elevation, with floodplains and at low gradient,
and large and medium rivers in karst region. 35% of
the river reaches lie in karst region.
• The mean annual flows at the confluence with the
Lower Thanlwin are 127 m3/sec with a minimum
flow of 11.7 m3/sec.
• The karst area reaches may contain endemic fish
species.
• Most of the sub-basin could be contained within the
concept of the Thanlwin Peace Park KBA
• Human pressures on the sub-basin include a high
rural population with increasing agriculture intensity
in the river valley
• One hydropower project is planned at Yunzalin (100
MW)
Terrestrial Biodiversity Rating 3
162
There is significant KBA (75%)
presence in the Yunzalin sub-basin and
moderate intact forest (30%) cover as
well. The KBA is a habitat for tiger
and elephants and includes the Shwe
Kyin and Paung Laung biodiversity
corridors as well. The protected Kahilu
Wildlife Sanctuary is located within
the sub-basin and makes up 3% of the
total area.
Social, livelihoods, and significant sites Rating N/A
The ethnic minority groups in the sub-basin are Chin (Asho)
Conflict Rating 3
• Sub-basin heavily influenced by ceasefire armed group KNU (medium)
• Eight estimated battle deaths 1989-2015 (very low)
• Six 2012-2016 media-reported armed conflict incidents (high)
• 18,452 estimated historical conflict-related displaced people (very high)
163
4.7.7 Thanlwin Upper
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
5 2 1 2 5
Overview
Thanlwin Upper is the third largest
sub-basin in the country and falls
within the Shan state in the eastern
region of Myanmar. It shares a border
with China.
Area: 29,352 km2
Average rainfall: 1,446 mm
Average sub-basin outflow: 2368.9
m3/s
Topography:
% cover of
Type
sub-basin
Slopes 3-10
26%
Hard rock
Slopes 3-10 soft
0%
rock
Slopes<3
0%
Elev<30m
Slopes<3
1%
Elev>30m
Slopes>10 hard
73%
rock
Slopes>10
0%
intermed rock
Population: 1,122,780
Ethnic diversity: Chinese (Han), Kachins (Singpho), Lahu, Lisu, Palaung,
Shan, Wa (Kawa)
Economic activities:
Socio-economic
+ Mining area: 2.9 km2 (covers 0.01% of sub-basin)
+ Navigable waterways: None
+ Land use: Plantation (1.8%); Agriculture-Rainfed-Single (14.7%),
Irrigated – Double (0.1%)
States/Regions: Shan
Administrative:
Major town/s: Kunlong, Nam Hpan
164
Existing: 0
Status of hydropower Under Construction: 0
development Planned: 2 (Kun Long – 1,400 MW, Naopha – 1,200 MW)
Identified potential site: 0
Geomorphology and sediment Rating 5
• The Thanlwin Upper is a very large (96th percentile) catchment on th
Shan Plateau and includes numerous tributaries flowing into the
Thanlwin ranging up to Strahler Order 3;
• There are no existing hydropower projects in the sub-basin, or on the
mainstem in China upstream;
• Deforestation and forestry plantations are evident in satellite photos
and may have altered sediment inputs, but this is not considered in the
evaluation;
• Overall the high connectivity, high inflow and potential sediment
scores result in a very high geomorphology rating for the sub-basin;
• NOTE: this sub-basin does not include the mainstem Thanlwin which
is considered as a separate unit with a geomorphology rating of 5
Aquatic ecology and fisheries Ecological Value rating 3
Human Pressure rating 2
• The Thanlwin Upper
extends for 644 km of rock cut
mainstem channel from the
Chinese border to the
confluence with the Nam Pang. The
sub-basin has two small
tributaries on the left bank,
including the Nam Hka,
described separately, and one
large tributary on the right
bank, Nam Pang.
• The sub-basin contains 12
river reach types of which 7 are
rare, making up 31% of all the
reach lengths with 41% of the
reaches flowing through karst
region.
• The mean annual
flows at the border with China is 1,689
m3/sec with a minimum flow of 292 m3/sec. At the lower end of
the sub-basin, the mean annual flows are 2368 m3/sec with a
contribution from the Nam Pang of 225 m3/sec.
• The upper Thanlwin reaches are reported to have relatively low
fish diversity, but this may be due to the absence of surveys.
• The lower reaches of the Nam Pang consist of the rare Large river,
in moist broadleaf forest region at low elevation, with low gradient, but higher up it flows through
karst region at high elevation. The Nam Pang has some unique geomorphological features – a series
of rapids and waterfalls in the lower end, and braided channel with islands and in-channel wetlands
extending for many kilometres upstream.
• There are no riverine KBAs identified in the sub-basin, though the Nam San mountain range KBA is
reported to be important for turtles and tortoises.
• Human pressures in this sub basin are low with low population densities, very low agricultural
intensity, low mining and good forest cover.
• There are two very large hydropower plants planned on the Upper Thanlwin – Nao Pha (1,200 MW)
and Kun Long (1,400 MW)
165
• Note: The Ecological Value rating is for the tributaries only, not for mainstem reaches
Terrestrial Biodiversity Rating 1
The Thanlwin Upper sub-basin is not very
biodiverse with 19% KBA and only 7%
intact forest. The KBA in the sub-basin is a
habitat for several aquatic species including
turtles and various endemic fish species.
Social, livelihoods, and significant sites Rating 2
In the Thanlwin Upper sub-basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 31% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 20% of the households on average. The average percentage of
HHs owning a TV, as a proxy for poverty levels, is 50%. The ethnic minority groups in the sub-basin are
Chinese (Han), Kachins (Singpho), Lahu, Lisu, Palaung, Shan and Wa (Kawa). On this basis, the sub-basin
vulnerability rating is 4.
Conflict Rating 5
• Multiple armed groups actively contesting the Myanmar Army (high)
• 660 estimated battle deaths 1989-2015 (very high)
• 209 2012-2016 media-reported armed conflict incidents (very high)
• 26,468 estimated historical conflict-related displaced people (very high)
166
4.7.8 Thanlwin Middle
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
5 4 3 4 4
Overview
Thanlwin Middle is one of the larger
sub-basin and spans several states in the
southeastern region of the main body of
Myanmar that borders Thailand.
Area: 20,264 km2
Average rainfall: 1,264 mm
Average sub-basin outflow: 3381 m3/s
Topography:
% cover of
Type
sub-basin
Slopes 3-10
1%
Hard rock
Slopes 3-10 soft
2%
rock
Slopes<3
0%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10 hard
97%
rock
Slopes>10
0%
intermed rock
Population: 134,457
Ethnic diversity: Karen, Kayah, Lao, Shan
Economic activities:
Socio-economic + Mining area: 0.9 km2
+ Navigable waterways: None
+ Land use: Plantation (0.2%); Agriculture-Rainfed-Single (2.2%),
Irrigated – Double (0.1%)
States/Regions: Kayah, Shan
Administrative: Major town/s: Mongton
Existing: 0
Under Construction: 0
Status of hydropower Planned: 2 (Mong Ton – 7,000 MW, Ywathit – 4,000 MW)
development Identified potential site: 0
167
Geomorphology and sediment Rating 5
• The Thanlwin Middle is a very large sub-basin (84th percentile) that
consists of steep mounts and contains high Strahler Order (3)
tributaries of the mainstem Thanlwin;
• The catchment is largely undeveloped and there is no flow regulation
in any of the water sheds within this sub-basin;
• The steep, crystalline mountains have high sediment production
potential and over all this sub-basin is considered to have a very high
geomorphology rating;
• NOTE: this sub-basin does not include the mainstem Thanlwin which
is considered as a separate unit with a geomorphology rating of 5.
Aquatic ecology and fisheries Ecological Value rating 4
Human Pressure rating 1
• The Thanlwin Middle sub-basin starts at the
confluence of the Nam Pang and the Thanlwin
mainstem and extends for 377 km of rock cut
channel to the confluence with the Nam Pawn.
Over this length the middle Thanlwin sub-
basin is very narrow with few tributaries
entering, so that there are only medium sized
rivers contributing to the flow.
