DWR Uses Oroville Spillway for First Time Since Reconstructed by Heather Engel Apr 2, 2019 Water News Due to forecast storms in the Feather River basin, the Department of Water Resources today started releasing water from the Oroville main spillway for the first time since it has been reconstructed. Water releases were expected to be approximately 8,300 cubic feet per second. DWR said it could increase releases to the Feather River again later this week to between 40,000 and 60,000 cfs to prepare for forecasted inflows. Additional releases are possible throughout the spring to manage snow melt and rain inflows. “Protecting communities from flooding is a vital part of the Department’s mission,” said DWR Director Karla Nemeth. “Today we inaugurate the reconstructed spillway to serve that essential purpose and to prepare us for the future.” The spillway was shut down in 2017 after massive damage destroyed much of the structure. An independent panel of engineers charged with determining the cause of the incident said there was no single root cause to blame. The report found the spillway incident was caused “by a long-term systemic failure of the California Department of Water Resources (DWR), regulatory, and general industry practices to recognize and address inherent spillway design and construction weaknesses, poor bedrock quality, and deteriorated service spillway chute conditions.” At a morning press conference, DWR officials expressed complete confidence for the new structure. “The Oroville main spillway was rebuilt using modern engineering practices with the oversight of state and federal regulators on site and a team of experts assisting the Department,” said Joel Ledesma, Deputy Director, State Water Project for DWR. “With an average concrete thickness of seven and a half feet, 12.4 million pounds of reinforcing steel, and approximately 7,000 anchors, the main spillway is ready to handle flows.” To prepare for potential use of the spillway, DWR last week removed construction equipment from the spillway chute and removed a temporary road below the main spillway that has been utilized during construction. DWR notified regulatory agencies, local maintaining agencies, local law enforcement and local elected officials regarding the anticipated use.