Changes to flood zone maps in South Kona could mean elevations of houses as well as insurance premiums.
The Federal Emergency Management Agency is in the process of updating flood maps for several areas in Hawaii County, with South Kona and Waikoloa among the most recent areas. South Hilo will also come under FEMA scrutiny in the near future.
Property owners are notified by letter if they live in an affected area, and are given 90 days to appeal the designation.
“If you are in an affected area, you would have received a letter from the Department of Public Works,” said Public Works spokeswoman Noelani Whittington.
Flood risks change over time because of environmental changes and development that can alter water flow patterns, according to FEMA. Federal standards have also tightened and new technology better tracks water flows.
People living near the ocean generally understand the risks. But upland property owners aren’t out of the woods either.
“The whole area is being affected because we’re a giant slope,” said Kailua-Kona Realtor Gretchen Lambeth. “Floodplains run all the way through all of Kona. Somebody’s usually touching it or close to it.”
Being in a flood hazard zone can affect property owners two ways, said Frank Goodale, a Kona broker for Clark Realty Corp. The county can add stricter requirements for new dwellings such as an elevated first floor. That could require stilts lifting the home off the ground in flood-prone areas. Some homes are already being constructed this way along Alii Drive, he said.
Insurance premiums could also go up significantly, by a factor as high as four, five or six times the current premium, he said.
“A $20,000 to $30,000 flood insurance bill could affect the affordability of the house,” he said.
Goodale said property owners and those interested in being property owners shouldn’t ignore the proposed changes.
“Hopefully, the community around those areas are getting additional information and paying attention to what’s happening,” Goodale said.
Hawaii County notified some 500 South Kona property owners in September for an area that includes properties in water courses 1 to 12, 21 to 25 and Captain Cook No. 1. The region starts at the Pacific Ocean and encompasses property about 1/2 mile upstream of Mamalahoa Highway, according to a March 23 letter from FEMA to Mayor Billy Kenoi.
“FEMA received no valid requests to the modified flood hazard information,” states the letter, signed by FEMA engineer Luis Rodriquez. “The modified flood hazard information will be used to calculate the appropriate flood insurance premium rates for all new buildings and their contents and for the second layer of insurance on existing buildings and their contents.”
FEMA sent a similar letter about an area around the Waikoloa Stream from about 70 feet upstream of Opelo Road to about 900 feet downstream of Lindsey Road.
Maps are not available online, but detailed zone maps can be viewed at Public Works Engineering Division offices at the West Hawaii Civic Center and the Aupuni Center in Hilo.