Municipal Separate Storm Sewer System

What is Storm Water?

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Description automatically generatedStorm water runoff is part of the natural hydrologic process and occurs when rainwater that does not infiltrate into the ground flows into water bodies such as creeks, lakes, streams, or rivers. In suburban areas, the storm water runoff often has the benefit of passing through naturally vegetated areas, which slows down the velocity of the water and ultimately filters it for pollutants and sediments. In urban settings, however, natural vegetation and topography have frequently been altered to prevent storm water from naturally soaking into the ground and so it is most often carried by storm drains.

When the drainage pattern of a watershed is altered with the addition of impervious surfaces such as driveways, parking lots, and buildings, flows increase in concentration and velocity and pick up sediments and pollutants from land surfaces at an increased rate. Storm water that flows through urbanized areas to receiving waters is called "urban storm water runoff."

The City of Auburn has developed a storm water program that manages the pollutants and impacts from urban storm water runoff. The program includes education, storm water quality and quantity measures.


Urban runoff is known to carry a wide range of pollutants including:

  • Heavy metals
  • Nutrients
  • Pathogens
  • Petroleum hydrocarbons
  • Sediments
  • Synthetic organics such as pesticides
  • Trash and debris

Once pollution reaches water bodies, it can harm aquatic life, damage ecosystems, and even end up in water used for drinking or recreation. Protecting our water bodies from all sources of contamination can be accomplished through the cooperation of citizens, government, and businesses.

Community Impacts

Because urban runoff does not originate from a distinct "point" source (e.g., an industrial discharge pipe), it is also often referred to as nonpoint source pollution. These pollutants in urban runoff could negatively impact the vitality of our municipality on many levels. 

Urban runoff can:

  • Alter the physical, chemical, and biological characteristics of water bodies to the detriment of aquatic and terrestrial organisms
  • Make beaches and rivers unsightly or unsafe for human contact
  • Negatively impact beneficial activities and users including water recreation, commercial fishing, tourism, and aquatic habitat

In some cases, pollutants of concern may not even be visible to the naked eye.

MS4 Program

The Indiana Department of Environmental Management (IDEM) designated the City of Auburn as a municipal separate storm sewer system (MS4) and is required to comply with a state-issued storm water permit (INR040119). Auburn is implementing a program to prevent storm water pollution and improve the water quality of local water bodies.

The Storm Water Quality Management Plan describes every aspect of Auburn’s MS4 program and how it is implemented. Annual Reporting of certain measures and goals is required to be submitted to IDEM.

  1. Auburn Storm Water Quality Management Plan
  2. Annual Report

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Description automatically generatedAs part of the MS4 Program, Auburn adopted Chapter 160, Chapter 161, and Chapter 162 to protect storm water. Only pure rainwater should enter storm drains or surface waters.   The ordinances prohibit illicit connections and discharges to the storm sewer and illegal dumping.  The ordinances also regulate storm water detention, water quality, and construction and post-construction practices.  

What is an Illicit Discharge?

An illicit discharge is an unlawful act of disposing, dumping, spilling, emitting, or other discharge of any substance other than storm water into the storm water drainage system. The storm water drainage system includes streets, ditches, catch basins, yard inlets, and streams.

Examples of Illicit Discharge include: 

  • Paint being poured into or near the storm drainage system
  • Changing oil or antifreeze over or near a storm structure
  • Washing vehicles where the runoff could drain into the storm drainage system
  • Washing dumpster pads and allowing the runoff to drain into the storm drainage system
  • Dumping grass clippings into a storm water basin or inlet or into the street

Illicit discharges cause water pollution by sending pollutants directly into creeks, streams, ponds, and lakes. Be sure you know what illicit discharges are so you can help prevent water pollution and keep our streams clean! Report illicit discharges by calling the Water Pollution Control department at 260-925-1714.

Public Education

Auburn is promoting pollution prevention activities and education as part of this program. The below educational brochures are available at the Water Pollution Control Plant and Utility Billing

  1. Household Hazardous Waste
  2. Proper Disposal of Pet Waste
  3. Green Landscaping
  4. Storm water Pollution
  5. Rain Barrel Brochure
  6. MS4 Fact Sheet
  7. Illicit Discharge Detection and Elimination

Citizen Involvement

If you have an emergent issue, please call Water Pollution Control at 260-925-1714. Citizens can report the illegal dumping of chemicals, heavy erosion from construction sites, polluted water, or other illegal connections to the storm system (such as septic tank discharges or washing machine wash water).  

What can you do to prevent storm water pollution?

  1. Clean up your property.  Properly dispose of outdated or unused household chemicals stored in your basement, garage, or barn by taking them to the Northeast Indiana Solid Waste Management District.   Do not store these materials outdoors.
  2. Recycle used oil, automotive fluids, batteries, and other products. Do not dispose of hazardous products in storm drains, alleys, or the ground. This pollutes the water supply. 
  3. Reduce the number of fertilizers, pesticides, or other hazardous chemicals that you use. Buy only what you need so that you do not have to dispose of leftovers. Read all the labels and follow directions. 
  4. Sweep up debris, rather than hosing down areas.
  5. Clean up after your pet and dispose of pet waste in a trash container or toilet. When left outdoors, pet waste contributes bacteria and nutrients to storm water.
  6. Use a commercial car wash or wash your car on an unpaved surface to reduce the amount of dirty, soapy water entering storm drains and waterways. 
  7. Cover piles of soil and mulch being used for landscaping projects.
  8. Prevent debris from entering nearby storm drains when conducting outdoor home improvement or landscaping projects.
  9. If you have a septic system, have it serviced regularly. Make sure it is not connected to the storm sewer or polluting a creek or body of water
  10. Drain your swimming pool only when a test kit shows non-detectable levels of chlorine.
  11. If you spill chemicals, oil, or fuel, clean it up with absorbent materials (for example kitty litter).  Do not let it soak into the ground.  Place absorbent in the trash.