New State Law Opens Door to Future Swimming at Santa Margarita Lake; County Says More Work Comes First

Author: Executive Office
Date: 9/4/2026 4:21 PM

Senate Bill 1253 may allow future recreation in Santa Margarita Lake

Governor Gavin Newsom signed Senate Bill 1253 on August 31, removing a longstanding state restriction and establishing a process through which the County of San Luis Obispo may allow body-contact recreation at Santa Margarita Lake after specified health, safety and water-quality requirements are met.

The law takes effect on January 1, 2027, but that date does not mean the public will be able to begin swimming in the lake on that date. County staff anticipate summer 2027 would be the earliest that could start. Implementation could take longer depending on the requirements, costs, infrastructure needs and policy decisions involved. Santa Margarita does currently allow boats, kayaks and other water vessels, but the new law opens new passive recreational opportunities, especially for those community members who do not have access to a boat to enjoy the lake.

"This is an exciting possibility for Santa Margarita Lake, but there is still a lot of work ahead of us," said Public Works Director John Diodati, who is also overseeing the Parks and Recreation Department. "Protecting drinking water and public safety will remain our first priorities."

The process will require not only direction from the Board of Supervisors, but coordination with the City of San Luis Obispo, which receives drinking water from Santa Margarita Lake, as well as County Public Health, Public Works, appropriate state agencies, the Sheriff's Office and County Fire.

"This legislation gives us an opportunity to consider something our community has talked about for many years, but it is important that we do this thoughtfully and responsibly," said San Luis Obispo County Supervisor Heather Moreno. "We know the lake is a special place for existing users and want to be mindful about how changes will impact those groups. The new law gives us an opportunity to explore additional recreational uses, but how and when that happens will require careful planning and coordination."

If the Board ultimately authorizes body contact, County staff currently envision lower-impact recreational activities such as swimming, stand-up paddleboarding, windsurfing, sail or foil boarding, and fishing activities involving body contact, such as float tubes or wading.
Higher-impact activities such as water skiing, wakeboarding, wake surfing and tow-behind activities are not currently envisioned.

California has historically restricted body contact in many reservoirs used as drinking-water supplies, reflecting limitations of earlier water-treatment technology. Modern treatment systems, however, can safely treat water from reservoirs where body contact occurs. Nacimiento Lake and Lopez Lake both allow body contact while serving as drinking-water sources.

The City of San Luis Obispo's existing water-treatment system already uses processes that meet state and federal drinking-water standards for treatment of raw water from body-contact reservoirs. However, approval from the State Water Resources Control Board's Division of Drinking Water specific to Santa Margarita Lake will still be required before swimming can be allowed. The County and City will also need to comply with water-testing and reporting requirements established by SB 1253.