Michigan Stormwater Regulations
Michigan splits stormwater oversight between EGLE, which issues NPDES permits under Part 31 of NREPA, and local agencies that issue Part 91 soil erosion permits for any earth change of 1 acre or more or within 500 feet of a lake or stream. Construction sites get stormwater coverage through a Permit-by-Rule tied to that local permit, and county drain commissioners control established drains. Civil fines reach $25,000 per day.
State Regulatory Overview
The Michigan Department of Environment, Great Lakes, and Energy (EGLE) is the state's NPDES permitting authority. Its Water Resources Division issues stormwater coverage for construction sites, industrial facilities, and municipal separate storm sewer systems (MS4s) under Part 31, Water Resources Protection, of the Natural Resources and Environmental Protection Act (NREPA). Michigan's MS4 permits are individual permits rather than one statewide general permit, and industrial general permits are reissued on a five-year watershed cycle.
Soil erosion is handled differently. Part 91, Soil Erosion and Sedimentation Control, makes each county responsible for permits and enforcement through a County Enforcing Agency chosen by the county board. Some cities, villages, and townships take over inside their own boundaries as a Municipal Enforcing Agency, and public agencies such as road commissions can be approved by EGLE to handle their own projects under approved procedures. EGLE oversees all of them and reviews each county program every five years. The office that issues your permit depends on where the site sits, so check EGLE's list of Part 91 agencies before you assume it's the county.
The third layer is the Drain Code of 1956. Each county elects a drain commissioner, called a water resources commissioner in some counties, with jurisdiction over established county drains. Properties inside a drainage district can be assessed for drain maintenance, and obstructing a drain makes the owner liable for the cost of clearing it. None of this replaces a Part 91 permit or an EGLE permit on the same site.
County Coverage
We have published county guides for three Michigan counties so far, from Grand Traverse County in the northwest to the Grand Rapids and Lansing metros. The state rules on this page apply in every Michigan county.
| County | MS4 Status | Key City | Penalties |
|---|---|---|---|
| Grand Traverse | Newly designated MS4 (2025) | Traverse City | Up to $25,000/day |
| Kent | Individual MS4 permits | Grand Rapids | Up to $25,000/day |
| Ingham | Individual MS4 permits | Lansing | Up to $25,000/day |
Key State Laws
- NREPA Part 91, Soil Erosion and Sedimentation Control (MCL 324.9101 to 324.9123) - Requires a local permit for earth changes, makes landowners maintain erosion and sediment controls, transfers permit obligations with the property, and sets civil fines from $2,500 up to $25,000 per day.
- Part 17 Rules (R 323.1701 to R 323.1714) - Set the permit trigger of 1 acre or 500 feet from a lake or stream, the contents of a soil erosion plan, a 30-day decision deadline for applications, and a 5-day deadline to put permanent erosion controls in place after final grading.
- NREPA Part 31, Water Resources Protection (MCL 324.3101 et seq.) - Michigan's water pollution law and the basis for EGLE's NPDES permits. Prohibits injurious discharges, sets stormwater fees, requires certified operators, and carries civil and felony penalties.
- Part 21 Rules, including the Permit-by-Rule (R 323.2161, R 323.2161a, R 323.2190) - Define who needs a stormwater permit, the minimum contents of an MS4 stormwater program, and the construction Permit-by-Rule.
- The Drain Code of 1956 (1956 PA 40) - Creates the county drain commissioner, governs established drains and drainage districts, and makes anyone who obstructs a drain pay for its removal.
Permit Types
Part 91 Soil Erosion and Sedimentation Control Permits
This is the base permit for earth work in Michigan, issued by the county or municipal enforcing agency. It's required for any earth change that disturbs 1 or more acres or sits within 500 feet of the water's edge of a lake or stream. The application includes a soil erosion and sedimentation control plan, and that plan has to name who will maintain the permanent controls after the project is done. Fees are set locally.
Construction Stormwater Permit-by-Rule
Construction sites of 1 acre or more with a discharge to state waters get NPDES coverage through Rule 2190 instead of a general permit. Coverage depends on the Part 91 permit: sites of 1 to 5 acres are covered automatically once it's issued, and sites of 5 acres or more also file a Notice of Coverage with EGLE and pay $400. An EGLE-certified storm water operator must inspect weekly and within 24 hours after any rain that causes a discharge, and the inspection log is kept for 3 years.
MS4 Permits
Cities, townships, villages, county agencies, universities, and school districts in urbanized areas hold individual NPDES MS4 permits from EGLE. Each permittee runs a stormwater management program that includes a post-construction ordinance for new development and redevelopment, with water quality and channel protection standards and long-term maintenance agreements for private stormwater controls. If your property drains to a regulated MS4, that ordinance is where your maintenance obligations usually come from.
Industrial Stormwater Permits
Regulated industrial facilities with exposed materials and a discharge to surface waters need NPDES coverage from EGLE, usually under the general permit for their watershed cycle year. Each facility needs an Industrial Stormwater Certified Operator, a Stormwater Pollution Prevention Plan, and quarterly inspections and visual assessments. Facilities with no exposure can file a No Exposure Certification instead.
Frequently Asked Questions
Who regulates stormwater in Michigan?
Three layers of government share it. The Michigan Department of Environment, Great Lakes, and Energy (EGLE) runs the NPDES stormwater permits for construction, industrial facilities, and municipal storm sewer systems under Part 31 of the Natural Resources and Environmental Protection Act (NREPA). Soil erosion permits under Part 91 come from a local enforcing agency: every county designates a County Enforcing Agency, and some cities and townships run their own program as a Municipal Enforcing Agency. County drains and drainage districts fall under the elected county Drain Commissioner through the Drain Code of 1956.
When do I need a soil erosion permit in Michigan?
The Part 91 rules require a permit before any earth change that disturbs 1 or more acres, or that is within 500 feet of the water's edge of a lake or stream, no matter how small (R 323.1704). The permit comes from the county or municipal enforcing agency, not from EGLE, and local ordinances can be stricter. A few minor activities are exempt, such as small homeowner projects that are stabilized within 24 hours and don't send sediment off site.
What is Michigan's construction stormwater Permit-by-Rule?
Michigan doesn't issue a construction general permit. Construction sites of 1 acre or more that discharge stormwater to state waters are covered by a Permit-by-Rule (R 323.2190), which only works once the site holds its Part 91 soil erosion permit. Sites of 1 to 5 acres are covered automatically. Sites of 5 acres or more must also file a Notice of Coverage with EGLE and pay a $400 fee. Every covered site needs an EGLE-certified storm water operator to inspect weekly and within 24 hours after any rain that causes a discharge.
What does a county drain commissioner do?
The drain commissioner is an elected county office under the Drain Code of 1956, renamed Water Resources Commissioner in some counties. The office has jurisdiction over established county drains, which can include creeks, ditches, storm sewers, and related structures, and drainage districts can be assessed for their upkeep. Obstructing an established drain, including narrowing it, makes the person responsible liable for the cost of removal, and that cost becomes a lien on the land. In some counties the same office is also the Part 91 soil erosion agency, but not in all of them.
What are the penalties for stormwater violations in Michigan?
Under Part 91, a violation is a civil infraction with a fine of up to $2,500. A knowing violation carries up to $10,000 per day, and a knowing violation after a notice of determination carries $2,500 to $25,000 per day. The enforcing agency can also install erosion controls itself and put a lien on the property for the cost. Under Part 31, a court must impose a civil fine of $2,500 to $25,000 per day of violation, and a discharge the person knew or should have known was unlawful can be prosecuted as a felony.
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