Waterlogged

Black Mountain resident Harry Hamil was alarmed. According to new flood maps released by the N.C. Department of Crime Control and Public Safety in October, a 100-year flood would place much of his property at 151 Ridgeway Ave. underwater.

River rising: New flood maps suggest that Ingles’ Swannanoa distribution center is at greater risk of flooding. In the map above, from 1998, the highest solid line shows the extent of a 100- year flood. In the one below, released in October, the crosshatched area indicates the present reach of a 100-year flood.

Even apart from any danger, the change could cost Hamil dearly, since the maps help determine insurance rates, property values and allowable uses for specific parcels. And while the new maps show portions of the Swannanoa Valley at considerably greater risk of flooding, some residents question their accuracy.

“Is it in danger because the land itself is too low, or is it because the map has some problems?” wonders Hamil. “My answer at this point is that it appears to be due to an error in the map.” On Nov. 11, Hamil filed an informal appeal with the state flood-mapping program, citing errors in the “base flood elevation” data used by the state, which is meant to indicate the crest of a 100-year flood (a flood so severe that there’s only a 1-percent chance of it occurring each year).

Homeowners aren’t the only ones affected by the new findings. The maps also show Ingles’ current distribution center in Swannanoa at risk. The regional supermarket chain ranks among the area’s largest employers.

But Buncombe County Floodplain Administrator Cynthia Barcklow says the new maps are more accurate than the previous ones, because they rely primarily on LIDAR (light detection and ranging) data to determine elevations. “There’s much better data than there was 10 years ago,” she says.

The county Planning Department began getting calls about the new maps last summer, and interest has continued unabated.

“A lot of realtors and surveyors started calling around July, asking, ‘Do you have them yet?’ But since the maps were released, we’ve been hearing a lot more from property owners,” notes Barcklow.

For now, the new maps are still considered preliminary—they won’t be binding until they’re published in the Federal Register sometime next year. A 90-day appeal period will run from Dec. 6 to March 4, 2008, allowing property owners to contest the maps’ findings.

The revised flood maps resulted from a partnership between the Federal Emergency Management Agency and the state. The devastating 1999 flooding in eastern North Carolina associated with Hurricane Floyd was the impetus for the new round of maps, replacing those issued in 1996, which proved inaccurate.

Meet the mapmakers

A 90-day appeal period for property owners seeking to contest the maps’ findings will run from Dec. 6 to March 4, 2008. Three meetings are scheduled for Buncombe County residents and the business community to review the preliminary Flood Insurance Rate Maps developed for the French Broad River basin. State, county and municipal officials will be on hand to present the maps and answer questions. FEMA representatives will also be present.

Black Mountain—Tues., Dec. 11, Black Mountain Public Safety Building, 106 Montreat Road. Maps will be on display beginning at 6 p.m.; a presentation will start at 6:30 p.m.

Enka—Wed., Dec. 12, A-B Tech Campus, 1459 Sand Hill Road, Haynes Building, Room 200. Maps will be on display beginning at 12:30 p.m.; a presentation will start at 1 p.m.

Asheville—Thur., Dec. 13, Asheville Public Works Building, room A109, 161 S. Charlotte St. The maps will be on display beginning at 6 p.m.; a presentation will begin at 6:30 p.m.

Digital versions of the preliminary Buncombe County maps may be viewed online at www.ncfloodmaps.com or at gis.buncombecounty.org.

 

The maps can impact landowners in a number of ways. Many lenders require homeowners with federally backed mortgages to have flood insurance if their home is located in the 100-year floodplain. A shift in the floodplain means that property owners could suddenly be facing substantially higher costs.

Randy Mundt, North Carolina’s hazard mitigation officer, attributes the changes to better data. “The maps right now are more than 11 years old,” says Mundt. “Conditions in Buncombe County have changed since 1996. There’s more development. There’s more development upstream. There’s less ground for the water to soak in, so it’s running off parking lots and rooftops and getting into streams faster.” The earlier maps were done largely by “approximate methods,” he says, often relying on decades-old topographic maps with inexact contour lines.

Mundt’s office had additional data to use when mapping Buncombe County; after the 2004 floods here, the city of Asheville contracted with the engineering firm Brown and Caldwell to do a floodplain study, which Mundt says showed significantly higher discharge rates into the watershed than previous studies had.

“We said OK, we’d like to be able to use that information,” says Mundt. “Of course, we reviewed it to make sure it was accurate.”

What puzzles Hamil, however, is the fact that the new maps dramatically expand the floodplain at his end of the county while showing little change elsewhere. “You go and pick any other place in the county, and chances are you won’t find squat in the way of expansion,” he says. “In fact, you’ll find contraction in a lot of places.”

