ABSTRACT:Human modifications of natural streams in the name of habitat improvement take various forms, and the impacts of those improvements, both positive and negative, vary by orders of magnitude from stream to stream. The positive impacts are achieved through careful and timely planning, design, installation and monitoring of projects. Negative impacts are the results of rush jobs dictated by available money, a lack of consideration for limiting factors, untrained and inexperienced personnel, force‐fitting structures instead of bending the flow, lack of a watershed plan, poor communication and cooperation among disciplines, not using the team approach, and single habitat solutions which neglect diversity and artificial constraints.These problems are discussed from various perspectives, but emphasis on an integrated, bioengineering approach is threaded throughout the discussion of the problems and benefits associated with stream improvements and fish response. A general systems approach is presented which uses common language as a focal point for interdisciplinary communication, which is one of the major problems in resource management. Various conceptual models are discussed to describe system complexities, and factors which constrain project evaluation in terms of biological, physical, economic and other components. Conclusions about why some projects are successful, while others are not, are followed by recommendations for concerted and diversified efforts to improve our success in stream stewardshi
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