The Robles Diversion Facility is located 2.3 miles downstream of Matilija Dam. It includes a 10-foot high wooden crib dam and sediment basin across the Ventura River, a fish ladder, intake screens, diversion control gates, and the top section of a 4-mile long concrete channel known as the Robles-Casitas Canal.

The Robles facility provides for the diversion and conveyance of water from the upper Ventura River into storage at Lake Casitas for eventual distribution to agricultural and municipal water users by the Casitas Municipal Water District. Originally constructed by the Bureau of Reclamation, the diversion facility was the focus of a design plan developed by the Army Corps of Engineers for a proposed High Flow Sediment Bypass that is currently being reformulated through a collaborative planning effort. Increased maintenance, modernized infrastructure, and other agreed-upon upgrades will improve the transport of fine and coarse sediment as part of dam removal, address current and future sediment management and associated water supply challenges, and improve endangered steelhead migration both to and from the Ventura River headwaters.