Restoring the El Segundo Sand Hills

We joined a dozen or so volunteers of The Bay Foundation this week, with the goal of removing invasive weeds from a recently unpaved portion of the LAX Dunes. Known in geological circles as the El Segundo Sand Hills, the LAX Dunes stretch from the Westchester Bluffs to Redondo Beach. Only the portion of the dunes beneath the LAX flight path remain undeveloped. All of Playa Del Rey, Westchester and the coastal neighborhoods of the South Bay are built atop the dunes.

Above: Bay Foundation CEO Tom Ford and Director of Programs Heather Burdick lead monthly restoration events at the LAX Dunes. An abandoned Surfridge neighborhood street is obvious.

The area we weeded today was once a residential street of the Surfridge neighborhood, condemned in the 1960s as LAX expanded from a small airfield to an international airport. The concrete street was demolished and removed just a few years ago, exposing the dune sand below. The Bay Foundation, in partnership with LAX, planted and seeded the area with native dune species.

Above: The former Surfridge neighborhood, removed in the 1960s as LAX expanded. The topography of the El Segundo Sand Hills is still evident. Photo by Bert Brautigan.

Our goal was to remove invasive mustard and fillaree plants so that the native species could expand their foothold. Native buttercup and coast goldenbush plants will spread over the dune sand in time if the invasive weeds are kept at bay. The Bay Foundation sponsors these restoration events every month.

Above: We removed mustard and filaree from around this buttercup plant. Below: An hour and a half of squatting reminded my knees of their seniority.

With regular weeding, the native plants will eventually dominate the dune space, leaving scant opportunity for the weeds. The native coastal buckwheat, also found elsewhere on the dunes, supports the endangered El Segundo Blue Butterfly, which spends its entire life cycle dependent upon the plant.

Above: The view from atop the ancient El Segundo Sand Hills, with Dockweiler Beach below.

Eight to ten thousand years ago, near the end of the last ice age, the Santa Monica Bay shoreline was located perhaps a thousand feet offshore from its current location, as the ice age glaciers had consumed enough ocean water to lower the sea level 80-100 feet at that time.

Above: Diagram of the Ballona/L.A. River Mouth and the El Segundo Sand Hills near the end of the last ice age, showing the receded shoreline. The dotted line denotes the present day shoreline. From Altshul, et al., 2006.

Cold, dry winds blew landward at 70-100 mph across the exposed sandy bottom of ancient Santa Monica Bay, piling the exposed sand into hundred foot-high dunes along the coast, stretching as far eastward as today’s Inglewood.

As the ice age ended and sea level rebounded toward the present elevation, the surf scoured the dunes landward, leaving the steep slopes seen today from Dockweiler Beach. The Los Angeles River, which prehistorically flowed out where Ballona Creek is today, kept the dune sand from accumulating north of where the Westchester Bluffs abruptly rise.

Above: The Westchester /Playa Del Rey Bluffs are the northern escarpment of the El Segundo Sand Hills, the dunes' northern extent defined by the prehistoric Los Angeles River.

References

J.H. Altshul, et al., 2006. Life at the nexus of the wetlands and coastal prairie, West Los Angeles. Proceedings of the Society for California Archaeology, Vol. 19, 2006.

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.