NATURAL RESOURCES CONSERVATION AND LIVELIHOODS
IN THE TONLE SAP BASIN
Water Resources and Environmental Management Specialist
This paper discusses the natural resources conservation and livelihoods. The natural
resources are critical to livelihoods of people living in the Tonle Sap Basin. The
interactions between natural resources and development activities have been elaborated
to show potential effects on the resources in the basin. Efforts by a number of institutions,
both national and international, are simultaneously discussed in the paper. It is a great
effort that integrated water resources management be integrated into national policy and
Keywords: Natural Resources Conservation, Livelihoods, poverty, Integrated Water
Resources Management, and water flow.
The Tonle Sap is the most important inland aquatic environment in Southeast Asia. It
forms a natural floodplain reservoir in the depression of the Cambodian plain. It consists
of twelve main tributaries forming sub-basins, and is drained by the Tonle Sap River into
the Mekong River near Phnom Penh. The Tonle Sap Basin, defined as the catchment
area of the Tonle Sap River at its confluence with the Mekong River, has an area of
85,000 km2, of which 80,000 km2 lies within Cambodia.
The annual flow of the Mekong waters into the Lake basin during the wet season raises
the Lake‟s water level from less than 2 m in the dry season, to deeper than 14 m at peak
flood. By late May, when the water level of the Mekong downstream of Tonle Sap
reaches a sufficient height of 9 m it starts to push water back upstream, thus reversing the
flow in the Tonle Sap River. This results in an accumulation of nutrient rich water from
upstream Mekong River sources covering the wetlands and flood plain and increasing the
water volume from 1.3 billion m3 to 70 billion m3. By October, the water level in the
Mekong River subsides and flow in the Tonle Sap empties into the Mekong delta.
However, when the level of the Mekong River is high the flow of the Tonle Sap River is
reversed and nutrient-rich water is pushed into the lake, raising its level by up to 10 m
and increasing its area from 2,500 km2 to 15,000 km2. This unusual hydrological cycle
and the vast area of seasonally flooded low forest and shrubs that it creates, in
conjunction with high temperatures, drives a very high biodiversity of fish, reptile, bird,
mammal, and plant species.
Another important consequence of the hydrology of the basin, is that, strictly
(hydrologically) speaking, the basin boundaries are those of the entire Mekong upstream
of Phnom Penh (the confluence of the Mekong and the Tonle Sap Rivers).
The lake supports a very large human population through its enormous fisheries
productivity and provides the last refuge for some of Asia‟s most globally significant
biodiversity. Additionally, the flooded areas offer breeding grounds and refuge areas for
fish that subsequently migrate back to the Mekong River, providing thereby a regionally
2. Geography and Population
The Tonle Sap Basin (TSB) within Cambodia, covers an area of approximately 80,000
km2. Eight provinces and one city share the basin, namely Kampong Chhnang,
Battambang, Pousat, Kampong Thom, Siem Reap, Banteay Meanchey, Preah Vihear,
Otdor Meanchey, and Pailin City. Main tributaries connecting to the Great Lake include
Stung Baribo, Stung Pousat, Stung Dauntry, Stung Sang Kae, Stung Battambang, Stung
Mongkul Borei, Stung Sisophon, Stung Sraeng, Stung Siem Reab, Stung Chikraeng,
Stung Staung, Stung Saen, and Stung Chinit (Table 1).
* TABLE 1 HERE *
The total population of the Tonle Sap Basin is approximately 4,198,096 in 2004 (Seila
Programme, 2004). The population density of the eight provinces and one city ranges
from 23 to 91 persons per km2 in 2004. The population density in Battambang and Siem
Reap province is higher than in the other provinces (Figure 1).
* FIGURE 1 HERE *
The reality of poverty is complex, but it is generally defined to be multidimensional
deprivation. The dimensions include low income and consumption; a lack of physical
necessities and assets; a lack of access to basic services; isolation; vulnerability to shocks
and a lack of means to cope with shock-induced losses; and powerlessness (RGC, 2001).
