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Wetlands, Lakes and Streams Regulation

Wetlands, Lakes & Streams > Isolated Wetlands Program > Understanding Isolated Wetland Exemptions Understanding Isolated Wetland Exemptions

Under Indiana’s Isolated Wetlands Law, certain activities are exempt from permitting, and certain wetlands are considered to be “exempt isolated wetlands.”

What activities are exempt from permitting?

Certain activities in isolated wetlands, as specified in 327 IAC 17-1-7, are exempt from permitting. The following are exempt activities in state regulated wetlands:

  • The discharge of dirt, sand, rock, stone, concrete, or other inert fill materials any of the following in a de minimis amount.
  • A wetland activity at a surface coal mine for which the Indiana Department of Natural Resources has approved a plan to minimize, to the extent practical using best technology currently available, disturbances and adverse effects on fish and wildlife; otherwise effectuate environmental values; and enhance those values where practicable.
  • Any activity listed under Section 404(f) of the Clean Water Act, including the following:
    1. Normal farming, silviculture, and ranching activities (such as plowing, seeding cultivating, minor drainage, harvesting for the production of food, fiber, and harvesting for the production of food, fiber, and forest products, or upland soil and water conservation practices.
    2. Maintenance, including emergency reconstruction of recently damaged parts of currently serviceable structures (such as dikes, dams, levees, groins, riprap, breakwaters, causeways and bridge abutments or approaches, transportation structures, and construction or maintenance of farm or stock ponds or irrigation ditches or the maintenance of drainage ditches).
    3. Construction of temporary sedimentation basins on a construction site that does not include placement of fill material into the navigable waters.
    4. Construction or maintenance of farm roads or forest roads, or temporary roads for moving mining equipment, where the roads are constructed and maintained, in accordance with best management practices that assure that flow and circulation patterns and chemical and biological characteristics of the navigable waters are not impaired, the reach of the navigable waters is not reduced, and that any adverse effect on the aquatic environment will be otherwise minimized.

What types of exemptions are there for Isolated Wetland Impacts?

IDEM does not have authority to regulate activities in “exempt isolated wetlands.” The term “exempt isolated wetland” includes the following situations:

  • An isolated wetland that is voluntarily created is exempt from regulation unless that wetland was constructed as compensatory mitigation in accordance with a permit issued under Section 404 of the Clean Water Act or IC 13-18-22.
  • An isolated wetland that is voluntarily created is exempt from regulation unless that wetland was reclassified as a State Regulated Wetland under IC 13-18-22-6(c), which states that “A wetland that is created or restored as a Water of the United States may be used, as an alternative to the creation or restoration of an isolated wetland, as compensatory mitigation. The replacement class of a wetland that is a Water of the United States shall be determined by applying the characteristics of a Class I, Class II, or Class III wetland, as appropriate, to the replacement wetland as if it were an isolated wetland.”
  • An isolated wetland that is voluntarily created is exempt from regulation unless the owner of the wetland declares, by a written instrument, that the wetland is to be considered in all respects a State Regulated Wetland. The written instrument must be recorded in the office of the recorder of the county or counties in which the wetland is located and also filed with IDEM.
  • An exempt isolated wetland is an isolated wetland that exists as an incidental feature in or on any of the following:
    1. A residential lawn.
    2. A lawn or landscaped area of a commercial or governmental complex.
    3. Agricultural land.
    4. A roadside ditch.
    5. An irrigation ditch.
    6. A manmade drainage control structure.

Note: An isolated wetland exists as an incidental feature

  1. If:
    1. the owner or operator of the property or facility described above does not intend the isolated wetland to be a wetland;
    2. the isolated wetland is not essential to the function or use of the property or facility; AND
    3. the isolated wetland arises spontaneously as a result of damp soil conditions incidental to the function or use of the property or facility; AND
  2. if the isolated wetland satisfies any other factors or criteria established in rules that are:
    1. adopted by the water pollution control board; and
    2. not inconsistent with the factors and criteria described in this clause.
  • An exempt isolated wetland is an isolated wetland that is a fringe wetland associated with a private pond.
  • An exempt isolated wetland is an isolated wetland that is, or is associated with, a manmade body of surface water of any size created by excavating, diking, or excavating and diking dry land to collect and retain water for or incidental to agricultural, commercial, industrial, or aesthetic purposes.
  • An exempt isolated wetland is an isolated wetland that is located on land:
    1. subject to regulation under the United States Department of Agriculture (USDA) wetland conservation rules, also known as Swampbuster (16 U.S.C. 3801-3862), because of voluntary enrollment in a federal farm program; and
    2. used for agricultural or associated purposes allowed under the rules referred to in this clause.

