New buildings in the floodplain must be protected from flood damage. Douglas County's building code requires that new structures must be elevated at least one foot above the base flood elevation (or a minimum of 2’ elevation in the Urban Growth Area of the City of Lawrence). No new construction or filling is allowed in the floodway, unless it can be demonstrated through hydrologic analysis that it will not increase in the base flood elevation. Development includes any man-made change to the land or buildings, including, but not limited to:
- the construction of structures or additions to structures,
- the placement of mobile homes or accessory structures,
- the renovation, repair or improvement of the interior and/or exterior of existing structures,
- the conversion of garages, carports, storage rooms, porches, patios and similar spaces into living space,
- the addition or replacement of any machinery and equipment (HVAC units, propane tanks, etc.) servicing the building,
- mining, dredging, filling, grading, paving, excavating, drilling,
- the storage of materials or equipment.
Structures are required to be dry floodproofed and have the lowest floor elevated at least 1’ above the Base Flood Elevation (or a minimum of 2’ elevation in the Urban Growth Area of Lawrence). The minimum elevation applies to HVAC, water heaters, heat pumps, and similar machinery and equipment.
Wet floodproofing is permitted for Ag buildings and other non-habitable structures.
Always call the Douglas County Zoning & Codes Department at 785.331.1343 before you build, alter, re-grade or fill on your property. If you see building or filling without the County's approval, please notify us. A permit is required to ensure that projects do not cause problems on other properties and meet local, State and Federal requirements.
If new construction or renovations are in the floodplain, a flood development permit is required prior to the issue of the building permit.
Please see Douglas County Floodplain Management Regulations 12-328 for construction in floodplains.
Additional helpful information:
- FEMA Technical Bulletin 1 - Openings in Foundation Walls and Walls with Enclosures
- FEMA Technical Bulletin 2 - Flood Resistant Materials: Flood damage resistant materials requirements for buildings located in the special flood hazard district
- FEMA Dry Floodproofing - Dry floodproofing structures
- FEMA Technical Bulletin 7 - Wet Floodproof: Wet floodproofing requirements for structures located in the special flood hazard areas
- FEMA Non-Residential Floodproofing - Requirements and certification for buildings located in special flood hazard areas
- Other FEMA Publications
