County turns over Groundwater Sustainability Agency management for San Luis Rey Valley Groundwater Basin

The County of San Diego will no longer manage the development of the Groundwater Sustainability Agency for the San Luis Rey Valley Groundwater Basin although the county will still participate in activities and will be funding part of the development of the plan.

A 4-0 San Diego County Board of Supervisors vote Nov. 14, with Kristin Gaspar absent, approved the county's withdrawal from the Memorandum Of Understanding for the development of a Groundwater Sustainability Agency plan while continuing to participate as a stakeholder.

The county will also contribute $150,000 toward the development of the plan not including a state Department of Water Resources grant the county received to help fund the development of the plan.

The Yuima Municipal Water District will take over as the lead agency. "We were happy with the resolution," said Supervisor Bill Horn.

In 2014, the State of California adopted the Sustainable Groundwater Management Act (SGMA). The intent of the law is to strengthen local groundwater.

The Department of Water Resources (DWR) has designated basins throughout California as high, medium, low, or very low priority. The SGMA requires local agencies to form a GSA for high-priority and medium-priority basins by June 2017 and to develop plans to achieve long-term groundwater sustainability by January 2022.

The state's 127 basins which require a GSA include four medium-priority basins in San Diego County: the Borrego Valley, San Diego River Valley, San Luis Rey Valley, and San Pasqual Valley basins. The county supervisors approved a GSA for the Borrego Valley Groundwater Basin in January 2016, and in August 2016 the supervisors adopted the resolution for the county to become a Groundwater Sustainability Agency (GSA) for the San Diego River Valley Groundwater Basin, the San Luis Rey Valley Groundwater Basin, and the San Pasqual Valley Groundwater Basin.

DWR defines the San Luis Rey Valley Groundwater Basin as beginning at the confluence of the San Luis Rey River and Paradise Creek and ending at the Pacific Ocean within the Oceanside city limits. The basin includes the Pauma, Pala, Bonsall, and Mission subbasins.

Subterranean streams are exempt from the SGMA requirements although the plan must cover the entire basin. DWR has determined that the Pala, Bonsall, and Mission subbasins are subterranean streams, so only the Pauma subbasin was initially subject to the SGMA requirements.

The county has the option of becoming 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 August 2016 action called for 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 county's area will not include the Indian reservations along the river basin although the Indian tribes will be involved in the work with stakeholders.

The county can submit a notice of election to become a GSA to DWR and then work with other local agencies to develop agreements. The estimated time to develop governance structures and legal agreements with other local agencies is six to 12 months, and in June 2017 the county supervisors approved a Memorandum Of Understanding to develop a groundwater sustainability plan for the San Luis Rey Valley Groundwater Basin.

The MOU which established the Pauma Valley GSA also included the Yuima Municipal Water District, the Pauma Valley Community Services District, and the Upper San Luis Rey Resource Conservation District.

"At that time the MOU included an alternative structure," said county groundwater geologist Jim Bennett.

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 which 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 Mootamai, Pauma, San Luis Rey, and Rainbow municipal water districts, the San Diego County Farm Bureau, DWR, the San Luis Rey Indian Water Authority, and the La Jolla, Pauma, San Pasqual, Rincon, and Pala tribes.

In 1894 the federal government allowed San Luis Rey Watershed supply to be diverted from Indian reservations for the benefit of local entities. A water rights settlement was reached more than a century later and became final in May 2017.

Legislation was introduced to ensure that the settlement would be considered during the GSA development, and in September 2018 Governor Brown signed Assembly Bill 1944 which divided the basin into the Upper San Luis Rey Valley Groundwater Subbasin which includes the Pala and Pauma subbasins and the Lower San Luis Rey Valley Groundwater Subbasin which includes the Bonsall and Mission subbasins.

AB 1944 specified that the entire upper subbasin would be subject to SGMA groundwater management while the lower subbasin would not, and AB 1944 also provided for sustainable groundwater management of all lands surrounding tribal land within the upper subbasin and ensured that the San Luis Rey Valley tribes would participate in the SGMA.

In April 2018, DWR awarded state grants totaling $1.3 million to the county and to the Yuima district to develop the plan, whose cost estimates ranged from $1.2 to $1.7 million prior to the additional requirements of AB 1944.

The tribal involvement and grants made the Yuima district willing to be the lead on the development of the plan. "Our goal was to withdraw the county from being the lead," Horn said.

The expanded management area will also require a new legal agreement to define roles and responsibilities throughout the plan's development and implementation. The tribes have also offered to help fund the development of the plan. "I'm glad they stepped up to contribute," Horn said.

The county's continued involvement will ensure that groundwater sustainability measures are integrated with the county's land use and well permitting responsibilities.