Re-calibrated federal maps show a significant increase in flood danger in Del Mar, where hundreds of homes are near sea level from 17th Street north to the San Dieguito River.
The Federal Emergency Management Association’s flood maps are less of an issue in San Diego County’s other coastal communities, where most of the homes are at an elevation of 50 feet or more.
Oceanside city staffers will meet this week to discuss the changes in their city and “what, if any, impacts the new maps will present,” City Engineer Brian Thomas said Wednesday, July 10. The areas there within the federal floodplain are mainly along the San Luis Rey River.
Del Mar is different. The northern third of the small city lies less than 20 feet above sea level and within the potential flood zone. The FEMA flood maps that take effect in December are based on new, more accurate data, and they have the potential to send insurance costs up and property values down.
The map revisions will require some homeowners to get flood insurance who were not previously required to have it. Also, the changes will increase the cost of insurance for some owners already in the hazard area whose level of risk goes up.
Homeowners within the FEMA flood risk area are required to have flood insurance if they have a federally-backed mortgage, such as a loan insured by the Federal Deposit Insurance Corp.
Property in the flood plain also could be subject to additional limits on development.
The Del Mar City Council has scheduled a public discussion of the revised flood map at a City Hall meeting Monday, July 15.
Also on the meeting’s agenda will be a discussion of Del Mar’s application to the California Coastal Commission for approval of a Local Coastal Program. At issue there is Del Mar’s decision to reject the strategy of “managed retreat” as one of the ways for adapting to sea-level rise.
Managed retreat is a term for moving structures to higher ground to avoid flooding and sea-level rise, and the Coastal Commission advises cities to consider that as a possible option. Del Mar residents say that’s not practical for them, and if the strategy were accepted their property values would be slashed.
The median home value in Del Mar is $2.5 million, according to the online real estate service Zillow.
FEMA’s new flood maps do not take sea-level rise into account, said Gregor Blackburn, a representative of the agency’s Oakland office at a May 15 meeting in Del Mar.
However, the new map for Del Mar places the “base flood elevation,” or the area likely to be reached by the 100-year-flood, six feet higher than it was in the previous map. The 100-year flood is the highest flood likely to occur once every century,
“There have been some serious changes to the flood risk as mapped,” Blackburn said.
The agency is updating its flood maps for the entire United States. The former ones were created in the 1980s, before the era of digital technology. Any errors found in the new maps can be corrected, he said.
“Maps can be changed through a number of processes,” Blackburn said, though any alterations require additional technical data.
“The anecdotal evidence of ‘I’ve lived here for x-number of years, and it’s never flooded’ is not technical or scientific,” he said.
A resident at the May meeting asked why the new map does not show most of Del Mar’s seawalls. Agency officials said that’s because the walls are insufficient to protect homes from the 100-year flood.
Typical seawalls in Del Mar reach a height of 15 feet above sea level, and the 100-year-flood level is 16 feet, said FEMA engineer Bradford Hartley Jr.
Also, some of the seawalls are made of vertical corrugated steel, which is inadequate, officials said. And the walls are not connected to each other, which can be another risk in extreme storms.
Anyone who wants to request a change in a flood map can file a “letter of map amendment” with the agency, officials said.
Newport Beach was able to have about 60 homes removed from its flood map, saving the owners about $10 million in insurance costs, said Del Mar resident Laura DeMarco.
“We would like to be part of that wave,” she said, adding that Del Mar’s newest map is already outdated because some seawalls have been replaced.
The Monday meeting is the first of three to discuss the flood map and the Local Coastal Plan. The next two are Aug. 5 and Sept. 9.
— Phil Diehl is a reporter for The San Diego Union-Tribune