• There are 6 medium river reach types of which
4 are rare, but making up only 9% of the
lengths and with 26% of the reaches flowing
through karst region, at both low and high
elevation. The predominant river reach type is
Medium river, in moist broadleaf forest region
at low elevation, with low gradient. These
reaches are mostly located in a left bank
tributary that joins shortly
after the Nam Pang,
• The mean annual flows in
the middle Thanlwin start at
2,597 m3/sec and exit the sub-basin at 3,381
m3/sec with a minimum flow of 603
m3/sec.
• The middle Thanlwin, is an important
migration route for fish, including the
Hilsa.
• The whole of the sub-basin lies within the
mainly terrestrial Thanlwin southern forest
KBA
• Human pressures are limited in this sub-basin,
with low rural population densities, limited
agriculture and mining activities.
• There are no hydropower projects at
present, although two large projects are
proposed at Ywathit (4,000 MW) 57 kms
upstream from the Nam Pawn confluence,
and Mong Ton (7,000 MW) which is 60 km downstream from the Nam Pawng confluence.
Note: The Ecological Value rating is for the tributaries only, not for mainstem reaches
Terrestrial Biodiversity Rating 3
168
The Thanlwin Middle sub-basin is
composed of nearly 85% KBA including the
Golden Triangle Area, an important habitat
for several species of aquatic plants and
vulnerable species of dragon flies. Due to
the comparably low intact forest cover
(17%), this sub-basin receives a biodiversity
rating of 3.
Social, livelihoods, and significant sites Rating 4
In the Thanlwin Middle sub-basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 35% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 19% of the households on average. The average percentage of
HHs owning a TV, as a proxy for poverty levels, is 42%. The ethnic minority groups in the sub-basin are
Karen, Kayah, Lao and Shan. On this basis, the sub-basin vulnerability rating is 4.
Conflict Rating 4
• Much of sub-basin influenced by multiple armed groups (high)
• 82 estimated battle deaths 1989-2015 (medium)
• 12 2012-2016 media-reported armed conflict incidents (very high)
• 49,557 estimated historical conflict-related displaced people (very high)
169
4.7.9 Thanlwin Lower
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
3 4 3 1 4
Overview
Lower Thanlwin is a medium sized
sub-basin that spans multiple states in
the southern branch of Myanmar that
borders Thailand.
Area: 13,972 km2
Average rainfall: 2,990 mm
Average sub-basin outflow: 5-93.8
m3/s
Topography:
% cover of sub-
Type
basin
Slopes 3-10
0%
Hard rock
Slopes 3-10
34%
soft rock
Slopes<3
31%
Elev<30m
Slopes<3
8%
Elev>30m
Slopes>10
27%
hard rock
Slopes>10
0%
intermed rock
Population: 1,716,525
Ethnic diversity: Karen, Kayah, Mon (Talaing)
Economic activities:
+ Mining area: 2.9 km2 (covers 0.02% of sub-basin)
Socio-economic
+ Navigable waterways: 87.7 km
+ Land use: Plantation (0.7%); Agriculture-Rainfed-Single (4.6%), Flood
Plain – Single (0.2%), Irrigated-Single (7.2%), Irrigated – Double (3.5%),
Irrigated-Triple (0.2%)
States/Regions: Kayah, Kayin, Mon
Administrative: Major town/s: Hpasawng, Thanbyuzayat, Thaton
170
Existing: 0
Under Construction: 0
Status of hydropower Planned: 1 (Hutgyi – 1,360 MW)
development Identified potential site: 0
Geomorphology and sediment Rating 3
• The Thanlwin Lower is a medium sized basin (67th percentile) that
consists of a number of small, Strahler Order 1 tributaries flowing
into the mainstem Thanlwin;
• The sub-basin is highly varied, as it encompasses the area where the
Thanlwin emerges from the mountains and flows through the coastal
plain;
• Rainfall is high and connectivity is not disrupted by any hydropower
developments within the catchment;
• The medium geomorphology rating is attributable to the low Strahler
Order and low sediment input potential.
• NOTE: this sub-basin does not include the mainstem Thanlwin
which is considered as a separate unit with a very high geomorphology rating (5).
Aquatic ecology and fisheries Ecological Value rating 4
Human Pressure rating 2
• The Thanlwin Lower sub-basin is a complex basin consisting of the narrow Thanlwin valley starting
at the Nam Pawn confluence, downstream to the confluence
with the Moei river flowing in from the south along the
border with Thailand and thence in a southwest
direction towards the estuary at Mawlaymyine.
• Most of the Thanlwin mainstem flows in a rock cut channel
(227 km), which changes to a meandering channel with
alluvium (113 km) as it starts to flow south west towards the
sea. The sub-basin contains 9 river reach types of which 3
are rare, representing 14% of the reach lengths. The
predominant reach types are the common Large and
medium rivers, in moist broadleaf forest region at low
elevation, with floodplains and at low gradient.
• The Thanlwin mainstem is an important migration route
for fish, including the smaller hilsa species.
The Moei river also contains endemic and
threatened mollusc and aquatic insect
species and the Dawna Range KBA along
this river is also important for the big-
headed turtle.
• The upper part of the sub-basin would form
part of the Thanlwin Peace Park KBA, and
the lower floodplain and estuary contains karst
limestone outcrops with important cave species
that form KBAs. The estuary of Thanlwin is part
of the Gulf of Mottama KBA.
• The upper part of the sub-basin is relatively
sparsely populated, while the lower alluvial part
has high population densities and is intensely
cultivated. There are several large towns along the
lower Thanlwin, contributing to pollution in the
lower reaches.
• Note: The Ecological Value rating is for the tributaries only, not for mainstem reaches
171
Terrestrial Biodiversity Rating 3
The Thanlwin Lower sub-basin is
notably biodiverse because 62% of the
sub-basin area is composed of KBA that
is home to a wide variety of fauna such
as sand pipers, turtles, bats, tigers, and
more. Only 17% of the sub-basin is
composed of intact forest, but another
9% contained Irrawaddy dry forests
(6%) and coastal mangrove forests (3%)
before human development started to
weaken these ecoregions.
Social, livelihoods, and significant sites Rating 1
In the Thanlwin Lower sub-basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 18% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 27% of the households on average. The average percentage of
HHs owning a TV, as a proxy for poverty levels, is 62%. The ethnic minority groups in the sub-basin are
Karen, Kayah and Mon (Talaing). On this basis, the sub-basin vulnerability rating is 1.
Conflict Rating 4
• Some of sub-basin influenced by multiple, sometimes competing armed groups (medium)
• 449 estimated battle deaths 1989-2015 (very high)
• 18 2012-2016 media-reported armed conflict incidents (very high)
• 23,706 estimated historical conflict-related displaced people (very high)
172
4.7.10 Lam Pha
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
2 3 1 4 4
Overview
Lam Pha is a medium-sized sub-basin
located in the Kayin and Mon states in the
southeastern branch of Myanmar that
borders Thailand.
Area: 8,910 km2
Average rainfall: 3,137 mm
Average sub-basin outflow: 660 m3/s
Topography:
% cover of sub-
Type
basin
Slopes 3-10
0%
Hard rock
Slopes 3-10 soft
47%
rock
Slopes<3
40%
Elev<30m
Slopes<3
1%
Elev>30m
Slopes>10 hard
13%
rock
Slopes>10
0%
intermed rock
Population: 486,225
Ethnic diversity: Karen, Mon (Talaing)
Economic activities:
Socio-economic + Mining area: No
+ Navigable waterways: 4 km
+ Land use: N/A
States/Regions: Kayin, Mon
Administrative: Major town/s: Hpa-an, Myawadi
173
Existing: 0
Under Construction: 0
Status of hydropower Planned: 0
development Identified potential site: 1 (Lam Pha – 19.5 MW)
Geomorphology and sediment Rating 2 (3)
• Lam Pha sub-basin is a medium sized (49th percentile) catchment with
a Strahler Order 3 mainstem that discharges in the same coastal area
as the Thanlwin and the Myet Taw Chaung sub-basin;
• The river network is structurally controlled, trending north south as it
flows between the ridges;
• Rainfall is moderate in the catchment, and much of the catchment is
occupied by flat lying coastal deposits;
• The geomorphology rating reflects the size of the basin, moderate
rainfall and relatively low sediment generation from “hard” geology
types.