Half of the villages have 40–60% of households below the poverty line, with a peak of
80% in some areas (ADB, 2005). Many households have no landholdings and are entirely
dependent on fishing and foraging, with access to fishing areas often under dispute.
Percentage of poor in 2000 varies from village to village and province to province
between 0.4% and 52.6% (Figure 2).
* FIGURE 2 HERE *
3. Natural Resources and Livelihoods
3.1. Water Resources
Cambodia is generally considered a “water-wealthy” country. In terms of its annual water
availability its gross water resources rank third in Southeast Asia. The average annual
rainfall varies across the Tonle Sap region from between 1,100 mm to 1,500 mm (Figure
3). Water inputs from the Tonle Sap watershed were estimated at (28 x 109) cubic meters
(Table 2). The estimated total volume of rainfall in Cambodia is about 426 billion m3 per
year, of which only 212.5 billion m3 (49.9 per cent) flows into water bodies. The
remainder is subject to evaporation and evapo-transpiration, and recharging of
* TABLE 2 HERE *
* FIGURE 3 HERE *
3.2. Fauna and Flora
Although deforestation in the Tonle Sap basin has been taken place, the forests are still
of importance habitats. The flooded forest of the Tonle Sap is still by far the greatest
continuous area of savannah swamp forest and inundated forest in the entire Asian
region. At least 200 species of fish, 42 species of reptiles, 225 species of birds, and 46
species of mammals within the Tonle Sap Lake have been recorded. Most People live
within the Tonle Sap region have much more benefited from the resources of the Tonle
The main livelihood in the Tonle Sap Lake Region is rice cultivation, which offers the
main source of food for the region‟s inhabitants. The rice cultivation is based on floating
and wet season rice (recession rice). The farmers do not commonly use fertilisers,
pesticides, or have irrigation and thus they are dependent on rainfall, as well as floods.
Cultivation of floating and wet season rice is heavily dependent on floods.
Total cultivated area in 2002 was approximately 939,745 hectares, accounting for 41.9%
of total cultivated area throughout the country (Figure 4). Yield per hectare ranged from
1.2 tons to 2.4 tons in 2002 (Figure 7).
* FIGURE 4 HERE *
* FIGURE 5 HERE *
* FIGURE 6 HERE *
* FIGURE 7 HERE *
The fresh water fishery is extremely important in maintaining minimum nutritional
requirements of large numbers of people. It has been recorded that the Tonle Sap alone
provides around 60% of the commercial freshwater fisheries production. However there
is evidence that the fishery yields are declining in the Tonle Sap Lake. Fisheries and the
natural aquatic habitats are under increasing pressure from alterations to flow regimes
increasing turbidity and degraded water quality. Wetlands are being filled, drained and
encroached upon. Development on the banks of rivers, increased urbanization and
industrialization, and aquaculture alter the characteristics of the habitat and the quality of
fresh water to support the population of fish (ADB, 2004). According to the NIS, the total
annual fish catch for the Tonle Sap Basin in 2002 was about 182,600 tons (Figure 8).
* FIGURE 8 HERE *
Ecotourism is at an early stage of development in the basin. Prek Toel Core area has a
significant number of globally rare species of birds and is attracting a number of
ornithologists. The site has presently attracted a number of tourists. The Tonle Sap Great
Lake landscape, the birds of Tonle Sap wetlands, and tropical forest of the Tonle Sap
have also been increasingly visited by tourists from over the world. Local communities
can further benefit from ecotourism additional to cultural sites. The ecotourism potential
is based on the conservation values of the flooded forest being maintained. Ecologically
significant sites are particularly sensitive to damage from overuse by tourists. There are
dangers from over concentration of visitors.
4. Major Threats to the Tonle Sap Basin
As mentioned above, most people living in the Tonle Sap Basin mainly depend upon rice
cultivation, which consumes large volume of water and exploitation of natural resources.
It has been indicated that incidence of poverty in the Tonle Sap Basin is higher than that
in other areas in the country. The exploitation of natural resources will therefore be
extremely increased due to the increase of population and poverty.
