100 Year Flood Maps

100 Year Flood Maps. Last Modified: July 5, 2023 (0 ratings, 0 comments, 11,951 views) Explore geographic data with this interactive ArcGIS web application.

Explore geographic data with this interactive ArcGIS web application. FEMA is the official public source for flood maps for insurance purposes:FEMA's Flood Map Service CenterFEMA's National Flood Hazard LayerNOAA is responsible for producing flood forecast maps that combine precipitation data with USGS streamflow data:NWS - National Water Prediction Service: River forecasts and long range flood outlookCoastal Inundation Dashboard: Real-time and historical.

A 1% annual risk of being flooded was the line FEMA drew A line had to be drawn somewhere to make the FEMA flood maps Those areas have at least a one-in-four chance of flooding during a 30-year mortgage.

. For instance, on a given river, the flood quantile corresponding to the 50-year flood might be 10,000 cubic feet per second (cfs) and the flood quantile corresponding to the 100-year flood might be 15,000 cfs. from 100-year flood, or shallow flooding areas with average depths of less than one foot or drainage areas less than 1 square mile

. A 1% annual risk of being flooded was the line FEMA drew The 100-year flood is referred to as the 1% annual exceedance probability flood, since it is a flood that has a 1% chance of being equaled or exceeded in any single year.