New assessment projects future flooding in Seal Beach
The sand berm that goes up every year in Seal Beach is an annual reminder that the coastal community is at risk for flooding.
But a new city assessment shows how rising sea levels could make the city even more vulnerable.
Rising sea levels could increase the frequency and severity of flooding in Seal Beach this century, possibly as early as 2050, with low-lying areas of Old Town and Surfside being the most susceptible if no action is taken.
That’s according to the city of Seal Beach’s Sea Level Rise Vulnerability Assessment which was presented at a public workshop on July 17 at Marina Community Center.
Future development and adaptation planning are central to this issue. That’s because the sea level rise assessment is part of the city’s effort to develop a Local Coastal Program (LCP). If certified, the LCP would give Seal Beach more control over the approval of some local development projects.
Right now, the California Coastal Commission (CCC) must authorize any development project within the city’s coastal zone. In 2017, the CCC gave Seal Beach a $200,000 grant to develop an LCP which must include the assessment on how to address sea level rise. Officials are expected to look at the risk of sea level rise when considering new development projects.
“All available evidence suggests that the area in and around Seal Beach is profoundly vulnerable to [sea level rise] so we need to be having discussions about what the future of the community should look like and how that affects land use decisions today,” California Coastal Commission Public Information Officer Noaki Schwartz wrote in an email. “It’s critically important that communities start planning now because sea level rise is happening – it’s not a matter of when but how much.”
Future flooding projections
The assessment projects how sea level rise of 1.6 feet, 3.3 feet, 4.9 feet and 6.6 feet could impact Seal Beach during non-storm conditions as well as during a 100-year storm. The probabilities for these scenarios are relatively low, some as low as 0.5%. According to the assessment, the scenarios are based on CCC guidelines from 2018 that recommend “more conservative” projections “would be appropriate for use on projects where damage from coastal hazards would carry a higher consequence and/or a lower ability to adapt such as residential and commercial structures.”
Sea level rise combined with extreme storms poses the biggest threat to the area, according to the assessment. Even with just 1.6 feet of sea level rise, a severe storm could send water from the San Gabriel River and Anaheim Bay into a large area of town just south of Pacific Coast Highway. “If flood mitigation measures are not in place, even minor flooding of the densely developed coastal areas within the Seal Beach waterfront and Surfside community can lead to extensive structural damages,” the assessment reads. It states there is less than a 5% probability 1.6 feet of sea level rise will happen before 2060.
At 4.9 feet of sea level rise, projected to happen as early as 2080, a 100-year storm could trigger flooding across a larger portion of Old Town, all beachfront property in Surfside and all of Leisure World.
The worst-case scenario examined is 6.6 feet of sea level rise. Under that amount, flooding could wash away more than 40% of the city’s sandy beach area and cause structural damage worth more than $600 million. There’s only a 0.5% probability that 6.6 feet of sea level rise would be seen this century.
Sea level rise could also impact the Seal Beach Pier, which was recently renovated after a destructive fire in 2016. According to the assessment, “the vulnerability of the pier deck increases substantially” with sea level rise of 3.3 feet or higher. In an extreme storm event, the assessment suggests the pier could be susceptible to damage with any amount of sea level rise.
Some residents at the workshop questioned the CCC’s use of scenarios with probabilities as low as a 1-in-200 chance. They suggested it overplayed how soon Seal Beach will face extreme flooding.
“The Coastal Commission generally advocates for a precautionary approach to sea level rise adaptation planning,” according to Schwartz. She said the CCC wants to make sure future sea level rise is not underestimated. “Emerging science on ice sheet melt has indicated that sea level rise may occur faster than previously thought,” Schwartz wrote and cautioned that some of that science was not included in the CCC’s guidance so the 0.5% probabilities could be higher.
‘We have to plan and prepare so that we don’t have to panic’
A vision of Seal Beach inundated with water prompted concern and questions from some of the 40 people at last week’s workshop.
Sarah Brink was one of them. Brink said her 107-year-old house in Old Town is paid for but she is now second-guessing plans to add square footage to the property. “Do I want to do that if my house is going to be flooded in 20 years?” she said.
“I’d be very worried about my property in Old Town,” Miriam Kelley said. Kelley lives on the Hill but has plans for her other real estate in town. “My kids want to inherit the property.”
“There’s no need to panic today. That’s not what this is about,” District One Councilman Joe Kalmick said in an interview after attending the workshop. Kalmick’s district includes Old Town and Surfside. “We have to plan and prepare so that we don’t have to panic.”
The assessment recommends possible adaptation strategies to deal with the effects of sea level rise including erecting seawalls or natural barriers like a sand dune, the elevating of structures using stilts, retrofitting buildings for flood resilience, relocating buildings or, perhaps the most severe, retreating and moving away from the coast.
“The residents should be aware that without change this worst-case scenario could be reality and they need to be informed so we can have a plan to respond to sea level rise,” Steve Fowler, Interim Director of Community Development for the city of Seal Beach wrote in an email. During the workshop, Fowler suggested that planning and response could be done incrementally as the effects of sea level rise are felt over time.
A woman at the workshop questioned who would pay for mitigation efforts.
Some help could come from the city’s recently adopted Local Hazard Mitigation Plan. The plan opens up federal funding opportunities to pay for projects to prepare for hazards, including sea level rise. One of the ideas in the LHMP is to retrofit structures in the coastal zone to elevate them above potential sea level rise projections, according to Seal Beach Police Department Sgt. Julia Clasby. The LHMP projects two feet of sea level rise by 2050 and five feet by 2100, according to an email from Sgt. Clasby.
Potential impact on development
Sea level rise is already impacting development in Seal Beach. Earlier this month, a staff report from the CCC cited the risk from sea level rise as the reason it recommended denial of a project to build two homes on a lot on 17th Street. Consideration of the project is on hold, according to Schwartz.
That is the first time a project in Seal Beach has received such a recommendation from CCC staff, according to Fowler. Will this affect future development? “Without an LCP, it is hard to say because the California Coastal Commission will continue to review all development in the coastal zone,” Fowler wrote in an email.
“People need to stay informed,” Councilman Kalmick advised. “Because of where we live we owe it to ourselves to be informed about what nature and the Coastal Commission can do.”
Another public meeting on the Local Coastal Plan is scheduled for August 21, from 6-8pm at the Marina Community Center, according the city’s website.
The full sea level rise assessment by Moffatt & Nichol is available on the city’s website and can be found by clicking on “Departments” on the home page, then on “Community Development” then on the tab “Local Coastal Plan Program.”
