Validation of paired watersheds for assessing conservation practices in the Upper Big Walnut Creek watershed, Ohio

Abstract

Impacts of watershed scale conservation practice adoption on sediment, nutrient, and pesticide losses and adjacent stream biota are not well understood. The objective of this study was to examine the suitability of selected paired watersheds to quantify hydrology, chemical, and ecology effects of conservation practice implementation for channelized and unchannelized watersheds in Upper Big Walnut Creek watershed, Ohio. Channelized watersheds were more similar in watershed characteristics than the unchannelized watersheds. One hydrology, eight water chemistry, and five fish community response variables were measured. Most response variables in both watershed pairs were moderately correlated (r > 0.6), but the minimum percent change required to detect a response difference was greater for the unchannelized watersheds. Detectable temporal trends in the difference between like response variables for the channelized and unchannelized watershed pairs were minimal. These results validate the paired watershed design and suggest that conservation practice induced changes in hydrology, water quality, and fish communities can be quantified.