For the seventh time over the past nine years, PG&E is requesting yet another flow variance at the Potter Valley Project due to limited water availability. As the utility explained to the Federal Energy Regulatory Commission (FERC), PG&E is cutting diversions to Potter Valley and the East Branch Russian River to roughly half those normally required by its federal license. Maintaining the scheduled diversion of 50 cubic feet per second (cfs) would have left only 5000 acre feet of water in the Lake Pillsbury reservoir by as soon as mid-August.
Water levels that low, PG&E says, raise the risk of potentially catastrophic damage to Scott Dam’s only outlet, the ‘needle valve’ at the bottom of the dam. On the upstream side of the dam, the box that surrounds the inlet to the valve has sediment piled up to its brim. If – or more honestly, when – more of the sediment stacked against the sides of the reservoir falls down, the valve is likely to become irreparably clogged. This would leave no way to release water from Scott Dam for Russian River diversions or Eel River fish.
It is clear that this aging and poorly designed infrastructure can no longer serve its purpose. Why maintain a system that requires thousands of acre feet of water be kept in a hot reservoir to avoid catastrophic dam failure? For that matter, if extreme dry and hot conditions are our new normal, why should we keep diverting water away from the Eel River?
Click here to read our comments on the latest variance request.