Demonstration Recharge, Extraction and Aquifer Management (DREAM) Project
The County and North San Joaquin Water Conversation District (NSJWCD), in partnership with the Eastern Water Alliance (EWA) and East Bay Municipal Utility District (EBMUD), have been working to implement the DREAM Project. The purpose of the DREAM Project is to develop a successful pilot scale groundwater banking project in Eastern San Joaquin County. The Project provides NSJWCD with up to 1,000 AF of EBMUD surface water from the Mokelumne River that participating landowners use for irrigation instead of pumping groundwater from the Eastern San Joaquin (ESJ) Subbasin, thereby storing groundwater for future use. In dry years, EBMUD can draw up to half of the banked groundwater for use as supplemental supply while the other half would remain in the Subbasin to help replenish it.
ESJ Subbasin has been designated as a critically overdrafted basin by the California Department of Water Resources. In January 2020, the ESJ County Groundwater Authority completed a Groundwater Sustainability Plan that identified groundwater banking/recharge as one of the project types that will help the ESJ Subbasin achieve sustainability. The DREAM project uses a portion of the 1 million acre-feet of available groundwater storage space in a managed way to benefit both the ESJ Subbasin and EBMUD.
On April 11, 2017, in accordance with the County Ordinance Code, the Board granted a Groundwater Export Permit for the DREAM Project allowing the partners to pursue additional permits, construction, and operation. The San Joaquin County Public Works Water Resources Division has continued to support the DREAM Project by convening a Monitoring Committee as required by the Ordinance and monitoring groundwater levels in wells near the irrigation well that will be used for the project to ensure that the DREAM Project meets the conditions of the Groundwater Export Permit.
Mokelumne River water released from Camanche Reservoir and transferred to NSJWCD pursuant to EBMUD’s water rights is used for irrigation in lieu of groundwater pumping for the Project. The released water is diverted at NSJWCD’s South System Pump Station located about 10 miles below Camanche Dam, minus channel losses of 10%, and conveyed to Pixley Slough where water is pump from the Pixley Slough pump and used to irrigate grape and walnut fields.
An existing irrigation well within the NSJWCD service that will be operated by NSJWCD during the project will extract the banked groundwater that is available to EBMUD. The groundwater will be delivered to EBMUD’s aqueducts using a nearly three-mile long new pipeline being constructed by NSJWCD and the aqueduct tie-in facility being constructed by EBMUD. Construction of these new facilities is currently underway and is expected to be completed in fall 2021.
Mokelumne River Water Releases from 2018 & 2019
In 2018 and 2019, 342 acre-feet of the 1,000 acre-feet of Mokelumne River water available for the DREAM recharge water was provided to NSJWCD by EBMUD. NSJWCD diverted about 104 acre-feet of the released water at the South System Pump Station and conveyed it to the Pixley Slough pump to be used for irrigation. About half of the diverted water was used for irrigation and the other half is accounted for as recharge in the NSJWCD service area.
The South System Pump Station and related recharge facilities were being tested by NSJWCD in 2018 and 2019. NSJWCD will be applying the three lessons learned below to maximize the amount of DREAM water that is diverted and used for irrigation when the remaining 658 acre-feet of Mokelumne River water is released by EBMUD in a future year when surplus water is available.
- Improving coordination of timing of releases with the diversions by adding telemetry and web interface to the South Pump operations
- More closely matching the release rate with the irrigation rate by adding more growers
- More accurately estimating diversions by installing a new meter at the South Pump Station.
Banked Groundwater & Basin Credits
Per the Groundwater Export Permit and Project Agreement terms, the amount of banked groundwater available for extraction is equal to half the amount of water diverted by NSJWCD at the South System Pump Station minus the annual 5% loss factor. Before accounting for losses, about 52 acre-feet of water is available for extraction based on the amount diverted in 2018 and 2019 and the remaining 52 acre-feet remains in the basin as in-lieu recharge.
Groundwater extraction, which is controlled by NSJWCD, is scheduled to take place for approximately two weeks in late 2021 to test the facilities. After the remaining 658 acre-feet of Mokelumne River water is released to NSJWCD, additional banked groundwater will be available for extraction to complete the pilot test.
The Monitoring Plan for the DREAM project can be found here.
The Plan is undergoing internal review; a few have presented themselves during implementation of the Monitoring Plan:
- Two of the four monitoring wells specified in the permit conditions are no longer accessible;
- The declining groundwater level trend was not factored into the minimum operating levels set by the Export Permit, and it has taken longer than expected to design and construct the project and other infrastructure needed to support it; and
- Current groundwater levels are below the specified minimum operating levels for the remaining two wells even though the DREAM Project has yet to extract groundwater.
Due to these issues, adjustments to the Monitoring Plan and the monitoring-related permit conditions are required. These adjustments will include revising the monitoring well network, re-establishing monitoring protocols, and revising minimum operating levels.
On July 27, 2021, due to the uncertainty of groundwater extraction timing and duration, the County Board of Supervisors authorized the Director of Public Works to confirm the Monitoring Committee appointments by the representing agencies and further authorized the Monitoring Committee to modify the Monitoring Plan in consultation with the EWA. These recommendations are expected to reduce project administrative costs while keeping the intended protections of the Export Permit conditions intact. The recommendations were supported by the Monitoring Committee and EWA.
Revisions to this Monitoring Plan will be discussed by the Monitoring Committee, and an updated monitoring plan will be posted on this website.
- Since 2018, San Joaquin County has been measuring groundwater levels at up to a monthly frequency in monitoring wells near the DREAM irrigation well to obtain baseline data for the Project.
- Groundwater extraction will adhere to the conditions in DREAM Groundwater Export Permit and will only commence after the approval of the appropriate Project decision-makers. The Export Permit allows extraction to occur between October through March and for up to half the amount of water that is recharged for the project. An annual 5% loss factor applies to the amount of groundwater available for extraction
On April 7, 2016, the Eastern Water Alliance (EWA) approved an application for a Permit to Export Groundwater (Export Permit) for the Project and subsequently summited it to the County for consideration. On April 17, 2017, by Resolution R-17-35, the Board granted the requested Export Permit and in accordance with Section 5-8345 of the County Ordinance Code, the Board established the Project Monitoring Committee as the following: the Director of Public Works and/or designee, the Director of Environmental Health and/or designee; a primary and alternate representative appointed by the EWA, a primary and alternate representative appointed by the NSJWCD, a primary and alternate representative of the landowners within two miles of the extraction well also to be appointed by the NSJWCD, and a representative from EBMUD who may serve as an Ex-Officio member of the Monitoring Committee. The Export Permit resolution required EWA, NSJWCD, and EBMUD to appoint members to the Monitoring Committee and that County Board confirm those appointments at a regularly scheduled meeting no less than 180 days before the first groundwater extraction for the purpose of export.
Accordingly, on June 8, 2021, County Board approved the following appointees to the Monitoring Committee:
|Monitoring Committee Seat
|County Director of Public Works (or Designee)
|County Director of Environmental Health
|Representative of landowners within two miles of the extraction well
|Ex-Officio Member from EBMUD