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MS4 Individual Permits

Municipal Separate Storm Sewer Systems (MS4s)

Municipal Separate Storm Sewer System (MS4) cities and universities in Iowa must abide by an individual stormwater permit to minimize stormwater runoff. MS4s are determined by the Iowa Department of Natural Resources and primarily dependent on population or proximity to a metropolitan area.

Permitted MS4s are required to have a construction site runoff erosion control ordinance and a post construction stormwater ordinance in place. Their program must also meet 6 minimum requirements.

  1. Public outreach on stormwater impacts
  2. Public involvement and participation
  3. Illicit discharge and elimination program and ordinance
  4. Construction site regulations and sediment and erosion control ordinance
  5. Post-construction on stormwater management and ordinance
  6. Good housekeeping policies

The majority of MS4s in Iowa are members of ISWEP. ISWEP assists cities that have regulated stormwater programs with resources to support their permit requirements, especially public education and outreach. ISWEP training and certification programs support city staff and contractors and provides information on best management practices applicable to their projects.

The following cities and universities are required to obtain an MS4 Individual Permit. If you plan to do work in one of the following cities or universities, please consult with their stormwater coordinator to ensure you are meeting MS4 regulations. Click Here to see a map.

Permitted MS4 Cities and Universities