Stormwater Impaired Waters

The management of stormwater runoff is a simple concept but a complex problem.  Water runs off from impervious surfaces rather then naturally infiltrating the soil.  The cumulative effect of the increased frequency, volume, and rate of stormwater runoff results in increases in wash-off pollutant loading to streams and destabilization of the stream channels.  ANR recognizes the importance of managing the quantity and quality of stormwater runoff, especially within Vermont’s stormwater impaired waters.

Seventeen of Vermont’s waters are listed as “impaired” primarily due to urban stormwater runoff.  These waters fail to meet the Vermont Water Quality Standards based primarily on biological monitoring data.  These impaired waters are listed on the State of Vermont’s 2008 List of Waters, Part A, prepared pursuant to Section 303(d) of the federal Clean Water Act. 

Once a water is listed as impaired, it is scheduled for the development of a Total Maximum Daily Load (TMDL).  A TMDL is an EPA approved document that attempts to limit and allocate discharge loads among the various dischargers to impaired waters in order to assure attainment with water quality standards.

Act 140, passed by the General Assembly in 2004, requires that ANR develop a TMDL or water quality remediation plan for each of these waters by January 15, 2010.  The Stormwater Management Section in DEC’s Water Quality Division is currently working on developing an implementation strategy for the TMDLs with input from the Stormwater Advisory Group (SWAG) using hydrologic modeling software developed by TetraTech, Inc.

During the interim period, projects in the affected watersheds (listed below) will have to comply with a "net zero" pollution standard described in the 9/27/2004 letter describing New Legislation relating to Stormwater Discharges. For information on permitting of a site in an impaired watershed, permittees should contact the permit reviewer for their district.

Stormwater Impaired Watersheds:

Updated: June 2009