Major threats to the Tonle Sap are as follows: (i) poverty-driven overexploitation of
fisheries and wildlife resources; (ii) conversion of the flooded forest to agriculture; (iii)
collection of fuel wood from the flooded forest; and (iv) possibly, decrease of water flow
in the wet season.
5. Environmental and Natural Resources Management
It has been indicated that most people lives in the Tonle Sap Basin is mostly dependant
on agriculture and resource extractive activities. Nine out of 10 poor persons identify
agriculture as their main source of income. Poverty is more pronounced in rural areas
40% compared to 30% in urban areas. In fact 90% of Cambodia‟s poor are found in the
rural areas. The Tonle Sap region has the highest degree of poverty at 38%.
5.1. Institutional Framework
Below the Council of Ministers, The Cambodia National Mekong Committee (CNMC)
has a membership of ten ministries and a linkage with the regional Mekong River
Commission. CNMC's role is to advise the Government on all matters related to the
formulation of water policy, strategy, management, preservation, investigation, planning,
and restoration and the development of the water and other natural resources of the
Mekong River Basin within Cambodia. Tonle Sap Biosphere Reserve Secretariat
(TSBRS) is also under control of the CNMC, which is headed by Deputy Secretary
General of the Executive Committee (Figure 9). It has a permanent Deputy Head and is
structured into three divisions: (i) policy, strategy, and networking; (ii) research,
monitoring, and data management; and (iii) administration and training.
* FIGURE 9 HERE *
Environmental management is fallen under responsibility of the Ministry of Environment
(MOE). The MOE is empowered to develop environmental policies in the spirit of
sustainable country development and to implement the National and Regional
Environmental Action Plans in collaboration with other concerned ministries. In practice,
it is required that the MOE closely collaborate and coordinate with ministries involved.
Those ministries include Ministry of Agriculture Forests and Fisheries (MAFF), Ministry
of Water Resources and Meteorology (MOWRAM), Ministry of Industry, Mines and
Energy (MIME), Ministry of Rural Development (MRD), Ministry of Tourism (MOT),
Ministry of Interior (MOI), and Ministry of Public Works and Transport (MPWT).
In addition, the provincial and municipal departments of environment are under the direct
control of the MOE and have obligations to be responsible for implementing
environmental policy, preventing and protecting environmental pollution in cooperation
with relevant departments.
5.2. Policy, Strategy and Plans
A number of important national strategies and plans regarding the environmental
management and natural resources conservation are summarised as follows:
The National Water Resources Policy (NWRP) was formulated in 2004 aiming at
providing guidelines for efficient and effective water resources management,
socio-economic development and welfare of the population and ensuring a
The Strategic Framework for the Water Sector followed on from ADB‟s
assistance in creating the National Water Sector Profile, and supported
MOWRAM in the development of its strategy.
The National Water Resources Strategy for Cambodia was formulated more or
less contemporaneously with the Strategic Framework for the Water Sector with
the support of the World Bank through its Agricultural Productivity Improvement
The Water Sector Roadmap summarises RGC‟s goals for the water sector as a
basis for setting priorities and planning investment and development assistance. It
lists a range of indicators for three areas of „water sector outcomes‟ (water
reforms, water resources management, water service delivery) and for specific
The Rural Water Supply and Sanitation Strategy (2001 - 2011) focuses on issues
and solutions for the small scale schemes that are under the control of the
Ministry of Rural Development.
The Second Socioeconomic Development Plan, 2001 – 2005 (SEDP II) is the
Government‟s principal strategy for economic growth and poverty reduction and
includes a target to reduce the poverty headcount index from 36 to 31 percent in
order to reduce poverty by half in fifteen years.
The National Poverty Reduction Strategy 2003 –2005 (NPRS) has been prepared
using SEDPII as its key building block. In it the priority poverty reduction
actions include maintaining macroeconomic stability; improving rural livelihoods;
expanding job opportunities; improving capabilities; strengthening institutions
and improving governance; reducing vulnerability and strengthening social
inclusion; promoting gender equity; and priority focus on people.
