Stormwater Information for New Construction

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Stormwater runoff from a construction site carries sediment and other pollutants that have a negative impact on water quality and aquatic life. According to a National Water Quality Inventory completed by the Environmental Protection Agency, stormwater runoff is a leading source of water pollution. The U.S. Environmental Protection Agency estimates that 20 to 150 tons of soil per acre are lost every year to stormwater runoff from construction sites.

 General Permit No. 2

Stormwater erosion control

Controlling erosion can significantly reduce the amount of sedimentation and other pollutants transported by runoff from construction sites. To keep our valuable water resources clean the Iowa Department of Natural Resources (IDNR) issues a General Permit no. 2 to construction site owners that require site owners and their contractors to meet several requirements that work to prevent stormwater pollution during and after construction.  

Construction projects that disturb one or more acres or less than one acre of soil if activity is part of a “larger common plan of development” greater than one acre are required to obtain a General Permit No. 2 through the Iowa Department of Natural Resources. General Permit no. 2 requires that a Stormwater Pollution Prevention Plan (SWPPP) be submitted to the Environmental Services Division for approval. 

Required Stormwater Pollution Prevention Plan (SWPPP) Documentation

  •  Description of the project
  • Contact information for project owner, contractor, and SWPPP manager
  • Certification Sheet signed by the owner, contractor, and any subcontractors
  • Site map showing where erosion control is to be implemented
  • Summary of stabilization practices
  • Copy of inspection sheet to be used for erosion control inspections completed every 7 calendar days
  • Permit Authorization issued by the Iowa DNR for General Permit No. 2
  • Copy of General Permit No. 2

The permit holder is responsible for compliance with permit requirements. The City’s MS4 Permit requires City staff to conduct inspections on all sites having an NPDES General Permit No. 2. General Permits can be applied for online on the DNR website.