Adelaida Area Hydrogeologic Study

The San Luis Obispo County Flood Control and Water Conservation District is coordinating with the U.S. Geological Survey (USGS) and the Upper Salinas-Las Tablas Resource Conservation District (RCD) to conduct a groundwater study in the Adelaida area west of the City of Paso Robles (click here to view an interactive map of the preliminary study area). The goal of this study is to provide a better understanding of the groundwater conditions in the Adelaida area so that informed decisions can be made about managing local water resources.

Please visit the links below for additional information.

Arroyo Grande Groundwater Basin

Due to the final results of DWR’s groundwater basin boundary modifications in 2019, the Santa Maria River Valley – Arroyo Grande (No. 3-12.02) Subbasin (AG Subbasin) and Santa Maria River Valley – Santa Maria (No. 3-12.01) Subbasin (Santa Maria Subbasin) were established as separate subbasins within the previous Santa Maria River Valley Basin (No. 3-12). The Arroyo Grande Subbasin is approximately seven miles long, oriented in a northeast-southwest direction, extending from Lopez Dam to the adjudicated area boundary (approximately coincident with the Wilmar Avenue Fault and Highway 101). The tributary valley of Tar Springs Creek is about three miles long, oriented east-west, and joins Arroyo Grande Creek about three miles upstream of Highway 101. Land surface of Arroyo Grande Creek valley extends from an altitude of about 380 feet Above Mean Sea Level (AMSL) at the base of Lopez Dam to about 100 ft AMSL at the bottom of the valley. Tar Springs Creek Valley extends from an altitude of about 360 ft AMSL to 160 ft AMSL at the confluence with Arroyo Grande Creek. Mountain ridges on the north side of the valley rise steeply to elevations of over 1500 feet AMSL near Lopez Dam.

Avila Beach Drainage Project

Avila Beach Drive at Highway 101 Interchange

Reconfigure the US 101 and Avila Beach Drive Interchange to reduce delay.

Cayucos Vets Hall Restoration

The Cayucos Vets Hall, formerly the Cass Warehouse, was constructed in 1875 by Capt. James Cass, founder of Cayucos. It is located at the base of the Cayucos Pier in Cayucos State Beach, a popular tourist area. Over the years the facility functioned as an important community and event center, but it was deemed structurally unsound in 2016 and closed to the public.

The County Board of Supervisors awarded the construction contract to restore the historic facility to JG Contracting of Nipomo in October 2022. Full rehabilitation of the facility and surrounding site will restore a central piece of Cayucos history and the heartbeat of the community where residents and visitors have gathered for generations.

Cecchetti Road Storm Repair

Cloud Seeding Program for Lopez Lake

The County of San Luis Obispo Flood Control and Water Conservation District (District) recently initiated Year 2, of a potential 3-year program of the Winter Cloud Seeding Program for Lopez Lake (Zone 3). The project objective is to increase precipitation in the Lopez Lake watershed during winter precipitation events. The seeding program will use a combination of ground-seeding sites and aircraft. For more information, please see Project Updates below.

County of San Luis Obispo Public Safety Communications Center

The County of San Luis Obispo is in the process of delivery of a new Public Safety Communications Center for operation by County Sheriff and County/Cal-Fire staff. The new facility will be located adjacent to the existing Sheriff sub-station off Main Street in Templeton and will play an important role in the County’s ongoing ability to provide emergency services to the region. When complete, the new facility will replace two antiquated and overcrowded dispatch centers with an efficient, state-of-the- art facility that will be able to meet Cal Fire/SLO County and Sheriff Dispatch's growing and emergency service response needs into the future.

Figure 1 below shows a conceptual layout of the Public Safety Communications Center Site Plan.

Desalination Executable Solution and Logistics Plan (DESAL Plan)

The San Luis Obispo County Flood Control and Water Conservation District (District) is kicking off Phase 1 of a 5-Phase effort to identify and implement a local desalination project. Desalination, the process of removing salt from seawater and/or brackish water to create a freshwater resource, can provide a safe, long-term, drought-proof, and resilient water supply.

Dover Canyon Road Bridge Replacement Project, Rural Templeton

The project will replace the existing bridge on Dover Canyon Road over Jack Creek with a new precast, concrete bridge.

El Camino Real Bridge Replacement Project, Santa Margarita

This project is under construction. The existing bridge on El Camino Real over the Santa Margarita Creek, which is deteriorating and hydraulicly inadequate, is being replaced with a new-cast-in place, concrete slab bridge.

