Dams on the Mekong

January 15th, 2013

Stuart Orr, WWF, Switzerland

Recent research carried out by WWF and The Australian National University shows the indirect impacts of 11 proposed dams on the mainstream of the lower Mekong River.1 The study evaluates the volume of additional water (water footprint) and area of land (land footprint) that would be required for the four Lower Mekong Basin (LMB) nations to replace calorie and protein loss from affected fish catches.

The water footprint and agricultural land analyses presented in this study are based on the limited available data. While the specific results may be contested, this research highlights the need for more detailed understanding of the indirect consequences of the proposed dams to better inform decision making.

Background

A recent Strategic Environmental Assessment of hydropower on the Mekong mainstream concluded that such projects would have significant negative impacts on both fisheries and agricultural sectors.2,3 The losses in fisheries due to the mainstream dams were estimated at US$476 million per year, excluding effects on the coastal and delta fisheries. In addition, 54% of all riverbank gardens along the Mekong would be inundated, which, combined with losses in agricultural land for reservoirs and transmission lines, was calculated at US$25.1 million per year.

Estimates of the freshwater fisheries catch in the LMB vary; for the purposes of this research, WWF has relied on the most recent MRC assessments.4 The annual yield is about 2.6 million tonnes, or 2% of global marine and freshwater fisheries landings. The per capita freshwater fish consumption in the region is 33.7 kg per year, or around 80g per person per day for each of the 60 million people in the basin. The economic value of the LMB wild migratory fishery is US$2.5 billion.

Research

This piece summarizes the land and water requirements for alternative livestock protein sources, assuming the 11 proposed mainstream dams reduce the production of fish by 60-70% as a major source of dietary protein for the people of the lower Mekong basin.

People might adopt any number of dietary habits to substitute the loss of calories and protein from fish. The dynamics of consumer behaviour are complex, and this study was limited to the most plausible scenario: that the share of meat and other proteins consumed in the LMB nations would increase. Vegetable protein intake could also increase and would come with its own costs – such scenarios have not been considered in this research, but should be explored.

Assuming greater demand for meat protein to replace lost fish catches, our calculations suggest that water consumption for livestock protein production – the water footprint – will increase from 6% to 17% and will be considerably higher in Cambodia and Laos. Southeast Asia as a whole is not particularly water scarce; however, such a major increase in consumption is likely to have significant opportunity costs. Substantial volumes of water in the natural environment are needed to sustain important ecosystem services in the basin, such as capture fisheries, low-input flood recession agriculture and maintenance of the delta. The proposed hydropower reservoirs would have a land footprint of at least 14,865 km2 – including 1,350 km2 of land proposed to be inundated for the dams – land that includes some of the most productive riverside farmland.

Additional pasture land required to replace fish protein with domestic livestock ranges from 7,080 to 24,188 km2 (13% to 63%). This will not be easy given that high quality agricultural land in the region is already occupied and agricultural rates of conversion are stagnant.

Consequently, the change in protein away from local river fisheries will have substantial social, economic and environmental implications, including greater water consumption, land use conversion, and greater reliance on imports. Increased food prices associated with higher costs of livestock production could impact the poor and exacerbate poverty.

The supporting institutional and investment infrastructure required to accommodate these changes is substantial, yet the very basics of ensuring that dam construction does not impact the food source for vulnerable populations have been overlooked. All stakeholders should be entitled to know what alternatives and strategies are in place for any situation where basic food supplies are at such high risk of disruption.

Conclusion

Hydropower development is often justified by the projections of social and economic advantages, using assessment processes that are often narrowly focussed only on the environmental and social impacts of the areas directly impacted by dam construction and inundation.5 Indeed the current assessment processes underway for the proposed dams on the main stem of the LMB appear to mirror this approach.

The data used in our assessment is the best available and these findings are first approximations of land and water requirements. The methods adopted here to estimate the impact on protein supplies due to dam construction are conservative in the use of SEA assessments of loss in ?sh production, and scaling up supply of other proteins in proportion to their existing consumption. FAO and MRC data used here does not yet account for future population increases and resulting demand for protein. Similarly, other possible protein scenarios could be modelled and would add considerably to a wider understanding of the impacts and options available. Fuller estimations are required to establish more detailed accounting of food costs, land and water use and access, livelihoods, equity and poverty. Studies for individual nations will determine a wider range of impacts and explore the institutional challenges that lay ahead. This way the bene?ts of dams can be better compared to the negative trade-offs involved.

Regulatory authorities for these dam projects have an obligation to draw on the best available data to ensure their decisions optimize the benefits for their citizens and the environment.

References:

1. Orr, S. et al. (2012), ‘Dams on the Mekong River: Lost fish protein and the implications for land and water resources’, Global Environmental Change, Volume 22, Issue 4, October 2012, Pages 925-932

2. ICEM, 2010a. MRC Strategic Environmental Assessment (SEA) for hydropower on the Mekong mainstream. Fisheries Baseline Assessment Working Paper. International Center for Environmental Management, Hanoi.

3. ICEM, 2010b. MRC Strategic Environmental Assessment (SEA) of hydropower on the Mekong mainstream: Final report. International Center for Environmental Management, Hanoi.

4. Baran, E., Myschowoda, C., 2009. Dams and ?sheries in the Mekong Basin. Aquatic Ecosystem Health & Management 12, 227-234.

5. WCD (2000), World Commission on Dams: Final Report, available at http://wwf.panda.org/what_we_do/footprint/water/dams_initiative/dams/wcd/

Stuart has been with WWF since 2006 and works with the private sector on a range of water related activities, from water accounting measures to public policy engagement. Stuart has published numerous papers on water measurement, agricultural policy and water-related risk, and is recently co-drafted guidelines for the UN Compact on corporate engagement in water policy. He has an academic and research background in agricultural systems and water resource management and worked for many years in the private sector in Asia and the US.

The views expressed in this article belong to the individual authors and do not represent the views of the Global Water Forum, the UNESCO Chair in Water Economics and Transboundary Water Governance, UNESCO, the Australian National University, or any of the institutions to which the authors are associated. Please see the Global Water Forum terms and conditions here.