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Stormwater Management


Plun CreekWhat is Stormwater?
Stormwater is rainwater that washes through our property and streets, taking with it any debris that may be in its path. This mixture of rain, debris, oil and waste is known as "runoff".

What is Stormwater Management?
Stormwater Management is a mechanism for controlling stormwater runoff. These practices are incorporated into the design of a development to mitigate any impacts the development may have on the aquatic environment. Stormwater Management practices address two major issues, the quantity or volume of stormwater and the quality of the stormwater.

Stormwater Quantity
Pervious (or vegetated) surfaces, such as fields, meadows and woodlands, absorb and infiltrate rainfall and generate little runoff. As land develops, these areas are typically covered with impervious surfaces, such as pavement and rooftops. These impervious surfaces generate more runoff every time it rains. The quantity of runoff from these areas can overwhelm natural channels and streams. Stormwater Management practices are designed to offset these increases in runoff.

Stormwater Quality
The pervious and impervious surfaces in the urbanized landscape collect pollutants such as automobile oil, grease, brake pad dust, sediment from construction sites, bacteria from animal waste, excess lawn care fertilizers and pesticides, as well as atmospheric deposition of phosphorus, nitrogen and other airborne pollutants. Rainfall washes these surfaces so that the initial flush of runoff can carry high concentrations of these pollutants to nearby drinking water supplies, waterways, beaches and properties. Pollution washed from the land surface by rainfall is called nonpoint source pollution. Stormwater Management practices also provide water quality treatment to help prevent additional pollution from entering streams and rivers.

Stormwater Management in Dyer
Throughout much of Dyer's history, storm water management has been part of the sanitary sewer utility. Most of Dyer’s sewers were “combined” and used for both sanitary and storm drainage. In the early 1980s, the sewer systems through federal mandates, were separated to meet federal and state regulations. The separate storm sewer system consists of over 100 miles of pipes, ditches, and 20 detention ponds. In 1991, the Town of Dyer created a Department of Storm Water Management with the responsibility of maintaining and operating this system.

Stormwater Regulations
The National Pollutant Discharge Elimination System (NPDES) Stormwater Program regulates stormwater discharges from three potential sources: Municipal Separate Storm Sewer Systems (MS4s), construction activities, and industrial activities. Most stormwater discharges are considered point sources, and operators of these sources may be required to receive an NPDES permit before they can discharge. This permitting mechanism is designed to prevent stormwater runoff from washing harmful pollutants into local surface waters such as streams, rivers, lakes or coastal waters.

The NPDES Stormwater Program is a comprehensive two-phased national program comprised as follows:

 

  • Phase I, issued in 1990, requires medium and large cities or certain counties with populations of 100,000 or more to obtain NPDES permit coverage for their stormwater discharges.
  • Phase II, issued in 1999, requires regulated small MS4s in urbanized areas as well as small MS4s outside the urbanized areas that are designated by the permitting authority, to obtain NPDES permit coverage for their stormwater discharges

In the State of Indiana, the Indiana Department of Environmental Management (IDEM) is responsible for the development and oversight of the NPDES Stormwater Program.

IDEM initiated adoption of the Phase II Rules which were codified as Rule 13 became effective on August 6, 2003 and requires designated MS4 entities to apply for permit coverage by submitting a Notice of Intent (NOI) and developing Storm Water Quality Management Plans (SWQMPs) through a phased submittal process. The IDEM’s phased submittal requirements includes the implementation of a Stormwater Quality Management Plan which was approved on March 1, 2005.

The Town of Dyer meets the criteria of a small MS4 entity. The Town of Dyer SWQMP submittals are presented below:

The Town has also established an Ordinance establishing the methods for managing the quantity and quality of stormwater entering into the Town of Dyer stormwater drainage system in order to comply with State and Federal requirements, as presented below:

In addition, the Town has established an Ordinance pertaining to flood hazards within the its jurisdiction, as presented below:

Stormwater System Map
The following is a copy of the Stormwater System Map for the Town of Dyer:

NIRPC Stormwater Information
The following is a link to useful information on stormwater management from the Northwestern Indiana Regional Planning Commission (NIRPC)