Evaluating Systems to Reduce Road Improvement Impacts on Mountain Streams

摘要

Sediment is the most common pollutant affecting North Carolinas waterways, impacting a range of aquatic organisms, reducing reservoir capacity, and hurting their aesthetic value. Construction activities, including roadway projects, are a significant contributor of state-wide sediment loading. The NC DOT program of widening and paving rural roads in the mountain region provided an opportunity to evaluate new types of roadside erosion control BMPs with the goal of protecting the particularly sensitive trout streams commonly found there. Two roadway paving projects were each divided into experimental sections installed with either (1) the standard DOT BMPs consisting of narrow sediment traps and rock checks, (2) the new fiber wattle check dams (consisting of a mix of straw wattles and coir logs) with 100 grams of granulated polyacrylamide (anionic PAM 705) added to each, or (3) the new wattle check dams alone (no PAM added).