Isolated Wetlands Frequently Asked Questions
This page provides basic information regarding the scope of IDEM's Isolated Wetland Permitting Program. It is intended to answer basic questions and frequently asked questions (FAQs) regarding IDEM's authority, regulated activities, and other information concerning the program's implementation. Since this is an overview, we recommend that you contact IDEM program staff if you have project-specific questions or other questions not specifically addressed on this page.
What is the purpose of IDEM Isolated Wetland Permits?
Applicants proposing an impact to an “isolated wetland,” which is a wetland that the U.S. Army Corps of Engineers has determined to be a non-federally jurisdictional wetland, are required to apply for an obtain Isolated Wetland Permits from IDEM. Isolated wetland permits are required under Indiana’s State Isolated Wetland Law (Indiana Code 13-18-22 and 327 Indiana Administrative Code 17).
Issuance of Isolated Wetland Permits from IDEM means that IDEM anticipates that an applicant’s project will comply with state law, water quality standards and other aquatic resource protection requirements under IDEM’s authority.
What types of activities require an IDEM Isolated Wetland Permit?
You need to apply for, and receive, an IDEM Isolated Wetland Permit if you are planning any of the following:
- Filling an isolated wetland
- Excavating an isolated wetland
- Mechanical clearing in an isolated wetland (using heavy equipment such as bulldozers to remove or clear trees and stumps)
- Constructing a pond in an isolated wetland
- Dredging an isolated wetland
- Dredging or excavation any potentially contaminated sediments from an isolated wetland
This list is NOT all-inclusive. There are other activities that trigger the need for Isolated Wetland Permits from but the aforementioned activities are more common.
How do I know if I have wetlands on my property/project site?
Wetlands do not have to have standing water in them in order to be regulated by IDEM or the U.S. Army Corps of Engineers. Determining the boundaries of wetlands is a task that must be conducted by a qualified wetland consultant. Wetlands are delineated by carefully examining a site for the presence of wetland indicators. In order to be a legal wetland, an area must have all three of the following present:
- A dominance of wetland vegetation
- The presence of soils exhibiting hydric characteristics
- Indicators of hydrology (the presence of surface water or waterlogged soils) for a sufficient period of time in most years to influence the types of plants and soils that occur in that area, in order to legally be considered a wetland.
In order to know if wetlands are on your property, you must hire a wetland or environmental consultant to conduct a wetland delineation on the property. The wetland consultant will put together a report for you, called a wetland delineation report. This report must be submitted to the U.S. Army Corps of Engineers for review and approval before the delineation report is considered accurate and legal. The U.S. Army Corps of Engineers has the responsibility of making wetland determinations and determining the limits of federal jurisdiction. The U.S. Army Corps of Engineers will write a letter to you once they have reviewed your wetland delineation report – this letter will state the jurisdiction of the delineated wetlands and will also state whether or not the U.S. Army Corps of Engineers concurs with the delineation. Keep this letter, and your wetland delineation report, in a safe place as you will need to submit a copy of both to IDEM if you wish to apply for permits.
How do I hire an environmental/wetland consultant?
IDEM can provide you with a list of environmental consultants who work in Indiana. The consultants included on this list are not recommendations of IDEM. Specifically, IDEM makes no endorsement or representation of any qualifications or lack of qualifications by any of the attached individuals or companies. Any firm that asks to be included is included without review of qualifications. You should investigate these businesses similar to any other service or establishment that you would deal with. When interviewing consultants, you should carefully evaluate their qualifications. IDEM has put together the following suggestions to help you make a selection:
- Check credentials: If you are looking for someone to help identify and locate wetlands, find out whether or not the consultant has a good background in hydrology, soil science, ecology, and (especially important) botany (plant identification). The consultant you select should have the ability to apply wetland identification methods required by state and federal agencies. Make sure that the consultant can identify wetlands and their boundaries consistent with regulating agencies.
- Make sure the consultant is knowledgeable: Is the wetland consultant familiar with local, state, and federal wetland regulations? Is this wetland consultant experienced with IDEM and the U.S. Army Corps of Engineers? Another way to ask this: Does the consultant or individual know the project managers at IDEM and the U.S. Army Corps of Engineers by name?
