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State Issues Final Three-Acre Stormwater General Permit


September 1, 2020 – The Vermont Department of Environmental Conservation (DEC) released the final Three Acre Stormwater General Permit (GP 3-9050) today. This permit fulfils a key requirement of Vermont’s 2015 Clean Water Act (Act 64) and achieves all Phase One milestones outlined in the Lake Champlain Phosphorus Total Maximum Daily Load (TMDL) Accountability Framework.

“Finalizing the Three-Acre Stormwater permit is a necessary step in Vermont’s efforts to improve water quality and meet our Lake Champlain clean-up goals. Better stormwater management will help us achieve these goals by reducing runoff from parking lots, roads and roofs,” said Julie Moore, Secretary of the Vermont Agency of Natural Resources.

Vermont needs to reduce stormwater runoff from commercial, industrial, residential and institutional properties by roughly 20 percent to meet clean water goals. The Three-Acre Stormwater Permit will help achieve these reductions. The permit requires landowners with more than three acres of ‘impervious surfaces’ such as roofs, driveways and parking areas, to develop and implement projects to treat runoff to remove phosphorus, sediment, and other pollutants.

DEC asked for public feedback on the permit earlier this year. In response to comments requesting additional time to prepare for the permit, DEC revised the application process:

  • The initial permit application will be due on a staggered schedule, beginning in December 2021, and will extend through early 2023. As part of the initial application, landowners will need to provide basic project information.
  • Landowners will then have 18 months to complete an engineering analysis to determine a “best-fit” stormwater system that uses modern stormwater treatment practices to filter, store or soak up runoff.
  • Once the stormwater system plan is approved, landowners will have five years to install new stormwater systems.

“We understand this is a significant undertaking for these properties and we’ve taken multiple steps to help those impacted. Additionally, in light of the current economic challenges, DEC is exercising the greatest flexibility possible to fulfill this important work directed by the legislature while reducing the financial impact to struggling Vermont institutions, businesses, and municipalities,” said Peter Walke, DEC Commissioner.

DEC will offer technical and financial aid to landowners, including resources to support engineering design as well as grants and low-cost loan packages to help with the cost of implementation. DEC will be pairing resources from the Clean Water Fund and its State Revolving Fund (SRF) to offer cost-share to landowners to complete the engineering analysis for their property, including making up to $2 million available in FY21. DEC is also working with the Department of Financial Regulation and several Vermont banks to evaluate a range of possible approaches for assisting landowners with low-cost, long-term financing. In addition, DEC has partnered with the Lake Champlain Basin Program to offer significant financial support to schools to implement stormwater systems.

For more information, please visit or contact Padraic Monks, Stormwater Program Manager at