Aquatic ecology and fisheries Ecological Value rating 3
Human Pressure rating 3
• The Gyaing River meets the Thanlwin river at Mawlamyine. It has two branches one from the north,
running parallel to the Thanlwin and one
flowing in from the south (Haungthayaw River).
The river has 5 river reach types of which one is
rare with 9% of the reach lengths, and a small
proportion (8%) of reaches in karst regions at
low elevation. The main reach types are Large
and medium rivers, in moist broadleaf forest
region at low elevation, with floodplains.
• The mean annual flow at the confluence with the
Thanlwin is 668 m3/sec with a minimum flow of
63 m3/sec
• The river has the presence of threatened fish and
aquatic plants and insects, raising its ecological
value
• Human pressures are moderate, with moderate
rural population density, and agricultural
intensity and little mining activity. There is a
large urban population of about 500,000 at
Mawlamyine, which will affect water quality in
the estuary.
• One hydropower dam is planned high up in the
southern catchment – Lam Pha HPP (19.5 MW).
Terrestrial Biodiversity Rating 1
174
The Lam Pha sub-basin contains
moderate KBA (19%) and intact forest
(18%) cover. The KBA is home to
numerous species of mammals
including elephants, tigers, bats, and
more. Although small (2%), the
Mulayit Wildlife sanctuary is located in
this sub-basin as well. Another 6% of
the basin was at least in the past
composed of the critically endangered
Irrawaddy dry forests ecoregion,
although it has been degraded recently
due to human influence.
Social, livelihoods, and significant sites Rating 4
In the Lam Pha sub-basin’s Townships, own account workers indicating livelihood dependence on agriculture
and natural resources comprise on average 21% of the workforce. Female-headed households, which indicate
social vulnerability accounts for 32% of the households on average. The average percentage of HHs owning a
TV, as a proxy for poverty levels, is 40%. The ethnic minority groups in the sub-basin are Karen and Mon
(Talaing). On this basis, the sub-basin vulnerability rating is 4.
Conflict Rating 4
• Multiple ceasefire and non-ceasefire armed groups are influential in the sub-basin (high)
• 14 estimated battle deaths 1989-2015 (low)
• 28 2012-2016 media-reported armed conflict incidents (very high)
• 12,839 estimated historical conflict-related displaced people (very high)
175
4.7.11 Myet Taw Chaung
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
1 3 1 2 4
Overview
Myet Taw Chaung is a relatively small
sub-basin that falls within the Kayin
and Mon states in the southeastern
branch of Myanmar that borders
Thailand.
Area: 5,665 km2
Average rainfall: 3,818 mm
Average sub-basin outflow: 502.01
m3/s
Topography:
% cover of sub-
Type
basin
Slopes 3-10
0%
Hard rock
Slopes 3-10
52%
soft rock
Slopes<3
31%
Elev<30m
Slopes<3
10%
Elev>30m
Slopes>10
7%
hard rock
Slopes>10
0%
intermed rock
Population: 450,659
Ethnic diversity: Karen, Mon (Talaing)
Economic activities:
Socio-economic
+ Mining area: 1.7 km2 (covers 0.03% of sub-basin)
+ Navigable waterways: None
+ Land use: N/A
States/Regions: Kayin, Mon
Administrative: Major town/s: Kya In, Mawlamyine
176
Existing: 0
Under Construction: 0
Status of hydropower Planned: 0
development Identified potential site: 1 (Myet Taw Chaung – 10 MW)
Geomorphology and sediment Rating 1 (3)
• rd
The Myet Taw Chaung is a small sub-basin (33 percentile) that lies
between the Thanlwin and the Tanintharyi, with the north south
trending river confined by the structurally controlled valley;
• The lower reaches of the river are separated from the coastal plain by
the hills south to Mawlamyine, where it joins the complex Thanlwin
estuary;
• Rainfall is very high, but the low Strahler Order (2) and small area of
the catchment, combined with a low sediment input potential result in
a low overall rating;
• Similar to other small sub-basins identified for future hydropower
development in this analysis, the rating of the individual sub-basin is
likely lower than if it were combined with a larger neighbouring sub-
basin.
Aquatic ecology and fisheries Ecological Value rating 3
Human Pressure rating 3
• The Ataran river flows into the Thanlwin
estuary at Mawlamyine from the south. It is a
relatively small lowland river with 5 river
reach types of which 1 is rare with just over
1% proportion of the reach lengths. There is
155 of the reach lengths in low elevation
karst region. The main reach types are Large
and medium river, in moist broadleaf forest
region at low elevation, with floodplains and
at low elevation.
• The mean annual flows at the confluence are
502 m3/sec with a very low minimum of 15
m3/sec.
• The river does have the presence of some
threatened fish species, and discharges into
the Gulf of Mottama KBA, important for
water birds
• Human pressures are moderate, with
moderate rural population density, and
agricultural intensity and little mining
activity. There is a large urban population of
about 500,000 at Mawlamyine, which will
affect water quality in the estuary.
• One hydropower plant is planned in the upper
reaches of the Ataran river, Myet Taw Chaung HPP (10 MW)
Terrestrial Biodiversity Rating 1
177
The Myet Taw Chaung sub-basin
contains little KBA (6%) and intact
forest (16%) cover and no protected
areas or critically endangered
ecoregions. The KBA is a habitat for the
spoon-billed sand piper and the black-
headed ibis.
Social, livelihoods, and significant sites Rating 4
In the Myet Taw Chaung sub-basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 22% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 24% of the households on average. The average percentage of
HHs owning a TV, as a proxy for poverty levels, is 48%. The ethnic minority groups in the sub-basin are
Karen and Mon (Talaing). On this basis, the sub-basin vulnerability rating is 4.
Conflict Rating 4
• Sub-basin is influenced by multiple armed groups (high)
• 28 estimated battle deaths 1989-2015 (medium)
• Three 2012-2016 media-reported armed conflict incidents (medium)
• 13,414 estimated historical conflict-related displaced people (very high)
178
4.8 Tanintharyi Coastal Basins
4.8.1 Tanintharyi
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
5 5 5 4 4
Overview
Tanintharyi is a relatively large sub-
basin that falls within the region of
the same name in the southern branch
of Myanmar and borders Thailand.
Area: 17,865 km2
Average rainfall: 2,123 mm
Average sub-basin outflow: 910.6
m3/s
Topography:
% cover of
Type
sub-basin
Slopes 3-10
0%
Hard rock
Slopes 3-10
25%
soft rock
Slopes<3
0%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10
75%
hard rock
Slopes>10
0%
intermed rock
Population: 253,817
Ethnic diversity: Karen, Siamese (Khon-Tai)
Economic activities:
Socio-economic + Mining area: 11.2 km2 (covers 0.06% of sub-basin)
+ Navigable waterways: None
+ Land use: N/A
States/Regions: Tanintharyi
Administrative: Major town/s: Tanintharyi
179
Existing: 0
Under Construction: 0
Status of hydropower Planned: 1 (Tanintharyi – 600 MW)
development Identified potential site: 3 (Sar Ra Wa Chaung – 11 MW, Tha Gyet Chaung –
20 MW, Thein Kun Chaung – 25 MW)
Geomorphology and sediment Rating 5
• The Tanintharyi River is a large sub-basin (77th percentile) that includes
the elevated Tenasserim Hills along the border with Thailand;
• The river lies in ta north south trending narrow coastal zone and the sub-
basin receives high rainfall and discharges directly to the sea;
• There is no existing hydropower in the sub-basin and the overall level of
development is low;
• These characteristics contribute to a very high geomorphology rating.
