Storm Water Program



Hot Topics:

Rulemaking to Renew Storm Water General Permits

The DNR is currently conducting rulemaking to renew the three storm water general permits (GPs 1, 2, and 3). For more information on the rulemaking and to view the proposed general permits, please see the NPDES Rules page.


General Information

Years after the Clean Water Act of 1972 was adopted, EPA completed rules to include storm water discharges in the NPDES permit program. Since Iowa was delegated the NPDES program for wastewater discharges, delegation was requested for storm water discharges as well. Information regarding the storm water permit program and how it is managed by the Iowa DNR can be found in the following pages:

  • State Revolving Fund - Offers low-interest loans for storm water practices that protect water quality. Eligible borrowers include both public and private entities.

Any discharge from a facility or construction site that may temporarily degrade an Outstanding National Resource Water or Outstanding State Resource Water is required to be permitted by an individual NPDES permit, as stipulated in subparagraph 567-64.7(2)f.(5) of the Iowa Administrative Code and in the Iowa Antidegradation Implementation Procedure. General permit coverage is not available for these discharges. The list of these waters is located in Appendix B of the Antidegradation Implementation Procedure


Contact Information