Can isolated wetlands be exempt due to their class and their acreage?

Class I Isolated Wetland Exemptions

The State Isolated Wetlands Law allows states that an exempt isolated wetland is an isolated wetland that is a Class I wetland with an area, as delineated, of one-half (1/2) acre or less.

Alternately, the total acreage of exempt Class I wetland acreage is limited to the larger of the following:

Option 1

Take the largest Class I wetland on the tract that is less than or equal to 0.50 acre in size and take this as your Class I wetland exemption.

Option 2

Step 1: If you have several Class I wetlands on a tract, add up the acreages of each Class I wetland that is less than or equal to 0.50 acre in size.

Step 2: Take that total acreage and divide it in half. You now have an acreage that is 50% of the cumulative acreage of your Class I wetlands on the site that are individually less than or equal to 0.50 acre in size. Fifty percent (50%) of the cumulative acreage of all individual isolated wetlands on the tract that would qualify for the individual Class I acreage exemption described in clause can be applied toward exemptions.

Step 3: Determine which wetlands’ acreage, when added up, get as close to that 50% cumulative acreage as possible without exceeding it.

Here is an example showing Option 1 and Option 2 with a hypothetical development. Let’s say that the following wetlands were delineated on a tract:

  • Wetland A: 0.58 acre
  • Wetland B: 0.23 acre
  • Wetland C: 0.09 acre
  • Wetland D: 1.17 acres
  • Wetland E: 0.48 acre
  • Wetland F: 0.36 acre

We can see that Wetland A and Wetland D are each greater than 0.50 acre. Therefore, these wetland are not eligible for a Class I wetland exemption.

  • Wetland A: 0.58 acre >> Not Eligible for Exemption Since it's Greater than 0.50 acre
  • Wetland B: 0.23 acre
  • Wetland C: 0.09 acre
  • Wetland D: 1.17 acres >> Not Eligible for Exemption Since it's Greater than 0.50 acre
  • Wetland E: 0.48 acre
  • Wetland F: 0.36 acre
Option 1

Take the largest Class I wetland on the tract that is less than or equal to 0.50 acre in size.

In this case, the largest Class I wetland that is less than or equal to 0.50 acre in size is Wetland E (0.48 acre). In this case, Wetland E would be your Class I exempt isolated wetland.

Option 2

Step 1: Add up the cumulative acreage of each eligible Class I wetland that is less than or equal to 0.50 acre in size.

  • Wetland B: 0.23 acre
  • Wetland C: 0.09 acre
  • Wetland E: 0.48 acre
  • Wetland F: 0.36 acre

Total: 1.16 acres

Step 2: Take that total acreage and divide it in half.

Take 50% of that cumulative acreage of 1.16 acres. We calculate that 50% of 1.16 acres = 0.58 acre.

Step 3: Determine which wetlands’ acreage, when added up, get as close to that 50% cumulative acreage as possible without exceeding it.

Match eligible Class I wetlands on your tract up to get as close to the 0.58 acre as possible without going over the eligible exemption acreage of 0.58 acre.

Here are three scenarios for calculating Class I exemption based on 50% cumulative acreage:

Scenario 1:
  • Wetland B: 0.23 acre
  • Wetland F: 0.36 acre

Total: 0.59 acre

This scenario will not work as it exceeds 0.58 acre.

Scenario 2:
  • Wetland C: 0.09 acre
  • Wetland F: 0.36 acre

Total: 0.45 acre

This scenario would work. Your calculated cumulative average, in this example, was 0.58 acre. Wetland C (0.09 acre) and Wetland F (0.45 acre) are both exempt Class I wetlands, and their total is less than the 0.58 acre.

Scenario 3:
  • Wetland C: 0.09 acre
  • Wetland E: 0.48 acre

Total: 0.57 acre

This scenario would also work as you are close to, but do not exceed, your cumulative acreage of 0.58 acre. This scenarios is as close as you can get to your exemption acreage of 0.58 acre without exceeding the acreage.

  • Note: More scenarios exist for determining exemptions. This just shows three examples.
  • Note: Wetlands are wholly exempt, or wholly regulated. Wetlands cannot be partially exempt.

    Class II Isolated Wetland Exemptions

    The State Isolated Wetlands Law states that an exempt isolated wetland is an isolated wetland that is a Class II wetland with an area, as delineated, of one-quarter (0.25) acre or less.

    Alternately, the total acreage of exempt Class II wetland acreage is limited to the larger of the following:

    Option 1

    Take the largest Class II wetland on the tract that is less than or equal to 0.25 acre in size (as described above) and declare that wetland to be exempt.

