Onsite and Offsite Effects of Converting Gravel or Native Roads to Pavement

Focus Area

Construction and Maintenance Practices


Environmental Process, Natural Resources







Research Idea Scope

Problem Statement:
When a gravel or native-surfaced road is paved, we do not know the effects of increased offsite soil erosion due to increase surface runoff.

Proposed Research:
It is becoming a common practice to pave roads in forested areas to decrease sedimentation. Field observations and model results, however, indicate that paving may increase sedimentation in many cases because there is greater runoff from paved surfaces than from graveled or non-surfaced roads. This increased runoff may cause increased erosion in drainage channels, and increased sediment delivery to nearby watercourses. Research is needed to measure effects of paving on sediment delivery. Sites should be identified where road managers are considering paving. Runoff water and sediment flux can then be monitored in ephemeral drainage channels above and below road crossings, and just before the drainage water enters a watercourse. This should be done for one to three years before the road is paved, and for an additional three years following paving. Results will be compared to nearby road segments that were not paved. This study should be carried out in two or three different climates, as road hydrologic responses in climates dominated by snowmelt will likely be different from climates dominated by winter rainfall or summer storms.


Suggested By

2002 Research Needs Conference Idea William J. Elliot, PE, PhD Project Leader, Soil and Water Engineering Rocky Mountain Research Station

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