Marsh Creek Water Quality

Water Quality Monitoring Throughout the Marsh Creek Watershed

Water Quality Monitoring Methods

Many people and groups have been monitoring water quality in Marsh Creek since 2000. Water quality monitoring can tell us important information about the health of a creek including if it is too warm for certain kinds of fish and if water quality is improving over time.

There are several ways to monitor water quality. One way is to use a probe that measures parameters such as water temperature, pH, dissolved oxygen, conductivity, and turbidity. Another way is to collect benthic (“bottom-dwelling”) macroinvertebrates (BMI), small aquatic animals without backbones that live on the bottom of creeks and can be seen without a microscope. BMI are useful indicators of water quality because they differ in pollution tolerance.

Between 2018 and 2023, American Rivers partnered with Friends of Marsh Creek Watershed and Earth Team to conduct monthly water quality monitoring at up to 14 sites along Marsh Creek and tributaries (Sand and Deer Creeks). American Rivers has also been working with Applied Marine Sciences (AMS) to monitor BMI on Marsh Creek every spring. The monitoring sites are located up and downstream of restoration projects where trees and native plants have been planted on the banks to measure possible water quality improvements over time.

Marsh Creek Water Quality Resources

To learn more about water quality in Marsh Creek, click on each resource below:

Who to Contact

You can make a difference if you see a problem on Marsh Creek!

To Report Real Time Illegal Dumping please contact your local response agency:

  • Antioch: 925-778-2441
  • Brentwood: 925-809-7911
  • Clayton: 925-673-7350
  • Oakley: 925-625-8060
  • Unincorporated Contra Costa County: 925-646-2441 

Here are ways you can take action if you see a problem on Marsh Creek:

  • Report multiple dead fish (fish kills) or other dead animals in Marsh Creek as soon as possible online to California Department of Fish and Wildlife or by calling 1‐888‐DFG‐CAL Tip (1‐888‐334‐2258). Take photos of any dead animals.
  • Report salmon poaching or spear fishing in Marsh Creek to 1‐888‐DFG‐CAL Tip (1‐888‐334‐2258)
  • To report illegal dumping or a spill visit the Contra Costa Clean Water Program or call the No Dumping Hotline at 1‐800‐NoDumping (1‐800‐663‐8674)
  • Watch to see if the water in Marsh Creek turns suddenly or unnaturally (not related to storm events) muddy or brown, an indicator of increased turbidity. Investigate the source causing increased turbidity levels and take photos if possible. Report information to the Contra Costa Clean Water Program.

Ways You can Help

There are lots of ways you can help improve Marsh Creek!

Here are some ideas:

  • Join the Friends of Marsh Creek Watershed and participate in Marsh Creek Watershed Council meetings to learn about cleanups and other volunteer opportunities
  • Garden with creek health in mind by planting native and drought tolerant plants in your gardens and yards. Native plants support butterflies, birds, and other wildlife and require less water, fertilizers, and pesticides
  • Use non-toxic cleaning products and pest control around your house
  • Bring a trash bag when walking on the Marsh Creek Trail and pick up trash you see along the creek banks and dispose of it properly
  • Pick up your pet waste and dispose of it properly
  • Use commercial car wash facilities rather than your street or driveway
  • Properly dispose o unused cleaning products, paints, solvents, etc. through household hazardous waste facilities
  • Do not dump harmful materials (i.e. chlorinated water from your swimming pool, toxic lawn products) into the storm drains, which drain straight to Marsh Creek
  • Support farmers that don’t use pesticides
  • Do not overwater your lawn, which drains nutrient‐filled water into the creek
  • Download the Seek app to identify plants and animals in the watershed
  • Download the iNaturalist app to record and share your observations along Marsh Creek.