That expansion, he believes, has major implications. “The single biggest development project in the history of the Swannanoa Valley is in danger,” he says. “The economic impact will be huge.”

If future manufacturing-and-distribution projects are stymied by the risk of flooding, Hamil predicts a “radically changed” economic future for his hometown.

“If these maps are upheld, then Black Mountain will have little chance of being more than a bedroom community for Asheville,” he predicts.

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3 thoughts on “Waterlogged

  1. Becky

    The 100 year flood (1 percent chance in any given year) does not apply to our section of the Swannanoa in East Asheville. It has flooded 3 times in the last 25 years, the last two catastrophic. It is interesting that in developed areas, the new maps seem to ‘take into consideration’ the development that is already there, and floodway boundaries (where the deep, swift, fast moving currents are — essentially the river itself at high water) have changed little in spite of the ‘real world’ flooding that has occurred. This is good for homeowners who live there, because their flood insurance will not go up. On the other hand, this allows for pretty much unimpeded development. A neighbor of ours recently paved over the majority of their lot for parking and storage, right up to the ‘floodway boundary.’ This was the only regulation that seemed to govern the development, other than the 30 foot trout stream boundary. The County has no stormwater regulations that apply in small lots like we have in our neighborhood. If everyone followed suit in our neighborhood, we were told by river/flood experts that it *would* worsen flooding conditions, as well as impact water quality on our regulated trout stream portion of the river. The floodway boundary is determined by a ‘formula’, and it is the best they can do given budget constraints (they can’t measure every inch of a river to take into account specific topographic changes that affect flooding conditions). But in our case it didn’t help much, in terms of setting a precedent that would protect our neighborhood in the future. As properties change hands and those unfamiliar with mountain environments develop close to rivers, while one project on its own may not have much impact except on its immediate neighbors, the cumulative effect can be significant. We need stronger regs in the County, not weaker ones. Flood insurance is subsidized by you and me, and our tax dollars. Living near water is a privilege, and good floodplain mgmt is presently under ‘the honor system.’ We need better education about wise floodplain mgmt., and preserving water quality and wildlife habitat. When you remove pervious surfaces and replace them with concrete, you permanently change the nature of the land in an adverse way, there is no getting around that, so it should be done wisely and with as much research and knowledge as possible. When you live on a body of water, you’re not in a typical suburban neighborhood where you can just put up a fence and do your own thing. You owe a duty to your neighbors and the ecology of the area.

  2. Becky

    Postscript to above: “good floodplain mgmt is presently under the honor system.” This should have said, *some* aspects of good floodplain mgmt are under the honor system, especially with smaller projects. The County floodway administrator does everything she can within the limits of the present ordinance to honor property owners’ rights, while at the same time protecting the community from the cumulative effects of adding concrete to the floodplain. “The honor system” refers to taking the initiative to educate oneself, and consider issues beyond the ordinance. State officials readily acknowledged to us that our County ordinance is inadequate in light of increasing development in our area. Wise use of the floodplain, especially when directly adjacent to protected water sources, ideally includes accessing river experts readily accessible here in Asheville. Examples are The French Broad River Watershed Education Training Center at the Arboretum, where NC State experts can provide a wealth of experience and assistance, or utilizing local firms like Equinox Environmental, who are eager to assist homeowners in developing their properties in a way respectful of the ecology of mountain rivers and of their neighbors. Less soil + more concrete = adverse effects. There is no way around that. Water quality and wildlife habitat are unavoidably linked with flood plain regulations, but in our area much of this IS entirely under the “honor system”. More knowledge, together with an open mind, can help owners make decisions that mitigate the inevitable harmful effects of developing near a mountain river or lake. Our mountain rivers function completely differently than water sources in flat areas like Florida, yet some developers use the same mindset in improving their properties here. It’s the same problem every beautiful resort area has — people move here because they love the beauty, yet sometimes do not take the time to understand the unique characteristics of the area, and end up destroying part of what they came here to enjoy. Even when profit is not the primary motive, bad development can happen just through ignorance of the issues at hand. Balancing property rights against protecting our mountain ecology is what our commissioners and city officials have to struggle with, with the money and power largely on the side of the profit-oriented developers, who increasingly swarm our area as real estate markets in other areas like Florida hit the skids. The attitude seems to be, hey, we’re improving your property values. What is forgotten is that a lot of us live here because of the quality of life, the beauty, and the abundant wildlife. Increasing “property values” by adding parking space and fences is not the primary motivation for some of us. Where some see a messy riverbank, others see a high quality riparian buffer full of wildlife. We need to speak out and give our commissioners and flood regulators our support, whatever side of the debate we’re on.

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