I echo Betsy Martin's [Letter, “Avoid Building in Floodplains,” Sept. 25 issue] concerns about building in the Mt. Vernon areas classified as 100-year flood area. My residence abuts Dogue Creek between Adrienne Drive and Old Mill Drive. ince we moved in 23 years ago, all 12 trees in the backyard have fallen after heavy rains. About a mile uphill from us are 10 new houses on Colonial Drive. Since they were built, my backyard is now a marsh. Please do not replace trees and vegetations with buildings. They too have their use.