Water quality trends in the Blackwater River watershed, Canaan Valley, West Virginia

The Blackwater River, historically an excellent brook trout ( Salvelinus fontinalis) fishery, has been affected by logging, fires, coal mining, acid rain, and land development. Trends in water quality data from 12 sites in the Blackwater River watershed were examined for a 14-year period (1980--1993) using the information-theoretic method and the seasonal Kendall with correlation correction analysis. For most sites (except Beaver Creek), downward trends in acidity and upward trends in alkalinity, conductivity, and hardness were consistent with decreases in hydrogen ion concentration. Dissolved oxygen trended downward possibly due to natural conditions, but remained above biological thresholds. The seasonal Kendall trend analysis provided similar results to the information-theoretic analysis, however, the information theoretic approach detected a higher number of trends. The seasonal Kendall analysis may have lacked the power to detect all trends present in the watershed. Additional comparisons of the seasonal Kendall, information theoretic, and other trend analyses are needed to further evaluate methodologies used for water quality trend assessments. Despite the trends supported by this data, water quality changed only slightly within the Blackwater watershed from 1980 to 1993, possibly owing to relatively minimal changes in development and landuse during this time period. These results have greatest potential as a baseline for future water quality assessments.