Minnesota Department of Transportation

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Project development

Environmental process | Environmental review



Wetland regulations require the need to address wetland impacts in the environmental assessment and documentation phase. The purpose of these regulations and guidelines is to protect aquatic resources (including wetlands) while allowing reasonable development to construct projects through fair, flexible, and balanced permit decisions. 

When to use this subject

If a proposed project has the potential to impact any measurable amount of wetland, the environmental document must address the anticipated impacts. Wetland impacts can be permanent or temporary and include fill (i.e., conversion of wetland to non-wetland), excavation (to a depth greater than two meters), and conversion of wetland classification type (either through draining or altering vegetation). The potential to affect wetlands should be investigated if a project involves purchase or easement of additional right of way and/or if the construction footprint is expected to go beyond the current toe of the in slope.

The inventory of wetland resources (including other aquatic features) is important because it forms the basis for all subsequent steps in documentation and permitting. The level of wetland inventory and assessment is dependent on the magnitude and timetable of the project.

OES recommends a two-step approach for large-scale projects with a range of alignment and/or corridor alternatives. District Hydraulics first inventories these wetlands using a Level 1 wetland delineation and then inventories them again later in project development using a Level 2 wetland delineation. In these cases, regulatory entities should review and approve the wetland delineation report during the selection of the preferred alternative or corridor.

For small-scale projects with short timelines, OES recommends a one-step approach. The one-step approach inventories wetlands once using the appropriate level of wetland delineation. For this approach, submit the wetland delineation and the permit application for review in tandem to the US Army Corps of Engineers (USACE) and OES.

For assistance with determining which level of wetland delineation to use, please refer to the Wetland Delineation Guidance on the BWSR website.

For specific process information, see the processother guidancepages, and/or contact the individual on the contacts page.

How this subject fits into the overall project development process

Start this process during the scoping phase. You must complete it by final design. Follow the required steps in the P6 process.

Organizations involved

  • MnDOT:
  • US Fish and Wildlife Service (USFWS)
  • US Forest Service (USFS)
  • Minnesota Department of Natural Resources (MNDNR)
  • Minnesota Pollution Control Agency (MPCA)
  • Board of Water and Soil Resources (BWSR)
  • Wetland Conservation Act (WCA) Local Government Units (LGUs)
  • Watershed Districts