Aquatic ecology and fisheries Ecological Value rating 5
Human Pressure rating 2
• The Tanintharyi river runs from the north to the south
parallel to the coast, meeting with a smaller branch
river from the south, before flowing west to the sea. It is
confined to the east by steep hills. The sub-basin contains 8
river reach types of which 2 are rare, making up 11% of the
reach length. It has 26% of the river reaches running
through karst region at low elevation, especially in the
southern branch. The predominant reach types are Large
river, in moist broadleaf forest region at low elevation,
with floodplains and with sediment, and Medium river, in
moist broadleaf forest region at low elevation, with low
gradient and with floodplains.
• The mean annual flow at the coast is 913 m3/sec with a
minimum flow of 93 m3/sec.
• The river has been recognised as an area of endemism
for aquatic species, including fish, with the
presence of Endangered and Vulnerable fish
species
• There are several terrestrial KBAs which cover
the sub-basin, including the Tanintharyi national
Park and Myinmoletkhat KBA. The river
discharges into the larger marine Meyik
Archipelago KBA and more locally into the estuarine Kyunsu
KBA.
• Human pressures on the sub-basin are low, with low rural
population, low agriculture intensity, moderate mining
activity and good forest cover.
• One hydropower project is planned and 3 others identified.
The Tanintharyi HPP (600 MW) would be located 140 km
upstream of the confluence of the north and south branches.
Terrestrial Biodiversity Rating 5
180
Almost 90% of the Tanintharyi sub-
basin is composed of KBA that is an
important corridor for tigers and
elephants. It contains 64% intact
forest and is a recognized forest
conservation area. The Tanintharyi
Nature Reserve is a protected area
that composes nearly 3% of the sub-
basin. It is one of only 6 out of 58
total sub-basins to receive a
biodiversity rating of 5.
Social, livelihoods, and significant sites Rating 4
In the Tanintharyi sub-basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 24% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 40% of the households on average. The average percentage
of HHs owning a TV, as a proxy for poverty levels, is 49%. The ethnic minority groups in the sub-basin are
Karen and Siamese (Khon – Tai). On this basis, the sub-basin vulnerability rating is 4.
Conflict Rating 4
• Ceasefire armed group (KNU) influential in much of the sub-basin (medium)
• 70 estimated battle deaths 1989-2015 (medium)
• Two 2012-2016 media-reported armed conflict incidents (medium)
• 20,441 estimated historical conflict-related displaced people (very high)
181
4.8.2 Glohong Kra
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
1 3 4 1 2
Overview
Glohong Kra is the fourth largest sub-
basin in the country and is in the
Tanintharyi region in the southern tip
of Myanmar.
Area: 992 km2
Average rainfall: 2,942 mm
Average sub-basin outflow: 8.05 m3/s
Topography:
% cover of
Type
sub-basin
Slopes 3-10
0%
Hard rock
Slopes 3-10 soft
100%
rock
Slopes<3
0%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10 hard
0%
rock
Slopes>10
0%
intermed rock
Population: 140,020
Ethnic diversity: Selung, Siamese (Khon-Tai)
Economic activities:
Socio-economic
+ Mining area: No
+ Navigable waterways: None
+ Land use: N/A
States/Regions: Tanintharyi
Administrative:
Major town/s:
182
Existing: 0
Under Construction: 0
Status of hydropower Planned: 0
development Identified potential site: 1 (Glohong Kra – 40 MW)
Geomorphology and sediment Rating 1 (5)
• This very small (5th percentile) sub-basin is situated within the coastal
hills and flows towards the south;
• It is undeveloped with respect to hydropower and receives high
rainfall, but its small size restricts its connectivity rating to a 1 when
compared to other basins;
• Sediment input is also considered to be relatively low, due to the
underlying geology, although it may provide a locally important input
to the coastal zone;
• Like other small sub-basins identified for potential hydropower
development, the geomorphic rating is low due to the large scale, basin
wide methodology adopted.
Aquatic ecology and fisheries Ecological Value rating 3
Human Pressure rating 3
• The sub-basin where the Glohong Kra HPP is proposed, is a
sub-set of the Thanintharyi coastal sub-basin. It is located at
the most southern end of the Myanmar coastal strip, and
borders with Thailand.
• It contains about 70 km of Medium river, in moist broadleaf
forest region at low elevation, with low gradient and with
floodplains, both common river reach types.
• As it discharges into the Kra Buri creek that is the border with
Thailand it has a mean annual flow of 85 m3/sec with a
minimum flow of 17 m3/sec
• It is thought to contain some endemic species of fish and some
threatened species of mollusc, reported from Thailand. The
headwaters of this sub-basin have been identified as part of the
Kara river KBA.
• Human pressures are moderate as with all the coastal strip –
moderate rural population density and agriculture, with some
loss of forest cover.
• One hydropower plant has been identified Glohong Kra HPP
(40 MW).
Terrestrial Biodiversity Rating 4
183
Although small, the Glohong Kra sub-
basin is still important from a biodiversity
standpoint. Over two thirds of the sub-
basin is composed of KBA that is an
important breeding ground for marine
fauna, but is threatened by infrastructure
and aquaculture development. Almost
62% is composed of intact forest.
Social, livelihoods, and significant sites Rating 1
In the Glohong Kra sub-basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 16% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 31% of the households on average. The average percentage of
HHs owning a TV, as a proxy for poverty levels, is 54%. The ethnic minority groups in the sub-basin are
Selung and Siamese (Khon-Tai). On this basis, the sub-basin vulnerability rating is 1.
Conflict Rating 2
• Ceasefire armed group (KNU) influential in small parts of the sub-basin (medium)
• Zero estimated battle deaths 1989-2015 (very low)
• Zero 2012-2016 media-reported armed conflict incidents (very low)
• Four estimated historical conflict-related displaced people (very low)
184
4.8.3 Tanintharyi Coastal Basins Other
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
5 3 4 2 4
Overview
Other Tanintharyi is the 5th largest sub-
basin and spans several states in the
southern branch of Myanmar. It borders
Thailand and outlets to the Andaman
Sea.
Area: 26,019 km2
Average rainfall: 3,615 mm
Average sub-basin outflow: 244.85 m3/s
Topography:
% cover of sub-
Type
basin
Slopes 3-10
0%
Hard rock
Slopes 3-10 soft
75%
rock
Slopes<3
6%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10 hard
19%
rock
Slopes>10
0%
intermed rock
Population: 1,448,724
Ethnic diversity: Karen, Mon (Talaing), Selung
Economic activities:
Socio-economic + Mining area: 15.1 km2 (covers 0.06% of sub-basin)
+ Navigable waterways: None
+ Land use: N/A
States/Regions: Kayin, Mon, Tanintharyi
Administrative: Major town/s: Bokpyin, Dawei, Kawthoung, Myeik, Ye
185
Existing: 0
Under Construction: 0
Status of hydropower Planned: 0
development Identified potential site: 0
Geomorphology and sediment Rating 5
• This “Other” Tanintharyi sub-basin is a very large area (93rd percentile)
composed of a number of small tributaries that drain the coastal range
and discharge directly to the sea;
• Although each individual catchment may be small, collectively they
contribute the majority of the Tanintharyi “basin”;
• The high rainfall results in high runoff, with moderate sediment loads
projected;
• The undeveloped nature of the sub-basins, combined with large size and
high rainfall result in a very high geomorphic rating.
Aquatic ecology and fisheries Ecological Value rating 3
Human Pressure rating 3
• The Tanintharyi coastal basin rivers are short medium
sized rivers rising in the ridge between the sea and the main
Thanintharyi river valley. There is one large river, Tavoy
discharging into its estuary at Dawei. Collectively all the
coastal rivers have 10 river reach types of which 4 are rare
covering about 7% of the reach lengths, and about 8%
reaches in karst region at low elevation.
• The predominant reach type in the Tavoy river is Large
river, in moist broadleaf forest region at low
elevation, with floodplains. Of the medium-sized rivers
the predominant reach types are Medium river, in moist
broadleaf forest region at low elevation, with low gradient,
and with floodplains.
