Monitoring & Data Collection

How do we know the condition of our streams, lakes, estuaries, and coastal waters?

How do we know if our waterways are safe enough to swim in, fish from, or use for drinking or irrigation purposes?

Monitoring provides basic information about baseline condition, current status and trends of our natural resources.

There are many types of water quality indicators:

  • Chemical make-up of water, sediments, and fish tissue.
  • Physical conditions, such as temperature, flow, color, and erosion of stream banks and lake shores 
  • Biological characteristics, such as abundance and diversity of aquatic plant and animal life and the ability of test organisms to survive in sample water.

When and where monitoring happens depends on the question. Here are examples of monitoring approaches

  • regular sites on a regular basis to track change over time
  • selected sites for short period of time to answer specific questions 
  • temporary or seasonal basis to track seasonal phenomenon (e.g. fish migration)
  • after an emergency, such as after a wildfire or flood.

Increasingly, monitoring efforts are aimed at determining the condition of entire watersheds -- the area drained by rivers, lakes, and estuaries. 

The responsibility to monitor water quality rests with many different public agencies and private entities. State pollution control agencies and Indian tribes have key monitoring responsibilities and conduct vigorous monitoring programs. Many local governments, such as city and county environmental offices, also conduct water quality monitoring. The USEPA helps administer grants for water quality monitoring and provides technical guidance on how to monitor and how to report monitoring results. Some of USEPA's technical monitoring guidance documents are provided through their website.

Other Federal agencies are also involved in water quality monitoring. The U.S. Geological Survey (USGS) conducts extensive chemical monitoring through its National Stream Quality Accounting Network (NASQAN) at fixed locations on large rivers around the country. Its National Water Quality Assessment Program (NAWQA) uses a regional focus to study status and trends in water, sediment, and biota. The U.S. Fish and Wildlife Service, the National Oceanic and Atmospheric Administration, the U.S. Army Corps of Engineers, and the Tennessee Valley Authority are other examples of Federal agencies that conduct water quality monitoring to support their programs and activities. The states, territories, and tribes maintain monitoring programs to support several objectives, including assessing whether water is safe for drinking, swimming, and fishing. States also use monitoring data to

  1. review and revise water quality standards,
  2. identify impaired and threatened waters under Clean Water Act Section 303(d),
  3. develop pollutant-specific total maximum daily loads or TMDLs (calculations of the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards and an allocation of that amount to the pollutant's sources),
  4. determine the effectiveness of control programs,
  5. measure progress toward clean water, and
  6. respond to citizen complaints or events such as spills and fish kills.

Private entities such as universities, watershed associations, environmental groups, and industries also conduct water quality monitoring. They may collect water quality data for their own purposes, or to share with government decision makers. Volunteer monitors -- private citizens who volunteer to regularly collect and analyze water samples, conduct visual assessments of physical conditions, and measure the biological health of waters -- are a rapidly growing contingent providing increasingly important watershed information.

Citizen monitoring is another viable source of monitoring and data collection that relies in a whole or in part on participation by community volunteers, students or non-paid staff. Resources for citizen monitoring and details about the Water Board's Clean Water Team (CWT) program can be found on the California Surface Water Ambient Monitoring Program (SWAMP) website.

The California Water Quality Monitoring Council works with agencies across California to develop specific recommendations to improve the coordination and cost-effectiveness of water quality and ecosystem monitoring and assessment, enhance the integration of monitoring data across departments and agencies, and increase public accessibility to monitoring data and assessment information.