Ballona Wetlands: Glimpse its Future at San Dieguito

The San Dieguito Wetlands live just two hours south of the Ballona Wetlands via Interstate 5, sandwiched between the coastal towns of Solana Beach and Del Mar. A three-phase restoration that began twenty years ago, San Dieguito is an excellent study for how the state plans to restore our Ballona Wetlands, and what Ballona will look like.

This video, produced by the San Dieguito River Valley Conservancy (SDRVC), provides a good overview of San Dieguito today as seen through the eyes of the young people now studying its habitat. Click the photo below to watch the video.

Like Ballona, San Dieguito was once a larger tidal wetlands that was filled in over time by development. Ranchers filled wetlands in the earliest days, followed by the U.S. Army, which built a blimp airfield that filled over 100 acres. Railroad and highway construction filled even more of the San Dieguito wetlands, with development of the Del Mar Fairgrounds and I-5 delivering the last big blows. At Ballona, roads, railroads, oil production and Marina Del Rey construction buried most former wetlands there.

Above: Like Ballona, the San Dieguito Wetlands were a broad, tidal marsh covering over a thousand acres. Below, in 1926, the U.S. Army filled a large area of San Dieguito for an airfield.

Many decades later, the local San Dieguito River Park Joint Powers Authority (JPA) was formed to acquire, protect and restore natural lands within the San Dieguito River Valley. To compensate for ocean fish impacts from the now-shuttered San Onofre power plant, Southern California Edison restored around 440 acres of San Dieguito's wetlands and uplands beginning in 2007, digging out 2.5 million cubic yards of fill dirt in the process. The excavated dirt was used to build flood control berms to protect reconstructed wetlands and ensure sand delivery to the beach when the San Dieguito River floods.

Above: SCE excavating the former airfield area at San Dieguito in 2007. Below: The completed wetlands basin which replaced the airfield land.

Our state Department of Fish and Wildlife plans to do the same thing at Ballona, excavating around 3 million cubic yards of fill dirt left from Marina construction to re-create wetlands once there. Modern, vegetated earthen berms built from the excavated dirt will replace a section of the obsolete, concrete Ballona Creek channel. Bike and foot paths will top the Ballona berms.

Above: The Ballona Wetlands today, and below, an artist's rendering of the restored Ballona Wetlands as planned by the state Department of Fish and Wildlife.

In the Conservancy video, most of the habitat shown was reconstructed or enhanced by the SCE project, which finished major earth work in 2007. Several years later, the Del Mar Fairgrounds restored additional area, converting a dirt parking lot into tidal wetlands as compensation for development within their property. This area can also be seen briefly in the video, the vegetation there now nearly mature.

Above: This recently restored portion of the San Dieguito Wetlands was previously the southern parking lot of the Del Mar Fairgrounds. Below: Just dig out the dirt and they will come.

The fill dirt removed to create the Fairgrounds wetlands shown above was used to build uplands habitat further inland. Our Fish and Wildlife Department will also build up native plant habitat at Ballona, using excess fill dirt to create vegetated knolls ringed by trails in the area east of Lincoln Blvd.

Above: Before and simulated after views of upland areas east of Lincoln Boulevard at the Ballona Wetlands, where excess excavated fill dirt will be fashioned into rolling knolls, ringed by footpaths. Below, footpaths at the San Dieguito Wetlands, also on uplands of excavated and revegetated fill dirt.

The third restoration phase at San Dieguito presently underway is creating an additional 60 acres of tidal wetlands east of the SCE restoration. Known as the W19 Project, this phase mitigates various road widening projects in north San Diego County, which impact some wetlands.

Above: Earthwork underway in 2022 at the third phase of San Dieguito's restoration, where 60 acres of new tidal wetland will be created on JPA-owned lands. Below: Aerial view of the W19 project. The San Dieguito River is seen at center. Part of the SCE restoration is seen at left.

The San Dieguito JPA is a consortium of cities and the county surrounding the San Dieguito River watershed. Each member city contributes funding to maintain the trails, wetlands and upland resources within a larger River Park, and also employ rangers and professional staff. At Ballona, the California Department of Fish and Wildlife will have those responsibilities.

Above: The San Dieguito JPA's newly constructed Ranger Station and Interpretive Center.

Visit San Dieguito and see what our own Ballona Wetlands Great Park will look like in the future. Exit I-5 South at Via De La Valle, turn left to San Andres Street, then turn right. Signs will lead you to the parking area and interpretive center.

Enjoy your Ballona Wetlands!

Author's note on affiliations:

Dr. David W. Kay served on the Board of Directors of the non-profit Friends of Ballona Wetlands from 2007 until 2015, and served as Board President in 2012-13. He presently serves on the Board of Ballona Discovery Park.

From 1984-2022, David was employed by Southern California Edison Company, exclusively in the company's environmental services organizations. His many responsibilities included restoration of the 440-acre San Dieguito Wetlands near Del Mar. He retired in 2022 as Senior Manager for Project Environmental Licensing at the company.

Dr. Kay is a staunch advocate for the State of California's Ballona Wetlands Restoration Project.
See Dr. Kay's Patch contributor profile here.