Region 7 Watersheds

Region 7 covers approximately 13,000,000 acres (20,000 square miles) in the southeastern portion of California. It includes all of Imperial County and portions of San Bernardino, Riverside, and San Diego Counties. It is bounded on the east by the Colorado River; to the south by the Republic of Mexico; the west by the Laguna, San Jacinto, and San Bernardino Mountains; and to the north by the New York, Providence, Granite, Old Dad, Bristol, Rodman, and Ord Mountain Ranges.

The Colorado River Basin Region is located in the most arid area of California. Despite the relatively dry climate, the Region contains some substantial surface water bodies, including the Colorado River and the Salton Sea.

Download the Region 7 Factsheet (PDF) and visit the Colorado River Basin Regional Water Quality Control Board Region 7 website for more information about watersheds in this area.

Major Water Bodies:

Colorado River, Salton Sea

If you would like to select one of these major water bodies as your collection site, follow these instructions to get the information you will need for the registration form:

Copy the name of the water body (e.g., San Marcos Creek).
Go to www.topozone.com and paste the water body name in the place name field.
Select CA and click the Search button. The results will look similar to the screenshot below:
The information you will need to write down or copy from the results are:
- Type: the water body type.
- USGS Quad: the Nearest City field on the registration form.
- Lat: the latitude.
- Lon: the longitude.
Enter the information into the Collection Site Information section of the registration form.

If you need assistance in selecting a collection site, please contact us. We'll be happy to help you find a site that's as close to your group' or school's location as possible.