What Happened to the Sand on Catalina Island's South Beach?
City of Avalon
Sand is always shifting. Though sand shift can be subtle or dramatic, it is constant - moving particles from the ocean to land and back.
According to the University of California Santa Barbara, it is "not uncommon for Southern California beaches to be missing close to 50 percent of their historical sand supply."
Less sand can be a result of human impacts to watersheds. Manmade structures such as jetties and breakwaters alter the natural flow of sand. The addition of the structures create areas here sand accumulates and subsequently causes erosion of beaches downstream.
In addition, prop wash from boats can create turbulence that disturbs the topography of the ocean floor further influencing the sand shifting process.
However, missing sand cannot be attributed to human impact alone. Beaches undergo dramatic seasonal changes due to shifts in wave energy. High-energy winter storm waves pull sand offshore. Lower, gentle summer waves carry sand onshore.
The City of Avalon is now in Task Four of a comprehensive sedimentation Study that will help provide further insight into where our beaches' sand is going, what effect manmade structures have on our beach sand and what can be done about it.
Director of Public Works, Bob Greenlaw, will use the study's findings to develop a strategic plan to combat the sand loss.
By David Jinkens, M.P.A., C.M.C