Rainbow approves Groundwater Sustainability Agency MOU

The development of a groundwater sustainability plan for the Upper San Luis Rey Groundwater Sub basin includes a Memorandum of Understanding identifying activity for the various agencies involved, and the Rainbow Municipal Water District has approved that MOU.

Michael Mack was not at the Jan. 22 Rainbow board meeting, but the other four board members all voted in favor of approving the MOU.

"We're developing a groundwater sustainability agency," said Rainbow general manager Tom Kennedy. "It's a process to start monitoring groundwater."

In 2014 the State of California adopted the Sustainable Groundwater Management Act. The intent of the law is to strengthen local groundwater. The state Department of Water Resources designated basins throughout California as high, medium, low or very low priority. The SGMA required local agencies to form a GSA for high-priority and medium-priority basins by July 2017 and has a January 2022 deadline to develop plans to achieve long-term groundwater sustainability. The state's 127 basins which require a GSA include the San Luis Rey Valley Groundwater Basin, which is designated as a medium-priority basin.

In August 2016 the San Diego County Board of Supervisors adopted a resolution for the county to become a Groundwater Sustainability Agency for the San Luis Rey, San Pasqual Valley, and San Diego River Valley basins. A county can form a GSA either within its entire jurisdiction including incorporated cities and water districts or only over the portions of the county which are not within the jurisdiction of another agency. The supervisors' 2016 action established GSAs covering the entire county jurisdiction. A local agency does not have regulatory authority to implement SGMA actions on tribal or Federal land so the Indian reservations along the San Luis Rey river basin are not included although the tribes will be involved in the work with stakeholders.

DWR defines the San Luis Rey Valley Groundwater Basin as beginning at the confluence of the San Luis River and Paradise Creek and ending at the Pacific Ocean within the Oceanside city limits. The basin includes the Pauma, Pala, Bonsall and Mission sub basins. Subterranean streams are exempt from SGMA requirements although the plan must cover the entire basin. DWR has determined that the Pala, Bonsall, and Mission sub basins are subterranean streams, so originally only the Pauma sub basin was subject to SGMA requirements.

The county can provide DWR with a notice of election to become a GSA and then work with other local agencies to develop agreements including governance structures. In June 2017 the board of supervisors approved a Memorandum of Understanding to develop a sustainability plan for the San Luis Rey Valley Groundwater Basin. The MOU included the Yuima Municipal Water district, the Pauma Valley Community Services District, and the Upper San Luis Rey Resource Conservation District as well as the county.

The SGMA language requires a GSA to work with stakeholders in the process of developing groundwater regulations. The stakeholders include well owners and other holders of groundwater rights, municipal well operators, public water systems, local land planning agencies, environmental users of groundwater, surface water users if a hydrologic connection between surface and groundwater bodies exists, the federal government including the military and managers of Federal lands, and Indian tribes.

A working group was established and included Indian tribes and local public agencies, and the tasks included determining a governance structure for the development of the plan. In addition to the four MOU partners the working group included the Rainbow, San Luis Rey, Mootamai and Pauma municipal water districts, the San Diego County Farm Bureau, DWR, the San Luis Rey Indian Water Authority and the Pala, Pauma, La Jolla, Rincon and San Pasqual tribes. Because the area covered by that MOU was outside the Rainbow boundaries the district was not a signatory.

A water rights settlement which allows San Luis Rey Watershed supply to be diverted from Indian reservations for the benefit of local entities was finalized in May 2017, and legislation was introduced to ensure that the settlement would be considered during the GSA development. In September 2018 Governor Brown signed Assembly Bill 1944 which divided the basin into the Upper San Luis Rey Groundwater Sub basin which includes the Pala and Pauma sub basins and the Lower San Luis Rey Valley Groundwater Sub basin which includes the Bonsall and Mission sub basins. AB 1944 specified that the entire upper sub basin would be subject to SGMA groundwater management while the lower sub basin would not, and AB 1944 also provides for sustainable groundwater management of all lands surrounding tribal land within the upper sub basin while ensuring that the San Luis Rey Valley tribes participate in the SGMA.

The dividing line between the upper and lower sub basins is Monserate Narrows, which is approximately a mile and a half east of Interstate 15. A special overlay area between Monserate Narrows and the Pauma Valley acknowledges the rights of both percolating groundwater for tribal use and subterranean streams for groundwater users with existing state diversion permits. Some of that area is within the Rainbow boundaries.

In April 2018 DWR awarded state grants totaling $1.3 million to the county and to the Yuima district to develop the plan. The tribal involvement and the grants made Yuima willing to be the lead on the development of the plan, and in November 2018 the board of supervisors voted to withdraw the county from the MOU while keeping the county involved as a stakeholder and funding $150,000 toward the development of the plan not including the DWR grant the county received. The county's continued involvement will ensure that groundwater sustainability measures are integrated with the county's land use and well permitting responsibilities.

The Memorandum of Understanding does not establish the new GSA but is a framework by which all parties agree to fund the data collection necessary to develop the groundwater sustainability plan. Rainbow's cost is capped at $12,500 although that doesn't include staff time to attend meetings or legal costs to review contracts or other documents. The data collection and the development of the groundwater sustainability plan will provide guidance for the governance of the GSA.

Joe Naiman can be reached by email at [email protected].