Home‎ > ‎

Water Quality Monitoring

For the past six years, SPAWNERS has been monitoring water quality in San Pablo Creek and several of its tributaries. Once a month we visit our sites and collect data on the health of the streams. We measure things like temperature, turbidity (a measure of how clear the water is), and dissolved oxygen. Dissolved oxygen is important to the organisms living in the creek, just as oxygen is important to our health. 

                                Map of SPAWNERS water quality testing sites


Explore the information below to learn more about the sites, what we measure, and how you can get involved!



San Pablo Creek site




Appian Creek site




Wilkie Creek site




Castro Creek site








We measure seven different parameters to investigate the health of our creeks: conductivity, dissolved oxygen, nitrates, phosphates, pH, turbidity, and water temperature. 

Find out why these measurements matter and see some preliminary results here.












The main channel of San Pablo Creek runs behind the El Sobrante Library, just after it is joined by Appian Creek. SPAWNERS has worked at this site since 2000. Volunteers have restored creek banks, installed native plant demonstration gardens and interpretive signs, and created an environmental mural. 









SPAWNERS transformed a section of Appian Creek behind the El Sobrante Boys and Girls Club into an environmental education site with help from the agency's staff and students. Volunteers have installed native plants and an interpretive sign and removed trash and invasive weeds. The site acts as a natural buffer between a paved parking lot and the creek, reducing erosion and water pollution. 







Interpretive signs and native plants now line this 150-foot stretch of Wilkie Creek behind De Anza High School, where invasive plants once dominated. SPAWNERS has worked with volunteers since 2010 to create this outdoor classroom for students and community members. SPAWNERS facilitates service-learning projects for De Anza High School students at the site. 








This site is located shortly before Castro Creek joins with San Pablo Creek. While the other sites are located in urbanized areas, Castro Creek drains mainly ranch land and a recreation area.












Have you ever wondered what lives at the bottom of our creeks? Are you interested in measuring our creeks' health? Join our new Water Bug Team! Find out more here.