ANTIOCH – Contra Loma Swim Lagoon will be closed for the swim season – the third time in three years – because of required maintenance and safety repairs, officials said.
The chlorinated lagoon, run by the East Bay Regional Park District and part of the 780-acre Contra Loma Regional Park, is one of the most popular swim areas in the region attracting some 60,000 visitors annually. It usually opens Memorial Day weekend and continues operations through Labor Day.
In March of 2023, the parks district board approved a $273,448 contract for architectural and engineering design services that would reconfigure the swim lagoon to eliminate the sand and under-pool lagoon piping, complete repairs to the gutters and drain covers and add new mechanical systems. But no work has begun as the park district continues to evaluate “ongoing maintenance and code compliance” issues, according to a spokesman.
“Contra Loma Swim Lagoon’s current design, which includes a sandy bottom, creates two challenges – operating the facility and maintaining public safety,” Jen Vanya, acting public information supervisor, said.
In addition, Vanya said the sandy bottom creates wear on both the lagoon’s shell waterproofing and mechanical filtration system.
“The sandy bottom also creates significant safety issues by reducing visibility in the water for lifeguards as it is churned up on busy swim days,” she added.
Sylvia Garcia and daughter Elisabeth, 8, both of Pittsburg, keep cool in the swim lagoon at the Contra Loma Regional Park in Antioch, Calif., on Saturday, June 23, 2018. The lagoon will be closed for the third year in summer 2024 as officials evaluate needed repairs, which could include removing the sand. (Anda Chu/Bay Area News Group)
The closure follows waterproofing repairs completed in 2020, according to park officials. That same year East Bay Regional Park District assessed the lagoon because of ongoing maintenance concerns, after which the waterproofing project was undertaken. But by the end of the 2021 swim season, which was limited due to COVID-19 concerns, the repairs were failing and no one knew exactly why, according to park officials.
The Contra Loma lagoon is one of three swim lagoons that the EBRPD operates. The others are Cull Canyon Regional Recreation Area Lagoon in Castro Valley and Don Castro Swim Lagoon in Hayward.
Swimmers access the unique Contra Loma swim lagoon via a sand entrance in the pool shell constructed of concrete with an acrylic-modified coating. Located at 1200 Frederickson Lane, the lagoon sits alongside the Contra Loma reservoir.
When the reservoir was first developed in 1968, recreationists swam in the lake and windsurfing was allowed. But by 1999, state regulations called for an end to the combined use of the reservoir, and since it provides water during emergencies, the lake had to be closed to preserve the quality of the water supply.
The lagoon was then built in 2002 as a part of the Contra Loma Water Quality Improvements Project completed by the Contra Costa Water District to replace lake swimming. When the swim lagoon was finished in 2003, the park district assumed responsibility for operation and maintenance of the swim lagoon system.
Vanya said the district’s design and construction division intends to present plans and cost estimates for consideration to the EBRPD board of directors this summer.
“The plans will enable the District to determine project funding and next steps for swim lagoon repairs,” she said.