The Carbon Creek Watershed covers 21.4 square miles in west Orange County. It includes portions of the cities of Anaheim, Brea, Buena Park, Cypress, Fullerton, La Palma, and Los Alamitos. Carbon Creek, its main tributary, begins in the foothills and empties into the San Gabriel River.

In 2001, the U.S. Army Corps of Engineers initiated a comprehensive watershed study. A Reconnaissance Study was completed in June 2001. Although it is titled the "Westminster Watershed Reconnaissance Study", it covers three Orange County watersheds: Coyote Creek, Carbon Creek, and Westminster. In fall 2002, the Corps of Engineers is scheduled to begin the Feasibility Phase of the watershed study. This phase will cover both the Coyote Creek and Carbon Creek watersheds in one effort.