What is compensatory storage?

Compensatory storage is an artificially excavated, storage volume within the 100-year floodplain that is required to offset the loss of natural storage capacity caused by the placement of fill, structures, or other materials above the existing natural grade. Compensatory storage must meet the following requirements (For the full description of the requirements, please see the Section 15.68 of the Village’s Flood Hazard Protection Ordinance and the MWRD WMO, Article 6):

  • Equal to at least 1.1 the volume of flood storage lost below the BFE;
  • Be operational prior to the placement of any fill;
  • Must be able to drain without the use of a pump or other mechanical means;
  • Must be freely flowing into and out of the storage facility (no underground compensatory storage unless at least one end of the pipe/system is exposed to the invert of the pipe/system).

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?