Construction & Design

urban runoff Hard surfaces, like parking lots, increases the amount of water that runs off the property into water ways. The water that runs off these surfaces are also more likely to be polluted with oils, litter and soil.

Stormwater runoff from construction activities can have a significant impact on water quality. As stormwater flows over a construction site, it can pick up pollutants like sediment, debris, and chemicals and transport these to a nearby storm sewer system or directly to a river or lake. Runoff going into separate storm sewers does not get treated at a wastewater treatment plant.

State Requirements

The NPDES stormwater program requires construction site operators engaged in clearing, grading, and excavating activities that disturb 1 acre or more, including smaller sites in a larger common plan of development, to obtain coverage under an NPDES permit for their stormwater discharges.

You can find the Illinois EPA’s permit requirements and forms here: (

Local Requirements

The Macon County MS4 Communities are also obligated to verify and enforce compliance of their local stormwater ordinances.  For this reason, a Land Disturbance Permit is included in the stormwater ordinances of the Macon County MS4 Communities.  The Land Disturbance Permit provides a system to notify the local MS4 of the construction activities about to begin and offsets some of the cost to inspect the site to verify compliance.

Land Disturbance Permits are required in if any of the below conditions are met:

  1. Land disturbing activity that disturbs one (1) or more acres of land;
  2. Land disturbing activity of less than one (1) acre of land if such activity is part of a larger common plan of development that affects one (1) or more acre of land (i.e. individual lot house construction in a subdivision);
  3. Land disturbing activity of less than one (1) acre of land, if in the discretion of the Municipality/ County poses a unique threat to water, or public health or safety because the activity by itself or of a cumulative effect negatively impacts water quality. **All properties located near Lake Decatur or any tributary creeks will meet this requirement.
  4. The creation and use of borrow pits;
  5. The creation and use of stockpiles greater than fifty (50) cubic yards in volume.
Pond with ducks If water quality is not maintained, it not just the environment that will suffer - the commercial and recreational value of our water resources will also diminish.

The Macon County MS4 communities take protecting water quality seriously and we hope you do as well. Failure to obtain the proper permits through the IEPA and your local municipality can result in additional permit fees and state & local fines.

How to get a Land Disturbance Permit

  1. Evaluate your site for areas where erosion could occur
  2. Find Best Management Practices (BMPs) that will reduce the chance for sediment to leave the site. The Illinois Urban Manual has several examples of these. You can find a complete list at:
  3. Some common BMPs can be found here.

  4. Create a Stormwater Pollution Prevention Plan (SWPPP) for your site, showing what BMP’s you plan to use.  For residential properties, the following form can be used: 

    Erosion Control Plan for Individual Lot Erosion Control Plan for Individual Lot (50 KB)

    SWPPP's for none-residential lots must be done by a professional engineer or other qualified professional.
  5. Get a copy of the Land Disturbance Permit for your locations.  They can be found here:
  6. Complete the Permit. Be sure that all sections are filled out and any required attachments are included.
  7. If your project is in Decatur, Mt. Zion or Forsyth, payment for the permit must be received by the Macon County Soil & Water Conservation District BEFORE the permit is submitted. They are located at 4004 College Park Road, Decatur; just north of Richland Community College.
  8. If your project is in Macon County, you maybe proceed with Step 7 and pay the County directly.

  9. Submit your fully completed permit to the following locations for each respective community.
erosion matting Bare soil increases soil erosion during a rain or wind. Vegetation is needed to reduce the risk of soil erosion and seeding is recommended for quick stabilization. Sometimes, matting installed over the seed is used to protect the seed and soil from washing away before the vegetation is established.

Macon County:
Planning & Zoning Department
141 South Main Street, Suite 501
Decatur, IL 62523

City of Decatur:
Engineering Department
#1 Gary K. Anderson Plaza
Decatur, IL 62523

Village of Forsyth:
301 S. US Route 51
Forsyth, IL 62535

Village of Mt. Zion:
1400 Mt. Zion Parkway
Mt. Zion, IL 62549

I’ve got the Land Disturbance Permit. Now What?

An inspector will stop by your construction site at least once during your project to verify that the Stormwater Pollution Prevention Plan (SWPPP) has been followed and there are Best Management Practices (BMPs) installed to prevent soil or contaminants from leaving the site.  Some tips to making sure your inspection goes well:

  1. Before you begin clearing, grubbing or disturbing the land at your site in any way, install the necessary erosion control BMPs.  
  2. Call the inspector to set up the intial erosion control inspection.
  3. Keep your SWPPP and permits available to anyone to view. They should not only be in a locked construction trailer, but also posted or in a covered, unlocked container.
  4. Keep your BMPs maintained …. Silt fence that has been run over does nothing to prevent soil from leaving the site when it rains.
  5. The inspector is there to assist you in keeping erosion from happening.  They will offer suggestions or point out susceptible areas.
  6. Follow up with the inspector once all BMPs have been installed or repaired.

Failure to install or maintain BMPs can result in fines or stop work orders from the local MS4 or IEPA.