Aitkin County Wetland Mitigation Project

A confidential client retained Hatch Mott MacDonald to provide “cradle to grave” wetland mitigation design/construction services to address a federal and state wetland credit shortage due to current projected wetland impacts at two Minnesota mining facilities.

The project involved a first phase restoration of ~1,416 acres with a potential build-out of ~4,400 acres. The Army Corps of Engineers, MN Technical Evaluation Panel (TEP), and local governing agencies (LGU) required the first phase of the mitigation to include emergent marsh type 2 and 3 wetlands, shrub-carr wetlands, and forested wetlands. The project involved wetland delineations requiring ~5,000 plus wetland delineation surveyed flags, hydrology and hydraulic studies/modeling (ModFlow), and various federal, state, and county compliance reports and local permits. Work included meetings and negotiations with federal, state, and local agencies for project approvals and concurrence.

HMM worked closely with the client to provide the required fieldwork and written documentation to support wetlands restoration of approximately 1,416 acres. The project included wetland reports, hydrology and hydraulic studies, wetland mitigation plantings, grading, as well as construction management, necessary to offset ongoing and projected wetland impacts at the client’s site in another watershed.

Project Highlights

• Wetland delineation for Phase 1 involved ~1,416 acres of agricultural land where approximately 5,000 plus wetland flags were placed in the field for federal and state review and jurisdictional approval


• Metes and bound survey and topographic survey, including ~15 mi of ditches


• Hydrology and hydraulic modeling for surface and groundwater involving more than 36 mi of drainage ditches, swales, streams, and wetlands


• Installation of nested piezometers, shallow/deep wells, and staff gauges in key hydrological locations with bi-weekly monitoring