The Rectangular Strategy 2003-2008 has good governance and implementation as
its backbone and will be announced as soon as the new government is formed.
The strategy has four pillars: (i) high economic growth and enhanced
competitiveness; (ii) job-creation; (iii) improved social equity; and (iv) increased
public sector effectiveness. The enabling environment for successful
implementation includes: (i) peace, political stability and social order; (ii)
partnership with development agencies; (iii) macroeconomic and financial
stability; and (iv) integration into the regional and world economy. The
Rectangular Strategy identifies the following as the priority sectors: (i)
agriculture; (ii) private sector development and employment; (iii) physical
infrastructure; and (iv) human resource development.
The Governance Action Plan of April 2001 (GAP) was prepared by the Council
for Administrative Reform and has as its main function the definition and
relationship of public power and authority to management and control over
societal resources. Crosscutting areas covered by GAP include public finance,
civil service reform and anti-corruption, judicial and legal system reform,
demobilization of armed forces and natural resource management. In the field of
natural resource management, issues related to land, forestry and fisheries
management are addressed as well as the social question of resource access.
The National Environmental Action Plan 1998 – 2002 (NEAP) aims to integrate
environmental concerns into economic activity and ensure future maintenance of
the functional capacities of Cambodia‟s ecosystems. NEAP adopts a
precautionary approach, concentrating on environmental protection rather than the
more difficult and costly post-impact rehabilitation. Priority areas of intervention
are forestry policy, fisheries and agriculture in the Tonle Sap, coastal fisheries
management, biodiversity conservation and protected areas, environmental
education, energy development and urban waste management.
The National Biodiversity Strategy and Action Plan NBSAP 2002 (NBSAP) was
created with a view towards integration of biodiversity conservation and
sustainable natural resource use concepts into an overall poverty reduction
strategy. NBSAP provides a framework for action at all levels that will enhance
productivity, diversity and integrity of natural resources.
5.3. Legal Framework
The Ministry of Environment (MOE) was created in September 1993 with a
responsibility to define environmental planning and actions, to oversee the environmental
impact assessment, the protection of the environment and preservation of ecological
balance, and development project monitoring and inspection in collaboration with line-
institutions and agencies. The followings are the national laws and regulations related to
environmental protection and management, and natural resources management:
Constitutional Law (1993);
Environmental Protection and Natural Resources Management Law (1996);
Fisheries Law (1987);
Forestry Management Law (1988)
Environmental Impact Assessment Process Sub-decree (1999);
Implementation of the Law on Investment Sub-decree (1997);
Water Pollution Control Sub-decree (1999);
Solid Waste Management Sub-decree (1999); and
Air Pollution and Noise Disturbance Control Sub-decree (2000).
The paper presents the natural resources conservation and livelihoods in the Tonle Sap
Basin. As mentioned above, most people living in the basin are mostly dependant on
extractions of natural resources, particularly water resource, from the basin. The natural
resources, for instance, biodiversity throughout the watershed is declining with increased
development, the destruction of habitats and the exploitation of endangered species.
Widespread deforestation, habitat encroachment, the decline in environmental quality,
and the hunting of animals for food and commercial purposes are prime contributors to
natural resources depletion. Ecotourism is also another pressure on the natural habitats
and wetlands in the basin.
The importance of effective management and sustainable exploitation of the nation's
natural resources as a vital tool in reducing poverty is becoming more widely accepted.
Recognizing the depletion of natural resources within the basin, a number of efforts made
by the MOE in collaboration with other ministries involved to suppress any activities that
are likely to deteriorate the natural resources in the basin as a whole and local
communities as a particular.
At the same time, a number of institutional arrangements and legal instruments have been
developed to successfully accomplish the goals of sustainable development and poverty
The author would like to thank H.E. Sin Niny, , who gave the author the great
opportunity to attend the International Forum on Integrated Water Resources
Management of the Mekong River Basin to be held in Chiang Rai, Thailand. Special
thanks are due to Dr. Tue Kell Nielsen for his invaluable advice and material supports.
ADB. (2002) The Tonle Sap in ADB‟s country strategies and programme. The Tonle Sap
ADB. (2005) The Tonle Sap Basin strategy. Author, Manila, p. 5.
CNMC. (2004) Sub-area analysis and development.The Tonle Sap sub-area (SA-9C).
Author, Phnom Penh, p.18.
DOFW. (2003) Forestry statistics to 2002. Author, Phnom Penh.
DOFW. (2003) Forestry statistics to 2002. Author, Phnom Penh.
DOFW. (2005) Forestry statistics to 2004. Author, Phnom Penh.
MAFF. (2002) Agricultural statistics 2001-2002. Author, Phnom Penh.
MOE. (2004) State of environment report. Author, Phnom Penh.
National Institute of Statistic. (1999) General population census of Cambodia 1998.
Final census results. Author, Phnom Penh.
National Institute of Statistic. (2003) Statistic year book. Author, Phnom Penh, pp. 6-7,
NCDP. (2004) Rapid institutional assessment, water resources (draft). pp. 20-22.
RGC. (2001) Second five-year socioeconomic development plan. Ministry of Planning,
Phnom Penh, pp. 45-46.
Wright, G., Moffatt, D., Wager, J., Yem, D., & Pang, P. (2004) Establishment of the
Tonle Sap Basin Management Organization. Author, Phnom Penh.
List of Tables
Table 1: Main Tributaries Connecting to the Tonle Sap Great Lake
No. Name Area, Km2
1 Daun Tri 3,530
2 Sangke 4,370
3 Mongkul Borei 11,350
4 Sisophon 3,120
5 Sreng 10,380
6 Siem Reap 3,060
7 Staung 4,370
8 Chikraing 2,750
9 Sen 16,250
10 Chinit 6,770
11 Boribo 6,080
12 Pursat 5,980
Source: ADB, 2004.
Table 2: Water Balance of the Great Lake Basin: Surface Water Availability
Inputs Annual Volume, (109 m³)
Inputs from the Tonle Sap watershed ( 67,600 km² ):
Inflow from the rivers +24.3
Rainfall on the Lake +13.9
Total inputs from the Lake Basin +28.0
Inputs from the Mekong River through Tonle Sap river:
Inflow to Tonle Sap at Prek Kdam to the Lake -45.0
Outflow from the Lake +72.9
Net Balance +27.9
Sources: Carbonnel, 1962-63 in CNMC, 2004.
List of Figures
Figure 1: Population Density in the Tonle Sap Basin in 2004 (Person/km2)
Figure 2: Percentage of Poor in the Tonle Sap Basin in 2000
Figure 3: Average Annual Rainfall (mm), 1998-2002
Average Annual Rainfall, mm
Battambang Kampong Kampong Pursat Siem Reap
Figure 4: Cultivated Areas by Province in the Tonle Sap Basin in 1993 (ha)
Figure 5: Cultivated Areas by Province in the Tonle Sap Basin in 2002 (ha)
Figure 6: Percentage Change of Cultivated Area (1993-2002)
Figure 7: Rice Yield in the Tonle Sap Basin in 2002 (tons/ha)
Figure 8: Fish Catch by Province in the Tonle Sap Basin in 2002 (tons)
Figure 9: Cambodia National Mekong Committee Structure
COUNCIL OF MINISTERS
Cambodia National Mekong
Planning Department Projects Department TSBR Secretariat
Administration and Administration and
Planning Bureau Agriculture Bureau
HRD Bureau Training Division
Socio-economic Water Resources Strategy, Policy and
Research Bureau Bureau Networking Division
Book-keeping and Management and Waterways and Research, Monitoring
Information Bureau Procurement Bureau Tourism Bureau and Data Mgt Division
Basin Development Water Utilization Finance Monitoring
Plan Unit Program Unit Unit
Capacity Building Environment Program
Program Team Unit
Figure 10: Percentage Change of Forest Area in the Tonle Sap Basin (1993-2002)