Academic journal article Forum for Applied Research and Public Policy

Undamning Dams: Despite Bad Press, Dams Are Critical to the Nation's Clean Water Program

Academic journal article Forum for Applied Research and Public Policy

Undamning Dams: Despite Bad Press, Dams Are Critical to the Nation's Clean Water Program

Article excerpt

On October 18, 1997, Vice President Gore introduced a major new initiative, the Clean Water Action Plan, commemorating the 25th anniversary of the Clean Water Act.(1) The action plan was designed to fulfill the promise of the Clean Water Act that all U.S. waterways would one day be fishable and swimmable.

The success of the Clean Water Act in cleaning up pollution from industrial, commercial, and municipal discharges is undisputed, but the promise of fishable, swimmable waters remains unfulfilled. After 25 years and the expenditure of nearly $100 billion through the Environmental Protection Agency's (EPA) Construction Grants Program, nearly 40 percent of the nation's waterways are still unsafe for fishing and swimming.(2) Nutrients, bacteria, sediment, and toxic chemicals continue to pollute the nation's waterways from diffuse sources such as animal feedlots, stormwater runoff, agricultural drainage, and soil erosion. It is these latter sources of pollution that the Clean Water Action Plan is expected to remedy.

The Clean Water Action Plan calls for a collaboration between the public and private sectors to restore not just waterways, but entire watersheds. To make water quality programs more effective, it asks that governments at all levels develop water quality standards based on achieving certain levels of performance rather than just installing the best technology. It calls for new financial and technical assistance programs for communities and landowners to implement pollution-prevention plans, restore habitat, and control polluted runoff. And it directs the federal government to help the public and private sectors make informed water-quality decisions.

While the action plan promotes a variety of approaches to improving water quality, it does not recognize the contribution dams can make to this program.

Water Quality and Dams

Two decades ago, the Water Resources Council pointed out that the most significant deficiency in the construction and operation of dams was the failure to adequately consider water quality.(3) The council noted that without proper integration of water quality planning into dam construction and operations, water quality goals would become unnecessarily difficult and expensive to achieve. Throughout the history of dam building, water quality has been virtually ignored. Dam builders were more interested in structures than sustainable development, and they tended to concentrate on optimizing hydropower generation and irrigation to the exclusion of other benefits. The shortcomings of this approach became the rallying point of special interest groups seeking to discredit all dams. Unfortunately, the views of these groups are often overstated, failing to fully recognize the other societal benefits of dams.

In fact, the present impact of dams on water quality is often overlooked. On the positive side, dams and their reservoirs tend to serve as settling basins. Studies have shown that turbidity can be reduced by two-thirds within reservoirs; color can be reduced by half, over and above the effects of dilution; and bacteriological quality can be improved 10- to 200-fold, depending on time of year, retention time, and water temperatures.(4)

These positive benefits, however, can be offset by the negative effects dam operations have on waters downstream from dams. Water quality conditions that pose problems in downstream waters include variable temperatures and volumes of flow, low dissolved oxygen, high concentrations of such minerals as iron and manganese, and gaseous supersaturations.(5)

Changes in Attitude

In the late 1970s, hydropower operations adversely affecting dissolved oxygen, temperature, the volume of water flow in tailwaters, and other environmental considerations resulted in a National Wildlife Federation suit claiming that EPA violated the Clean Water Act when it designated America's 2 million dams as nonpoint sources. …

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