Temescal Creek (Riverside County)

Temescal Creek
Map of the Santa Ana River watershed. Temescal Creek connects the San Jacinto River to the Santa Ana River at Lake Elsinore.
Country	United States
Basin features
Main source	Lake Elsinore
River mouth	Santa Ana River
Progression	Southeast-northwest
Basin size	850 square miles (2,200 km2)
Tributaries	Left: Rice Canyon Creek, Horsetheif Canyon Creek, Indian Canyon Creek, Mayhew Canyon Creek, Coldwater Canyon Creek, Brown Canyon Creek, Bedford Canyon Wash, Joseph Canyon Creek, Main Street Canyon Wash, Oak Avenue Drain Right: Wasson Canyon Creek, Arroyo Del Toro, Stovepipe Canyon Wash, Gavilan Wash, Alberhill Canyon Creek, Ceramic Canyon Creek, Dawson Canyon Creek, Olsen Canyon Creek, Cajalco Creek, Arlington Valley Channel
Physical characteristics
Length	20 miles (32 km)
Discharge	Average rate: 30 cubic feet per second (0.85 m3/s)

Temescal Creek (shown on federal maps as Temescal Wash) is an approximately 29-mile-long (47 km) watercourse in Riverside County, in the U.S. state of California. Flowing primarily in a northwestern direction, it connects Lake Elsinore with the Santa Ana River. It drains the eastern slopes of the Santa Ana Mountains on its left and on its right the western slopes of the Temescal Mountains along its length. With a drainage basin of about 1,000 square miles (2,600 km²), it is the largest tributary of the Santa Ana River, hydrologically connecting the 720-square-mile (1,900 km²) San Jacinto River and Lake Elsinore watersheds to the rest of the Santa Ana watershed. However, flowing through an arid rain shadow zone of the Santa Ana Mountains, and with diversion of ground water for human use, the creek today is ephemeral for most of its length, except for runoff from housing developments and agricultural return flows.

Prior to 1886, Temescal Valley and Temescal Creek that flowed through it had much more water than today. In May, 1886 the South Riverside Land and Water Company was incorporated, and it purchased the lands of Rancho La Sierra of Bernardo Yorba, and the Rancho Temescal grant where the colony of South Riverside was laid out. They also secured the water rights to Temescal Creek, its tributaries and Lee Lake. Dams and pipelines were built to carry the water to the colony. In 1889 the Temescal Water Company was incorporated, to supply water for the new colony. This company purchased all the water-bearing lands in the valley and began drilling artesian wells.