• The mean annual flow from the Tavoy river is 345 m3/sec
with a minimum flow of 15 m3/sec
• The Tavoy river contains some threatened species of fish
and other aquatic organisms, but it is unlikely that the
smaller rivers will contain such species. However,
the rivers are discharging into an ecologically
sensitive marine environment. These are
recognised as coastal and mangrove KBAs
including the Myeik Archipelago and Moscos Kyun.
• In the southern part one of the larger coastal rivers is the Leyna
river, which is known to have high fish diversity including
endemic species. The Leyna KBA reflects this.
• Human pressures are higher than in the Tanintharyi river, mainly
because of population density in the coastal zone and higher
agricultural activity and road density. No hydropower dams are
planned in this coastal basin.
186
Terrestrial Biodiversity Rating 4
The Tanintharyi other sub-basin
contains 46% KBA and 45% intact
forest. Similarly, to other large sub-
basins, there are numerous KBAs that
provide habitats for various species of
birds, mammals, and aquatic flora and
fauna including coral reefs, sharks, and
dugongs. Three protected areas make up
approximately 5% of the sub-basin: the
Moscos Kyun Wildlife Sanctuary, the
Lampi Island Marine National Park, and
the Thanintharyi Nature Reserve.
Another 5% of the sub-basin was
composed of the critically endangered
coastal mangrove ecoregion in the past
as well.
Social, livelihoods, and significant sites Rating 2
In the Tanintharyi Other Coastal sub-basin’s Townships, own account workers indicating livelihood
dependence on agriculture and natural resources comprise on average 21% of the workforce. Female-headed
households, which indicate social vulnerability accounts for 27% of the households on average. The average
percentage of HHs owning a TV, as a proxy for poverty levels, is 49%. The ethnic minority groups in the
sub-basin are Karen, Mon (Talaing), and Selung. On this basis, the sub-basin vulnerability rating is 2.
Conflict Rating 4
• Ceasefire armed group (KNU) influential in small parts of the sub-basin (low)
• 95 estimated battle deaths 1989-2015 (high)
• Five 2012-2016 media-reported armed conflict incidents (high)
• 86,576 estimated historical conflict-related displaced people (very high)
187
4.9 Rakhine Coastal Basins
4.9.1 Kaladan
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
5 4 2 3 4
Overview
Kaladan is a medium to large-sized
sub-basin located in the Chin and
Rakhine states in the western part of
Myanmar.
Area: 13,618 km2
Average rainfall: 2,665 mm
Average sub-basin outflow: N/A
Topography:
% cover of
Type
sub-basin
Slopes 3-10
0%
Hard rock
Slopes 3-10
5%
soft rock
Slopes<3
4%
Elev<30m
Slopes<3
2%
Elev>30m
Slopes>10
0%
hard rock
Slopes>10
89%
intermed rock
Population: 320,527
Ethnic diversity: Chini, Lushei
Economic activities:
Socio-economic + Mining area: No
+ Navigable waterways: 92.5 km
+ Land use: N/A
States/Regions: Chin, Rakhine
Administrative: Major town/s: Paletwa, Kyauktaw, Rezua, Rihkhawdar, Thantlang
188
Existing: 0
Under Construction: 0
Status of hydropower Planned: 0
development Identified potential site: 1 (Mi Chaung – 200 MW)
Geomorphology and sediment Rating 5
• The Kaladan is a large sub-basin (65th percentile) and the largest
individual tributary in the Rakhine “basin”, with a Strahler Order 2
mainstem;
• It flows from the steep mountains in the Arakan range delivering
sediment to the Rakhine coast;
• It is considered in very good geomorphic condition similar to the other
intact sub-basins in this area.
Aquatic ecology and fisheries Ecological Value rating 4
Human Pressure rating 3
• The Kaladan river rises in the Chin hills and
flows south west and into its delta and estuary
at Sitwe. The Chin Hills have a karst
limestone area and it is expected that the river
reach types in the upper part of the sub-basin
will be similar to the Manipur river. In the
lower part the Kaladan river will probably
consist of large and medium rivers in moist
broadleaf forest region at low elevation. When
the river reaches the floodplain area it
broadens and forms islands and multiple
channels.
• The Kaladan river (similar to the Manipur
river) is expected to be an area of endemism
for fish and other aquatic organisms. There is
the Mouth of the Kaladan river marine KBA, which
is important for water birds, cranes, dolphins and
crabs, and the Kaladan river itself has been
recognised as a riverine KBA
• Human pressures on the aquatic ecology
are focussed on the floodplain area with high
189
population density and agriculture.
• One hydropower project has been identified – Mi Chaung HPP (200 MW).
Terrestrial Biodiversity Rating 2
The Kaladan sub-basin is moderately
covered with KBA (18%) and intact
forest (29%). The KBA is a habitat for
elephants and is an important trans-
boundary wildlife corridor. Many
endemic species of fish reside in this
sub-basin as well. Although it only
makes up a small portion of the total
area (<1%), the Kyaukpantaung
Wildlife Sanctuary is in the sub-basin as
well.
Social, livelihoods, and significant sites Rating 3
In the Kaladan sub-basin’s Townships, own account workers indicating livelihood dependence on agriculture
and natural resources comprise on average 22% of the workforce. Female-headed households, which indicate
social vulnerability accounts for 21% of the households on average. The average percentage of HHs owning a
TV, as a proxy for poverty levels, is 20%. The ethnic minority groups in the sub-basin are Chini and Lushei.
On this basis, the sub-basin vulnerability rating is 3.
Conflict Rating 5
• Multiple armed group influential in less than half of the sub-basin (medium)
• 16 estimated battle deaths 1989-2015 (low)
• 11 2012-2016 media-reported armed conflict incidents (very high)
• 4732 estimated historical conflict-related displaced people (high)
• These ratings were calculated before the intense violence and displacement close to this region in
2017. The vulnerability has been upgraded to 5.
190
4.9.2 Saing Din Creek
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
1 2 3 2 3
Overview
Saing Din Creek is a small sub-basin
located in the Rakhine state in the
western region of Myanmar and shares
a border with Bangladesh.
Area: 2,331 km2
Average rainfall: 4,428 mm
Average sub-basin outflow: N/A
Topography:
% cover of
Type
sub-basin
Slopes 3-10
0%
Hard rock
Slopes 3-10
95%
soft rock
Slopes<3
5%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10
0%
hard rock
Slopes>10
0%
intermed rock
Population: 55,545
Ethnic diversity: Mru, Chin (Mro-Khimi),
Economic activities:
Socio-economic
+ Mining area: No
+ Navigable waterways: 74.4 km
+ Land use: N/A
States/Regions: Chin, Rakhine
Administrative: Major town/s: Buthidaung
191
Existing: 0
Under Construction: 0
Status of hydropower Planned: 0
development Identified potential site: 1 (Saing Din – 76.5 MW)
Geomorphology and sediment Rating 1 (5)
• The Saing Din Creek sub-basin is very small (16th percentile) with a
low Strahler Order river;
• The sub-basin includes the undulating hills in the Rakhine Coastal
area;
• The small sub-basin has low geomorphology indicators owning to
the low flow and sediment potential and low Strahler Order;
• Like the other small Rakhine sub-basins, the low rating is
predominantly attributable to the very small size of the sub-basin
compared to other sub-basins in the Rakhine and elsewhere.
Aquatic ecology and fisheries Ecological Value rating 2
Human Pressure rating 3
• The sub-basin where the Saing Din HPP has been identified, is a small sub-basin flowing parallel to
the coastline between two low ridges in a wide floodplain some 10 – 15 km wide. The river itself
rises in Bangladesh.
• In Myanmar, the river is expected to be a Large river, in moist broadleaf forest region at low
elevation, with floodplains.
• Three coastal KBAs are located near the mouth of the river, May Yu, Nantha Island and Oyster
Island KBASs
• Human pressures on this sub-basin are moderate with high population density in the flood plain area
and agricultural intensity, but little mining activity.
