Opportunities / Science

GIS Mapping Project assists the Otter Creek Tactical Basin Plan

Impervious surfaces in urban settings are inevitable as the natural landscape is replaced by streets, buildings, houses and parking lots. This built environment results in reduced infiltration during heavy rain storms. As a result, stormwater can overwhelm urban drainage systems and result in street flooding and pollutants in streams. There are a number of places in the City of Rutland where this occurs on a regular basis. Downtown Rutland is one of them.

The Rutland Regional Planning Commission (RRPC), along with the other RPCs in Vermont, is under contract to the Watershed Management Division to assist in the development of tactical basin plans. As part of this work, RRPC Geographic Mapping Manager Steve Schild set out to map these potential problem areas and to correct some inconsistencies he noticed in the existing impervious cover map done for the state. To do this, Steve worked with Geographic Information System student specialists from Green Mountain College.

Using aerial image data from the Vermont Center for Geographic Information (VCGI), the students imported an already existing impervious raster layer from satellite imagery available from the Agency of Natural Resources. It was clear that this was not a complete picture of the downtown’s impervious surface areas and more data were needed (image below).

20160531GISMappingProjectAssiststheOtterCreekTacticalBasinPlan

An already existing impervious layer from satellite imagery of Rutland city. This is before the map was updated.

The students divided the city into north and south sections equally to add extra areas of missing impervious surfaces. This patchwork was then stitched together to recombine the north and south sections, and an updated impervious surface layer was created. The result was a much more detailed and, hopefully, useful visual of impervious surface areas in the City of Rutland (image below).

20160531GISMappingProjectAssiststheOtterCreekTacticalBasinPlan1

The updated impervious surface layer of Rutland city.

These data will be critical to identify key areas in Rutland where stormwater management efforts can be targeted by the City, and where Clean Water Initiative funding may support the installation of Green or traditional stormwater infrastructure.

This FLOW Post was prepared by Rutland RPC to showcase examples of work that the regional planning commissions are doing jointly with the Division, to assist in the development of tactical basin plans