Working to improve and protect water quality
Cities, towns, and the three regent universities in Iowa all share the responsibility of protecting and improving the quality of local rivers, streams, and lakes. This responsibility touches nearly every decision made by local leaders including elected officials, appointed boards, and municipal staff. From land use planning to infrastructure maintenance, everyday actions can either protect water resources or contribute to their degradation.
To help guide these efforts, the U.S. Environmental Protection Agency created the National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) permit program. In Iowa, the program is administered by the Iowa Department of Natural Resources (IDNR). Even in communities that don’t yet hold a formal permit, the MS4 program provides a strong framework for protecting water quality.
At the heart of the MS4 program are six Minimum Control Measures. These measures outline essential activities that help reduce stormwater pollution and safeguard local water bodies.
- Public education and outreach focuses on helping residents understand how everyday actions impact stormwater quality and what they can do to make a difference. This may include sharing information about proper lawn care, responsible pet waste disposal, or avoiding dumping substances into storm drains.
- Public participation and involvement encourages community members to play an active role in local stormwater efforts. Public meetings, cleanup events, and citizen reporting systems are just a few ways residents can contribute.
- Illicit discharge detection and elimination ensures that non-stormwater flows – like illegal dumping, cross-connected sewers, or wash water – are identified and removed from the storm sewer system.
- Construction site runoff control requires developers and contractors to minimize erosion and sediment runoff on active construction sites, particularly for projects that disturb an acre or more of land.
- Post-construction runoff control addresses how stormwater will be managed after development is complete. Communities often require long-term solutions such as rain gardens, detention basins, or green roofs to keep runoff in check.
- Pollution prevention and good housekeeping focuses on municipal operations. This includes training public works and parks staff to minimize pollution from everyday activities like street sweeping, vehicle maintenance, or managing public spaces.
Local ordinance & policy guidance
The Iowa Stormwater Management Manual (ISWMM) includes a section that serves as a guidance document for local jurisdictions seeking to adopt post-construction stormwater management policies.
ISWMM Chapter 3.01-7: Guidance Language (pgs 38-39)
Model ordinances
ISWEP has developed model ordinances related to stormwater management for communities to use when drafting or revising their language. We’ve also compiled adopted ordinances from across the state in both MS4 and non-MS4 communities. Please contact ISWEP if your community has an ordinance that should be listed below.
Post construction: Model Ordinance
Stormwater utilities: Model ordinance
Illicit discharge: Model ordinance
Construction site runoff control: Model ordinance
Post construction stormwater facilities maintenance agreements
City of Waukee example
City of Johnston example
City of Ankeny example
Other examples
Johnson County Unified Development Code
Polk County Zoning Ordinance
Cedar Falls Floodplain and Floodway Ordinance