• The Saing Din HPP (75 MW) has been identified on the Saing Din Creek which is a tributary of the
main river, rising in the hills to the east of the sub-basin
Terrestrial Biodiversity Rating 3
192
The Saing Din Creek sub-basin
contains significant regions of KBA
(61%), but little intact forest (11%)
cover. The KBA in the sub-basin is a
habitat for elephants and includes the
Northern Yakhine forest complex, an
important trans-boundary wildlife
corridor.
Social, livelihoods, and significant sites Rating 2
In the Saing Din Creek sub-basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 19% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 22% of the households on average. The average percentage
of HHs owning a TV, as a proxy for poverty levels, is 24%. The ethnic minority groups in the sub-basin are
Mru and Chin (Mro-Khimi). On this basis, the sub-basin vulnerability rating is 2.
Conflict Rating 5
• Armed group influence in some of the sub-basin (medium)
• 29 estimated battle deaths 1989-2015 (medium)
• Two 2012-2016 media-reported armed conflict incidents (low)
• 614 estimated historical conflict-related displaced people (medium)
• These ratings were calculated before violence and displacement in this region in 2017. The
vulnerability has been upgraded to 5.
193
4.9.3 Lemro
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
5 3 3 3 2
Baseline Value Ratings
Lemro is a medium-sized sub-basin
located in the Chin and Rakhine
states in the western region of
Myanmar.
Area: 9,955 km2
Average rainfall: 2,750 mm
Average sub-basin outflow: N/A
Topography:
% cover of
Type
sub-basin
Slopes 3-10
0%
Hard rock
Slopes 3-10
6%
soft rock
Slopes<3
5%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10
0%
hard rock
Slopes>10
89%
intermed rock
Population: 410,189
Ethnic diversity: Chini
Economic activities:
Socio-economic + Mining area: No
+ Navigable waterways: None
+ Land use: N/A
States/Regions: Chin, Magway, Rakhine
Administrative:
Major town/s: Mynbya
194
Existing: 0
Under Construction: 0
Status of hydropower Planned: 2 (Lemro 1 – 600 MW, Lemro 2 – 90 MW)
development Identified potential site: 0
Geomorphology and sediment Rating 5
• The Lemro is a medium sized (56th percentile) sub-basin that lies
predominantly within the Arakan ranges and discharges to the Rakhine
coastal strip;
• The river basin structurally controlled and generally trends in a north
south pattern. The large basin is relatively undeveloped, has a Strahler
Order of 3, and very high rainfall;
• Like the “other Rakhine” sub-basin these characteristics contribute to a
high geomorphology rating of 5.
Aquatic ecology and fisheries Ecological Value rating 3
Human Pressure rating 3
• The Lemro river rises in the norther Rakhine Yoma and flows south joining the Kaladan at its estuary
at Sitwe. The predominant river reach types are probably large and medium rivers in moist broadleaf
forest region at low elevation. In the hills, the river tends to be narrow and fast flowing but when it
reaches the coastal plain, it widens within a floodplain with islands and multiple channels.
• The Lemro river is expected to have endemic species of fish, and an assemblage of fish species that
are different from the Chindwin tributaries to the east. It has one terrestrial KBA – Min Byar KBA in
the centre of the sub-basin.
• The Lemro has moderate human pressures with high rural population in the coastal plain, but lower
in the hills, with extensive agriculture in the coastal plain.
• Two hydropower projects are planned Lemro 1 (600 MW) and Lemro 2 (90 MW)
195
Terrestrial Biodiversity Rating 3
196
With over 40% of the Lemro sub-basin
composed of KBA and nearly 40%
composed of intact forest, it has
considerable biodiversity value. The
KBA is a habitat for land and marine
fauna including bears, leopards, crabs,
and more. Natmataung National Park
is a protected located in the sub-basin
that makes up around 2% of the total
area.
Social, livelihoods, and significant sites Rating 3
In the Lemro sub-basin’s Townships, own account workers indicating livelihood dependence on agriculture
and natural resources comprise on average 14% of the workforce. Female-headed households, which indicate
social vulnerability accounts for 24% of the households on average. The average percentage of HHs owning a
TV, as a proxy for poverty levels, is 20%. The ethnic minority group in the sub-basin is Chini. On this basis,
the sub-basin vulnerability rating is 3.
Conflict Rating 4
• Some armed group influence in some of the sub-basin (low)
• 9 estimated battle deaths 1989-2015 (very low)
• Zero 2012-2016 media-reported armed conflict incidents (very low)
• 6185 estimated historical conflict-related displaced people (high)
• These ratings were calculated prior to violence and displacement close to this region in 2017. The
vulnerability has been upgraded to 4.
197
4.9.4 Thatay
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
1 4 4 N/A 1
Overview
Thatay is one of the smaller sub-basins
and falls within the Bago and Rakhine
regions in the western part of
Myanmar.
Area: 1,289 km2
Average rainfall: 2,545 mm
Average sub-basin outflow: N/A
Topography:
% cover of sub-
Type
basin
Slopes 3-10
0%
Hard rock
Slopes 3-10
0%
soft rock
Slopes<3
1%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10
0%
hard rock
Slopes>10
99%
intermed rock
Population: 10,943
Ethnic diversity: Chin (Asho)
Economic activities:
Socio-economic + Mining area: No
+ Navigable waterways: None
+ Land use: N/A
States/Regions: Ayeyarwady, Bago, Rakhine
Administrative: Major town/s:
198
Existing: 0
Under Construction: 1 (Thahtay – 111 MW)
Status of hydropower Planned: 0
development Identified potential site: 0
Geomorphology and sediment Rating 1
• The Thatay is a very small sub-basin (12th percentile) in the southern
Rakhine;
• The river emerges from the steep Arakan mountains and discharges
via a very narrow coastal strip;
• The sub-basin receives high rainfall, and has a high sediment input,
but a hydropower development near the mouth of the river has
regulated has broken the connectivity between the coast and >90% of
the catchment area;
• The small size and high degree of regulation contribute to the low
geomorphic rating.
Aquatic ecology and fisheries Ecological Value 4
rating
Human Pressure rating 3
• The Thatay river is a small river in the southern part of the
Rakhine coastal basin, about 20 km north from Thandwe. The
river rises in the southern Rakhine Yoma, and it is probable that
the upper reaches flow through a karst limestone area, while the
lower reaches are likely to be Large river, in moist broadleaf
forest region at low elevation, with floodplains. It has a relatively
short floodplain before forming a multiple channel estuary with
islands near Shwehle.
• Rising in the Eastern Rakhine Yoma KBA and Rakhine Yoma
Elephant Range, it is expected to have high aquatic biodiversity,
including endemic fish and turtles. It will have a different
assemblage of fish species compared to rivers such as the Man
Chaung on the other side of the Rakhine Yoma.
• Human pressures are moderate, with relatively high populations
density in the lower reaches and agriculture intensity, but low
mining activity.
• The Thatay HPP (111 MW) is under construction, though currently stalled. It is located at the point
before the river emerges from the hills into the floodplains.
199
Terrestrial Biodiversity Rating 4
The Thatay sub-basin is composed
mostly of KBA (89%) along with
moderate intact forest (37%) cover. The
KBA in the region is an important
habitat for endemic birds including the
spoon-billed sand piper. The Rakhine
Yoma Elephant Range is a protected
area that encompasses 21% of the sub-
basin and in the past another 1% of it
contained the critically endangered
coastal mangrove ecoregion.
Social, livelihoods, and significant sites Rating N/A
The ethnic minority groups in the sub-basin are Chin (Asho)
Conflict Rating 1
• No or low armed group presence (very low)
• Zero estimated battle deaths 1989-2015 (very low)
• Zero 2012-2016 media-reported armed conflict incidents (very low)
• Zero estimated historical conflict-related displaced people (very low)
200
4.9.5 Than Dwe
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
1 2 4 1 1
Overview
Than Dwe is one of the smaller sub-
basins and falls within the Rakhine
state in the western region of
Myanmar.