- Examine workmanship: Ask the wetland consultant for examples of previous work similar to the services you are requesting. What type of track record does this company or individual have with local, state, and federal agencies? Request references that include clients who have had projects reviewed and approved by IDEM. Check all references.
- Ask others: Ask colleagues and other businesses, such as real estate, development, homebuilders, etc. that are routinely involved in wetland concerns. Ask them about their experiences and knowledge regarding the wetland consultant you are considering.
What is the difference between Isolated Wetlands and Federally Jurisdictional Wetlands?
Once you have hired a wetland consultant to determine if your property has wetlands, the wetland consultant will, after studying the site, put together a report for you called a wetland delineation report. This wetland delineation report must be submitted to the U.S. Army Corps of Engineers for review and approval before the delineation report is considered accurate and legal. The U.S. Army Corps of Engineers has the responsibility of making wetland determinations and determining the limits of federal jurisdiction. The U.S. Army Corps of Engineers will write a letter to you once they have reviewed your wetland delineation report – this letter will state the jurisdiction of the delineated wetlands and will also state whether or not the U.S. Army Corps of Engineers concurs with the delineation.
Wetlands are either considered to be “federally jurisdictional” or “isolated.”
Federally jurisdictional wetlands are wetlands that abut or are adjacent to a federally regulated stream, lake, river, or other Water of the U.S. Waters of the U.S. are defined in the Code of Federal Regulations (CFR) at 40 CFR 230.3(s). Impacts to federally jurisdictional wetlands are regulated by the U.S. Army Corps of Engineers under Section 404 of the Clean Water Act. Impacts to federally regulated wetlands are also regulated by IDEM.
"Isolated wetlands", for purposes of IC 13-18, are defined by state law as those wetlands that are not subject to regulation under Section 404(a) of the Federal Clean Water Act. Since 2004, IDEM has regulated isolated wetlands under Indiana’s State Isolated Wetlands Law (IC 13-18-22). Indiana’s State Isolated Wetlands Law creates a category of Waters of the State known as state regulated wetlands. A state regulated wetland is defined as an isolated wetland located in Indiana that is not an exempt isolated wetland. This law establishes a classification system for wetlands and a set of general permits, exemption criteria, and individual permitting authority for IDEM to regulate the placement of dredged or fill material into non-exempt isolated wetlands. Any activity that would result in a discharge to a non-exempt state isolated wetland is regulated by IDEM under IC 13-18-22.
How do I contact the U.S. Army Corps of Engineers?
There are three (3) districts of the U.S. Army Corps of Engineers located in Indiana. The Detroit District of the U.S. Army Corps of Engineers covers the northern portions of the state. The Chicago District of the U.S. Army Corps of Engineers covers a small portion of northwest Indiana primarily associated with the drainage area of Lake Michigan. The Louisville District of the U.S. Army Corps of Engineers covers the majority of the state except for several northern counties covered by Chicago and Detroit.
Information and jurisdictional maps related to each U.S. Army Corps of Engineers District is available on the U.S. Army Corps of Engineers page.
What are the different types of state isolated wetlands?
By law, Indiana’s isolated wetlands are defined as being a Class I, Class II, or Class III wetland; these definitions are listed in Indiana Code 13-11-2-25.8.
For purposes of IC 13-18:
- "Class I wetland" means an isolated wetland described by one (1) or both of the following:
- At least fifty percent (50%) of the wetland has been disturbed or affected by human activity or development by one (1) or more of the following:
- Removal or replacement of the natural vegetation.
- Modification of the natural hydrology.
- The wetland supports only minimal wildlife or aquatic habitat or hydrologic function because the wetland does not provide critical habitat for threatened or endangered species listed in accordance with the Endangered Species Act of 1973 (16 U.S.C. 1531 et seq.) and the wetland is characterized by at least one (1) of the following:
- The wetland is typified by low species diversity.
- The wetland contains greater than fifty percent (50%) areal coverage of non native invasive species of vegetation.
