Water will cascade more lavishly over the Spokane River’s waterfalls in years to come.
Even during dry years, at least 300 cubic feet of water a second will flow over the north channel of Upper Falls Dam in downtown Spokane, the Washington Department of Ecology announced Tuesday. The flows – equivalent to about 2,250 gallons per second – are required from 10 a.m. to a half-hour after sunset from Memorial Day through the end of September. In the past, the channel dried up completely during hot summers when the water was diverted through the dam’s powerhouse for electric generation.
“People will start to see more consistency in the beauty of the falls,” said Jani Gilbert, Ecology spokeswoman.
The department set the flow requirement as a condition of the federal relicensing of four Avista Corp. hydropower dams on the Washington side of the Spokane River.
Some river advocates, however, say that 300 cubic feet per second is still too skimpy.
“Who wants to look at dry falls?” said Rich Eichstaedt, an attorney for the Center for Justice, a public-interest law firm that represents the Sierra Club. “Three hundred is better than zero, but it’s not the equivalent of 500 cubic feet per second.”
Avista’s own survey shows that most people preferred the look of 500 cubic feet of water per second, Eichstaedt said.
Mayor Mary Verner also lobbied for more robust flows.
“It was less than what she had hoped for,” city spokeswoman Marlene Feist said of the 300 cubic feet per second.
In a letter to Ecology last month, Verner said she supported Avista’s plans to modify the channel so that a lesser amount of water could mimic flows of 500 cubic feet per second. But Ecology should stick to 500 cubic feet per second as a safeguard, just in case Avista’s channel work doesn’t turn out as planned, Verner wrote.
“We don’t think anyone really knows what it will take to restore aesthetic-looking falls during the summer,” said Hugh Imhof, Avista spokesman. “What we’re after is the sound of the water and the sight of it splashing over the rocks. We’re going to do our best to return that while still producing power.”
Avista’s five Spokane River dams produce about 105 megawatts of electricity, or roughly enough energy to power 68,000 homes. Reducing summer generation at one dam may not sound significant, but the utility has to replace those megawatts, Imhof said.
Eichstaedt, however, said the water dedicated to fuller flows represents a tiny amount of electricity generation.
Avista managers hope to wrap up the relicensing process before the end of the year. The new flow requirements take effect when the Federal Energy Regulatory Commission issues the licenses for the dams. Fuller-looking flows could be in place by summer 2009.
“It’s an issue only in dry years,” Imhof added, noting deep snowpacks are contributing to high flows this year.