| Agua Chinon Creek | |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | California |
| Length Mi: | 7.96 |
| Length Ref: | [1] |
| Source1: | The Sinks |
| Source1 Location: | Limestone Canyon Nature Preserve, Santa Ana Mountains |
| Source1 Coordinates: | 33.7131°N -117.6583°W[2] |
| Source1 Elevation: | 1400feet |
| Mouth: | San Diego Creek |
| Mouth Location: | Irvine |
| Mouth Coordinates: | 33.6542°N -117.7586°W |
| Mouth Elevation: | 167feet |
| Basin Size Mi2: | 11.01 |
Agua Chinon Creek or Agua Chinon Wash is an urban stream in the city of Irvine, Orange County, California. The creek flows southwest from its headwaters in the foothills of the Santa Ana Mountains for about 8miles to join San Diego Creek near the Verizon Amphitheatre. The creek drains a total watershed area of 7049acres.[3]
The headwaters of the creek consist of approximately 1200acres of undeveloped canyonlands in the Limestone Canyon Nature Preserve.[4] The area includes the badlands known as The Sinks, which are nicknamed "the Grand Canyon of Orange County" due to its sheer cliffs.[5] At the bottom of the canyons Agua Chinon Creek flows under State Route 241 and is impounded by the Agua Chinon Debris Dam, which provides flood control to the valley below. Completed in 1998, the dam has a capacity of 256acre feet of water.[6]
The middle section of Agua Chinon Creek flows through a culvert underneath the former El Toro Marine Corps Air Station. The redevelopment of the air base as Orange County Great Park includes plans to daylight the creek and restore streambank habitat.[7] This work is proposed to create a wildlife corridor between the Cleveland National Forest and the Laguna Coast wilderness area (Crystal Cove State Park).[8]
Below the Air Base/Great Park the creek continues in a buried channel under the BNSF Railway tracks, Interstate 5 and the Irvine Spectrum Center, and is joined from the left by its main tributary, Borrego Canyon Wash. It emerges as an open channel just a few hundred feet before its confluence with San Diego Creek. The confluence is situated just north of the Interstate 405 near the 405/133 interchange.