The U.S. Army Corps of Engineers authorizes projects in several different ways with several different types of permits. This page is meant to provide you with a brief overview of the three (3) most common types of U.S. Army Corps of Engineers permits - the Nationwide Permits, the Regional General Permit No. 1, and the Individual Permit.
Application for IDEM authorization can be made online at https://stormwater.idem.in.gov/.
U.S. Army Corps of Engineers Nationwide Permits (NWPs)
What are Nationwide Permits?
According to the U.S. Army Corps of Engineers (Corps), the Nationwide Permits are meant to authorize activities that are "similar in nature, cause only minimal adverse environmental effects when performed separately, and cause only minimal cumulative adverse effects on the aquatic environment." The Nationwide Permits allow the Corps to focus their limited resources on activities important to them. It is not surprising that, given the Corps' much broader focus both in terms of geography and in terms of public interest review, their focus would differ somewhat from Indiana's focus. Congress must have anticipated this because they created a mechanism for the states to use to ensure that activities permitted by the Corps do not degrade water quality or violate other applicable laws. That mechanism is the State Water Quality Certification (also known as Section 401 Water Quality Certification).
For activities that are approved with General and Specific Conditions, please refer to the IDEM Section 401 Water Quality Certification for the 16 NWPs (below).
If an activity does not comply with the project description, impact limitations, or conditions published in the Federal Register Notice and comply with all the General and Specific Conditions IDEM placed on the NWPs, then a site-specific Individual Section 401 Water Quality Certification is required from IDEM.
Application for IDEM authorization under a general certification or an individual water quality certification can be made online at https://stormwater.idem.in.gov/.
If an activity does not comply with all General and Specific Conditions IDEM placed on the NWPs, then a site-specific Individual Section 401 Water Quality Certification is required from IDEM. Please download State Form 51821 and submit all required information to IDEM.
- December 16, 2025, IDEM Section 401 Water Quality Certification for the Nationwide Permits [PDF]
- March 10, 2026, Corps of Engineers Public Notice and Indiana Regional Conditions for the Nationwide Permits [PDF]
What does it mean if Section 401 Water Quality Certification for a Nationwide Permit is denied?
If IDEM has denied Section 401 Water Quality Certification for a Nationwide Permit, it just means that IDEM wants to take a closer look at that particular activity; IDEM's closer look means that the project will require an individual, site-specific Section 401 Water Quality Certification. Most of the Nationwide Permit activities that IDEM denied certification on, such as shellfish aquaculture activities and cranberry production, are not applicable in Indiana, but some are denied because IDEM must ensure that the activity does not result in degradation of water quality or violation of other applicable state laws.
U.S. Army Corps of Engineers Individual Permit (IP)
What is a U.S. Army Corps of Engineers Individual Permit?
The Corps' Individual Permit (IP) is used for projects proposing extensive impacts or impacts to rare or special aquatic types. Generally speaking, the Corps' IP is always used for projects that propose impacts equal to or greater than one (1) acre of wetland or stream. The Corps can, at their discretion, elevate any project to be reviewed as an Individual Permit.
Individual Permits require the evaluation of U.S. Army Corps of Engineers applications under a public interest review and the environmental criteria set forth in the Clean Water Act Section 404(b)(1) Guidelines.
U.S. Army Corps of Engineers Regional General Permit No. 1 (U.S. ACE RGP No. 1)
What is the Regional General Permit No. 1?
The Louisville, Detroit, and Chicago Districts of the U.S. Army Corps of Engineers established the Indiana Regional General Permit No. 1 (Corps RGP) on December 15, 2024. If a project is not large enough to require an Individual Permit and is not small enough to fall under a Nationwide Permit, the U.S. Army Corps of Engineers will review an application under their RGP No. 1.
The Corps' Regional General Permit No. 1 is NOT the same as IDEM's Regional General Permit Notification Form. The names are just similar.
In general, the Corps' Regional General Permit No. 1 can be used by the Corps to authorize most projects that affect less than one (1) acre of waters of the United States. The following types of activities can be authorized by the Corps' RGP No. 1:
- Bank Stabilization Activities
- Transportation Projects
- Residential, Commercial, Institutional, Industrial, Municipal, and Recreational Developments
- Boat Ramps
- Minor Discharges and Excavation Activities
- Agricultural Activities
- Mining Activities
For activities that fall under RGP 1, please refer to the IDEM Section 401 Water Quality Certification for the RGP (below). Please download State Form 51937 (from the state forms web page) and submit all required information to IDEM. If an activity does not comply with all conditions IDEM placed on the RGP, then a site-specific Individual Section 401 Water Quality Certification is required from IDEM. Please download State Form 51821 (from the state forms web page) and submit all required information to IDEM.