    Option 2

    Step 1: If you have several Class II wetlands on a tract, add up the acreages of each Class II wetland that is less than or equal to 0.25 acre in size.

    Step 2: Take that acreage and divide it in three. You now have an acreage that is 33 1/3% of the cumulative acreage of your Class II wetlands on the site that are individually less than or equal to 0.25 acre in size. Thirty-three and one-third (33 1/3%) of the cumulative acreage of all individual isolated wetlands on the tract that would qualify for the individual Class II acreage exemption described in clause can be applied toward exemptions.

    Step 3: Determine which wetlands’ acreage, when added up, get as close to that 33 1/3% cumulative acreage as possible without exceeding it.

    Here is an example showing these Option 1 and Option 2 with a hypothetical development. Let’s say that the following wetlands were delineated on a tract:

    Class II Wetlands delineated on a tract:
    • Wetland G: 0.07 acre
    • Wetland H: 1.36 acres
    • Wetland I: 0.14 acre
    • Wetland J: 0.03 acre
    • Wetland K: 0.24 acre
    • Wetland L: 0.38 acre
    • Wetland M: 0.19 acre
    • Wetland N: 0.11 acre

    We can see that Wetland H and Wetland L are each greater than 0.25 acre. Therefore, these wetland are not eligible for a Class II wetland exemption

    • Wetland G: 0.07 acre
    • Wetland H: 1.36 acres >> Not Eligible for Exemption Since it's Greater than 0.25 acre
    • Wetland I: 0.14 acre
    • Wetland J: 0.03 acre
    • Wetland K: 0.24 acre
    • Wetland L: 0.38 acre >> Not Eligible for Exemption Since it's Greater than 0.25 acre
    • Wetland M: 0.19 acre
    • Wetland N: 0.11 acre
    Option 1

    Take the largest Class II wetland on the tract that is less than or equal to 0.25 acre in size.

    In this case, the largest Class II wetland that is less than or equal to 0.25 acre in size is Wetland K (0.24 acre). In this case, Wetland K would be your Class II exempt wetland.

    Option 2

    Step 1: Add up the cumulative acreage of each eligible Class II wetland that is less than or equal to 0.25 acre in size.

    • Wetland G: 0.07 acre
    • Wetland I: 0.14 acre
    • Wetland J: 0.03 acre
    • Wetland K: 0.24 acre
    • Wetland M: 0.19 acre
    • Wetland N: 0.11 acre

    Total: 0.78 acre

    Step 2: Take that acreage and divide it in three. You now have an acreage that is 33 1/3% of the cumulative acreage of your Class II wetlands on the site that are individually less than or equal to 0.25 acre in size.

    Take 33 1/3% of that cumulative acreage of 0.78 acre. We calculate that 331/3% of 0.78 acre = 0.26 acre.

    Step 3: Determine which wetlands’ acreage, when added up, get as close to that 33 1/3% cumulative acreage as possible without exceeding it.

    Here are four scenarios for calculating Class II exemption based on 33 1/3% cumulative acreage:

    Scenario 1:
    • Wetland J: 0.03 acre
    • Wetland K: 0.24 acre

    Total: 0.27 acre

    This scenario will not work as it exceeds your cumulative acreage of 0.26 acre.

    Scenario 2:
    • Wetland G: 0.07 acre
    • Wetland J: 0.03 acre
    • Wetland N: 0.11 acre

    Total: 0.21 acre

    This scenario would work as you are close to, but do not exceed, your cumulative acreage of 0.26 acre.

    Scenario 3:
    • Wetland G: 0.07 acre
    • Wetland I: 0.14 acre
    • Wetland J: 0.03 acre

    Total: 0.24 acre

    This scenario would also work as you are close to, but do not exceed, your cumulative acreage of 0.26 acre.

    Scenario 4:
    • Wetland G: 0.07 acre
    • Wetland M: 0.19 acre

    Total: 0.26 acre

    This scenario would also work as you equal, but do not exceed, your cumulative acreage of 0.26 acre. This scenario is as close as you can get to your exemption acreage of 0.26 acre without exceeding the acreage.

    • Note: More scenarios exist for determining exemptions. This just shows four examples.
    • Note: Wetlands are wholly exempt, or wholly regulated. Wetlands cannot be partially exempt.

      An isolated wetland that is isolated due to its size (Class I and Class II wetland size exemptions as described above) does not include an isolated wetland on a tract that contains more than one (1) of the same Cass of wetland until the owner of the tract notifies IDEM that the owner has selected the isolated wetland to be an exempt isolated wetland, consistent with the applicable limitations as described above.

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