Ongoing County Restoration Efforts Require Transport of Sediment to Local Beaches

“Where is the mud and debris from Montecito going” by Oscar Flores
Source: KEYT online

Carpinteria Beach and other local beaches are the preferred locations for receiving excess sediment from the recent extreme flood event. Normally this sediment would have made its way to the coast in a controlled manner over the course of many years. But in the present case, heavy rainfall coupled with burned hillsides caused the sudden release of a large amount of sediment and debris leading to widespread flooding and damage.
When sediment arrives at the beach either by stream or by truck, natural wave action sends the finer material (clays and silts) offshore leaving the coarser material (sand, gravel and cobbles) nearshore. Further wave action mixes the gravel and cobble fractions downward into the beach face where they eventually form a hidden protective layer. The remaining sand fraction stays in the nearshore helping to nourish the beach profile.
Ash Avenue is an excellent receiver site for the excess storm sediments. Located at the end of a long rock revetment, it is the first to lose its sand during storm wave attack and the last to recover its sand during milder conditions. Placing excess storm sediment on the beach widens it providing added protection against storm wave attack and creates space in local debris to combat future flooding events.

Jim Bailard, Ph.D.
BEACON Technical Advisor