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Arkansas - Lower White Bayou Des Arc Watershed

Base Level Engineering
Case Number
Region VI
Preliminary map
Appeal & Comment
Projected Effective
Project Status

Base Level Engineering (BLE) project:  FEMA has prepared cursory flood risk assessment at a watershed level to support the review and validation of the flood hazard information shown on the Flood Insurance Rate Maps (FIRM). The Base Level Engineering approach uses high resolution ground elevation data, calculates high level flood flow estimations, and prepares hydraulic modeling to determine how natural water courses convey the calculated flood flows.  The Base Level Engineering produces estimated flood extents for a variety of flood events, including the 1% and 0.2% annual chance events.

This assessment is based on current conditions is informed by readily available land use data, providing valuable flood risk information for a number of streams that are currently not included in FEMA’s flood inventory. This effort provides flood hazard data for the 1-percent annual chance flood event, providing data that can be used for local planning and development and in advance of a FIRM update. Base Level Engineering information DOES NOT replace the information shown on any current effective FIRM panel in a community.  This data may be used by local community officials where the Flood Insurance Rate Maps (FIRMs) may not have flood risk information coverage.

Discovery Information: A Discovery effort, led by the State Cooperating Technical Partner, Arkansas Natural Resources Commission (ANRC), is currently in the planning stages.  The State will be reaching out to communities within the watershed to coordinate prior to any Discovery Meetings being held.

The Discovery process includes an opportunity for local communities to provide information about their concerns related to flood and other natural hazard risks. FEMA relies heavily on the information and data provided at the local level, and uses the input collected in Discovery to identify future Flood Risk Projects, specifically focused to identify:

  • areas where the current flood hazard inventory does not provide adequate detail to support local floodplain management activities,
  • areas of mitigation interest that may require more detailed engineering information than is currently available, and
  • community intent to reduce the risk throughout the watershed to assist FEMA’s future investment in these project areas.

    FEMA and its mapping partners will work closely with communities to determine the appropriate analysis approach, based on the data needs throughout the community. These potential projects may include local training sessions, data development activities, outreach support to local communities wanting to step up their efforts, or the development of flood risk datasets within areas of concern to allow a more in-depth discussion of risk. Communities may inform FEMA’s future project identification effort by providing previously prepared survey data, as-built stream crossing information, and engineering flood risk studies for incorporation.Next Project Step:         Discovery


    Project Meetings: Discovery - PENDING

    Documents and Data:

    BLE Data Available:      PENDING

    View BLE Data:             PENDING

Additional Resources: What is Risk MAP?; FAQs - Flood Hazard Mapping; ANRC – Floodplain Management References;