Flooding in Conklin, New York, June 28, 2006
Improving the accuracy of maps can change the floodplain boundary and, thus, which properties are designated within the floodplain. Landowners often seek to avoid this designation,a which can have the effect of increasing insurance premiums, reducing property values, restricting development, and/or requiring costly mitigation efforts, such as raising the elevation of structures. At the same time, home and business owners have a strong financial interest in having their structures properly insured against flood damage. Residents of communities that are not in mapped 100-year floodplains often have no idea they are vulnerable to property losses until they are inundated. Yet one-third of flood insurance claims are for areas beyond the 100-year floodplain.b For example, the largest flood recorded in the Binghamton, New York, area extended beyond the 100-year floodplain to areas where flood insurance is not required, catching residents of the Conklin community off guard. As reported in the Press & Sun-Bulletin:c
When Abby Mack moved into her home on Grandview Avenue in Conklin four years ago, her bank told her she didn’t need flood insurance. A check of information-based flood maps—which officials rely on to predict the frequency and impact of floods—shows her home is above the flood plain. But as the Susquehanna River continued to rise through the twilight hours of June 28, it became clear that her home and others on her street were threatened. Police evacuated bewildered residents shortly before the river began creeping up their tidy lawns and driveways and pouring into basements.… The Mack residence, which lost a hot water heater, other major appliances and carpeting, fared relatively well. The damage was much more extensive just down the street and in other places in Conklin that, according to the maps, shouldn’t have been touched by the flood.… “The whole flood plain has to be studied and re-evaluated,” said Debbie Preston, supervisor of the Town of Conklin, where the recent flood ruined hundreds of properties and forced the evacuation of the entire town.