A US District Court judge has lifted an injunction against running pump back turbines to produce electricity at the Lake Russell dam in South Carolina. The decision is the latest move in an environmental legal battle that started in 1988.

The US Army Corps of Engineers (USACE), which built and runs the dam’s hydroelectric plant, said the court agreed that the project met all requirements of the National Environmental Policy Act and should be allowed to operate.

The Wildlife Associations of South Carolina and Missouri had filed a suit requesting the injunctions. Several years later the state of Georgia also joined the legal fight against the pump turbines.

USACE wants to use the four reversible turbines to pump water between lakes Russell and Thurmond along the Savannah river and create electricity at night with the water used during the day. The plaintiffs won an injunction blocking the turbines’ use until USACE showed they would not harm the environment.

In 1999, USACE asked that the injunction be lifted after US$34M in studies and fish protection measures proved the turbines could work safely. The turbines would kill between 6M and 12M fish a year, but that represents less than 1% of Lake Thurmond’s fish population and the numbers have no significant impact, USACE said.

The pumped storage will give more than US$57.2M a year in economic benefits to residents in the southeast in lower energy costs, the USACE official added.

Russell dam, upstream of Thurmond lake above Augusta Georgia, had long hosted four conventional turbines. But when the four reversible units were installed, the fear was that water pumped from Thurmond back into Russell for reuse during peak power demands would take too heavy a toll on the environment.

• Meanwhile, a new turbine proposed by the USACE and the Bonneville Power Administration (BPA) to install and test a prototype turbine that could lead to improved power generation and fish preservation is to be installed in the McNary dam power house near Umatilla, in the state of Oregon, US.

According to the agencies, a turbine has a typical lifespan of about 25 to 30 years, while the McNary dam power house is almost 50 years old. There has been no significant work done to improve the efficiency of the generating units during that time.

If successful, this project could result in the replacement of all 14 turbines and related equipment at the dam.