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Arkansas - L'Anguille Watershed

Base Level Engineering
Case Number: 
Affected Counties: 
Craighead County, AR
Cross County, AR
Lee County, AR
Poinsett County, AR
St. Francis County, AR
Woodruff County, AR
Preliminary map: 
Projected Effective: 
Project Status: 

To allow individuals, communities, States and Federal entities an opportunity to engage with the Base Level Engineering watershed assessment results, FEMA developed the Estimated Base Flood Elevation (BFE) Viewer. The viewer provides an estimated flood risk (high, moderate, low), returns site specific estimated flood elevations and flood depths.

Base Level Engineering (BLE) project:  FEMA has prepared cursory flood hazard analysis at a watershed level to support the assessment of the flood hazard data shown on their 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 predicted flood and defines estimated flood extents.

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 underway.  The State has been working with communities in the watershed area to identify flood concerns and flood data needs to inform future flood risk assessments and studies.

Future Project Identification: 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 identified by the watershed communities. 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.

Next Project Step:         Future Project Identification

Dates: BLE Data Available (11/29/2017)

Project Meetings: Discovery (07/12 - 13/2017)

Documents and Data:

BLE Data Available:      11/29/2017 (pending upload to viewer)

View BLE Data:   

Additional Resources: What is Risk MAP?; FAQs - Flood Hazard Mapping; ANRC – Floodplain Management References; L’Anguille Watershed Flood Risk Report