Publication Date
4-7-2007
Abstract
We examined the spatial distribution of hydrologic alteration among the Connecticut River and its 44 major tributaries as a tool for watershed-scale conservation planning and to assist in development of strategies for mitigating threats to aquatic ecosystems in the basin. Specifically, we (1) examined the spatial extent and distribution of hydrologic alteration by developing indices of potential flow alteration for individual watersheds, (2) analyzed data from US Geological Survey stream gages with sufficient periods of record (i.e., at least 20-years pre- and post- dam construction) to determine the types and degree of hydrologic alteration, and created unimpaired flow data sets for rivers of conservation interest that did not have sufficient flow data, (3) analyzed hourly flow data over a 9-year period to examine diurnal flow fluctuations below hydropower dams compared with reference sites and identify individual sites that had short-term flow variability that was higher than expected for reference locations and (4) Examined the authorized water withdrawals and discharges in the Connecticut and Massachusetts portions of the Connecticut River watershed. Our results form the basis for flow restoration plans, both to protect areas with low risk for hydrologic alteration and to develop strategies to mitigate threats in higher-risk watersheds. These analyses will be used to prioritize restoration efforts based on hydrologic analyses and presence of conservation targets (species and natural communities of conservation interest), and select locations eligible for more detailed site-specific hydrologic and ecological studies.