What are the criteria for being able to construct a new home with a basement in the 100-year flood plain?

There are two main criteria:

  1. There is the Minimum Average Lot Grade Requirement:
    • Per the Village’s flood hazard protection ordinance, the Average Lot Grade must be greater than the Minimum Average Lot Grade. That means that if you took the average lot grade, which is the average of the existing elevations taken at the intersection of the setback lines, it must be a greater value than the Minimum Average Lot Grade. The Minimum Average Lot Grade Equations is as follows:
      • Minimum Average Lot Grade: (627.3-2) - [(total required side yard permitted by Zoning - 12 feet) x 0.0833]
    • It is recommended that the prospective builder consult with a Professional Civil Engineer to investigate the logistics of constructing a new home with a basement on a lot.
  2. There are clay pad construction restrictions which may directly affect the size of the home, and are as follows:
    • The lowest finished grade for the top of the clay pad must be at least to the Flood Protection Elevation (FPE), and extend at least 10’ beyond the exterior face of the home’s foundation wall, around the entire perimeter of the home, before dropping to the Base Flood Elevation (BFE)
    • The BFE must extend at least 20 feet beyond the exterior face of the home’s foundation wall, around the entire perimeter of the home, before dropping below the BFE
    • The basement floor elevation can be no deeper than 5’ below the BFE
    • The elevation of the lowest opening in the basement wall (i.e. window wells, access ways…) must be at or above the FPE. This means that all window wells/access ways must be integrally constructed with the foundation wall without joints or seams

There are additional criteria that must be met, but they are more material-related.

Show All Answers

1. What is the 100-year flood plain?
2. What regulations must be followed for construction within and adjacent to the flood plain?
3. What is the Base Flood Elevation (BFE)?
4. What is the Flood Protection Elevation (FPE)?
5. When is my house considered in the flood plain?
6. My property was never in the flood plain before, why is it in the flood plain now?
7. When do I need to buy flood insurance?
8. Can I build in the flood plain?
9. Are there any restrictions for construction for homes adjacent to the 100-year flood plain?
10. What are the criteria for being able to construct a new home with a basement in the 100-year flood plain?
11. Can I make improvements to my existing home in the flood plain?
12. What is compensatory storage?
13. How can I find out if my property is located within the flood plain?