Environmental Flow Assessment


Book Description

Provides critiques of current practices for environmental flow assessment and shows how they can be improved, using case studies. In Environmental Flow Assessment: Methods and Applications, four leading experts critique methods used to manage flows in regulated streams and rivers to balance environmental (instream) and out-of-stream uses of water. Intended for managers as well as practitioners, the book dissects the shortcomings of commonly used approaches, and offers practical advice for selecting and implementing better ones. The authors argue that methods for environmental flow assessment (EFA) can be defensible as well as practicable only if they squarely address uncertainty, and provide guidance for doing so. Introductory chapters describe the scientific and social reasons that EFA is hard, and provide a brief history. Because management of regulated streams starts with understanding freshwater ecosystems, Environmental Flow Assessment: Methods and Applications includes chapters on flow and organisms in streams. The following chapters assess standard and emerging methods, how they should be tested, and how they should (or should not) be applied. The book concludes with practical recommendations for implementing environmental flow assessment. Describes historical and recent trends in environmental flow assessment Directly addresses practical difficulties with applying a scientifically informed approach in contentious circumstances Serves as an effective introduction to the relevant literature, with many references to articles in related scientific fields Pays close attention to statistical issues such as sampling, estimation of statistical uncertainty, and model selection Includes recommendations for methods and approaches Examines how methods have been tested in the past and shows how they should be tested today and in the future Environmental Flow Assessment: Methods and Applications is an excellent book for biologists and specialists in allied fields such as engineering, ecology, fluvial geomorphology, environmental planning, landscape architecture, along with river managers and decision makers.













The Science of Instream Flows


Book Description

Across the United States, municipalities, counties, and states grapple with issues of ensuring adequate amounts of water in times of high demand and low supply. Instream flow programs aim to balance ecosystem requirements and human uses of water, and try to determine how much water should be in rivers. With its range of river and ecosystem conditions, growing population, and high demands on water, Texas is representative of instream flow challenges across the United States, and its instream flow program may be a model for other jurisdictions. Three state agenciesâ€"the Texas Water Development Board (TWDB), the Texas Parks and Wildlife Department (TPWD), and the Texas Commission on Environmental Quality (TCEQ)â€"asked a committee of the National Research Council (NRC) to review the Programmatic Work Plan (PWP) and Technical Overview Document (TOD) that outline the state's instream flow initiative. The committee suggested several changes to the proposed plan, such as establishing clearer goals, modifying the flow chart that outlines the necessary steps for conducting an instream flow study, and provide better linkages between individual studies of biology, hydrology and hydraulics, physical processes, and water quality.













Improving the Assessment of Instream Flow Needs for Fish Populations


Book Description

Instream flow requirements are one of the most frequent and most costly environmental issues that must be addressed in developing hydroelectric projects. Existing assessment methods for determining instream flow requirements have been criticized for not including all the biological response mechanisms that regulate fishery resources. A new project has been initiated to study the biological responses of fish populations to altered stream flows and to develop improved ways of managing instream flows. 21 refs., 3 figs.