The San Antonio Creek blow-off structure was constructed as an addition to the Cachuma Project facilities in 1958. It was constructed to provide a method for water release and draining of Lauro Reservoir during an Emergency Scenario. The structure’s sole purpose is to respond to dam safety considerations. The existing structure includes an 18-inch and a 16-inch gate valve. The 18- and 16-inch valves would be removed and replaced. The project will require a shutdown of the South Coast Conduit.