Many Manhattan Beach motorists, joggers, and walkers are wondering: What's all the construction on the Greenbelt? The short answer is, it's a Los Angeles County Public Works project to build new wells that will keep our fresh water fresh, without seawater intrusion.

The project is part of a major update to the West Coast Basin Barrier Project (WCBBP). The WCBBP was designed and constructed in the early 1950's to prevent seawater from intruding into the underlying aquifers of the West Coast Groundwater Basin in L.A. County. It is made up of seawater barriers that L.A. County Public Works operates to prevent seawater from contaminating the groundwater, by injecting freshwater to form a protective pressure ridge.

The project along the Greenbelt is to construct 11 injection wells and one monitoring well to replace and supplement existing barriers located within Manhattan Beach and Hermosa Beach. Nine injection wells will be constructed to replace existing injection wells that are beyond their useful life and require immediate replacement. Two new injection wells will be constructed at additional locations (in between existing injection wells) to increase the integrity of the barrier and provide increased protection against seawater intrusion.

The benefits to the city (and the greater Los Angeles area), according to L.A. County Public Works, include water conservation, increased protection of the city's groundwater resources, and new well locations that will blend in with the surrounding environment (e.g., wood chip access points and plantable retaining walls).

Additionally, the project will create permanent staging areas for future maintenance activities to avoid traffic impacts.

The project is expected to be completed in April 2022. 

The replacement well/construction locations in Manhattan Beach and Hermosa Beach are: