Water Quality Monitoring Data

Monitoring Reports:

Data from water quality and other environmental monitoring efforts is summarized and analyzed on an annual basis in Section 11 of the Orange County Stormwater Program Unified Program Effectiveness Assessment (Unified PEA). The Unified PEA is finalized by November 15th of each year and covers a reporting period of July 1st through June 30th.

The 2012-13 Unified PEA (as well as the Unified PEA from prior reporting periods) is available at the following link:
(Please note that all water quality monitoring data is reported in Section 11 of the document)

The 2013 Santa Ana Region State of the Environment Report is also now available. This report represents our commitment to periodically present a comprehensive picture of the quality of Orange County’s creeks, rivers, bays and coastal waters and the actions being taken by the Orange County Stormwater Program (the Program) to protect and restore them.

Monitoring Data Portal:

To view OC Watersheds monitoring programs, sample locations and water quality data -

Click on the interactive map below.
(For best performance- use Google Chrome or Mozilla Firefox browser to view map)


*For your convenience, OC Watersheds has provided a short demonstration video of how to use the
interactive map and download the data through the following link:


(For best performance - copy the link and open it in Google Chrome browser)

Direct access to OC Watersheds monitoring program data (without using the map) -  
Click on the monitoring program to get to the data download files.

Santa Ana Region


Coyote Creek Metals TMDL

Dry Weather


Mass Emissions

Newport Bay Nutrient TMDL - Algae

Newport Bay Nutrient TMDL - Watershed

Nitrogen and Selenium Management Program

Pathogens and Bacteria



San Diego Region

Aliso Creek Bacteria TMDL

Ambient Coastal Receiving Water


Coastal Storm Drain Outfall

Mass Emissions

Non-Stormwater Action Level

San Juan Creek Bacteria TMDL

Stormwater Action Limits

For questions or information regarding water quality monitoring data and data requests,  please contact Michael Fennessy Chief, Environmental Data Management Unit.