Boundary Reservoir, on the Pend Oreille River, formed by Boundary Dam near the Canadian Border is located in a scenic valley of northeast Washington State. This reservoir is operated by Seattle City Light as a load-following facility for hydropower production. This historically low productivity reservoir is undergoing relicensing efforts and the potential production of periphyton, benthic macroinvertebrates (BMI), and macrophytes was assessed using habitat suitability indices (HSI). Specifically, the daily pool level fluctuation caused by project operations was studied to determine how various operations affected periphyton, BMI, and macrophyte production. This deep, high flow, and low retention time reservoir presented logistical difficulties in collection of data, and analysis of data to formulate HSI relationships. The HSI curves for periphyton, BMI, and macrophytes were developed using a multi-tiered approach. The first step was for provisional HSI curves to be developed from existing literature information and professional judgment. Next, site specific periphyton, BMI, and macrophyte data were collected at various locations and depths within the reservoir. These site-specific field data were used to create suitability values for physical habitat parameters using statistical programs. The final HSI curves were developed using both the provisional and site-specific curves and from input from relicensing participants.
A new generation of hydropower technologies, the kinetic hydro and wave energy conversion devices, offers the possibility of generating electricity from the movements of water, without the need for dams and diversions. The Energy Policy Act of 2005 encouraged the development of these sources of renewable energy in the United States, and there is growing interest in deploying them globally. The technologies that would extract electricity from free-flowing streams, estuaries, and oceans have not been widely tested. Consequently, the U.S. Department of Energy convened a workshop to (1) identify the varieties of hydrokinetic energy and wave energy conversion devices and their stages of development, (2) identify where these technologies can best operate, (3) identify the potential environmental issues associated with these technologies and possible mitigation measures, and (4) develop a list of research needs and/or practical solutions to address unresolved environmental issues. We review the results of that workshop, focusing on potential effects on freshwater, estuarine, and marine ecosystems, and we describe recent national and international developments.
Habitat unit classification can be a useful descriptive tool in hierarchical stream classification. However, a critical evaluation reveals that it is applied inappropriately when used to quantify aquatic habitat or channel morphology in an attempt to monitor the response of individual streams to human activities. First, due to the subjectivity of the measure, observer bias seriously compromises repeatability, precision, and transferability of the method. Second, important geomorphic and ecological changes in stream habitats are not always manifested as changes in habitat-unit or frequency or characteristics. Third, classification data are nominal, which can intrinsically limit their amenability to statistical analysis. Finally, using the frequency of specific habitat-unit types (e.g. pool/riffle ration or percent pool) as a response variable for stream monitoring commonly leads to the establishment of management thresholds or targets for habitat-unit types. This, in turn, encourages managers to focus on direct manipulation or replacement of habitat structures while neglecting long-term maintenance or re-establishment of habitat-forming biophysical processes. Stream habitat managers and scientists should only use habitat unit classification to descriptively stratify in-stream conditions. They should not use habitat unit classification as a means of quantifying and monitoring aquatic habitat and channel morphology. Monitoring must instead focus on direct, repeatable, cost-efficient, and quantitative measures of selected physical, chemical, and biological components and processes spanning several scales of resolution.