Stream Team

Water Quality Monitoring with the Tuolumne County Stream Team

Corinne At Sullivan At BergelThe Tuolumne County Water Quality Plan calls for monitoring targeted local streams to determine the effectiveness of plan implementation — enter the Tuolumne County Stream Team — a group of local citizens trained to monitor stream health.  On September 17, 2005 Erick Burres of the State Water Resources Control Board Clean Water Team visited Tuolumne County to provide training for a few of the team’s future crew leaders. In 2007, the Tuolumne County Resource Conservation District took over responsibility of Stream Team.

Water quality is defined as a measure of the physical, chemical, biological, and microbiological characteristics of water,  monitoring water quality provides empirical evidence to support decision making on health and environmental issues. A day of Stream Team starts with calibrating a Hanna Instruments multi parameter probe to acquire temperature (C°), pH, electrical conductivity (EC[µS/cm]), dissolved oxygen (%, ppm), and turbidity data (FNU). Tools are carefully checked to ensure that the instrument reads accurately in the field.


Water Quality Monitoring Program Data

Field Observations

Stream Team

At each site, observations of water color, odor, litter, vegetative conditions, bank disturbance, canopy cover, algae, cobble sizes, aquatic life, temperature, weather, and flow levels can be made and recorded on a field data sheet. While these observations are being made, the probe should be submerged to record data logs for the parameters it was calibrated for. This entails three readings, each three minutes long, for an average.

Nutrient Testing


Stream TeamIn addition to the various parameters tested with the probes, water samples at random locations are collected to then test for nitrogen (N), potassium (P), and phosphorous (K) levels. In excessive amounts the nutrients are a form of pollution but in desired amounts the nutrients are vital indicators of riparian health. Using a nutrient analysis photometer and reagent solutions back in the lab we are able to test levels in mg/L from each of our samples indicating location specific data.

What’s Next?

Stream Team

Multiple citizen volunteers have been trained for Stream Team. The team members collect and analyze stream samples the first weekend of each month. We hope to expand our volunteer base and add new sampling locations, so please let us know if there are any streams or rivers you think we should sample.

Our current monitoring locations include 16 sites along Woods Creek, Sonora Creek, Sullivan Creek, and Curtis Creek.

If you would like to join the Tuolumne County Stream Team, or have any questions or suggestions, please contact Lindsay Rosasco at (209) 984-0500 or by e-mail at