Anteater Family Weekend

Southern California beaches have begun to disappear. This is a problem we can manage if we have a vision about what’s happening, and we know what to do. I wrote up a an OpEd about this which was published by the Los Angeles Times.

Video by Jeff Gritchen, OC Register, shows southerly waves (swell) crashing into residential development and beach parks along the southern Orange County Coast. There is no longer sufficient beach sand to make waves break further offshore.

Drone imagery of San Clemente Beach Loss at Cotton’s Point. Imagery shows the loss of beach sand over a relatively short period of time (~year).

*Cotton’s Point During and After Wave Damage (Aug/Sept 2021) *from Wm. Copie Fuller Photography*.* Placement of riprap offers some protection against immediate local damage, but further amplifies offshore transport of sand at the toe of the slope and may significantly disrupt the natural redistribution of sand along the coast by waves.

How did we lose the beach?

Energetic waves pull sand offshore.

Beaches with a healthy supply of sand widen during summer under mild waves, and narrow in winter when wave energy is higher. Sand pulled offshore by large waves often forms a sandbar, causing waves to break further offshore and reducing the erosive stress on beaches.

*Comparison of Dana Point in 1930s and 2020s. (Photos from Doheny State Beach Interpretive Association (left) and UCI Flood Lab (right)).*

Flood management infrastructure constructed after World War II across California now represents a major barrier to sustainability, including water conservation, water quality, sediment delivery the coast, and riparian urban amenities. Investment in erodible corridors is needed to achieve greater sustainability. (Sanders and Grant 2020)

Diminishing Sand Supplies is a Global Challenge

Questions for today:

How did southern California lose its sand?

Can we get it back and preserve California’s iconic beaches for future generations?

Photo of Corona Del Mar in Newport Beach by Michael Heiman

Five Steps to Restore California’s Beaches

Graphic from Sanders and Grant (2020)

Previously published language from Los Angeles Times (2021)

We can retool our flood channels and dams to deliver more sediment to the coast rather than capturing it upstream.
We can ensure that armoring projects intended to prevent shoreline retreat account for diminished supply of sediment — and make sure those projects do not create barriers to public access.
We can streamline permitting so local governments can more easily experiment and innovate with dredging and sediment placement, as well as using natural infrastructure such as vegetated dunes so beaches rise with sea level.
The state and the region can more aggressively pursue federal funding for shoreline stabilization.
We can collect data and build modeling systems that give us the understanding needed to manage these coastal systems better, avoiding the worst outcomes, sustaining our ecosystems and maximizing the delivery of benefits we’ve enjoyed for decades.