Storm Water Program

Required for use by Small MS4 operators to submit annual reports. Small MS4 annual reports are due on April 1.

Regulated Small MS4s’ 2017 annual reports are due, on or before, April 1, 2018.  Beginning February 1, 2017 these reports can be submitted electronically via Ohio EPA’s eBusiness Center.  For a step-by-step walkthrough on entering and submitting the electronic report view the MS4 Annual Report Quick Guide.  Small MS4s are encouraged to submit their report electronically, but Ohio EPA will still accept paper reports for 2017.  If you have any questions on submitting your Small MS4 annual report electronically, please contact the following:

• Paper Annual Report Form  

If you qualify for no exposure certification, you are exempt from permit requirements until your facility no longer qualifies for no exposure certification. If your facility changes and can no longer claim no exposure to storm water, you must submit the appropriate permit application for storm water discharge. The No Exposure Certification form must be submitted to Ohio EPA at least once every five years. Access electronic versions through your Ohio EPA eBusiness Center account and submit electronically.

• Industrial No Exposure Certification Fact Sheet
• Industrial No Exposure Certification Guidance Document

• Construction Site Storm Water
  • Statewide Construction, includes Big Darby Creek Watershed and Portions of Olentangy River Watershed
  • Olentangy River Watershed
• Industrial Storm Water
• Small MS4 Storm Water

Construction sites impact Ohio's waters by:

• adding pollutants, especially sediment, to rainwater running off of construction sites during construction; and
• making long-term land use changes that alter the hydrology and pollutant loading of local streams.

To limit the negative impacts of construction projects on Ohio's waters, Ohio EPA administers a permitting program designed to document construction activity in the state and require practices that keep pollutants out of the streams. The permitting program is mandated in the Clean Water Act and is part of the NPDES (National Pollutant Discharge Elimination System) program. 

Who needs a permit?

As of March 10, 2003, if your project disturbs 1 or more acres of ground, you must get a permit to discharge storm water from your site. If your project disturbs less than 1 acre but is part of a larger plan of development or sale, you also need a permit to discharge storm water from the site.

How do I get a permit?

Most sites may get permit coverage under the general permit for discharge of storm water associated with construction activity. To get permit coverage, follow these steps, in order:

• Develop a Storm Water Pollution Prevention Plan (SWP3) for the construction site;
• Submit a Notice of Intent (NOI) requesting coverage for your discharges under the general permit;
• Wait until you receive the Ohio EPA approval letter stating that you are covered under the general permit;
• Ensure that contractors, subcontractors and staff understand their roles in carrying out the SWP3;
• Implement the SWP3;

• Proceed with construction, including regular maintenance and inspection of sediment and erosion controls and storm water management facilities.

• Erosivity Waiver 
• Routine Maintenance Exclusion from Small Construction Activity Permitting

• Ohio's Current Rainwater and Land Development Manual
  • Chapters and appendices
  • Critical Storm Method
  • Practice Data Sheets
• Storm Water Post-Construction Questions and Answers
• Storm Water Pollution Prevention Plan (SWP3) Check List
• U.S. EPA Guidance for Developing SWP3 for Construction Activities
• Construction Site Inspection Checklist
• Construction Storm Water Permit Requirements for Agricultural Projects
• Interactive Map of Construction Storm Water Permits issued since January 2011
• Oil and Gas Exemption - U.S. EPA web page
  • Storm Water Permitting for Oil- and Gas-Related Operations - Ohio EPA fact sheet
• Chagrin River Watershed Partners, Inc. (CRWP) has developed a model agreement that a municipality may use to ensure the long-term operation and maintenance of post-construction best management practices (BMPs). This language may need to be modified to reflect local requirements and should be reviewed by the municipality's legal council. The link below will redirect you from Ohio EPA to CRWP's website.
  • CRWP Model Long-Term Post-Construction BMP Maintenance Agreement
• Northeast Ohio Storm Water Training Council's Maintaining Storm Water Control Measures, Guidance for Private Owners and Operators

• Construction Site Storm Water (OHC000005)
• Construction Site Storm Water in the Olentangy River Watershed (OHCO00002)

What is a Municipal Separate Storm Sewer System (MS4)?

