Continuous Water Quality Background

Program Information

Continuous Environmental Monitoring Program

The Continuous Environmental Monitoring Program (CEMP) provides real-time quarter-hourly water quality from 15 automated sampling stations in the estuary. The stations provide continuous measurements of 6 water quality parameters and up to 4 environmental parameters at select locations. State Water Project (SWP) and the Central Valley Project (CVP) Operations and Maintenance staff use these measurements to assess impacts and to adjust operations as necessary to comply with mandated water quality standards. The CEMP has been in operation since 1983.

Suisun Marsh Water Quality Program

The Suisun Marsh Water Quality Program (SMWQP) provides real-time quarter-hourly water quality data from 12 automated sampling locations in Suisun Marsh. The stations measure up to 6 water quality parameters. Additionally, quarter-hour river stage measurements are recorded at 12 locations throughout Suisun Marsh—10 in parallel with the water quality measurements, and 2 at stage-only stations.

For D-1641, SMWQP data are used to assess the impacts of water exports on the ecosystem and determine compliance with water quality standards. Apart from D-1641-mandated monitoring, SMWQP monitoring fulfills a variety of mandates, including the Suisun Marsh Preservation Agreement, the summer operations of the Suisun Marsh Salinity Control Gates as required by the 2024 US Fish and Wildlife Biological Opinion for the Central Valley Project and the CDFW Incidental Take Permit for the State Water Project, and to meet the SWRCB TMDL requirements for Dissolved Oxygen. The Suisun Marsh Water Quality Program has been in operation since 1983.

Bureau of Reclamation Delta Water Quality Monitoring

The Bureau of Reclamation (Reclamation) provides real-time quarter-hourly water quality from six automated sampling stations in the estuary. The stations provide continuous measurements of two water quality parameters at select locations. State Water Project (SWP) and the Central Valley Project (CVP) Operations and Maintenance staff use these measurements to assess impacts and to adjust operations as necessary to comply with mandated water quality standards. Data are available starting 1999.