Chesterton Tribune



Stormwater board successfully appeals FEMA inaccurate flood map

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What’s the difference between 628 feet above mean sea level and 636 feet?

Hundreds of dollars or more, perhaps, if your house near the banks of Sand Creek appears on the Town of Chesterton’s flood insurance rate map at the 628-foot elevation. That’s the base-flood elevation in the area, at which there is technically a 1-percent chance of your home’s being flooded by a two-hour--or 100-year--rain, and therefore a 100-percent chance of a home lender’s requiring you to obtain flood insurance.

“No question, you’d have to get it at 628 feet,” MS4 Operator Jennifer Gadzala, the town’s point person for everything water, recently told the Chesterton Tribune.

On the other hand, at 630 feet--only two feet above the base-flood elevation--your home is officially safe from a 100-year rain, according to the Federal Emergency Management Agency, and so exempt from the insurance requirement (although a bank could, at its discretion, still insist on a policy).

A mistake of a few feet, in other words, could hit a home buyer hard in the wallet. Could hit a homeowner as well, should a revised flood insurance rate map erroneously include his or her house in the floodplain.

So when, last year, Gadzala received from FEMA a preliminary version of a new map--meant to replace the one in use since 1984--she noticed, without thinking too much about it, that “nothing seemed to be changing in the way the lines were drawn.”

“I saw a few minor adjustments,” Gadzala said. “But I’m a stickler for reviewing all the little details.”

Which she did.

To discover that, on both the current map and the preliminary one, “buildings were being partially covered or touched by a floodplain.” In the end, Gadzala said, the floodplain as drawn by the Indiana Department of Natural Resources--which does the actual mapping on behalf of FEMA--cut across or encroached on “40-some” buildings.

Possibly those buildings had been built sometime since 1984, Gadzala said, but there was no way of knowing for sure without additional research, because the 1984 map was not superimposed over an aerial photograph, as the preliminary map was.

So Gadzala put the 1984 map under the microscope and what she found baffled her. The floodplain as drawn on that document was not based on “ground-truthed” elevations at all but instead on a topography map showing 10-foot contour lines. Not only that, though. The floodplain as drawn by DNR didn’t even, in some cases, follow the particular water body on the topo map, be it Sand Creek, Coffee Creek, or the eastern branch of the Little Calumet River.

Gadzala’s next step was to compare elevations on the current and preliminary maps to those derived from a 2010 LIDAR survey contracted by the Porter County Commissioners. LIDAR, which “shoots a lot of points from a plane to the ground,” produces a highly accurate body of elevations, far more accurate as it turned out than those on either of the maps drawn by DNR.

Thus, for instance, a pair of houses near the banks of Sand Creek is shown on those two maps to be at the base-elevation of 628 feet. In fact, the ground-truthed elevations in that little bit of map vary from 628 feet to all of 636 feet--a “tremendous” difference of eight feet, Gadzala noted--while the back of each house came in at 632-633 feet: four to five feet above the base-elevation, and fully two to three feet above the legal threshold at which home lenders require flood insurance.

In the end, the Stormwater Management Board authorized Gadzala In July 2014 to file an official appeal of the preliminary map and at the same time retained the services of engineering consultant DLZ to prepare a revision of the DNR’s preliminary map. That revision, based on the LIDAR data, carved out of the preliminary map all but two of the 40-some buildings.

On Dec. 19, FEMA notified Gadzala that it had resolved the appeal in the town’s favor and that the DNR will re-draw the preliminary map in accordance with the new data. “There was no way they could argue against this,” she said.

Seventeen homes in Chesterton not incorrectly mapped are currently covered by the National Flood Insurance Program. Those policies provide for total coverage of $4.3 million at a total annual premium cost of $9,000, averaging $530 per policy, Gadzala noted. Not chicken-feed at all.

But under the Homeowner Flood Insurance Affordability Act of 2014, premiums which are currently subsidized--“artificially low,” as FEMA puts it--are going to rise by no less than 5 percent per year, until the particular class of policy reaches its full-risk rate.

How big an expense that ultimately might have proved to any of the 40-some property owners whose homes or buildings were incorrectly mapped is unclear. It could have been a lot, though, Gadzala said. “It’s hard to say because FEMA has never said what the cost will increase to. But they’ve used the work ‘significant.’”

“It was worth doing the appeal,” Gadzala added. “In the long run it will save a lot of homeowners the time and money of having to prove they’re not in the new floodplain.”

For more information, call Jennifer Gadzala at the Stormwater Utility, (219) 728-1336.


Posted 1/29/2015





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