Old River (California)
The Old River is a tidal distributary of the San Joaquin River that flows for about through the Sacramento–San Joaquin River Delta in Northern California. The Old River was once the main channel of the San Joaquin until navigation (Stockton Deepwater Shipping Channel) and flood control projects in the late 19th and 20th century fixed the San Joaquin to its present course past Stockton. It diverges from the San Joaquin near Tracy, about upstream from Antioch, and first runs west towards Mountain House, then north to rejoin the San Joaquin above Antioch. The river is lined with levees that prevent flooding of the adjacent Delta islands, many of which lie below sea level. The Middle River runs east of and roughly parallel to Old River. False River diverges from Old River about a mile (1.6 km) above the Old River's mouth and runs westward to join the San Joaquin at a point closer to Antioch. Part of the Old River forms the boundary between San Joaquin County on the east and Contra Costa County to the west. About halfway along its course the Old River passes by the Clifton Court Forebay, where water is pumped from the Delta to support