The Piru Creek Basin is part of the Santa Clara River Watershed. Piru Creek drains approximately 497 square miles. The creek runs about 50 miles from its headwaters in the Tehachapi Mountains in the Los Padres National Forest and enters the Santa Clara River at the town of Piru.
The creek provides the Santa Clara River with almost half of its flow and is fed by both runoff and springs. Historically, the creek was host to Southern California steelhead and today only a few fish return to spawn.
The major barriers on Piru Creek are the Pyramid and Santa Felicia Dams.