The Ecosystem Restoration Program (ERP) recently completed draft stormwater geographic information system (GIS) drainage maps for 21 urbanized cities, villages and hamlets in the Lake Memphremagog, Upper Connecticut River, Passumpsic River, and Stevens-Wells-Waits-Ompompanoosuc River watersheds. The Program plans to complete a statewide drainage map of all urbanized areas by 2017.
The maps will be used to assist the Vermont Department of Environmental Conservation (DEC) and communities with a variety of tasks. The maps are meant to provide an overall picture of the connectedness of the storm drainage system on both public and private properties in order to raise the public’s awareness of the impact of stormwater runoff to Vermont’s waterways and the need for regular drainage system maintenance as well as pollution prevention.
When water drains directly to rivers and streams in pipes without passing thru vegetation or over soil, pollutants move with that water contributing to both water quality impairments and an increased risk of flooding. In addition, having an understanding of the connectedness of the drainage system is also a valuable tool for hazardous spill prevention for local fire and police departments.
Information on the extent of the connected drain system and how it is associated with the municipal sewer system is also essential for the detection and elimination of illicit discharges. Illicit discharges are improperly connected sewer or wastewater lines to stormwater lines. Knowledge of which areas of the sewer service area have combined stormwater and sewer systems can better assist the larger municipalities, such as St Johnsbury, in planning and implementing combined sewer separation projects. Knowledge of the layout and extent of the stormwater system can inform options for cleaning up existing polluted stormwater discharges.
The DEC mapping project provides information, guidance and funding assistance for potential stormwater retrofit and clean up opportunities. Knowledge of where storm drains are located can also assist municipalities and residents with emergency preparedness for large rainfall events (i.e. Tropical Storms or Hurricanes) or spring snowmelt runoff events. By keeping storm drains clean and clear a great deal of localized flooding and property damage can be prevented. Finally, by providing a more thorough understanding of the drainage system these maps could be the basis for a local stormwater ordinance or be used to help create or enhance a municipal stormwater management program.
The 21 urbanized areas mapped are: Barton Village, Orleans Village, Bradford Village, Island Pond Village, E. Burke Village and Burke Mt Ski Area, Canaan Village, Beecher Falls Village, Concord Village, Derby Line, Derby Center, Fairlee Village, Groton Village, Lunenburg Village, Gilman Village, Lyndonville, Newbury Village, Wells River-Boltonville, Newport City, ST Johnsbury, Danville Village, and Norwich Village. Final reports and data of the mapping project are provided to each municipality and are also available at: http://www.watershedmanagement.vt.gov/erp/htm/SW_IDDE_program.htm