SEATTLE UTILITY SPILLS AT DAM TO PROTECT SALMON
Date: 21-May-99
Country: USA
Seattle City Light said the voluntary releases - which have exposed parts of the lakebed behind the hydropower dam for the first time since it was built in the 1950s - are expected to save 6,000 fish nests downstream from the dam by keeping them underwater.
Because of heavier-than-normal runoff last summer and fall, fish eggs were laid at relatively high elevations. In addition, the melting snow that usually fills the river by this time of year has yet to arrive.
Cool mountain temperatures have pushed the start of the region's peak hydropower generating season into late April or early May.
"The reservoir level is too low for us to generate power," a spokeswoman for the municipal utility said. "Snowpack this year is 160 percent of normal - the second highest on record. But the melt is starting much later than usual."
She noted that the utility expects to refill the reservoir behind the 450-megawatt (MW) Ross Dam by June.
Meanwhile, water released from Ross, the utility's highest elevation project, is flowing through its Diablo (159 MW) and Gorge (180 MW) dams, the utility said.
Seattle City Light noted that the protective step is one of the first since nine more species of Northwest salmon and steelhead trout were declared as threatened under the Endangered Species Act about a month ago.
The listings affect a swath of Washington and Oregon, including the Seattle metropolitan area, marking the first time the environmental protection law will impact an urban area so broadly.
The Seattle utility has said it plans to restore 17 miles of salmon stream habitat and building more fish ladders around its dams due to the latest listings.
The releases at Ross, however, are aimed at protecting Chum salmon, a species which is not considered endangered.
The utility said it expects to continue releasing water through Friday of this week or until runoff from the mountains increases.
