One critical component of stormwater management in many municipalities is the use of stormwater retention ponds. These ponds temporarily store stormwater runoff and release it through a designed outlet structure that helps reduce pollutant loads into waterways and controls erosion.
Legislation enacted on April 26, 2016, 2015 Wisconsin Act 387, provides greater latitude for municipalities to use and maintain stormwater ponds for stormwater runoff management. The following provisions of the bill are of particular import for municipalities managing stormwater.
Exemption from Dredging Permit Requirements. This new legislation exempts the dredging of an existing stormwater management pond from the dredging permit requirements of Wis. Stat. ch. 30. This provision should help to streamline maintenance of stormwater ponds so that they can operate at their full potential.
Exemption from Wetland Permit Requirements. 2015 Wisconsin Act 387 also exempts discharges to wetlands that are the result of maintenance, operation, or abandonment of a sedimentation or stormwater detention basin and associated conveyance features that were not originally constructed in a wetland. This exemption clarifies that upland stormwater ponds can be maintained without a wetland permit and facilitates the maintenance of these ponds.
Compliance with Prescribed Performance Standards. DNR rules regulating nonpoint source pollution require compliance with certain performance standards for sources of nonpoint pollution, including stormwater runoff. These rules provide that, for the purpose of determining compliance with performance standards, DNR generally may not give credits for practices located in navigable waters such as inline stormwater ponds. This new legislation allows DNR to give credit for on-line ponds in artificial waterways as a method for achieving compliance with performance standards. This effectively broadens the credits otherwise provided under DNR regulations.
Consideration of Sediment Control and Water Quality Improvements. Stormwater credit is one issue for constructing inline ponds, but Chapter 30 permits are another. Act387 has a parallel provision in Wis. Stat. § 30.19 which specifically requires the DNR to consider sediment control in and water quality improvements to the watershed as a whole that result from an on-line pond in determining whether to issue an individual permit for the project. Thus, while a Chapter 30 permit is still required for an on-line pond, this provision requires DNR to take a holistic view of the benefits from such a pond.