Water Quality Monitoring

Volunteers of all ages can be river stewards! Here a volunteer uses a grab sampler to prepare for water quality testing.

Volunteers Needed!

Water quality monitoring teams are forming now. People of all ages are encouraged to participate. Young people under 18 are welcome and require adult supervision. Each team must commit to monitoring their assigned site four scheduled times per year.

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About the Project

Since 2004, the Upper Merced River Watershed Council has conducted water quality monitoring along the Merced River with teams of community volunteers. 

After a break due to the pandemic, we're relaunching our water quality monitoring program and seeking interested community members to volunteer quarterly to collect data along four sites west of the Yosemite boundary: the Sand Pit (above the NPS maintenance complex in El Portal), the South Fork confluence at the Hite Cove trailhead, Briceburg, and Railroad Flat.

Data is collected on the following:

• Air + water temperature 

• pH

• Total dissolved solids

• Dissolved oxygen 

• Turbidity 

• Photo point survey of general conditions

• COMING SOON: Nitrates/nitrites and macroinvertebrates

Each team is given a monitoring kit along with detailed written instructions outlining protocols to be followed consistently at each site and with each monitoring session.  Documentation is collected on data sheets and the results are reported annually to the National Park Service and a national database.

The 2025 calendar of quarterly monitoring weekends is as follows:

• May 17 @ 10am-noon - TRAINING DAY at Briceburg, Merced River Recreation Area. We'll show you everything you need to know!

• May 16-19 (kits are dropped of the 16th, collected the 19th) - TRAINING DAY ON MAY 17 for new monitors or refresher

• August 22-25 (kits are dropped of the 22nd, collected the 25th)

• Nov. 14-16 (kits are dropped of the 14th, collected the 25th)

This program is made possible thanks to a River Network Wild & Scenic Rivers Partnership grant and a Bureau of Reclamation WaterSMART Cooperative Watershed Management grant.