The Metropolitan Water Reclamation District (MWRD’s) Watershed Management Ordinance (WMO) requires that new home construction and/or substantial improvements to existing homes need to prove, by means of a topographic survey, that the existing/new home and/or improvements are above the Base Flood Elevation (BFE) by at least 0.10 feet.
Regardless, if you are considering constructing a new home that is within 100’ of the BFE, the following design criteria must be met:
- The top of foundation (and any opening in those foundations) must be at or above the Flood Protection Elevation (FPE).
- It must also be demonstrated that the building and foundation below the BFE are reasonably safe from flooding, per design standard requirements in FEMA Technical Bulletin 10-01.
These requirements include:
- Providing integrally cast window wells with the foundation wall
- Maintaining the top of foundation at a minimum elevation of the FPE
- The foundation must be constructed of poured concrete without seams/joints
- All attendant utilities, including the air conditioning units must be set to at least the FPE
- The foundation elements must be designed and certified to withstand any applied hydrostatic pressures