Southern California Edison announces plans to remove pumps installed earlier this summer from the Rush Creek Dam system
Representatives from Southern California Edison (SCE) and the U.S. Forest Service held a town hall meeting at the June Lake Community Center to discuss the Rush Creek Hydroelectric system on Tuesday, August 15. One major takeaway from the meeting was that, without the series of dams located above Silver and Grant Lakes, flooding in the area would have been far worse this summer.
“It’s the highest snowpack we’ve ever recorded in history up at Gem and Agnew Lake,” said Wayne Allen, Licensing and Compliance Manager for SCE. “That equated to 80,000 acre-feet of water…all that water has to go somewhere into the Rush Creek system. All of this snowmelt has to pass through our system down through Silver Lake, Grant Lake, and out into Mono Lake.” One acre-foot is water one foot deep per acre of land.
SCE first held a town hall meeting to address concerns from June Lake residents about runoff on June 19, at which its representatives explained the steps they were taking to ensure that water levels in the series of dams in the Rush Creek Hydroelectric System (at Gem Lake, Agnew Lake, and Waugh Lake) were maintained at safe levels. The agency is required to keep the water level low in case a seismic event were to damage one of the dams (see “”Dam! That’s a lot of water!” May 27 and “Hot Dams,” June 23), as they are within a few miles of the Silver Lake earthquake fault, which runs adjacent to portions of the June Lake Loop.
SCE first began reassessing safety precautions in the system in 2012, said Nicolas von Gersdorff, Dam Safety Manager, following a 2007 finding that the Silver Lake Fault was considered geologically active. “That led to a series of studies to reassess dams based on awareness there is a fault right there,” said von Gersdorff. “By 2012 it was very clear it was prudent to restrict the reservoir [level] at Gem and Rush [Meadows, the dam at Waugh Lake], and CEQA [California Environmental Quality Act] analysis at Agnew showed that should also be restricted.”
SCE ended up flying a dozen industrial pumps up to Agnew Lake this spring, each of which could accommodate 100 cubic feet per second (cfs), at a cost which none of the officials present at Tuesday’s meeting could determine. That was “Phase 1” of the project, said Gonzales, and this past Tuesday’s meeting marked the beginning of “Phase 2,” or the decommissioning of the pump system. Allen said that SCE recognized that June Lake residents had complained about the flight path of the helicopters that delivered the equipment and the resulting noise (the staging area was at the June Mountain parking lot). He said that SCE was currently trying to get the necessary permits to operate the staging area at the “dump site,” an alternative landing spot north of June Lake that would allow the helicopter flight path to bypass most residential areas. However, “currently everything will continue out of the June Mountain site” said Allen. SCE also will discontinue use of the loud “Huey” helicopter and bring in a quieter sky crane, said Allen. Finally, SCE will be employing a tram system that makes its way from the Rush Creek Powerhouse to Agnew Lake to transport any items possible, which should not disturb residents as much as a helicopter.