Don Bauder 7:49 p.m., May 22
More Sand for San Diego Shores
The San Diego Association of Governments (SANDAG) is preparing to embark on its second Regional Beach Sand Project (RBSP II) next spring. RBSP I, which took place in 2001, involved the dredging of 2.1 million cubic yards of sand, used to replenish beaches suffering from erosion. Human alteration of rivers and the construction of seawalls to prevent cliff erosion have impacted the beaches’ ability to naturally replenish sand lost to erosion in the last several decades.
A draft Environmental Impact Review for RBSP II was released in February, at which point SANDAG solicited public comment on the plan. The San Diego chapter of the Surfrider Foundation claims they were the only environmental group to submit concerns. The group is generally opposed to beach nourishment (SANDAG’s term, critics prefer ‘dredge and fill’), recommending it only as a last resort. Surfrider prefers instead managed retreat, a process that allows the shoreline to gradually move inland unimpeded, with oceanfront housing and other infrastructure demolished or relocated as it becomes endangered by the ocean.
The main concern with the practice of dredging sand to replace beach erosion voiced by Surfrider is that the model used to predict the effects of the fill sand doesn’t adequately address cross-shelf transport, which is the major cause of erosion in the first place. This occurs as beaches naturally move along the coast, until sand falls into an offshore canyon which is too deep to recover it from. Similarly, the impact of storms was not addressed, as significant weather events are a major driver of cross-shelf transport. Also a concern was the suggestion that some reefs could temporarily become covered in sand, significantly altering surf breaks.
After consultation and public comment, two alternatives to the original sand replenishment proposal were presented. SANDAG’s official choice was Alternative 2, which, after accepting a revision request from Surfrider cutting the amount of beach sand to be added to Solana Beach by 200,000 cubic yards, was approved. A total of 2.5 million cubic yards of sand will be added to shorelines stretching from Oceanside to Imperial Beach.