As the lake surface continued to recede, a pumping plant was installed, and pumping was continued a few seasons, but the concentration of salts in the lake, due to the evaporation and lack of rainfall, soon made the water unfit for irrigation, and the project was abandoned by the company.

The water shortage was relieved by the construction of the Colorado River Aqueduct and the building of its terminal reservoir Lake Mathews in 1939.

The reservoir is in the upper part of Cajalco Canyon and the lower reach of the Cajalco Valley, on the course of Cajalco Creek, tributary to Temescal Wash. Today Temescal Creek begins as the Elsinore Spillway Channel, an overflow channel that now confines its upper reaches through the middle of downtown Lake Elsinore, then turns and passes northwestward into the Warm Springs Valley, past its confluence with Wasson Canyon Wash, on the right, until it is past the water treatment plant.

Descending through this unnamed canyon, the creek makes a half circle around the ridge to the north of Lee Lake to enter the Temescal Valley.

As it emerges from Temescal Canyon, north of El Cerrito the creek enters a second reservoir and is forced into a concrete channel.

It then flows through the northern part of the city of Corona taking in the Main Street Canyon Wash and Oak Avenue Drain on its left and Arlington Valley Channel on its right before entering into the Prado Flood Control Basin, formed by the Prado Dam across the Santa Ana River.