- The wetland does not support significant wildlife or aquatic habitat.
- The wetland does not possess significant hydrologic function.
- At least fifty percent (50%) of the wetland has been disturbed or affected by human activity or development by one (1) or more of the following:
- "Class II wetland" means either of the following:
- An isolated wetland that is not a Class I or Class III wetland; or
- A type of wetland listed in subdivision (3)(B) that would meet the definition of Class I wetland if the wetland were not a rare or ecologically important type; and
- "Class III wetland" means an isolated wetland:
- That is located in a setting undisturbed or minimally disturbed by human activity or development and that supports more than minimal wildlife or aquatic habitat or hydrologic function; or
- unless classified as a Class II wetland under subdivision (2)(B), that is of one (1) of the following rare and ecologically important types:
- Acid bog.
- Acid seep.
- Circumneutral bog.
- Circumneutral seep.
- Cypress swamp.
- Dune and swale.
- Forested fen.
- Forested swamp.
- Marl beach.
- Muck flat.
- Sand flat.
- Sedge meadow.
- Shrub swamp.
- Sinkhole pond.
- Sinkhole swamp.
- Wet floodplain forest.
- Wet prairie.
- Wet sand prairie.
What is the difference between an Isolated Wetland General Permit (IWGP) and an Isolated Wetland Individual Permit (IWIP)?
Impacts to non-exempt Class I isolated wetlands, regardless of the acreage of impact, are commonly regulated by a general permit known as an Isolated Wetland General Permit (IWGP). An impact of 0.10 acre or less to a non-exempt Class II isolated wetland is also usually regulated under an Isolated Wetland General Permit.
Other wetland activities in non-exempt Class I and Class II isolated wetlands that will have minimal impacts can also be covered by an Isolated Wetland General Permit. These are discussed more in depth on the Overview of IDEM Isolated Wetland Permits page.
Under certain circumstances, IDEM will require a 327 IAC 17-3 permit (an IWGP for significant impacts to Class I wetlands) or a 327 IAC 17-4 permit (an Isolated Wetland Individual Permit Individual Permit for activities in Class II and Class III wetlands). Under these circumstances, IDEM will notify the applicant that the project does not qualify for an Isolated Wetland General Permit under this rule and instruct the applicant on the procedures to seek authorization under the 327 IAC 17-3 or 327 IAC 17-4 permit.
How do I apply for an Isolated Wetland Permit/Permits?
Application forms are available for download on our application page. You may wish to hire an environmental consultant to determine your scope of impacts, prepare your application, and submit your application along with all required enclosures (maps/plans/figures) that must be included with your application form.
Which application form do I need to use?
The required application form for any impacts to isolated wetlands is the Application for Authorization to Discharge Dredged or Fill Material to Isolated Wetlands and/or Waters of the State. Applications are available for download from our application page.
What is mitigation?
Applicants must demonstrate to IDEM how they are avoiding impacts to wetlands. If an applicant is unable to completely avoid impacts, they must demonstrate how their proposed project and unavoidable impacts to isolated wetlands have been minimized. Applicants must provide compensatory mitigation for any remaining adverse impacts to isolated wetlands.
Compensatory mitigation is the last step in the previously mentioned three-step approach of
- minimization, and
The purpose of mitigation is to compensate for unavoidable impacts to isolated wetlands.
Compensatory actions are actions taken that provide some form of substitute aquatic resource for the impacted aquatic resource. Compensatory mitigation may involve:
- Restoration of existing degraded wetlands or areas that were previously wetland
- Creation of new wetlands
- Preservation of existing wetland and streams, when utilized in conjunction with creation or restoration
- Preservation or restoration of upland buffers adjacent to surface waters, when utilized in conjunction with creation or restoration
- Enhancement of existing wetlands
Why does IDEM require compensatory mitigation?
