Basin Monitoring

As part of Sustainable Groundwater Management Act (SGMA) compliance requirements, MGA works with its members and other local agencies to monitor groundwater levels, groundwater quality and streamflow conditions in the Santa Cruz Mid-County Groundwater Basin (Basin). 

By each April, MGA issues an Annual Report on Basin conditions as required by SGMA. The Annual Report summarizes groundwater elevation and groundwater quality trends, while streamflow information is summarized in separate reports that are provided below. 

Additional County-wide monitoring information can be found at the Santa Cruz Countywide Data Viewer.

Streamflow Monitoring

The Basin currently has a network of 7 stream gages on Soquel and Aptos creek that are monitored directly by MGA. Funding for establishing and monitoring the sites has been provided in part from the Budget Act of 2021 and through an agreement with the State Department of Water Resources. The sites are monitored during the dry season (typically May through October) to better understand the contribution of groundwater to stream baseflow. Annual reports of monitoring are posted below as they become available. 

Water Year 2024 Dry Season Stream Monitoring Report

Water Year 2023 Dry Season Stream Monitoring Report

Groundwater Level Monitoring

The Basin currently has a network of 148 wells that are monitored at least twice each year. The network includes seven monitoring wells installed in 2022 and 2023 to increase the current understanding and assess future conditions of the Basin. Funding for the monitoring wells installed in 2023 was provided in part from the Water Quality, Supply, and Infrastructure Improvement Act of 2014 and the Parks, Environment, and Water Bond of 2018 and from the Budget Act of 2021 through an agreement with the Department of Water Resources (DWR). 

Water level data from the full monitoring network is submitted to DWR twice each year by January 1st and July 1st. Once submitted, the data is available to the public on the DWR site in the form of a hydrograph and a table of data. The monitoring sites listed below and associated information can be found on the California Department of Water Resources website and through the provided links.