Progress / Science

Road erosion mapping in Chittenden County

In an effort to help its municipalities prepare for DEC’s pending Municipal Roads General Permit, the Chittenden County Regional Planning Commission (CCRPC) completed several municipal Road Erosion Inventories this past summer. Working in partnership with Jim Ryan and other DEC staff, CCRPC adapted DEC’s inventory questions for use in a mobile app (Esri’s Collector for ArcGIS). Inventory data were collected on each 100-meter road segment that was determined to by “hydrologically-connected” such as roads that cross streams, lakes or wetlands or are within 100 ft. of these waterbodies. The questions focused on assessing the road condition and management practices for example adequate drainage, ditching and culvert sizing and installation. The inventories were carried out by summer interns from the University of Vermont. In addition to collecting statistical data, the interns also mapped discrete problems such as gullies forming in the roadbed, inadequate culverts or road runoff flowing unabated into streams.

Inventories were completed on more than 4,500 hundred-meter road segments in the towns of Underhill, Jericho, Bolton, Huntington, Richmond, St. George, Essex and Williston.175 erosion points were also mapped. With data collection now complete CCRPC, using several Better Roads grants, has hired Fitzgerald Environmental and Milone-MacBroom to review the data, develop a road erosion prioritization methodology and develop conceptual treatment designs to address high priority road erosion problem locations. The prioritization methodology will be developed with our municipalities and then shared with DEC, VAOT and the other RPCs The treatment designs can be used by the towns to apply for project implementation funds.

To see an example of this work, check out CCRPC’s map viewer for the Town of Jericho and then select the requisite data layers in the upper left corner.

ESRI's Collector app screenshot

CCRPC used ESRI’s Collector app to gather data on road conditions such as grading, drainage and culverts.