Date of Award

2015

Document Type

Project

Advisor(s)

Beverley Wemple, PhD

Deane Wang, PhD

Christopher Koliba, PhD

Abstract

Repeated erosion of over 7,000 miles of unpaved roads in Vermont is degrading water quality and draining limited town budgets. Best Management Practices (BMPs), including stone-lined ditches, turn outs, check dams, revetments, culverts and vegetative controls, are recommended by the Vermont Department of Transportation as low cost means of reducing the sediment and phosphorous run-off from backroads. However, their effectiveness, longevity and cost benefit are unknown. To address this gap, I assessed 100 BMPs at 43 erosion control projects constructed between 2005 and 2012 with funding from the Vermont Better Backroads program. BMP condition was compared to environmental factors that foreseeably affected how long they would remain intact. Increased road grade and exposure to flood events were the most significant predictors of project deterioration, although increased age affected specific BMPs. Only ten percent of assessed BMPs had failed, indicating that when properly maintained, BMPs may remain operable for over eight years. To understand the availability and distribution of town funds spent on backroad maintenance, I interviewed road foremen in five small, mountainous towns in Vermont. Town expenditures on repairing repeated road washouts were comparable to annual funds needed for “permanent fixes” of roads preliminarily identified to pose the highest risk to water quality. All towns indicated a willingness to construct more BMPs with further funding, suggesting that a proactive approach to erosion control on backroads will be an efficient use of state money allocated to improving water quality.