Page - 45 - in Book of Full Papers - Symposium Hydro Engineering

of the Emergency Spillway was not cleared of vegetation because of the predicted infrequent use of the Emergency Spillway (once in 800 years), and for economic, cultural, and aesthetic reasons. Although the Emergency Spillway was designed to withstand extreme flows, some erosion of the hill slope and debris were expected if the Emergency Spillway was ever engaged. However, the actual weir was not anticipated to be endangered from erosion during flows, based on the original design. Additional discussion and figures regarding the hydrologic and hydraulic information and data related to Oroville Dam and the Oroville Emergency Response and Recovery are provided in accompanying DWR papers noted earlier, and the references cited. Two 6.7 m (22 ft) diameter penstock tunnels leading from the reservoir to three reversible pump turbines and three conventional turbines feed the Hyatt Powerplant. The maximum combined release capacity of the Hyatt Powerplant is 479.9 m3/s (16,950 ft3/s). The facility also includes a River Valve Outlet system. The River Valve Outlet is at the lowest elevation that accesses the reservoir with a modest maximum capacity of approximately 122 m3/s (4300 ft3/s). Water from the Hyatt Powerplant and the River Valve Outlet flows into diversion tunnels, which exit near the downstream toe of the dam and into the tailrace, which eventually leads back to the Feather River channel. Normal emergency drawdown of the reservoir is typically through the FCO Spillway and/or the Hyatt Powerplant. The River Valve Outlet is only used when the reservoir level is too low for the Hyatt Powerplant to efficiently operate. 3. CALIFORNIA’S EMERGENCY MANAGEMENT SYSTEM 3.1 CALIFORNIA EMERGENCY MANAGEMENT California has faced many disasters and emergencies over the years. The State has developed a robust emergency management community and has been a national leader in developing regulations, plans, and policies. DWR is an integral part of California’s system and has other responsibilities beyond the SWP, including providing support and technical assistance to local agencies during floods. California’s emergency management system works in layers to streamline communication and ensure resources are being delivered to the highest priority emergencies statewide. The following is a brief overview of the emergency management practice that is used during emergency events, such as the Oroville Emergency Response. 3.1.1 California State Emergency Plan The foundation for emergency management in California is the State Emergency Plan (SEP). This plan describes how responses to natural and/or human-caused emergencies should occur in the State. The plan describes: methods for conducting emergency operations, the process for rendering mutual aid, emergency services of government agencies, how resources are mobilized, how the public is informed, and how continuity of government is maintained during an emergency. The SEP also 45