Ash Avenue beach dumping under review

Walk out to the beach at the end of Ash Avenue and what do you find? If it is not high tide, you see huge ribbons of rocks ranging from pebbles to softball-sized and even larger. They fill this section of the beach, and require a detour to get around, or ninja-like care to walk across. These are the remnants from the most recent round of sediment dumping on the beach almost a year later. 

A year ago, the sediment dumped on this beach was from the Santa Monica Debris Basin, and that included much of the rock that remains there today. In 2018, in the immediate aftermath of the debris flow and flooding following the Thomas Fire, sediment from both the debris basin and the creek channels in the Carpinteria Salt Marsh was dumped on this beach. This removal of sediment was urgently needed to reduce the chance of additional debris flows and flooding, and the beach was the most expedient disposal location.

Over these past two years, all this work, along with the dump trucks driving though Carpinteria and leaking mud along the way, was done under emergency permits. This means the work was done with little or no analysis of the potential impacts because it was so critical and urgent to clear the debris basin and the creek channels to avoid more flooding if additional heavy rains arrived.

Our mountains are well into their recovery from the Thomas Fire, and the expected amount of debris and sediment that might be washed down by a large rain event is much less. Therefore, flood control planning is now proceeding with full analysis of the activities rather than under emergency permits.

One key agency responsible for part of this work is the Santa Barbara County Flood Control District. To me, they are a lot like the offensive linemen in a football game. If they do their job really, really well, nobody knows who they are. But if something goes wrong, then the referee tells everybody exactly who is guilty of a penalty, or the TV announcer narrates a replay showing who missed a block that led to a quarterback sack. If there is no flooding, and if we don’t see the work being done to clear debris basins or creek channels, we are perfectly happy. But when the work catches our attention, we may not be as happy.

Over the past two years, there have been severe impacts to the ocean, beach, our roads and our air quality from the effort to clear the debris basin and creek channels and deposit the sediment on the beach, all under emergency permits. Many in our community are understandably resistant to such activities resuming.

But things may be changing. County Flood Control is working to get their work approved through the normal process, requiring more analysis and review and not the emergency permit process. The goal is to stay on top of the necessary regular maintenance of removing accumulated sediment from the Franklin and Santa Monica Creek channels in the Carpinteria Salt Marsh.

Back in 2003, after an Environmental Impact Report (EIR) with detailed analysis of this work was approved, maintenance was done as needed, with the removed sediment typically hauled to “upland disposal locations,” which means somewhere on land. But now County Flood Control is proposing to change the plan and dispose of the sediment on the beach near the salt marsh mouth and at the Ash Avenue beach.

Because this is a change to the plan that was previously analyzed and approved, this project requires detailed analysis of the impacts. So, a Supplemental EIR (SEIR) is in process. As is the normal process, the public and relevant governmental agencies provided comments on the draft version of that SEIR, and a final version will be completed soon.

The biggest issue identified in the comments was that the sediment will be up to 60 percent “fines,” which means it is very silty or muddy and with not as much sand or rock. Some of the analysis of the impacts in the SEIR is based on observations from last year where the sediment (from the debris basin) was less than 25 percent fines. The larger amount of this silt or mud in the sediment means impacts in the ocean will be more severe than the draft SEIR suggests and include turbidity (water cloudiness) and siltation, bacteria levels, ammonia levels and the resulting effects on kelp beds and marine wildlife. 

The one benefit purported by the draft SEIR is beach nourishment—the addition of sand and rock to counter beach erosion and storm threats to houses. However, comments from the Central Coast Regional Water Quality Control Board pointed out that requirements for beach nourishment call for material that is no more than 50 percent fines. Since this material is up to 60 percent fines, it may not be appropriate for beach nourishment since the smaller-grain the material, the more quickly it washes away from the beach.

In other words, the single benefit asserted for the proposed change in the approved project may not be beneficial at all. So, our community could again endure beach sediment dumping with the dump truck traffic, noise, air pollution and mud on the road for as much as six weeks, without seeing any benefit over the previous approach of upland disposal of the sediment. 

Once the final SEIR is issued, the permitting agencies will use it as key input for their decisions. We are in a wait-and-see mode now. In any case, I, for one, am glad that this proposed project received the comprehensive analysis of an EIR, including the required public review and comment. 

In the near future, a walk on the beach at the end of Ash Avenue will show us how well the process worked.

This post is from the Coastal View News and ran on February 3rd, 2020.