Santa Ana River Watershed

The Santa Ana River Watershed is our major focus. This watershed covers more than 3,000 square miles of San Bernardino, Riverside and Orange Counties, and a small portion of Los Angeles County. It also encompasses the San Jacinto River Watershed. The Santa Ana River flows approximately 110 miles from the San Bernardino Mountains to Huntington Beach, where it empties into the Pacific Ocean.

Humans have inhabited this biologically rich watershed for the past 12,000 years, but it has changed most dramatically since the Spanish explorers arrived in 1769. Modern development has transformed 3,900 miles of naturally meandering and flooding streams into straight and concrete-lined channels to control flooding and develop agricultural diversions. Damming of the river and withdrawal of water for human consumption have reduced the flow of water and impeded sediment from flushing through the watershed to sustain plants and animals dependent on the river.

To see the native fish of the Santa Ana River, click here.

The Santa Ana River is home to at least 200 species of birds, 50 mammals, 13 reptiles, 7 amphibians and 15 types of fish. Many of these are threatened or endangered. Urban and industrial pollution as well as reduced space for habitat are constant threats to the river and the watershed as a whole. It is the goal of Inland Empire Waterkeeper to protect and preserve all of the waterways in the Santa Ana River Watershed, while maintaining a balance between human and environmental interests.

Inland Empire Waterkeeper also actively protects and advocates for the portion of the Santa Margarita River Watershed that lies in southwestern Riverside County, and the part of the Mojave River Watershed that lies in the San Bernardino Mountains.

Report Pollution - Who to Contact

 How to Report a Problem

  1. Most problems related to water quality can be addressed by the Santa Ana Regional Water Quality Control Board located on Main Street in Riverside, (951) 782-4130 

  2. Problems related to flood control channels can be addressed by the Riverside County Flood Control & Water Conservation District(951) 955-1200 .

  3. Each City has their own facilities maintenance/inspection teams or stormwater division/department/group that can address problems.

  4. Likewise, each County has stormwater and code enforcement teams.

  5. To report oil and chemical spills:   1-800-424-8802  and  1-800-852-7550.

Types of Problems to Report 

  1. Dirty stormwater runoff or washwater from a construction site that is draining to streets and storm drains.

  2. Someone dumping anything other than water down a storm drain.

  3. Illegal dumping, oil spill, chemical spill or sewage spill of any sort.

  4. Agricultural runoff draining to streets and storm drains.

  5. Broken water/irrigation lines - any water that flows all day.

  6. Algal blooms in waterways and fish kills.


If you need assistance, please contact us.