Rock Island District Mitigation Banking/ILF Guidance Version 2.0 (Revision)

TO WHOM IT MAY CONCERN: The U.S Army Corps of Engineers Rock Island District, with the assistance of both the Iowa and Illinois interagency review teams (IRT), including Illinois DNR, and USEPA (Regions 5 & 7) have revised the original mitigation banking guidance last updated in July of 2019. The revised guidance provides direction to prospective mitigation bankers within the Rock Island District boundary (Iowa and Illinois). The banking guidance has been revised to update outdated information and to incorporate new guidance. This guidance contains procedures and information to initiate the development of new mitigation bank/ILF proposals or amendments to existing mitigation banks within Rock Island District pursuant to 404 of the Clean Water Act (33 USC 1344) and Section 10 of the Rivers and Harbors Act (33 USC 403).

APPLICANT: The U.S. Army Corps of Engineers, Rock Island District

SIGNIFICANT CHANGES:  

1. Incorporation of FAA site selection criteria, which advise against establishing new mitigation sites that may serve as hazardous wildlife attractants within a 5-mile radius of an airport's approach, departure, and circling airspace.
2. Provided guidance on the application of the watershed approach for bank site selection, emphasizing alignment with regional ecological priorities and watershed-scale planning objectives.
3. Incorporated updated cultural resource requirements to assist the Bank Sponsor in identifying potential cultural concerns that may inform and enhance bank design. The revised guidance outlines the specific types of cultural resource surveys required and establishes the appropriate phases within the process for their implementation. Furthermore, it requires that the final Mitigation Banking Instrument (MBI) clearly delineate all areas of ground disturbance, areas with no anticipated ground disturbance, and locations subject to hydrologic modification. This information must be presented on a detailed map specifically designed to identify areas requiring archaeological surveys.
4. Provides enhanced guidance on the required baseline information, including the assessment of existing stream conditions and related concerns, as well as the incorporation of both qualitative and quantitative vegetative assessments.
5. Establishes a hydrology requirement that exceeds the minimum 14-day saturation and inundation standard set forth in the 1987 U.S. Army Corps of Engineers Wetland Delineation Manual and the Midwest Regional Supplement, by mandating a minimum of 21 consecutive days of saturation and/or inundation during the growing season.
6. Revised groundwater monitoring well requirements to mandate installation at the highest elevations within delineated wetland boundaries. These locations are intended to confirm the presence of wetland hydrology in marginal areas where hydrologic indicators may be less evident. While these points often align with the inner buffer margins, exceptions may be warranted based on site-specific topographic conditions. Additional monitoring wells may be installed, as necessary, to resolve uncertainties regarding the presence or absence of wetland hydrology in specific areas.
7. Revised multiple wetland and buffer performance standards, including an increase in the allowable invasive species coverage threshold from 5% to 10% across all wetland and wetland buffer areas. Additionally, new performance standards were established for forested enhancement wetlands to better evaluate and guide ecological outcomes in these areas.
8. Revised in-stream performance standards include new requirements for comprehensive physical, chemical, and biological assessments, ensuring a more holistic evaluation of stream restoration success.
9. Established formal accounting procedures, including the requirement that mitigation credits may not be sold without an officially signed U.S. Army Corps of Engineers (USACE) permit. Additionally, credits shall not be reserved by applicants until a permit application has been submitted to the USACE and a permit number has been assigned to the project.

GUIDANCE LOCATION: The updated mitigation banking/ILF guidance can be found at the following location: https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll9/id/3143

COMMENTS:  This notice is meant to inform the public on the issuance of the updated mitigation banking/ILF guidance.  The Corps is not seeking comments as we have reviewed as a result of the December 10, 2024, public notice.  We have addressed and incorporated those comments that the IRT and Corps felt prudent and necessary. 

REPLY TO THE CORPS OF ENGINEERS:  Comments or questions concerning this notice may be sent via email to iowaregulatory@usace.army.mil or by calling 309-794-5377, or by writing to the following address: US Army Corps of Engineers, Rock Island District, ATTN: Regulatory Department, Clock Tower Building - Post Office Box 2004, Rock Island, Illinois 61204-2004.