Drought Hastens End of a Region’s Hydropower Era

Source: By JIM MALEWITZ, New York Times • Posted: Tuesday, March 11, 2014

One of the six dams operated by the Lower Colorado River Authority, which generates about a third of the hydropower it did in 2011. CreditSpencer Selvidge for the Texas Tribune
The years long drought in Central Texas could eventually snuff out a renewable power source that fueled the region’s early growth: hydropower.

Faced with dwindling water supplies, the Lower Colorado River Authority, which supplies water and energy to much of Central Texas, is limiting downstream water releases for activities like rice farming. Aside from stirring controversy among water users, the changes have shrunk the amount of electricity the agency generates from its six Colorado River dams.

“Your hydropower becomes an innocent bystander of the conditions around it,” said Robert Cullick, a former River Authority spokesman who is now a consultant. (The authority has been a corporate sponsor of The Texas Tribune.)

Hydroelectricity makes up a sliver of the L.C.R.A.’s energy portfolio, a mix of coal, natural gas and wind energy, and its further decline would probably not affect the region’s energy reliability. But its possible extinction would close the book on a fuel source that played a major role in the history of Central Texas and the creation of the River Authority, whose dams make up about 40 percent of the state’s hydropower capacity.

“Certainly, the history of the L.C.R.A. is all wrapped up in hydroelectricity generation,” said Michael E. Webber, deputy director of the Energy Institute at the University of Texas at Austin. (The university is a corporate sponsor of The Tribune.)

In the early 1930s, Texas lawmakers sought federal money to dam the Colorado River to prevent flooding and shore up the region’s water supply. Because that funding could only go to a public agency, they created the L.C.R.A. and agreed to pay off the federal loan with revenue from hydropower sales.

Until the mid-1960s, the agency generated most of its electricity from its Colorado River dams, before the region’s growth outpaced the generators’ capacity, forcing the L.C.R.A. to build other power plants, and hydropower faded in importance. Now, it makes up less than 6 percent of the agency’s total energy capacity, and the generators are rarely used to their full potential. In recent decades, they have been run only when releasing water downstream for other purposes.

The River Authority’s more recent curbs on downstream releases have sped hydropower’s decline.

The agency now generates about a third of the hydropower it did in 2011, the last year that most rice farmers received Colorado River water.

If the drought persists, said Ryan Rowney, executive manager of water operations at the L.C.R.A., water levels could fall “within several years” below levels needed to turn the agency’s hydropower generators.

“We have models and things, but we don’t truly know how quickly the lakes will fall,” Mr. Rowney said.

As a low-cost, no-pollution energy source that can be quickly turned on and off, hydroelectricity is a coveted power source, said Mr. Webber, but it’s a “pretty limited option” for Texas, where the geography and climate are ill suited for it. And since the state long ago dammed its best rivers, it is unlikely to grow much in the future. ”You’re driven by Mother Nature,” he said. “And Mother Nature has already voted.”