Construction Stormwater Controls

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​​​ Fourth floor, 301 E Huron St., P.O. Box 8647, Ann Arbor, MI 48107​

Jennifer Lawson, C.S.M.
Water Quality Manager

734.794.6430 x43735

Jerry Hancock,
Stormwater and Floodplain Program Coordinator

734.794.6430 x43709

Kerry Gray,
Urban Forestry and Natural Resources Planner

734.794.6430 x43703

Troy Baughman, P.E.
Senior Project Engineer

734.794.6430 x43798

Uncontrolled run-off from construction sites adversely impacts receiving waters. Sediment, one of the most significant pollutants from construction activities, can reduce the amount of sunlight reaching aquatic plants, clog fish gills, and smother aquatic habitat and spawning areas. Under the Construction Stormwater Control measure, the City of Ann Arbor has a regulatory program in place to control stormwater run-off from construction sites per Chapter 63 of the Code of the City of Ann Arbor: Stormwater and Soil Erosion and Sedimentation Control.


  • A Grading/ Soil Erosion Permit (available from Planning and Development) is required when your project will result in greater than 225 square feet of "earth disturbance," or is located within 500 feet from the w​ater's edge of a lake, wetland, or watercourse.
  • Earth d​isturbance should not be confused with the square footage of impervious surface proposed with the project. Earth disturbance is the area of the site that will be disturbed by the proposed activity including but not limited to: grubbing, grading, excavations, embankments, land development, road reconstruction, and the moving, depositing, stockpiling or storing of soil, rock, or earth materials.
  • ​Clearing more than 10,000 square feet of vegetative canopy, or disturbing a natural feature, also requires a valid grading permit.

Additional requirements​

Construction activities disturbing five acres or more, with a point discharge to the surface waters of the state, are required to submit a Notice of Coverage (NOC) to the Department of Natural Resources and Environment (DNRE) to obtain coverage under Permit-by-Rule. Prior to submitting the NOC, the permittee must obtain coverage under Part 91, Soil Erosion and Sedimentation Control (SESC), of the Natural Resources and Environmental Protection Act, 1994 PA 451, as amended, by obtaining an SESC permit from the City of Ann Arbor.

Regardless if the site is 5 or more acres or receives automatic coverage (1-5 acres), the permittee must comply with all requirements of Permit-by-Rule. One of the primary requirements of Permit-by-Rule is that all permitted sites must be inspected weekly and within 24 hours of a rain or snowmelt event that results in a discharge from the site. The inspections must be conducted and documented on an inspection report form or log by a certified stormwater operator trained and certified by the DNRE.

Common construction stormwater controls

The following are examples of construction stormwater controls commonly used in Ann Arbor. These controls are generally temporary, and are intended to keep construction site stormwater runoff from getting into the storm drain system.

Silt fence

  • Filters stormwater leaving site

Storm sewer inlet filter

  • Filters water entering storm sewer 

Mud tracking mat

  • Releases sediment from vehicle tires prior to entering street

Sediment basin

  • ​Traps sediment 


  • ​Provides suitable growing medium​


  • Provides cover and moisture control for seeds

Straw erosion control blanket

  • Erosion control blanket
  • Holds soil in place until vegetation establishes