A five-year maintenance plan to help with flood control in the Carpinteria Salt Marsh was approved by the California Coastal Commission earlier this month.

The Santa Barbara County Flood Control District’s plan would allow the periodic dredging and removal of sediments in the 250-acre marsh, which is located just outside of city of Carpinteria limits.

Walt Deppe, commission environmental scientist, said all three components of the current plan had already been separately approved by the commission in some form or another over the years. 

Those three components include the periodic dredging; as-needed mechanical opening of the marsh’s mouth, where a sandbar has caused low dissolved oxygen levels, to help with tidal flow and water flow improvements; and as-needed maintenance in the south part of the marsh’s drainage system.

Dredging will typically be done every five to 10 years, but can be done up to annually if needed, under the plan approved by the commission. 

Staff said between 3,000 and 6,000 cubic yards of sediment would be dredged per operation from the Franklin and Santa Monia creeks, as well as the Main Marsh Channel. 

Previous dredging activities included dragline dredging. The updated plan includes hydraulic and dragline dredging of both the upper and lower channels within the marsh. 

Dragline dredging utilizes cables and a dragline excavator to scoop up sediment, while hydraulic dredging uses pipes and pumps. Hydraulic methods of dredging have previously only been allowed in emergencies. 

Sediment would be allowed to be piled nearby, but only for limited periods of time, per commission staff. 

The commission also approved a County Flood Control-funded scientific study with the Southern California Coastal Water Research Project to look at the impacts. The study will help influence further sediment management in the area, per commission staff.

The commission had limited comments on the project, but they praised the people who had worked on the project so far.

The Coastal Commission approved the plan unanimously at the Aug. 13 meeting.  

The city is “generally supportive” of the plan, Carpinteria Community Development Director Nick Bobroff said in a letter submitted to the commission. 

However, the city did have some concerns about possible traffic, noise and other impacts to the city that come with a trucking operation, Bobroff wrote.

A pre-operation plan will be provided to all of the nearby impacted areas, and the County Flood Control must obtain all necessary approvals before work begins, per commission staff. 

“The city looks forward to continuing to work collaboratively with the California Coastal Commission and Santa Barbara County Flood Control District to protect the Carpinteria community from flooding while also protecting the Carpinteria Salt Marsh, Carpinteria City Beach, coastal resources, and public recreational opportunities,” Bobroff wrote.