A conveyance or system of conveyances (including roads, catch basins, curbs, gutters, ditches, man-made channels, or storm drains):

• Owned or operated by a public body
• Designed and used for collecting storm water
• Is not a combined sewer
• Is not part of a Publicly Owned Treatment Works (POTW)

The U.S. EPA's storm water program addressed storm water runoff in two phases. Phase I addressed storm water runoff from large and medium MS4s. Large municipalities with a separate storm sewer system serving a population greater than 250,000 and medium municipalities with a service population between 100,000 and 250,000 had to obtain NPDES permits. Initial application deadlines for large and medium municipalities were November 16, 1992 and May 17, 1993, respectively. As part of their individual NPDES permit applications, the large and medium MS4s had to develop a storm water management program (SWMP).

Individual MS4 permits for discharge of storm water

• City of Dayton
• City of Toledo
• City of Akron
• City of Columbus

The Phase II regulations address storm water runoff of MS4s serving populations less than 100,000, called small MS4s. More particularly, small MS4s located partially or fully within urbanized areas (UAs), as determined by the U.S. Bureau of the Census, and also on a case-by-case basis for those small MS4s located outside of UAs that Ohio EPA designates into the program. Automatically designated Small MS4s, those in UAs, were required to apply for permit coverage and develop and submit a SWMP by March 10, 2003.

U.S. EPA developed a Fact Sheet [PDF 239K] explaining how urbanized areas affect water quality through increased runoff and pollutant loads and what homeowners can do to prevent storm water pollution.

Ohio EPA developed two general permits that were issued to Phase II Small MS4 communities under the first generation permitting in 2003. The Baseline General Permit allowed a full 5 years for SWMP development/implementation; whereas, the Alternative General Permit for MS4s Located within Rapidly Developing Watersheds required development/implementation of the Construction and Post-Construction minimum control measures within 3 years. The alternative general permit was issued to a select group of MS4s that Ohio EPA considered being located within rapidly developing watersheds. All MS4s will now be covered under the general permit renewal that was issued on January 31, 2009

USEPA developed a set of digitized maps which display detailed urbanized area maps. See the following link:

USEPA Urbanized Area Maps

Ohio EPA developed a set of digitized maps which display detailed area maps for watersheds that Ohio EPA has identified as being rapidly developing. See the following link:

Rapidly Developing Watersheds

• Ohio EPA MS4 Workshops
• USEPA Storm Water Phase II Fact Sheets 
• USEPA National Menu of Best Management Practices
• USEPA Measurable Goals Guidance for Phase II Small MS4s
• USEPA Storm Water Phase II Compliance Assistance Guide [PDF 1,466K]
• OEPA Guidance Brochure for Phase II Small Municipal Separate Storm Sewer System (MS4) Operators [PDF 95K]
• USEPA Storm Water Case Studies
• USEPA Nonpoint Source Outreach Toolbox

• MS4 General Permit
• Ohio Storm Water Rules
• Example Model Ordinances
  • Chagrin River Watershed Partners, Inc.
  • Stormwater Manager's Resource Center (see Ordinance)
  • Northeast Ohio Areawide Coordinating Agency
• USEPA Educational Outreach Materials
• Illicit Discharge Detection And Elimination Manual by New England Interstate Water Pollution Control Commission
• MS4 Program Evaluation Guidance Document
• Illicit Discharge Detection and Elimination Program Manual - A Guidance Manual for the State of Ohio
• Chagrin River Watershed Partners, Inc. (CRWP) has developed a model agreement that a municipality may use to ensure the long-term operation and maintenance of post-construction best management practices (BMPs). This language may need to be modified to reflect local requirements and should be reviewed by the municipality's legal council. The link below will redirect you from Ohio EPA to CRWP's website.
  • CRWP Model Long-Term Post-Construction BMP Maintenance Agreement

• Ohio Environmental Education Fund
• Ohio Water Pollution Control Loan Fund
• Storm Water Utility Information
  • Stormwater Manager's Resource Center (see Program Resources)
  • An Internet Guide to Financing Stormwater Management
  • Guidance For Municipal Stormwater Funding [PDF]
• Catalog of Federal Funding Sources for Watershed Protection