Office of Location and Environment


NE Iowa Fall trees

Many of the documents OLE prepares are completed to meet federal standards. The main documents are:

  1. Section 404 permits of the Clean Water Act
  2. National Environmental Policy Act (NEPA) documents
  3. Section 4(f)
  4. Interchange Justification Reports (IJR)
  5. National Historic Preservation Act (NHPA) compliance

The Section 404 permit is part of the Clean Water Act. Its goal is to, "regulate the discharge of dredged or fill material into waters of the United States, including wetlands. Regulated activities include fills for development, water resource projects, infrastructure development, and conversion of wetlands to uplands for farming and forestry."

So if a wetland or stream is unable to be avoided by a road project, OLE applies for a permit from the Army Corps of Engineers. In this permit, OLE staff outlines the effort to avoid the impact and the plan to mitigate for any loss.

The National Environmental Policy Act requires agencies to integrate environmental values into their decision-making process by considering the environmental impacts of their proposed actions and reasonable alternatives to these actions. OLE prepares documents to show how the Iowa DOT is meeting these requirements. There are three levels of documents that can be prepared depending on how many variables are affected by a project.

  • A categorical exclusion is written when the road project will not have a significant impact on the environment.
  • An environmental assessment is written when an environmental impact will occur, but the significance is not clearly established.
  • An environmental impact statement is the most comprehensive of the documents and is written when the impact to the environment will be significant.

Section 4(f) regulation of the federal Department of Transportation Act of 1966 requires the Iowa DOT to avoid significant publicly owned lands such as parks, recreation areas, wildlife and waterfowl refuges, and historic sites.

Another document OLE prepares for the Federal government is an Interchange Justification Report. These are prepared any time an interchange is modified or added to an existing interstate system.

Section 106 of the National Historic Preservation Act requires federal agencies to take into account the effects of their undertakings on cultural resources and provide the Advisory Council on Historic Preservation a reasonable opportunity to comment. Compliance is most often accomplished through consultation with the Iowa State Historic Preservation Officer (SHPO) and may include the submittal of archaeological and historical surveys.

When appropriate, the reports are shared with the public and many different local, state and federal agencies having an interest in the protection of Iowa's resources — both natural and cultural. The Iowa DOT will not make important decisions about the location or design features of any highway improvement project being planned without first giving careful consideration to this information and making sure the project will cause as little harm to the environment as possible. The reviewing resource agencies, and the public, will have an opportunity to send comments to the Iowa DOT after reading the reports.