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Water & Shorelines > Water monitoring & research > Freshwater monitoring

Freshwater monitoring

Our freshwater monitoring program examines current water quality and streamflow conditions and studies trends in stream health over time. We also study habitat to learn what kinds of plants and animals freshwater ecosystems support. We:

  • Sample water to identify chemicals, bacteria, oxygen levels, and other parameters.
  • Measure how much water is in rivers and streams across the state.
  • Measure toxic chemicals in freshwater environments by studying toxic chemicals in fish tissue, algae, and suspended sediments.

The data we collect help us make decisions on how to meet the water needs of people, wildlife, and the natural environment.

Rivers and streams

Our River and streamflow monitoring scientists collect long-term data about rivers and streams across the state. Healthy communities rely on rivers and streams to meet their needs. Healthy rivers and streams depend on clean and abundant water supplies. 

Stream habitats and watershed health

We monitor plants and animals in rivers and streams across the state to assess the health of watersheds. This information helps fish and wildlife biologists protect our state's aquatic plant and animal species. It also provides important information to decision-makers associated with land-use and environmental protection.

Toxic chemicals in lakes, rivers and fish

Toxic chemical exposures in fish species can indicate ongoing sources of pollution, such as mercury and other heavy metals. Understanding what pollutants affect fish allows health officials know whether the fish is safe to eat. They issue fish consumption advisories using our data, and state and local agencies may launch cleanup plans to eliminate pollution to our freshwater lakes, rivers and creeks.

  • The freshwater fish contaminant monitoring program samples fish and water across Washington to characterize levels of toxic contaminants and determine changes in levels over time.
  • The mercury in fish tissue study samples fish in rivers, streams, and lakes for mercury contamination. We have been looking at trends in mercury since 2005.