CA - UCSB alumna’s erosion report evaluates coast erosion solutions, recommends more community outreach

The project was motivated by issues of cliff erosion causing unsafe housing structures in the past, according to Robinson.

In 2017, an Isla Vista apartment building balcony collapsed. Though it was an incident with no injuries, the collapse caused 28 residents living on the property to evacuate. Additionally, at least 30 buildingswere cut back from the bluffs due to cliff erosion in recent decades.

Last spring, Robinson interviewed Isla Vista residents and experts in coastal erosion and related fields, finding a “very strong resignation” on the fate of Del Playa Drive (DP) and Isla Vista. Much of the general public opinion came from a survey aimed at long-term I.V. residents.

“One of the people responded from that form and said, ‘you people are on a dead-end path.’ Meaning that coastal management is just what it is going to be,” Robinson said during the meeting.

Another common sentiment Robinson noted from the survey was that residents were paying too much for property in a “dilapidated” state. After the community outreach stage of the project, she looked into the action plans of other coastal communities and assessed the pros and cons of possible researched erosion solutions.

The most popular solution to erosion is to install sea walls, Robinson said. Charles Lester, a UCSB researcher and the former head of the California Coastal Commission (CCC), conferred with Robinson that there’s antipathy from the CCC and other non-profits toward sea walls because they are short-term solutions.

“They will protect properties for a specific amount of time, but then the sea will continue to rise and those sea walls will no longer be helpful in preventing erosion,” Robinson said. “They also will erode the beach in front of a seawall.”

Sea walls only protect the land behind them, Robinson noted. There are two sea walls installed around the narrowest parts of the coast in Isla Vista. The beach gets narrower near Campus Point because of “downstream erosion.”

A “mid-term” solution is to install a groin or jetty — structures built perpendicular to a body of water — to interrupt water flow and sediment movement. Such structures can artificially widen the beach so the waves will not hit the cliffs as much. Robinson said according to coast professionals, a groin could be implemented at the edge of Isla Vista and UCSB and form a “crescent beach” to protect the bluffs.

Differently from the seawall solution, this solution would offset the potential for downstream erosion due to Campus Point acting as a natural groin. However, there are concerns of cost of development, greenhouse-gas emissions from material transport and beach access.

Another mid-term solution is beach nourishment, which essentially involves artificially adding sand to a beach to widen it. Robinson called this “high-risk, high-reward,” as the solution could last years or wash away in one storm.

Last winter quarter, UCSB experienced large storms that flooded the streets of I.V., damaged infrastructure and resulted in class cancellations and campus closures. Along with the same concerns of the groin solution, the CCC has many specifications about where and how much sand is put on the beach.

“You have to be very specific and make sure that you’re finding sand that is not going to disrupt the existing ecosystem in the sand. So it requires a lot of research,” Robinson said.

Some California coastal communities have turned to planting deep-rooted plants to stabilize eroding cliffs. Director of Ecosystem Management for UCSB’s Cheadle Center for Biodiversity and Ecological Restoration Lisa Stratton told Robinson this was an ineffective solution due to the geological nature of the bluffs. Stratton suggested that another mitigation strategy was to remove irrigation within 2,000 feet, as when bluffs are saturated with water, they are “more likely to fall.”

Currently, the Santa Barbara County Isla Vista Bluff Policy — which was developed in 2004 and most recently revised in 2020 — mandates that once a property is within 20 feet of a cliff edge, one of three options are available.

A property owner can hire a geotechnical engineer to study the site and determine its safety, hire a geotechnical engineer to evaluate the site’s foundation and potential for additional strengthening or cut back their properties before they reach 10 feet from the edge.

If the violation isn’t addressed within 30 days, a fine will be charged to the property owner. The longer the violation is put off, the more the fine accumulates. To avoid private contractor “buy-outs,” geotechnical engineers from the county assess the validity of private property reports.

Property buyouts — a proposed solution to private owners inadequately addressing cliff erosion — have historically failed to pass in California due to the financial burden the California government assumes with at-risk properties.

Robinson’s last solution referenced the formerly failed Isla Vista Master Plan (IVMP), which designates rezones of I.V. for building up and making space for more housing. Concerns include cost, the CCC’s oceanside views protection act and incentivizing landlords to redevelop.

“Property owners are making so much money off of their properties right now, even if they’re not putting that much investment into them. Because there’s just like a huge housing bubble in demand,” Robinson said.