Village Updating Floodplain Maps, Data
The information now shows that Lake Pinehurst's theoretical potential 100-year flood water level is a foot lower than reported in an earlier official flood plain map done in 1989.
The data is required by Federal Emergency Management Agency (FEMA) and is based on a 2000 study done by consulting engineers Withers & Ravenel for the village, and older studies. The county has also updated its Flood Damage and Prevention Ordinance, as required by FEMA in order for property owners to remain eligible for federal flood insurance.
The revised study shows a three-foot increase in flood water level over the mean sea level (normal water level) of Lake Pinehurst at 410 feet could be expected in the rare, serious 1 percent of storms that occur historically about once a century in the flood plain. The updated statistics have the flood level a foot lower than the four feet the last study done 17 years ago cited by.
The change in official map and data could affect the flood insurance premium for individual property owners who are in a flood plain. In order to obtain a building permit, FEMA requires that it be two feet above the 100-year-flood water level, adjusted for different river basins.
The one for Pinehurst now requires minimum elevation for construction at the lake to be 415 feet instead of 416 feet under the old study. There are only a few vacant lots left around the lake for new construction, according to village Planner Bruce Gould.
The council must vote on accepting the new map and data to replace the existing ones. That is expected to be on the agenda for a September meeting after going to the Planning and Zoning Board.
Fifty-five homes built around the lake over a 30-year period, however, are below the flood plain. If more than 50 percent of the home is destroyed by a flood, it must be rebuilt to FEMA standards, meaning on higher ground, required for new homes, Gould said.
One homeowner estimated that it could cost $25,000 to bring in additional dirt and infill to meet the FEMA requirement.
The village has yet to experience such a catastrophic storm and flooding to bring that scenario into reality.
No Past Flood Damage
Streams and springs were impounded to create the lake and the dam created in the early 1970s when a private development company, Diamondhead Corp., was platting and selling home sites.
Mayor Pro Tem George Hillier built a retirement home on the lake in 1996. Before that, he had a condominium on the lake.
"I'm not aware of any flood damage to any of the homes," Hiller said.
He said the lake level rose to the top of his bulkhead but did not overflow after a period of heavy rains.
New home sites continue to be developed upstream from Lake Pinehurst, creating more stormwater runoff that could increase the water level, Gould warned.
The village became a municipality with an elected council and taxing authority in 1981. Before that, construction and building permits were handled by the county and private developers.
Even until the late 1990s, residents such as Hillier could deal with builders and village permitting officials without anyone mentioning the subject of floods or the elevation of homes on the lake.
"The key is for the council to adopt the floodplain map," he said.
Hillier said the data now is more precise and useful.
FEMA and other government entities require municipalities, counties and local governments to update floodplain maps showing development and where flooding is statistically likely to damage or destroy homes and other buildings, in order to regulate development in flood-prone areas.
Federal flood insurance and cleanups from natural disasters costing millions of dollars or more are at stake when developments occur in areas subject to natural disasters.
Development over relatively short periods of time can affect flooding patterns as well as water levels, Gould pointed out.
Bill Kerchof and Andrew Steidinger, president of the Lake Pinehurst Association, wanted to know how long the current flood plain elevation and flood data are valid. No one could answer that.
Gould said a local government could do another study, which is expensive, at any time. This one was mandated by FEMA in North Carolina because of damage from Hurricane Floyd in the 1990s. This enables federal and state funds to help with the expense.
Steidinger, who recently built a home at 35 Queens Court, was pleased that new homes can now be built one foot lower, at 415 feet, than the 416-foot elevation required for his residence.
Gould said he expected "no change in the number of people with flood insurance."
If the council adopts the map, the building permit requirements automatically adjust the two-foot requirement from a 416-foot minimum elevation for new construction down to 415 feet, so that no amendment of the Pine-hurst Development Ordinance is necessary to enforce it, Gould said later.
"The lake water level moves around quite a bit," Steidinger said in an interview. "It (the new map) is more precise."
Gould said FEMA had previously supplied "proximate" ranges of predicted flood levels, but now the data is "greatly updated and refined. We are very pleased with this."
Sara Lindau can be reached at 693-2473 or by e-mail at email@example.com.
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