December 02, 2024

Extension Notebook: Rules for dam maintenance or construction

For those having ponds, there is eventually a need for maintenance of the pond and dam. Most of the time, this can be done without getting governmental approval. However, certain situations require getting approval for dam maintenance or construction. The following information comes from the Illinois Department of Natural Resources.

The IDNR Division of Water Resource Management issues permits for work in and along the rivers, lakes and streams of the state, for activities in and along the public waters, and for the construction and maintenance of dams. Generally, the division issues an individual formal permit to the applicant to demonstrate compliance with the rules. In some cases, the division has issued statewide, regional and general permits to reduce paperwork for the applicant. The statewide and regional permits describe a general project type and set limits on the scope of the work. If the proposed work meets all the specified limits, the project is approved under the statewide or regional permit. For projects covered by a statewide or regional permit, one does not need to submit a permit application.

All construction activities in the floodways of streams (the channel and the adjacent portion of the floodplain that is needed to safely convey and store flood waters) in urban areas where the stream drainage area is one square mile or more or in rural areas where the stream drainage area is 10 square miles or more must be permitted by the division prior to construction. Floodways have been delineated for many of these streams and appear on the Federal Emergency Management Agency’s Flood Insurance Rate Maps. Those maps are available for viewing at the local building and/or zoning offices and FEMA’s Map Service Center. If a floodway has not been previously delineated, the division generally requires permits for work anywhere in the floodplain. A number of common minor construction activities are automatically authorized by statewide permits. A permit application submittal to the division is not needed for a construction activity that meets the terms and conditions of a statewide permit.

In general, the applicant must demonstrate that the appropriate use will not reduce floodway conveyance or storage, and will not increase velocities and flood heights. These rules also include requirements for revising the designated floodway boundary and/or flood profiles.

All applications and written inquiries received will be reviewed free of charge to determine whether or not the public water, dam and/or floodway work proposed requires authorization by the department, so long as sufficient information is provided for the department to make that determination.

For information on what are considered public waters of Illinois, visit the IDNR website at:https://dnr.illinois.gov/waterresources/damsafetyprogram.html.

Duane Friend is the state master naturalist coordinator and climate specialist with University of Illinois Extension.