California Aqueduct - Background

Background

The aqueduct begins at the San Joaquin-Sacramento River Delta at the Banks Pumping Plant, which pumps from the Clifton Court Forebay. Water is pumped by the Banks Pumping Plant to the Bethany Reservoir. The reservoir serves as a forebay for the South Bay Aqueduct via the South Bay Pumping Plant. From the Bethany Reservoir, the aqueduct flows by gravity approximately 60 mi (97 km) to the O'Neil Forebay at the San Luis Reservoir. From the O'Neil Forebay, it flows approximately 16 mi (26 km) to the Dos Amigos Pumping Plant. After Dos Amigos, the aqueduct flows about 95 mi (153 km) to where the Coastal Branch splits from the "main line". The split is approximately 16 mi (26 km) south-southeast of Kettleman City. After the coastal branch, the line continues by gravity another 66 mi (106 km) to the Buena Vista Pumping Plant. From the Buena Vista, it flows approximately 27 mi (43 km) to the Teerink Pumping Plant. After Teerink it flows about 2.5 mi (4.0 km) to the Chrisman Pumping Plant. Chrisman is the last pumping plant before Edmonston Pumping Plant, which is 13 mi (21 km) from Chrisman. South of the plant the west branch splits off in a southwesterly direction to serve the Los Angeles Basin. At Edmonston Pumping Plant it is pumped 1,926 ft (587 m) over the Tehachapi Mountains.

Water flows through the aqueduct in a series of abrupt rises and gradual falls. The water flows down a long segment, built at a slight grade, and arrives at a pumping station powered by Path 66 or Path 15. The pumping station raises the water, where it again gradually flows downhill to the next station. However, where there are substantial drops, the water's potential energy is recaptured by hydroelectric plants. The initial pumping station fed by the Sacramento River Delta raises the water 240 ft (73 m), while a series of pumps culminating at the Edmonston Pumping Plant raises the water 1,926 ft (587 m) over the Tehachapi Mountains. The Edmonston Pumping station requires so much power that several power lines off of Path 15 and Path 26 are needed to ensure proper operation of the pumps.

A typical section has a concrete-lined channel 40 feet (12 m) at the base and an average water depth of about 30 ft (9.1 m). The widest section of the aqueduct is 110 feet (34 m) and the deepest is 32 feet (9.8 m). Channel capacity is 13,100 cubic feet per second (370 m3/s) and the largest pumping plant capacity at Dos Amigos is 15,450 cubic feet per second (437 m3/s).