Salinas Dam (forming Santa Margarita Lake) was built in 1941 under a military directive to supply water to Camp San Luis Obispo to support training needs for the Army during World War II. Due to this, the dam does not have a Civil Works Authority nor is it authorized for any flood risk management purposes. Shortly after it was built, Camp San Luis Obispo was no longer an active military facility, and the military transferred ownership to the Army Corps of Engineers (USACE) in 1955. USACE subsequently leased the facility to the San Luis Obispo County Flood Control and Water Conservation District (District) to operate the dam to provide water supply for the City of San Luis Obispo (City). The City has existing water rights for 45,000 acre-feet of storage, however current storage capacity is 23,843 acre-feet because the gate in the spillway was not installed as planned during construction due to structural concerns (indicated by arrow). Transferring ownership and putting in the gate is identified as an opportunity for securing additional water supplies to address needs in San Luis Obispo County in the County-wide Master Water Report, the 2020 Paso Basin Groundwater Sustainability Plan, and the County's 2022 Legislative Platform.
A USACE Disposition Study has been funded and is being coordinated by the USACE Los Angeles office with the District and the City. If disposition to the District from the USACE is feasible, local ownership is intended to ensure long-term security of a critical local water supply and facilitate opportunities for additional supply to the Paso Robles Groundwater Basin, designated as in critical overdraft by the State. The USACE completed a semi-quantitative risk assessment of the Salinas Dam in 2019 and have provisionally rated it a Dam Safety Action Classification System Level IV (Low Urgency), however, if the dam transfers to a local entity it would fall under jurisdiction of the California Division of Safety of Dams (DSOD) and require a retrofit to meet State seismic safety standards. It is envisioned that funding partnerships will be sought to help with any costs associated with transferring the dam to local ownership, retrofitting and installing the gates for increased water supply. Additionally, it is anticipated that a combination of Federal, State and local funding sources will be required to fully realize the benefits of the Salinas Dam and Santa Margarita Lake.
Staff are currently coordinating with the USACE, the DSOD, State and Federal Representatives to understand whether it is feasible to transfer the dam to the District, what the process would be and what technical, administrative and financial issues may need to be addressed. USACE anticipates releasing a draft of the Disposition Study in late 2022.
Disposition Study Scoping Process
USACE must satisfy requirements of the National Environmental Policy Act (NEPA) as part of the Disposition Study effort to ensure that the environmental impacts of the project are considered. As part of the NEPA scoping process, USACE held a virtual Scoping Meeting and a Public Scoping Comment Period in late 2021 to invite the public, stakeholders, and agencies to provide comments on issues and concerns pertaining to the Salinas Dam Disposition Study. The Scoping Meeting Slides are posted on USACE's project webpage.