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Soil Erosion and Sedimentation Control

Welcome to the Soil Erosion and Sedimentation Control homepage. The purpose of our program is to deliver water quality protection, for the benefit of the people and wildlife of Michigan within Washtenaw County.

Our office regulates earth moving activities for all of Washtenaw County except City of Ann Arbor, City of Chelsea, Bridgewater Township, Dexter Township, Freedom Township, Lima Township, Lyndon Township, Manchester Township, Pittsfield Township, Sharon Township, Sylvan Township, Ypsilanti Township, and the Village of Manchester. 

Our webpage includes the following information:



Why is Sedimentation Control Important?

Safety Reasons

  • Eroded soils can enter water bodies and channels, raising water levels and blocking culverts. This can increase the chances for inundation of surrounding land.
  • Sediment (soil that has been eroded) can get deposited onto streets and roads by vehicles leaving the site or by stormwater runoff. When wet, these sediments can be dangerous for drivers and bicycle riders.

Environmental Reasons

  • Sediment in water bodies can cover the eggs of fish and other organisms, preventing them from reproducing.
  • Excess sediment that is suspended in streams and rivers acts like sandpaper on fish and other organisms. Suspended sediment can also abrade the tissues of plants that live in the water.
  • Sediment in water bodies can clog the gills of fish and other organisms that have gills, making breathing difficult.
  • Sediment reduces light penetration, making photosynthesis more difficult for water plants.
  • While blocking light penetration, the soil particles absorb the heat from sunlight and later release it, thereby raising the temperature of the water and driving off desirable fish populations.

Aesthetic & Recreational Reasons

  • Clear water is more desirable for swimming, boating, canoeing and fishing than mud-filled water.
  • Excess sediments build up in lakes and rivers. This raises the water level but reduces water depth, which decreases canoeing and fishing opportunities.

Economic Reasons

  • Excess sediment can increase the cost of treating drinking water and negatively affect the equipment used in the drinking water treatment process. This increases the cost of treating drinking water.
  • Other pollutants such as pesticides, herbicides and oil, can become attached to eroded soils and enter water bodies along with the soil. These contaminants can making swimming unhealthy for children and adults.

Grading Requirements

  • A project/property identifier must be posted and visible from the road at time of application in order to conduct a preliminary inspection which is required before a permit may be issued.
  • A copy of the permit and approved plans must be kept at the work site and visible from the road, and available at time of inspection.
  • No earth moving activity can begin without a grading permit.
  • Silt fencing, if required, must be trenched in a minimum of 6 inches and backfilled. The fencing may be toed-in with pea gravel if installed in winter.
  • Stone access drives must be installed prior to construction with a minimum of 50 feet in length.
  • Stockpiling of any excavated material must be kept away from sensitive areas and adequate controls must be in place.
  • Catch basins, if installed, must be protected with silt sacks or Catch-All type protection.
  • Dewatering operations must have some type of control, e.g. filter bag, vegetative filter area. There shall be no dewatering of unfiltered water.
  • Erosion control blankets are required on slopes of 4:1 or steeper.
  • Rock check dams are to be used instead of straw bales or silt fencing in concentrated flow locations such as ditches.
  • Immediately after installation of stormwater outlets, rip rap must be installed.
  • All areas of a project that are disturbed must be temporarily or permanently stabilized by December 1.
  • All earth changes shall be designed, constructed and completed in such a manner which limits the exposed area of any disturbed land for the shortest possible period of time.

Grading Standards

  • Detention/retention/sedimentation ponds must be constructed and stabilized prior to other earth moving activities to collect sediment caused by erosion. This shall be designed and constructed to reduce the water flow to a non-erosive velocity (see Washtenaw County Water Resource Commissioner's Specifications).
  • After all temporary erosion control measures have been installed, the owner/contractor shall call this office for an installation inspection.
  • Permanent erosion control measures shall be completed within 15 calendar days after final grading or earth moving activity has been completed. A final inspection shall be scheduled by the owner/contractor.
  • All soil, miscellaneous debris or other materials spilled, dumped, or otherwise deposited on streets, highways, sidewalks or other thoroughfares during transit to or from the earth change site shall be removed promptly.

Plan Review Requirements for Minor Projects

(All information must be provided by the applicant.)

  • Name, address and telephone number of owner.
  • Vicinity map, clearly indicating the exact location of the property.
  • A site map showing the extent of the proposed project, all adjacent properties and proximity to all surface waters within 500 feet of the property's perimeter.
  • Location of structures and vegetation on the site and extending just beyond the property's perimeter.
  • Existing and proposed topography (including cut and fill).
  • Description and location of existing and proposed on-site drainage, including surface runoff and drainage ditches.
  • Delineation of disturbed areas of the project (with all features and sizes indicated).
  • Location and duration of stockpile for excavated material.
  • If dewatering, location and control measures used.
  • Location, types, and cross-sectional views of temporary and permanent erosion and sedimentation control measures.
  • Name and phone number of party responsible for on-going maintenance of all permanent erosion control measures.

Plan Review Requirements for Major Projects

(All information must be provided by the applicant.)

  • Names, addresses and telephone numbers of the owner, developer and petitioner.
  • Legal description and vicinity map, clearly indicating the exact location of the property.
  • A site map showing the extent of the proposed project, all adjacent properties and proximity to all surface waters within 500 feet of the property's perimeter.
  • A site plan at a scale of not more than 1 inch equals 100 feet which includes:
    • Location of structures and vegetation on the site and extending 50 feet beyond the property's perimeter.
    • Location of soil types and associated written description.
    • Existing and proposed topography at a minimum of two (2) foot contour intervals extending 50 feet beyond the property's perimeter.
    • Description and location of existing and proposed on-site drainage, including surface runoff, drainage ditches, and detailed storm sewer plans.
    • Delineation of disturbed areas of the project (with all features and sizes indicated).
    • Location and duration of stockpile for excavated material.
    • If dewatering, location and control measures used.
    • Location, types and cross-sectional views of temporary and permanent erosion and sedimentation control measures.
    • Name and phone number of party responsible for on-going maintenance of all permanent erosion control measures.

Soil Erosion Forms

Soil Erosion Permit Application

Resource Remediation

Soil Erosion Waiver Application

Credit Card Authorization Form

Freedom of Information Act (FOIA) Form

Soil Erosion Links

Washtenaw County Conservation District

International Erosion Control Association

Michigan Department of Environmental Quality

ESCN TV - Weekly national television show on soil erosion topics.

Program Staff

Lee, Katie, Soil Erosion Control Officer, 734-222-3978, leek@ewashtenaw.org