Roger Mills, Oklahoma and the Washita Headwaters HUC8 watershed will be studied within the State of Oklahoma to produce updated Flood Risk information. This Flood Risk Study will prepare:
Hydrology Analysis will be prepared to determine the amount of flood water expected during a range of storm events. Hydrology will be prepared for the following annual chance storm event frequencies: 10%, 4%, 2%, 1%, and 0.2%. FEMA will also prepare a 1%+ and a 1%- event frequency events to assess the current flood hazard inventory within the watershed area. A 1% annual chance storm has the potential described as a 1 in 100 chance of occurring in any calendar year. The 1% annual chance storm is the standard floodplain delineated on a Flood Insurance Rate Map, or FIRM.
Hydraulic Analysis will be prepared to review how these storm waters are conveyed by the overland natural drainage (creeks, rivers, streams) within the watershed. These hydraulic models will estimate the flood volume that can be conveyed in the natural drainage courses and will identify the areas where floodwater will inundate the larger and natural floodplain that extends beyond the everyday stream channel.
Floodplain Mapping is then prepared on high quality digital ground elevation information to identify the physical extent and location of the expected floodwater (described as the floodplain) during each of the storm event frequencies. These floodplain extents can be used to investigate the flood risk, vulnerability and extent of flooding expected in any community assessed.
The engineering analysis will also prepare a range of Flood Risk Datasets that will allow local community officials to better understand the potential flood risk and the variability of flood risk throughout any identified floodplain area. Community officials and technical staff will be engaged throughout the development of this flood hazard information.
For more helpful information, look under Resources and Related Links.
For mapping questions, contact the FEMA Mapping Information eXchange (FMIX) – 1-877-336-2627.