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Project ID: 2004WV26B

Title: Changes to In-Stream Suspended Sediment and Turbidity Following Improvements to a Forest Road in West Virginia

Project Type: Research

Focus Categories: Non Point Pollution, Sediments, Water Quality

Keywords: Suspended sediment, turbidity, forest road construction, sediment delivery, road improvements, best management practices

Start Date: 05/01/2004

End Date: 09/01/2006

Federal Funds: $25,060

Non-Federal Matching Funds: $50,230

Congressional District: WV 01

Principal Investigators:
Jingxin Wang

Pamela Edwards

Joseph F. McNeel


In-stream sediment is the most common water pollutant throughout the world. While forests contribute few pollutants to surface waters, sediment is the one most associated with forestry operations, with most originating from the construction and presence of forest roads. Most research in the East examining the effects on forest road construction on water quality, particularly in the central Appalachians, has involved the careful use of best management practices on soils that are not highly susceptible to erosion. Little work has been done to determine how water quality is affected by road construction that uses lower levels of care that are commonly observed, especially on private land. Because privately owned forest lands make up more than 80 percent of forests in West Virginia, demands for wood extraction are increasing, and the most productive sites in West Virginia are on highly erodible soils, it is important to understand how typical road construction practices used in forestry operations will affect suspended sediment and turbidity levels. This proposal requests funding to continue sampling and turbidity in an-already established study. A forest road was constructed through a watershed in summer 2002. It was left in poor condition from fall 2002 through mid-summer 2003. In mid-summer its condition was improved through the installation of more and better water control features and sediment traps, seeding of the fill slopes and cut banks, and graveling of the driving surface because water quality problems were found and reported. Water samples were collected located near the mouth of the treatment watershed and from a paired control watershed with automatic samplers during almost every storm event for three years prior to road construction and during the first year after road construction (through fall 2003). Samples were analyzed for turbidity using a Hach Ratio Turbidimeter and for total suspended sediment and mineral suspended sediment using standard vacuum filtration and filter drying/burning procedures. Turbidity and suspended sediment levels in both the control and treatment watersheds were in expected ranges during the 3 pretreatment years prior to road construction. By contrast, both parameters increased to very high levels during the spring and early summer 2003 before the road condition was improved and finalized. After road improvements were finalized, reductions in turbidity and suspended sediment occurred. By continuing the stream water sampling phase of this study, we will specifically address whether: 1) the rapid recovery is real or simply an artifact of the numbers and characteristics of the storms that have occurred since the road has been completed and improved, 2) storms with certain attributes, particularly very large ones, continue to result in extremely elevated turbidity and suspended sediment (presumably due to sediment stored in the channel), even if more “average” storms no longer have elevated sediment, 3) recovery is linear, exponential, or it levels off at some point in time, and 4) suspended sediment and turbidity increase again in the future as some situations develop over time, such as extension of erosion features below culvert outlets toward the stream channel.

Progress/Completion Report PDF

U.S. Department of the Interior, U.S. Geological Survey
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Last Updated: Wednesday July 13, 2005 6:14 PM
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