State law requires that applicants perform compensatory wetland mitigation when an applicant proposes to impact a non-exempt isolated wetland. Mitigation ratios are written into the State Isolated Wetland law and can be found at IC 13-18-22-6. Filling a wetland eliminates its existing and potential uses. Therefore, IDEM would not be maintaining and protecting the uses of that Water if IDEM did not require replacement of the filled wetland. Additionally, the filled wetland would violate the state’s narrative minimum surface water quality standards (327 IAC 2-1-6 and 327 2-1.5-8) if mitigation were not provided for its impact. In other words, compensatory mitigation provides IDEM with the flexibility to authorize projects that IDEM would otherwise have to deny for violating the antidegradation rules and minimum water quality standards.
Does IDEM use set mitigation ratios/ have specific mitigation requirements?
State law requires that applicants perform compensatory wetland mitigation when an applicant proposes to impact a non-exempt isolated wetland. In general, IDEM requires that impacted wetlands be replaced with wetlands of the same type (e.g., a forested wetland that is filled must be replaced with a forested wetland). However, IDEM may, under limited circumstances and in rare occasions, allow an applicant to create or restore a different type of wetland or aquatic habitat if that “out-of-kind” mitigation will provide better water quality.
Mitigation ratios are written into Indiana’s State Isolated Wetland law and can be found at IC 13-18-22-6.
Compensatory mitigation shall be provided in accordance with the following table:
|Class of Impacted Wetland||Class of Replacement Wetland||Ratio for on-site mitigation||Ratio for off-site mitigation|
|Class I||Class I||1.5 to 1||1.5 to 1|
|Class I||Class II||1 to 1||1 to 1|
|Class II||Class II or Class III||1.5 to 1 Non-forested
2 to 1 Forested
|2 to 1 Non-forested
2.5 to 1 Forested
|Class III||Class III||2 to 1 Non-Forested
2.5 to 1 Forested
|2.5 to 1 Non-forested
3 to 1 Forested
The larger ratios (e.g., 3:1) reflect the increased difficulty of recreating the type of wetland destroyed and the temporal loss associated with the time it takes to create the wetland. In some cases IDEM will not permit mitigation at any ratio, regardless of the wetland type, if the proposed project would degrade water quality in such a manner that mitigation could not offset the loss of protected uses.
If mitigation is off-site, the mitigation must be within the same eight (8) digit U.S. Geological Service hydrologic unit code or within the county of the wetland impact. Exempt isolated wetlands may be used to provide compensatory mitigation for approved wetland impacts. An exempt isolated wetland that is used to provide compensatory mitigation becomes a state regulated wetland. There are minimum success criteria that all wetland mitigation sites must meet. The IDEM Non Rule Policy Document, Minimum Success Criteria for Wetland Compensatory Mitigation (NRPD-Water-010, available on the IDEM Nonrules Policies page) was put into effect on September 8, 2006.
How much are the application fees for Isolated Wetland Permits?
There is, currently, no fee to apply for any Isolated Wetland Permit.
Where do I send my application form?
Send your application form via certified mail to the Office of Water Quality Wetlands and Storm Water Section.
What do I have to submit with my application form?
Required enclosures and submittals are specified on Page 2 of the Application for Authorization to Discharge Dredged or Fill Material to Isolated Wetlands and/or Waters of the U.S., please refer to Page 2 of the application. All required enclosures and submittals are specified in Section 6 (Drawing/Plan Requirements) and Section 7 (Supplemental Application Materials) of the application.
How can I avoid delays in the IDEM review process?
It is strongly recommended that you contact the IDEM project manager for the county you are working in if the scope of your proposed activities will require an Isolated Wetland Individual Permit (impacts to Class II wetlands greater than 0.10 acre or any impacts to a Class III wetland).
Additionally, it is recommended that you contact IDEM to set up a pre-application meeting, either in our office or out on your site, to discuss your project. IDEM staff will meet with you, as time allows, to discuss your proposed project. Complex projects with a larger scope of impact may have priority over pre-application meetings for smaller projects.
IDEM cannot process any application proposing impacts to wetlands without a copy of a wetland delineation report and a copy of correspondence from the U.S. Army Corps of Engineers stating the jurisdiction of the wetlands. If you submit an application to IDEM proposing wetland impacts without a copy of U.S. Army Corps of Engineers correspondence, your application will be rejected by the IDEM project manager who reviews the application.
