Broken Rivers, Broken Policies: Where to from Here?

Grace Mang
Thursday, December 8, 2011

Freshwater biodiversity is in a state of crisis. Recent efforts to protect and sustainably manage freshwater ecosystems have done little to offset the consequences of decades of human exploitation of rivers: large dams, water pollution and over-extraction. While the sources of water pollution can be found and stopped and over-extraction by irrigators can be curtailed, the consequences of building large dams across rivers are largely irreversible. Large dams permanently fragment riverine ecosystems by isolating species (both fish and mammals), interrupting the exchange of nutrients between ecosystems, and cutting off migration routes between feeding and spawning sites. At the ecosystem level, the cumulative impacts increase the vulnerability of entire ecosystems to other threats, such as climate change.

The severe consequences of large dams are well known, yet every year more rivers are dammed. Given the urgency and severity of the threats to rivers, the current set of policy tools are surprisingly short-sighted, and are mainly directed toward mitigating the negative impacts of dams rather than equipping us with the tools to protect and sustainably utilize healthy rivers. In the policy space, comparatively much more work has gone into environmental flows methodology and its application to existing or proposed dams, compared with developing policy to protect vital ecosystems or to design hydropower projects that do less harm to rivers. There are, however, three policy approaches that could be effective in protecting rivers and their biodiversity if we can muster sufficient political will to implement them. They are the landscape approach to protected areas; utilizing ecosystem services methodology in hydropower development decision-making, and whole-basin dam removal policies.

Landscape Approach to Protected Areas

A landscape ecology approach to river and watershed management requires that protected areas must be comprehensive, adequate and representative. Rather than carving out discreet no-go zones for development while allowing projects to go ahead that lead to badly degraded river systems, this policy approach prioritizes ecological integrity first and foremost. A landscape approach requires that a network of regional-scale ecosystems be protected; that sufficient levels of each ecosystem are included to make protected areas ecologically viable and to maintain the integrity of populations, species and communities, and that the protected areas encompass variability of habitat within ecosystems.

While a compromised example, China’s Upper Yangtze Rare and Endemic Fish Nature Reserve was created to protect important remaining freshwater ecosystems and high-priority conservation areas. The reserve was originally intended as compensation for the Three Gorges Project and in recognition that the Yangtze River is home to around a third of all fish species in China, of which half are found nowhere else in the world. At the time of its creation in 1996, the reserve was a 400-kilometer corridor, which acted as a virtual no-go zone for hydropower development.

Over time, the environmental policy for the protected area has been compromised by the government’s desire to build large dams on the Upper Yangtze. In early 2011, the boundaries of the fish reserve were changed to accommodate new proposed dams such as Xiaonanhai. More than 22 kilometers of the Yangtze River have been removed from the protected area and 73 kilometers of protected areas were re-classified as a buffer zone, for “experimental development.” The failure of the protected area to prevent plans for large dams such as Xiaonanhai demonstrates the basic limitations of any policy approach, which ultimately relies on the will of the government to realize the stated objectives.

Ecosystem Services

The practice of valuing nature’s services is not technically a policy approach but represents a tool for assessing whether a proposed dam is viable based on the cost of the dam to the environment. Ecosystem services are functions performed by ecosystems that lead to desirable environmental outcomes, such as air and water purification, land fertilization, drought and flood mitigation, and climate stabilization. Compared to an environmental impact assessment, the ecosystem services methodology enables a monetary value to be put on the environmental impacts so they can be compared with any purported revenue or economic benefit estimated to come from the project.

A study conducted by a group of Chinese scientists from the Coastal and Ocean Management Institute of Xiamen University found that for each of three proposed dams examined in the Jiulong Watershed in Southeast China, more than 90% of the environmental cost of the dam (in monetary terms) was attributed to biodiversity loss. They found that in the case of the Tiangong Hydropower Project, once the environmental costs were offset against the benefits from the dam, the project was only marginally cost effective. The studies also found the dams were unprofitable under China’s current power tariff structure, as the cost to ecosystem services equated to about three-quarters of the on-grid power tariff.

A 2002 study of a proposed Kano River irrigation project in arid northern Nigeria that would have diverted water from the large Hadejia-Nguru wetland predicted that every 1,000 cubic meters of water used on the irrigation scheme would generate net economic benefits of four US cents (taking account of the costs of constructing and operating the project). But the net economic benefits of traditional uses of the floodplain (an estimated 10 million people use the wetlands for rice farming, grazing, fisheries and other economic activities) were calculated to be $32 per 1,000 cubic meters of water – 800 times greater than using the water for irrigation.  

While price is only one factor that should affect decision-making, the aim of utilizing ecosystem service methodology is to get the price closer to being “right,” so that better decisions about whether dams should be built can be made.

Dam Removal Policies

Dam removal is perhaps the most dramatic approach examined, but unlike the ecosystem services methodology or the landscape protected area policy, this approach only seeks to address problems of already fragmented river systems.

Dam removal policies have evolved from a dam-by-dam approach to the watershed scale. Restoration efforts are now being prioritized or planned at the ecosystem scale in areas such as the United States, Europe and Australia. One example is the Penobscot River in Maine, where more than 1,000 miles of river habitat will be restored in the coming years. The catchment scale plan seeks the removal of two dams and the decommissioning of a third dam, while at the same time increasing energy production at other dams on the tributaries to compensate for any lost capacity. The Penobscot River Restoration Trust, which is coordinating the project, hopes to see migratory fish species such as salmon, sturgeon and bass increase by as much as 500% once the dams are removed.  Colin Apse, the Nature Conservancy’s Deputy Director of Fresh Water Science, says, “I hope this project inspires energy planners to place dams in locations that are least disruptive to key processes, like migration, and to operate them in ways that maintain all of nature’s key services. The best thing you can do to make an ecosystem more resilient is to keep it together.”

Policy Challenges

The reality is that the current set of policy tools and approaches for protecting global freshwater systems from the impacts of dams are neither inspiring nor innovative. In fact, from a policy perspective, we are unprepared to answer fundamental questions, such as “Can the ecology of rivers can support large-dam development?” The development and testing of promising frameworks, such as the Ecological Limits of Hydrological Alteration framework (a tool for assessing and managing environmental flows across large regions), indicates that scientists and policy makers are working hard come up with new ways to better manage the world’s rivers.

However, without the political will to protect biodiversity, all policy tools are prone to failure. One recent example is the Lao government’s determination to dam the Mekong Mainstream, despite the recommendations of a Strategic Environmental Assessment of the Lower Mekong River to place a 10-year moratorium on dam development on the Lower Mekong River. The current threats to the Upper Yangtze Rare and Endemic Fish Nature Reserve are also created by the desire of the Chinese government to place energy needs above the health of the river system.

It will take our collective political will to drive the policy innovations needed to protect rivers and the life they support. With large dam proposals currently slated for important and largely uncompromised river systems such as the Mekong and Irrawaddy River in Southeast Asia, the Amazon in Latin America, and the Congo in Africa, the need for a renewed global promise to protect rivers and their inherent biodiversity is urgent.