Little Elm, TX Environmental Rules: Flood Zones (2026)

Little Elm has extensive FEMA-mapped special flood hazard areas due to its location on the shores of Lewisville Lake and downstream of the Lewisville Lake Dam operated by the U.S. Army Corps of Engineers. The town participates in the National Flood Insurance Program (NFIP) and enforces flood damage prevention ordinance standards that meet or exceed FEMA minimum requirements. Base Flood Elevations (BFEs) represent the water surface elevation of the 100-year flood (1-percent-annual-chance flood) for both stream flooding and lake-related flooding. New construction and substantial improvements in the Special Flood Hazard Area must have the lowest floor elevated to or above the BFE plus any locally required freeboard. Substantial improvements (exceeding 50 percent of market value) to existing structures in the floodplain trigger the elevation requirement. Development in the floodway is generally prohibited unless a no-rise certification from a licensed professional engineer demonstrates zero increase in flood levels. Flood insurance is required by mortgage lenders for properties with federally-backed loans in FEMA-mapped flood zones. The town maintains current Flood Insurance Rate Map (FIRM) panels and provides flood zone determination assistance through the Development Services department. Denton County also administers floodplain management for unincorporated areas near Little Elm.