Santa Margarita Groundwater Agency

Sustainability Program / Basin Monitoring

Basin Monitoring

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

By each April, SMGWA 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.

Groundwater Level Monitoring

The Basin currently has a network of 40 wells that are monitored at least twice each year. The network includes seven monitoring wells installed in 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 through an agreement with the Department of Water Resources (DWR). Click here to see the Monitoring Well Installation Report.

Water level data from the full monitoring network is submitted to DWR twice each year by January 1^st and July 1^st. 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 map below shows the locations and the aquifers being monitored by each well. The list of wells below the map includes a link to the well on the DWR site. Wells in bold are used for evaluating sustainable management criteria for water levels in the Basin. Wells in the table without a link have not yet been added to the DWR site, but they will be soon.

A Map of the santa margarita watershed, marking aquifers and other water bodies

Local Well Name	Formation Monitored	Local Well Name	Formation Monitored
MHA #1	Santa Margarita/Lompico	SVWD #15 MW	Lompico/Butano
MHA #2	Lompico	SVWD #3B	Monterey/Lompico/Butano
MHA #3	Lompico	SVWD #9	Monterey
MHA-MW1	Lompico	SVWD AB303 MW-1	Santa Margarita
SLVWD Olympia #2	Santa Margarita	SVWD AB303 MW-2	Lompico
SLVWD Olympia #3	Santa Margarita	SVWD AB303 MW-3A	Lompico
SLVWD Pasatiempo MW-1	Lompico	SVWD AB303 MW-3B	Santa Margarita
SLVWD Pasatiempo MW-2	Santa Margarita	SVWD Canham Well	Butano
SLVWD Pasatiempo #5A	Lompico	SVWD Orchard Well	Lompico/Butano
SLVWD Pasatiempo #7	Lompico	SVWD Stonewood Well	Butano
SLVWD Pasatiempo #8	Lompico	SVWD SV4-MW	Santa Margarita
SLVWD Quail #4A	Santa Margarita	SVWD TW-18	Santa Margarita
SLVWD Quail #5A	Santa Margarita	SVWD TW-19	Lompico
SLVWD Quail MW-A	Santa Margarita	SMGWA-2	Lompico/Butano
SLVWD Quail MW-B	Santa Margarita	SMGWA-3	Santa Margarita
SLVWD Quail MW-C	Santa Margarita	SMGWA-4	Santa Margarita
SVWD #10	Santa Margarita/Lompico	SMGWA-5	Santa Margarita
SVWD #10A	Lompico	SMGWA-6	Santa Margarita
SVWD #11A	Lompico	SMGWA-7	Monterey
SVWD #11B	Lompico	SMGWA-8	Monterey