Area: 1,359 km2
Average rainfall: 3,093 mm
Average sub-basin outflow: N/A
Topography:
% cover of
Type
sub-basin
Slopes 3-10
0%
Hard rock
Slopes 3-10
43%
soft rock
Slopes<3
0%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10
0%
hard rock
Slopes>10
57%
intermed rock
Population: 38,34
Ethnic diversity: Chini
Economic activities:
Socio-economic + Mining area: No
+ Navigable waterways: None
+ Land use: N/A
States/Regions: Ayeyarwady, Rakhine
Administrative: Major town/s: Thandwe
201
Existing: 0
Under Construction: 0
Status of hydropower Planned: 0
development Identified potential site: 1 (Than Dwe – 39 MW)
Geomorphology and sediment Rating 1 (5)
• The Than Dwe sub-basin, targeted for hydropower development, is a
very small catchment (14th percentile) with a low order mainstem
(Strahler Order -= 1)
• The catchment includes a large area of the gently sloping coastal hills
as well as draining the steep Rakhine coastal ranges;
• It receives high rainfall, but due to its very small size and low Order
river it has a low geomorphology rating;
• If it was included within the “Other Rakhine” sub-basin it would not
alter the “5” score of the other catchment. The low rating indicates it
has low geomorphic value on a basin or national scale, largely due to
its very small size.
Aquatic ecology and fisheries Ecological Value rating 2
Human Pressure rating 2
• The sub-basin where the Than Dwe HPP has been
identified is a small sub-basin just south of the Thathay
river. The river rises in the southern Rakhine Yoma, and
it is probable that the upper reaches flow through a karst
limestone area, while the lower reaches are likely to be
Large river, in moist broadleaf forest region at low
elevation, with floodplains and sediment.
• Rising in the Eastern Rakhine Yoma KBA and Rakhine
Yoma Elephant Range, it is expected to have high
aquatic biodiversity, including endemic fish and turtles.
It will have a different assemblage of fish species
compared to rivers such as the Man Chaung on the other
side of the Rakhine Yoma.
• Human pressures are moderate, with relatively high
populations density in the lower reaches and agriculture
intensity, but low mining activity. The town of Thandwe
lies on both banks of the river about 18 km
from the estuary, and the river valley is
well populated and cultivated.
• One hydropower project has been
identified for this river basin – Thandwe
(39 MW) but the location is not available.
Terrestrial Biodiversity Rating 4
202
The Than Dwe sub-basin contains
significant KBA (73%) and notable
intact forest (44%) cover as well. The
KBA in the region is an important
habitat for elephants, sun bears, and
white handed gibbons. The Rakhine
Yoma Elephant Range is a protected
area that encompasses 32% of the
sub-basin and in the past another 3%
of it contained the critically
endangered coastal mangrove
ecoregion.
Social, livelihoods, and significant sites Rating 1
In the Than Dwe sub-basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 22% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 19% of the households on average. The average percentage of
HHs owning a TV, as a proxy for poverty levels, is 38%. The ethnic minority groups in the sub-basin are
Chini. On this basis, the sub-basin vulnerability rating is 1
Conflict Rating 1
• No or low armed group presence (very low)
• One estimated battle deaths 1989-2015 (very low)
• Zero 2012-2016 media-reported armed conflict incidents (very low)
• Zero estimated historical conflict-related displaced people (very low)
203
4.9.6 Kyein Ta Li
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
1 2 4 N/A 1
Overview
Kyein Ta Li is the fifth smallest sub-
basin and is in the Rakhine state in
the southwestern region of Myanmar.
Area: 1,061 km2
Average rainfall: 3,027 mm
Average sub-basin outflow: N/A
Topography:
% cover of
Type
sub-basin
Slopes 3-10
0%
Hard rock
Slopes 3-10
32%
soft rock
Slopes<3
0%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10
0%
hard rock
Slopes>10
68%
intermed rock
Population: 9,842
Ethnic diversity: Chin, Asho
Economic activities:
Socio-economic + Mining area: No
+ Navigable waterways: None
+ Land use: N/A
States/Regions: Ayeyarwady, Rakhine
Administrative: Major town/s:
204
Existing: 0
Under Construction: 0
Status of hydropower Planned: 0
development Identified potential site: 1 (Kyein Ta Li – 28 MW)
Geomorphology and sediment Rating 1 (5)
• This very small sub-basin (7th percentile) is very similar to the Than Dwe,
in its size and because it is targeted for potential hydropower development;
• Compared to the large sub-basins in the Rakhine and rest of Myanmar, it
has low geomorphic significance, due to its small size and low Strahler
Order tributary
Aquatic ecology and fisheries Ecological Value rating 2
Human Pressure rating 2
• The sub-basin where the Kyein Ta Li HPP has been
identified is a small sub-basin just south of the
Thandwe river. The river rises in the southern Rakhine
Yoma, and it is probable that the upper reaches flow
through moist broadleaf region with low and high
gradients, while the lower reaches are likely to be
Large river, in moist broadleaf forest region at low
elevation, with floodplains and sediment. It flows into
a very complex delta area with many channels and
alluvial deposits, before reaching the sea
• Rising in the Rakhine Yoma Elephant Range, it is
expected to have high aquatic biodiversity, including
endemic fish and turtles. It will have a different
assemblage of fish species compared to rivers such as
the Man Chaung on the other side of the Rakhine
Yoma.
• Human pressures are moderate, with relatively high
populations density in the lower reaches and
agriculture intensity, but low mining activity.
• One hydropower project has been identified for this
river basin – Kyein Ta Li HPP (28 MW) but the location is not available.
Terrestrial Biodiversity Rating 4
205
The Kyein Ta Li sub-basin is small, but still
an important area in the context of
biodiversity. Over 84% of the sub-basin is
composed of KBA that provides a habitat for
Dugongs, which is considered a vulnerable
species. Intact forest makes up more than
32% of the sub-basin, and over 70% is a
protected area known as the Rakhine Yoma
Elephant Range. There is also a small
presence (1%) of the critically endangered
coastal mangrove ecoregion.
Social, livelihoods, and significant sites Rating N/A
The ethnic minority groups in the sub-basin are Chin and Asho.
Conflict Rating 1
• No or low armed group presence (very low)
• Zero estimated battle deaths 1989-2015 (very low)
• Zero 2012-2016 media-reported armed conflict incidents (very low)
• Zero estimated historical conflict-related displaced people (very low)
206
4.9.7 Rakhine Coastal Basins Other
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social and
ecology and Conflict
and sediment Biodiversity livelihoods
fisheries
5 2 3 3 4
Overview
Rakhine Other is the 6th largest sub-
basin and spans several states in the
western-most region of Myanmar. It
shares a border with Bangladesh and
outlets to the Andaman Sea.
Area: 25,796 km2
Average rainfall: 3,679 mm
Average sub-basin outflow: N/A
Topography:
% cover of
Type
sub-basin
Slopes 3-10
0%
Hard rock
Slopes 3-10 soft
47%
rock
Slopes<3
26%
Elev<30m
Slopes<3
0%
Elev>30m
Slopes>10 hard
0%
rock
Slopes>10
27%
intermed rock
Population: 1,377,840
Ethnic diversity: Chini
Economic activities:
Socio-economic + Mining area: 0.1 km2
+ Navigable waterways: None
+ Land use: N/A
States/Regions: Ayeyarwady, Bago, Chin, Magway, Rakhine
Administrative: Major town/s: Ann, Mrauk, Munaung, Myebon, Ramree, Sittwe
207
Existing: 0
Under Construction: 0
Status of hydropower Planned: 0
development Identified potential site: 0
Geomorphology and sediment Rating 5
• This sub-basin consists of a group of coastal tributaries that
collectively occupy a very large area (91st percentile) and have
numerous Strahler Order 3 rivers;
• The catchments drain the steeply sloping “soft” Western Ranges and
then spill out onto a low lying coastal complex;
• The coastal areas receive very high rainfall, and all of these factors:
size, good connectivity, high sediment and flow input combine for a
geomorphology rating of 5.