What can I expect once I’ve sent in my application form?
First, be sure to submit your application form to IDEM via certified mail to ensure that it is received by the agency.
Applications submitted for an Isolated Wetland General Permit (IWGP) have a review timeframe of 30 days from the date of receipt by IDEM. Applicants will receive a formal response letter from IDEM which notifies them whether the project falls within the scope of the terms and conditions of the Isolated Wetland General Permit or whether the project falls outside the scope of the IWGP.
Upon receipt of an application for an Isolated Wetland Individual Permit, IDEM staff will review the application and required enclosures for completeness and accuracy. If any deficiencies are noted in the application, IDEM staff will send a Letter of Deficiency (LOD) to both the applicant and agent noted on the application form within 15 business days of receipt of the application by IDEM. In the interest of time, IDEM staff may send a LOD email to both the applicant and agent instead of a LOD sent through U.S. Mail. Once IDEM has a complete application, the agency has one hundred twenty (120) days to make an agency decision (approval or denial). Public notice and comment are integral components of IDEM’s IWIP review. IDEM is required to public notice the receipt of all applications requiring an IWIP. IDEM public notice periods for Isolated Wetland Individual Permits run for 30 days. Notice is served to adjacent property owners, other state and federal agencies, and any person who has requested to receive public notices for IWIP applications. Public notices are also posted on the IDEM Public Notices portal.
No agency decision can be made until the 30-day public notice has expired and all comments have been addressed (if any were received). IDEM has 120 days from receipt of a complete IWIP application to make a formal agency decision (approval or denial).
Is there an opportunity to comment on applications for Isolated Wetland Individual Permits?
All applications for Isolated Wetland Individual Permits are subject to public comment. As stated above, IDEM will issue a public notice allowing 30 days for comments on water quality to be submitted to IDEM. All public notices are also posted electronically on the IDEM Public Notices portal.
In addition to submitting comments on water quality, interested parties may also request a public hearing on the application. If there is significant public interest in the application or if substantial questions or new information pertaining to water quality issues are raised, then IDEM may hold a public hearing.
Will I receive a document in writing stating that my application has been approved or denied?
Applicants will receive a formal agency decision via certified mail once IDEM’s review of the application is complete. For Isolated Wetland General Permits, applicants will receive a formal response letter from IDEM which notifies them whether the project falls within the scope of the terms and conditions of the Isolated Wetland General Permit or whether the project falls outside the scope of the IWGP.
For Isolated Wetland Individual Permits, applicants will receive either a written Isolated Wetland Individual Permit approval or denial. Approvals of Isolated Wetland Individual Permits typically have conditions imposed by IDEM included as part of the approval.
What types of conditions might IDEM impose as part of an approval of an Isolated Wetland Individual Permit?
Typical “special conditions” include minimization of impacts, compensatory mitigation for wetland impacts, monitoring requirements for required compensatory wetland mitigation, establishment of buffer zones around waterbodies, prohibitions on work during certain periods of the year, the implementation of storm water management measures, including erosion control and sediment control measures, conservation easements/deed restrictions or equivalents, and additional monitoring or water quality studies.
Are there any other permits I might need to apply for if I want to work in a wetland, stream, lake, river, or other Water?
The granting of Isolated Wetland Permits and/or Section 401 Water Quality Certification from IDEM does not relieve you of the responsibility of obtaining any other state, local or federal authorizations.
The Indiana Department of Natural Resources (IDNR) Division of Water (DOW) has their own permitting mechanism for working in Indiana Streams, Lakes, and Floodways; your project may require a Construction in a Floodway Permit or a Public Freshwater Lake Permit from IDNR. More than 50% of the projects requiring IDEM Section 401 Water Quality Certification will also require a Construction in a Floodway Permit from DNR.
You may also need a permit from your County Surveyor if you wish to work in a stream or river that your county has determined to be a “legal drain.”
Additionally, if you are planning to disturb an acre or more of soil during the construction of your project, you will need a Construction/Land Disturbance Run-off general permit from the Office of Water Quality Storm Water Program.