Huasna Road Bridge Replacement Project, Arroyo Grande

The project proposes replacing the existing bridge on Huasna Road over Arroyo Grande Creek with a new precast, concrete bridge.

Huasna Townsite Bridge Replacement

The project will replace the Huasna Townsite Bridge over Huasna River.  The project is at the south end of the Huasna Valley, near the intersection of Huasna Townsite Road and Huasna River Road. The bridge collapsed during the January 2023 flooding.  

Jack Creek Road Bridge Replacement

The project proposes replacing the existing bridge on Jack Creek Road over Paso Robles Creek with a new bridge.

Lopez Drive Bridge Seismic Retrofit, Arroyo Grande

The project is under construction. The project is retrofitting the existing bridge on Lopez Drive over Lopez Lake. The project is constructing a catcher bent system, new columns, and seismic cable restraints beneath the bridge.

Los Osos Wastewater Project

Evaluation and development of a wastewater treatment system for Los Osos, CA.

Master Water Report and Data Information System

The San Luis Obispo County Flood Control and Water Conservation District (District) compiles and conducts analyses that communicate the current and projected future ability of water supplies to meet demands on a county-wide basis via production of a Master Water Report. 

Mid-Higuera Bypass Project

The Mid-Higuera Bypass Project is proposed to increase the flood control capacity of the San Luis Obispo Creek between Marsh Street and Madonna Road.

Nacimiento Water Project

One of the largest value projects the County has ever completed, the Nacimiento Water Project began operations in 2011 after the construction of the $176 million, 45-mile pipeline from Lake Nacimiento to San Luis Obispo was completed. Today County staff oversee the operations and management of the pipeline.

Oak Shores Wastewater Treatment Facility Upgrade

This project includes improvements to increase system capacity, provide nitrogen removal, increase flow capacity, and upgrade the collection system for the community of Oak Shores.

Probation Department Building

The Board of Supervisors has approved moving forward with a new Probation Department Building project. The new building will replace the Probation Department’s main office in San Luis Obispo on Bishop Street, referred to as Casa Loma. The Casa Loma facility was built in 1940, is in need of constant repair, short on space and ill-suited for today’s Probation Department needs. The new facility will be a state-of-the-art facility that will meet the Probation Department’s needs for decades to come.

Regional Water Infrastructure Resiliency Planning

Public Draft of the Regional Water Infrastructure Resiliency Plan is now available! Click here.

In response to the recent drought and in anticipation of future drought conditions, the Water Resources Division is coordinating with key water agencies throughout the county to develop a balanced action plan for mitigating vulnerabilities and enhancing reliability, resilience, and optimum utilization of existing and future regional water infrastructure. This effort implements State priorities related to countywide drought planning and key recommendations from the Countywide Master Water Report:

• Lead efforts to optimize the use of unsubscribed and/or underutilized water from the State Water Project and Nacimiento Water Project, in conjunction with other facilities, to promote enhanced use of existing available resources that support local agency use and exchanges (Section 4.8.2.1)
• Support development of contingency plans (Section 4.8.1)
• Develop “boiler plate” agreements, streamlined processes for local interagency collaboration and governance structures for future projects and programs (Section 4.8.6)

When complete, specific prioritized actions to address priority vulnerabilities will be identified along with sample agreements to assist with moving forward on those actions.

Salinas Dam Disposition Study

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.  

The USACE Disposition Study is paused while District staff coordinate 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. To help fund these efforts, the state included a $500,000 allocation under Assembly Bill 102 for a Salinas Dam Feasibility Study, which is anticipated to start in early 2025. 

SLO Watershed

Watershed maps and data for San Luis Obispo County.

South Bay Bridge Replacement Project, Los Osos

The project proposes replacing the existing bridge on South Bay Boulevard near Los Osos with a new concrete box girder bridge.

State Water Project Water Management Tools Study

The San Luis Obispo County Flood Control and Water Conservation District (District) recently coordinated with the Central Coast Water Authority (CCWA) to conduct a study on the new Water Management Tools that are a part of a new State Water Project (SWP) Contract Amendment.

The final report is available here, and the conclusions and recommendations can be found on pages 54 – 55. Future efforts associated with the use of the Tools will be coordinated through the SWP Subcontractors.

Templeton to Atascadero Connector Bicycle Trail

The project proposes a new Class I multi-use trail connecting Templeton to Atascadero.

Toro Creek Road Bridge Replacement

The project proposes replacing the existing bridge on Toro Creek Road across Toro Creek.