Wetland Mitigation Bank

Prairie Green Preserve also contains a wetland mitigation bank comprised of 106 acres (76 acres of wetland and 30 acres of associated buffer and prairie areas). The purpose of the bank is to mitigate wetland impacts primarily in the Fox River watershed.

The Federal government (under section 404 of the Clean Water Act) requires mitigation for the destruction or disturbance of any jurisdictional wetland area. Developers can purchase wetland mitigation bank credits to mitigate the adverse impact a specific land development has on a wetland.

An Interagency Coordination Agreement (ICA) has been established between the Chicago District of the U.S. Army Corps of Engineers, the U.S. Environmental Protection Agency, and the U.S. Fish and Wildlife Service.

The ICA serves as the basis for the establishment and certification of the City’s mitigation bank, as well as authorizes the withdrawal of credits from the bank. In 2008, the U.S Army Corps of Engineers formally approved the Prairie Green Preserve wetland mitigation bank. Prairie Green Preserve’s 106 acres represents a total of 83 acre credits (the credits are less than actual acreage because a 25 percent credit ratio is applied to the 21 acre buffer and nine-acre prairie). The first phase of wetland construction (approximately 30 acres) was completed in 2007.

The Army Corps of Engineers approved wetland mitigation bank must be operated in accordance with the wetland banking instrument, which has been executed by several national agencies and the City of Geneva. Under the provisions of the instrument, credits can be sold as either uncertified or certified credits.

In 2010, the Corps approved the as-built construction drawings for Prairie Green Preserve and released 24.99 credits (30 percent of the 83 acre credits) to the City for immediate sale as uncertified credits.

An additional 16.66 (20 percent) of credits will be released for sale as uncertified credits after a review the wetland hydrology of the site and the established plantings are approved. The final 50 percent of the credits will be available when performance criteria for the entire Prairie Green Wetland Mitigation Bank Site are met and approved by the Corps.

ICA Established Rules For Acquiring Credits

Credits may be acquired by qualified buyers as compensatory mitigation to offset unavoidable wetland losses on the following basis:

  • In cases where wetland banking credits are based on created or restored wetlands and are being acquired within the same watershed as the bank site (as defined on the watershed map labeled Attachment A), the following criteria apply:
    • If the wetland credits are certified by the Corps, one wetland credit shall be acquired for every acre of wetland to be filled or adversely impacted;

    • If the wetland credits are either uncertified or conditionally certified by the Corps, qualified buyers must acquire 1.5 wetland credit for every acre of wetland filled or adversely impacted.

  • If credits are sought from outside the watershed of the bank site, the above ratios shall be multiplied by a factor of two. If wetland banking credits are based on enhancement, higher mitigation ratios shall apply as determined by the Corps in coordination with the other signatories. The use of a bank to compensate for impacts outside the watershed boundaries established in this agreement may be authorized on a case-by-case basis at the discretion of the mitigation bank review team, where the team has determined it to be practicable and environmentally desirable.