Watershed Stormwater Permit

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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

​​​​​The Middle Huron Watershed covers nearly 300 square miles. It includes 16 townships, 3 cities, 3 villages, and 2 counties.​ The City of Ann Arbor is one of several Huron River communities partnering to develop a watershed-based stormwater permit. Working collaboratively provides all watershed permit partners greater flexibility in developing strategies and implementing the permit requirements. The collaborative approach is designed to accomplish stormwater quality improvements watershed-wide, and provides an added benefit of cost sharing for some stormwater controls.

Ann Arbor's stormwater permit

Federal and state regulations require urban communities to address both the amount of runoff and the pollution carried by that runoff that is deposited, untreated, into surface waters. Specifically, stormwater discharges in Ann Arbor are regulated under the National Pollution Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) permit. Under this permit, the city must comply with several requirements, which, if implemented, should result in a significant reduction in pollutants discharged to receiving waters. Watershed Stormwater Permit Partners include:

  • City of Ann Arbor
  • City of Ypsilanti
  • Eastern Michigan University
  • Charter Township of Pittsfield
  • Village of Dexter
  • Charter Township of Ypsilanti
  • Washtenaw County Road Commission
  • Washtenaw County Water Resources Commissioner​

Required components of the permit

Watershed Manage​ment Plan

​The Middle Huron River Watershed M​anagement Plan was developed in 1994, and was updated in 2000 and again in 2008. The plan lays out strategies to protect sensitive natural areas in the Middle Huron Watershed, mitigate impacts of existing point and non-point source pollution, and restore degraded areas. 

Public Participation Plan (PPP)

Municipalities must develop a procedure for giving the public an opportunity to participate in both the development and implementation of a stormwater program. The Public Participation Plan for the Middle Huron River Subwatershed (PDF) was developed and submitted to the MDNRE in August 2009.

Stormwater Management Program (SWMP)

The Stormwater Management P​rogram​ (PDF) details the specific actions watershed partners will implement to meet the permit requirements. The SWMP has six main pieces.

Total Maximum Daily Lo​ad (TMDL)

When a lake or stream does not meet its designated uses, it is considered "impaired" and a Total Maximum Daily Load (TMDL) must be developed. Municipalities must then identify and prioritize actions to reduce pollutants in stormwater discharges to make progress toward meeting water quality standards.

Public Education Program (PEP)

Municipalities must develop a program​ to promote, publicize, and facilitate educational materials and activities on stormwater and pollution prevention. This plan must be developed and implemented in partnership with other permitted communities in the watershed.

Illicit Discharge Elimination Program (IDEP)

Municipalities must develop a plan with mechanisms designed to locate and eliminate discharges​ into storm sewer from sources other than stormwater.

Post Construction Stormwater Management

Municipalities must have a program requiring new and redevelopment projects to implement on site controls that will reduce pollutant loads in stormwater runoff.

Constructi​on Stormw​ater Controls

Municipalities must have a regulatory mechanism in place for erosion and sediment control, as well as best management practices (BMPs) for preventing or reducing other pollutants associated with construction activity.

Pollution Prevention a​nd Good Housekeeping Practices for Municipal Operations

Municipalities must have an operation and maintenance program​ to prevent or reduce pollutant runoff from municipal operations.​