The studies described in this report developed flood hazard data that will be used to establish actuarial flood insurance rates and to assist communities in efforts to implement sound floodplain management. This Flood Insurance Study (FIS) Report revises and updates information on the existence and severity of flood hazards for the study area. Ĭall your local municipality, FEMA's Map Specialist at (877) FEMA MAP (1-87), or Chester County at 61 for help with any questions regarding FEMA floodplains. You can also click on a box to see the two-foot contours if you are interested in the topography.įor more information behind the science of the 100-year flood and floodplains, visit this USGS webpage. Click on 'TOC' and click on the 'Flood Risk Mapping' to see the FEMA floodplain boundaries. To better understand the location of the FEMA floodplain boundary to your property boundary, you can use ChescoViews. A devastating rainstorm can occur and many properties outside the 100-year floodplain may be flooded in any given year. The FEMA map also does not imply that properties outside of the 100-year floodplain will never flood. A 100-year flood could occur twice in five years. It is more accurate to refer to it as a 1% annual chance of the area flooding in any given year. However, a 100-year flood is not something that occurs once every 100 years. FEMA chose a 'standard size' storm to approximate the floodplain map boundaries, and that storm was the 100-year flood event. You are also welcome to call us at the Chester County Water Resources Authority at 61 or email us at with any questions.įEMA's mapping of floodplains approximates where floodwaters may rise, however even if the property is outside of a FEMA floodplain, it may still flood. Call FEMA Map Specialists at 1-877-FEMA-MAP. To view the new interactive online FEMA floodplain maps, visit their Map Service Center website and type in the street address for the property of interest. The Federal Emergency Management Agency updated the floodplain maps for portions of Chester County in 2017, and these maps went into effect on September 29, 2017.

Fema all possible flood zone types