Aquatic ecology and fisheries Ecological Value rating 2
Human Pressure rating 2
• The Rakhine coastal basins are defined by the narrow coastal plain which rises steeply to the east into
the Rakhine Yoma, which separates this basin from the Ayeyarwady and Chindwin basins. They fall
into the Chin Hills-Arakan Yoma montane forests ecoregion. The area experiences very heavy
rainfall during the monsoon because the hills create a rain shadow in the central dry Zone. As a
result, the rivers have a more marked difference in flows between wet and dry seasons, with very
large flows in wet season and low flows in dry season.
• Apart from the sub-basins described separately, the relatively short rivers all rise in the Arakan
• mountains and flow westwards towards the sea and often create well defined estuaries and small
deltas which lead to important island complexes, mangrove areas and sea grass beds.
• The Rakhine Yoma and the rivers flowing from it is a recognised area for endemic fish and other
aquatic species. The Chin hills and the lower Rakhine Yoma are also hotspots for endangered and
vulnerable fish species, and rare turtle species.
• There are many aquatic KBAs in the area, including the May Yu and Kaladan River estuary in the
north, and many of the coastal areas and islands have proposed marine KBAs which are often
associated with the estuaries of the rivers.
• Human pressure is largely due to high rural populations and moderately intensive agriculture. Loss of
forest cover has occurred in the lower parts of the basin, but the hills have relatively good forest
cover.
208
Terrestrial Biodiversity Rating 3
The Other Rakhine sub-basin contains
58% KBA and 20% intact forest. The
KBA in this sub-basin is a habitat for
numerous species, including various birds,
mammals, marine fauna, and even marine
flora such as coral and sea grass. Nearly
1% of the sub-basin is composed of the
Rakhine Yoma Elephant Range. Further,
over 15% was made of the critically
endangered coast mangrove ecoregion
before human development impacted the
region.
Social, livelihoods, and significant sites Rating 3
209
In the Other Rakhine Coastal Basin’s Townships, own account workers indicating livelihood dependence on
agriculture and natural resources comprise on average 21% of the workforce. Female-headed households,
which indicate social vulnerability accounts for 23% of the households on average. The average percentage of
HHs owning a TV, as a proxy for poverty levels, is 22%. The ethnic minority groups in the sub-basin are
Chini. On this basis, the sub-basin vulnerability rating is 3.
Conflict Rating 5
• Low armed group influence in some of the sub-basin (very low)
• 61 estimated battle deaths 1989-2015 (medium)
• 13 2012-2016 media-reported armed conflict incidents (very high)
• 125,081 estimated historical conflict-related displaced people (very high)
• These ratings were calculated before the violence and displacement in this region in 2017. The
vulnerability has been upgraded to 5.
210
4.10 Surma-Meghna Basin
4.10.1 Barak
Baseline value ratings
Aquatic
Geomorphology Terrestrial Social &
ecology & Conflict
& sediment biodiversity livelihoods
fisheries
1 3 2 N/A 1
Overview
Sub-basin size = third-smallest in Myanmar
Location = Chin State, western Myanmar, bordering India
Part of the Surma-Meghna basin
Topography:
Type % cover of sub-basin
Slopes>10 intermed rock 100%
Physical Area: 792 km2
211
Average rainfall: N/A
Average outflow: N/A
Minimum outflow: N/A
Population: N/A
Ethnic diversity: Chin (Tedim), Chin (Mizo)
Economic activities:
Socio-economic + Land use: N/A
+ Mining area: No
+ Navigable waterways: None
States/Regions: Chin
Administration
Major town/s: Tedim
Existing: 0
Hydropower Under Construction: 0
development Planned: 0
Identified potential site: 0
Geomorphology and sediment Rating 1
Sub-basin size: very small (4th percentile; maximum Strahler Order 2)
• Located entirely in the Western Ranges and characterized by
elevated steep slopes underlain by erodible material and high
rainfall.
• Drains north-west out of Myanmar into the Surma river.
• Generally forested but there are denuded areas and evidence of land
slips in satellite images.
• The area likely produces a large volume of sediment, which
ultimately flows to the Brahmaputra Delta via the Meghna River.
Aquatic ecology and fisheries Ecological value rating 4
Human pressure rating 2
212
• This sub-basin is a small part of the wider Barak catchment, south of the Manipur sub-basin
and bordering Myanmar and India.
• The adjoining Manipur river system has a high degree of fish biodiversity; the Barak may
have high endemicity with different endemic fish species as it flows into a different river
system.
• One of the tributaries of the Surma-Meghna river system; no information is available on the
river reach types or flows.
• The Barak rises in the hills, which are generally forested. However, the valleys are populated
and intensely cultivated with terraced field systems.
Terrestrial biodiversity Rating 2
213
Intact forest cover = 34%
KBA = <1%
Protected area = 0%
Critically endangered ecoregions =
0%
• A large area of intact
forest, particularly around the
eastern border, which is the primary
justification for the biodiversity
score.
Social, livelihoods, and significant sites Rating N/A
No Census 2014 data were available for the Barak sub-basin.
Conflict Rating 1
Armed group presence = none to very low
Est. battle deaths (1989-2015) = 0
Media-reported armed conflict incidents (2012-2016) = 0
Historical conflict-related displaced people (est.) = 0
214
REFERENCES
ADB, 2016, Myanmar transport sector policy note: Rural roads and access. Mandaluyong City, the
Philippines: Asian Development Bank, 2016.
Bhagwat, T., A. Hess, N. Horning, Thiri Khaing, Zaw Min Thein, Kyaw Moe Aung, Kyaw Htet
Aung, Paing Phyo, Ye Lin Tun, Aung Htat Oo, A. Neil, Win Myo Thu, M. Songer, K. LaJeunesse
Connette, A. Bernd, G. Connette, P. Leimgruber, 2016. Losing a Jewel—Rapid Declines in
Myanmar’s Intact Forests from 2002-2014.
BirdLife International (2017) The World Database of Key Biodiversity Areas. Developed by the Key
Biodiversity Areas Partnership: BirdLife International, IUCN, Amphibian Survival Alliance,
Conservation International, Critical Ecosystem Partnership Fund, Global Environment Facility,
Global Wildlife Conservation, NatureServe, Royal Society for the Protection of Birds, World Wildlife
Fund and Wildlife Conservation Society.
Connette, L. Et al, 2016, Assessment of Mining Extent and Expansion in Myanmar Based on Freely-
Available Satellite Imagery
G. Pegram, Y. Li, T. Le. Quesne, R. Speed, J. Li, and F. Shen. 2013. River basin planning: Principles,
procedures and approaches for strategic basin planning. Paris, UNESCO.
Grill, G. a. (2016). Hydropower development options and their environmental impact in the Greater
Mekong Region for different energy development scenarios. WWF - Greater Mekong Programme.
IFC, MOEE and MONREC, Strategic Environmental Assessment (SEA) of the Hydropower Sector:
Baseline Assessment Reports. Yangon and Nay Pyi Taw, Myanmar, 2017.
IUCN 2017. The IUCN Red List of Threatened Species. Version 2016-3, www.iucnredlist.org>,
downloaded 1 July 2017
Lehner, B. a. (2014). River reach classification for the Greater Mekong Region. WWF Greater
Mekong.
Myanmar Forest Cover Change (2002-2014) data: ftp://glcf.umd.edu/glcf/Myanmar_ForestChange/
Myanmar Key Biodiveristy Areas 2017, Myanamr Biodiveristy,
, downloaded 1
June 2017
Myanmar Peace Monitor 2017, , visited 9 September 2017
Ramsar Convention. (Downloaded April 2017). http://www.ramsar.org/wetland/myanmar
UNESCO 2017, World Heritage Sites, < https://aseanup.com/unesco-world-heritage-sites-myanmar/>
visited 8 August 2018
WWF 2017b. Southeastern Asia: China, Laos, Myanmar, Thailand, and Vietnam. Ecoregions.
URL: https://www.worldwildlife.org/ecoregions/im0137
WWF, 2017a. HydroSHEDs, , visited 10 August
2017
215
IFC Myanmar Country Office:
No. 57, Pyay Road,
6 ½ miles, Hlaing Township
Yangon
www.ifc.org/hydroadvisory
216