About one-half of the structures in Chelsea village are located within regulatory floodplain. Federal floodplain maps first became effective in Chelsea in 1980 and Chelsea adopted its first flood hazard bylaw at that time. Towns have come under greater pressure to enforce their flood hazard regulations since Tropical Storm Irene in 2011, and homeowners have seen their flood insurance rates jump since Congress adopted flood insurance reforms in 2012. Unfortunately, the floodplain maps are difficult to read and interpret, are in some places out-of-date or inaccurate, and often require additional survey or engineering work (at the landowners’ expense) to precisely determine whether a property is located within regulatory floodplain, and if it is, what the base flood elevation (BFE) would be. In addition to Chelsea village, there is regulatory floodplain along the First Branch White River and South Washington Brook, as well as portions of Crams Brook.
New structures constructed within regulatory floodplain must have their lowest floor elevated above base flood elevation (BFE), repairs or renovation to an existing structure that equal or exceed 50% or the market value of the property (a “substantial improvement”) could likewise trigger the requirement that the lowest floor be elevated above BFE.
Chelsea’s current Flood Hazard Bylaw was adopted on November 7, 2017 and is attached below: