Storm-Water And Wetlands: Planning and Evaluation Guidelines for Addressing Potential Impacts of Urban Storm-Water and Snow- Melt Runoff on Wetlands

This publication presents recommended guidelines of current concepts for managing storm-water and snow-melt runoff when it is necessary to use wetland areas. The Urban Storm Water Advisory Group acknowledges that wetlands are often affected by storm-water management; decisions and wetland responses to changes in storm-water flows can be highly complex and can affect other waters, such as lakes and streams. Though this document focuses on avoiding impacts to wetlands from storm water and snow melt, keep in mind that wetlands are part of a larger hydrologic system. Poor storm-water management can readily damage not only wetlands, but lakes, streams and ground-water resources as well. This guidance seeks to balance storm-water and flood-flow management with ecological protection. Comprehensive plans for local government units, including cities, counties, and watershed management organizations, should address the management of the effects of urban storm-water and snow-melt runoff on wetlands and associated water courses and basins. These guidelines should be considered whenever there are storm-water discharges to natural water courses and basins, including wetlands, so as to minimize any adverse impacts to the diverse biological systems. The aim of these guidelines is to reduce chemical and physical degradation to water uses, aquatic habitats, and the level of water quality necessary to sustain such uses. These guidelines are intended to assist managers in designing a process that minimizes wetland impacts. The guidance does not take the place of any criteria administered by local, state, and federal agencies. The project must meet any requirements of the state Environmental Policy Act (M.S. 116D) and the state Environmental Rights Act (M.S. 116B), and comply with all permits issued by any unit of government. The permits include, but are not limited to, those issued by local governments under the state Wetland Conservation Act of 1991 (M.S. 103G), Protected Waters permits (M.S. 103G.245) issued by the Minnesota Department of Natural Resources, permits issued by the U.S. Army Corps of Engineers under Section 404 of the Clean Water Act, and certifications by the Minnesota Pollution Control Agency under Section 401 of Clean Water Act. This guidance was developed to summarize the existing knowledge about impacts of runoff to wetlands. Recommendations are included that attempt to standardize how various units of government can implement the guidance in existing planning and regulatory processes. New regulatory programs based on the guidelines may need to be developed, but this should be done if current programs cannot effectively incorporate the guidance concepts, and only after significant public and governmental input. The advisory group that developed the guidance intends that it become a source of common understanding so that current required programs can be made more effective in controlling environmental impacts at the same time they can be made less burdensome through procedural simplification and clear statements of regulatory expectations.