Bayside Groundwater Facility

Groundwater can provide water during prolonged drought

Groundwater can provide water during prolonged drought

Water for future droughts

The Bayside Groundwater Facility is a supplemental source of water supply that will help protect EBMUD's 1.4 million customers against severe water rationing in the event of a prolonged drought. The facility is developed to tap into local groundwater resources to supplement supply needs.

The groundwater aquifer beneath San Leandro and San Lorenzo has been a source of local drinking water since the early 1900's. With sustainable groundwater management, it can be a reliable source of local water during droughts.

The Bayside Facility recharges this natural storage basin by adding water to the aquifer in wet years. During dry years or drought, local ground water will be extracted, treated, and distributed to customers along with our existing supplies.

Groundwater supply is one of a portfolio of supplemental supply options to help EBMUD meet demands during droughts. This portfolio includes conservation, water recycling, and acquisition of other imported supplemental supplies from our Freeport Regional Water Facilities near Sacramento.

Facility description

The Bayside Groundwater Facility was constructed in 2009. Testing was completed at the end of the first year of operation of the Phase 1 facility. The facility can inject up to 1 million gallons a day (MGD) of surplus drinking water into the underground sand layers of the basin during wet years. During droughts, it can deliver an average of 1 million gallons a day (MGD) of water to EBMUD customers. All extracted water would be treated and tested to meet state and federal drinking water requirements. EBMUD continues to partner with the U.S. Geological Survey to monitor that the Facility is geologically sound.

Planning began in 2001. The Environmental Impact Report was approved by the EBMUD Board of Directors in November 2005. The project's construction was completed in 2009.

Future Phases

After successfully operating the Facility for some time, EBMUD will consider development of a larger facility in the local area that would have a storage capacity of 2 to 10 MGD, providing even greater drought resilience. The larger facility development would first be subjected to the same environmental and public review as the first project, and EBMUD will review results of the groundwater monitoring system and "Extensometer", which measures minute changes in ground surface elevation.

The Bayside Groundwater Facility is but one of many ways EBMUD explores bringing greater water supply reliability to the District's ratepayers during drought, emergency, or for everyday needs.

Monitoring Data & Reports 

Type Depth, feet below ground surface USGS Site Number USGS Site Name
Extensometer 598 374004122092001 003S003W14K015M
Extensometer 980 374005122092001 003S003W14K016M
Piezometer 1,010* 374004122092101 003S003W14K017
Piezometer 860 374004122092102 003S003W14K018M
Piezometer 640 374004122092103 003S003W14K019M8
Piezometer 318 374004122092104 003S003W14K020M
Piezometer 138 374004122092105 003S003W14K021M
Piezometer 45 374004122092106 003S003W14K022M

* Upon completion of the piezometer construction, test equipment could not be lowered past a depth of 1,000 ft into the 2.5-in. PVC piezometer casing. Repeated attempts were made to clear the 1,000 to 1,010 ft interval by using airlifting techniques; however, by January 2008, silt filled the bottom 60 ft of the piezometer, including the screened interval, which, therefore, was not well-connected to the aquifer system. 

MW-1 51410
MW-2s 50317
MW-2i 50318
MW-3 50319
MW-4 50320
MW-5s 50321
MW-5i 50322
MW-5d 50323
MW-6 50324
MW-7 51411
MW-8d 50325
MW-9s 50326
MW-9i 50327
MW-9d 50328
MW-10s 50329
MW-10i 50330
MW-10d 50331


Brad Ledesma, Project Manager
Phone: 510-287-1053

Emergencies or after-hours, call EBMUD at 866-403-2683.