Monitoring data collected in the Lost River watershed and Walnut Bottom watershed in the Mid-Atlantic Highlands region, USA, during 1997-present, were analyzed to explore the hierarchical effects of a four-lane new highway construction on stream macroinvertebrates and water quality. Field sampling of macroinvertebrate and water were conducted before, during, and after highway construction at upstream sites and downstream sites. A macroinvertebrate-based index, West Virginia Stream Condition Index (WVSCI), was used as a biological indicator for stream health. In addition, fifteen water quality parameters were used as physical and chemical indicators for stream health. Statistical methods, including analysis of variance (ANOVA), principal components analysis (PCA), and discriminant function analysis (DFA) were used to partition differences of response variables.

Results/Conclusions

In the Lost River watershed, the rating of WVSCI remained as “Good” before, during and after the highway construction at the downstream sites. The rating of WVSCI increased from “Good” before and during the highway construction to “Excellent” after the highway construction at the upstream sites.  The highway construction had no statistically significant effects on the primary water quality variables (PC1) such as calcium, alkalinity, and conductivity. It only had slight but statistically significant effects on the secondary water quality variables (PC2) such as total suspended solids, turbidity, acidity, sulfate, nitrate, and iron. The biological and water quality conditions in the two watersheds during the three highway construction phases will be compared to examine the effects of highway construction on stream health.