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Evansville, IN 47708
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Storm Water Information

About Vanderburgh County's MS4

The United States Environmental Protection Agency developed the National Pollutant Discharge Elimination System program in response to the 1987 Amendments to the Clean Water Act to reduce the amount of pollution in the nation's stormwater runoff and is requiring communities to develop a comprehensive stormwater quality management plan for preventing local waterways from becoming affected by polluted stormwater runoff.  Phase I of the NPDES program was developed in 1990 for medium and large Municipal Separate Storm Sewer Systems (MS4s), industrial activities, and construction activities that disturbed five or more acres of land.  All of which were determined to have the greatest potential to negatively impact water quality.  Phase II was developed in 1999 and required NPDES permit coverage for discharges from small MS4s and construction activities disturbing between one and five acres of land.  Vanderburgh County falls under the requirements of Phase II.

The Indiana Department of Environmental Management (IDEM), enacted what was commonly known as Rule 13 (formerly 327 IAC, Article 15) in 2003 to comply with the NPDES program.  Since then, IDEM has changed to the Municipal Separate Storm Sewer (MS4) General Permit (MS4GP) that regulates MS4s.  The MS4GP addresses the following minimum control measures:

MCM #1 - Public Education and Outreach - This minimum control measure requires Vanderburgh County to develop a storm water management program that includes methods and measurable goals that will be used to inform residents, visitors, public service employees, commercial and industrial facilities, and construction site personnel within the MS4 area about the impacts polluted storm water run-off can have on water quality and ways they can minimize their impact on storm water quality. This can include the distribution of educational materials and performing outreach to inform citizens about the impacts polluted storm water runoff discharges can have on water quality.

MCM #2 - Public Participation/Involvement – This MCM requires the development of a storm water quality management plan that includes provisions to allow opportunities for constituents within the MS4 area to participate in the storm water management program development and implementation. Examples of this include providing opportunities for citizens to participate in program development and implementation, including effectively publicizing public hearings and/or encouraging citizen representatives on a storm water management panel.

MCM #3 - Illicit Discharge Detection and Elimination – An illicit discharge is defined as any discharge to an storm water conveyance that is not composed entirely of storm water, except naturally occurring floatables, such as leaves or tree limbs. Sources of illicit discharges include sanitary wastewater, septic tank effluent, car wash wastewater, oil disposal, radiator flushing disposal, laundry wastewater, roadway accident spillage, and household hazardous wastes. This minimum control measure mandates the development and implementation of a plan to detect and eliminate illicit discharges to the storm sewer system. This includes developing a storm drainage system map, inspecting outfalls, and informing the community about hazards associated with illegal discharges and improper disposal of waste.

Click here for more information on MCM #3.

MCM #4 - Construction Site Runoff Control – This minimum control measure necessitates the development, implementation, management, and enforcement of an erosion and sediment control program for construction activities that disturb one (1) or more acres of land within the MS4 area.

Click here for more information on MCM #4.

MCM #5 - Post-Construction Site Runoff Control – This minimum control measure calls for the development of a program that implements, manages, and enforces a program to address discharges of post-construction storm water run-off from new development and redevelopment areas that disturb one (1) or more acres of land. Best management practices for this control measure could include preventive actions such as protecting sensitive areas such as wetlands or the use of structural BMPs such as grass swales, porous pavement, or the installation of manufactured products such as separator devices and filters.

Click here for more information on MCM #5.

 MCM #6 - Pollution Prevention and Good Housekeeping – This measure requires Vanderburgh County to develop and implement a program to prevent or reduce pollutant run-off from municipal operations within the MS4 area. The program must include municipal staff training on pollution prevention measures and techniques (e.g., regular street sweeping, reduction in the use of pesticides or street salt, or frequent catch-basin cleaning).


Click here for IDEM's Minimum Control Measure page

Vanderburgh County Stormwater Links

Below you will find links to items related to Vanderburgh County's efforts to comply with these regulations: from reports to new ordinances and associated plans and policies to public awareness information.  We plan to add content useful to designers in the future, so keep checking for updates.

Vanderburgh County MS4 Program Storm Water Quality Management Plan

2022 MS4 Annual Report

Construction Site Stormwater Runoff Control Ordinance

Illicit Discharge into Storm Water System Ordinance

Construction/ Stormwater Pollution Prevention Plan Technical Review Checklist

Vanderburgh County Recycling Programs and Services

Contact Information

If you have any questions or complaints regarding erosion problems or to report pollutant discharges into a storm drainage system, please send an email to or call the County Engineering Department at (812) 435-5773.

General questions regarding Vanderburgh County's stormwater program can be e-mailed to

Other Online Resources

Vanderburgh County SWCD - Homepage for the Vanderburgh County Soil and Water Conservation District. Homepage for IDEM storm water regulations.

U.S. EPA Water Topics - Homepage for EPA Region 5 water quality information.

Center for Watershed Protection - A non-profit corporation that provides technical tools to local governments, activists, and watershed organizations around the country.

Ohio River Valley Water Sanitation Commission (ORSANCO) - An interstate commission representing eight states and the federal government that operates programs to improve water quality in the Ohio River and its tributaries.

U.S. Army Corps of Engineers Great Lakes and Ohio River Division - Webpage for the  Louisville district of the U.S. Army Corps of Engineers.