Progress report on the effects of highway construction on suspended-sediment discharge in the Coal River and Trace Fork, West Virginia, 1975-81

Construction of the four-lane Appalachian Corridon G highway disturbed about 2 sq mi in the Coal River and 0.35 sq mi of the 4.75 sq mi Trace Fork basin in southern West Virginia. Construction had a negligible effect on runoff and suspended-sediment load in the Coal River and its major tributaries, the Little Coal and Big Coal Rivers. Drainage areas of the mainstem sites in the Coal River basin ranged from 269 to 862 sq mi, and average annual suspended-sediment yields ranged from 535 to 614 tons/sq mi for the 1975-81 water years. Suspended-sediment load in the smaller Trace Fork basin (4.72 sq mi) was significantly affected by the highway construction. Based on data from undisturbed areas upstream from construction, the normal background load at Trace Fork downstream from construction during the period July 1980 to September 1981 was estimated to be 830 tons; the measured load was 2,385 tons. Runoff from the 0.35 sq mi area disturbed by highway construction transported approximately 1,550 tons of sediment. Suspended-sediment loads from the construction zone were also higher than normal background loads during storms. (USGS)