Water Resources Research Act Program

Details for Project ID 2019AL012B

Beaver Impoundments as Flow Experiments: effects of Dam Removal on Instream flow, Water Quality, and Species Diversity

Institute: Alabama
Year Established: 2019 Start Date: 2019-03-01 End Date: 2020-02-28
Total Federal Funds: $25,000 Total Non-Federal Funds: $50,000

Principal Investigators: Jennifer Howeth

Abstract: Identifying effects of instream flow on the biotic integrity and ecosystem function of freshwater systems is critical to sustain Alabama’s natural resources in the presence of rapid human population growth and environmental change. Instream flow can be defined as the amount of water required for maintaining: 1) water quality, 2) habitat and associated natural variability in key habitat parameters, 3) sustainable population sizes of native species, and 4) ecosystem services, including recreation, navigation, and power generation (AWAWG 2013). According to the Alabama Water Agencies Working Group (AWAWG 2013), there is inadequate research for Alabama streams relating instream flow to biological condition, habitat quality, and ecosystem function. Identifying environmental flows required to maintain biotic integrity is particularly critical in the Southeastern United States, where freshwater species diversity and extinction rates are highest in North America (Abell et al. 2011, Jenkins et al. 2015). State and federal agencies, as well as private industry, require coupled streamflow and ecological response data from natural systems to understand effects of flow alteration on crayfish and fish species, two of the most highly diverse and imperiled taxonomic groups in Alabama (ADCNR 2015), in order to inform new state policy. The Alabama Department of Conservation and Natural Resources (ADCNR) recently instituted an instream flow policy to provide guidance for regulation of large rivers with navigable channels and hydroelectric dams (AWAWG 2013). These physically modified ecosystems are difficult to manipulate experimentally for the purposes of evaluating altered flow on ecological response, and are notrepresentative of the full range of environmental flow regimes in the region. More common flow regimes in the state are encompassed by the smaller streams and tributaries that harbor much of the regional biodiversity. Streams offer the opportunity to manipulate flow without disrupting ecosystem services and still yield meaningful results that can be scaled-up to larger ecosystems. Here, we propose to experimentally alter streamflow by removing beaverformed dams to identify the concurrent response of crayfish and fish populations, and water quality, to the altered hydrologic regime. As a consequence of the need for data on instream flows to inform new policy on water quantity management in Alabama, this work will be of particular interest to state agencies and entities, including the Alabama Office of Water Resources, the ADCNR, the Alabama Department of Environmental Management (ADEM), and the Geological Survey of Alabama (GSA).