Spatial Variation in Stream Water Quality in Relation to Riparian Buffer Dimensions in a Rural Watershed of Eastern New York State

Studies of forested rural watersheds provide estimates of background contamination for comparison with streams and rivers in other settings. We performed a landscape analysis and measured major dissolved ions and benthic macroinvertebrates for a small rural watershed in Albany County, NY, to determine spatial variation in water quality. An estimated 73% of the surface cover is post-agricultural forest, with only 2.3% of the watershed covered by roads and other impervious surfaces. Although water quality was consistently high in most of the creek, we detected three relatively distinct zones separated by impoundments; zonation was most apparent in relative concentrations of major ions, less so with benthic macroinvertebrate community similarity. At ten sample stations, buffer size, measured as upstream land cover and distance to nearest road, did not correlate well with chemical water quality indicators. In particular, we found the highest levels of chloride, indicative of road-salt contamination, in areas of maximum forest buffer. Small feeder creeks that drain nearby roads may function as “leaks” in otherwise well-buffered watersheds with low road densities.