Crews race to fix California dam before more rain falls
Feb 17 2017 by Cristina Jennings
Workers installed flashboards atop the dam's gates to increase reservoir capacity before closing and rebuilding the spillways. Engineers can release excess water through these chutes in a controlled manner in order to prevent flooding. The rising water topped over the earthen back-up spillway, which has a concrete top, for the first time in the dam's 50-year history over the weekend.
Officials had managed to avert an expected structural collapse of the top portion of the dam's emergency spillway by releasing massive amounts of water via the damaged mail spillway, lowering the level of the lake so that it no longer poured over the concrete berm at 901 feet above sea level.
Dump trucks and helicopters have dropped thousands of tons of rocks and sandbags over the past couple of days to shore up the dam's spillways, and avoid what officials had warned could be a catastrophic failure and flood downstream.
ABC10 received a comment about the possibility of there being boils on the dam's emergency spillway.
This left the emergency spillway badly eroded with a gaping hole.
More rain was forecast for as early as Wednesday and through Sunday, according to the National Weather Service, but the state Department of Water Resourcessaid the upcoming storms were unlikely to threaten the emergency spillway.
Those fears had ebbed by Tuesday, when the evacuation order was lifted.