Hydraulic and Geomorphic Impacts of Dam Removal on the Upper Baraboo River, Wisconsin

Dam removal;Geomorphology;Hydraulics;Baraboo River

Greene, Samantha L.

University of Wisconsin

关键词: Dam removal;    Geomorphology;    Hydraulics;    Baraboo River;   

Others  :  https://minds.wisconsin.edu/bitstream/handle/1793/47069/Greene%20Samantha%20L.%202010.pdf?sequence=6&isAllowed=y

瑞士|英语

来源: University of Wisconsin

【 摘 要 】

Over time, human interaction with space and place has led to shifts in cultural dominance andmodes of subsistence. Societies depend on the access to particular natural resources forsubsistence, mainly soil, water and timber. This research examines, 1) a brief history ofhuman settlement within the Baraboo River watershed and the drivers behind the shifts ofcultural dominance as related to the dependence on soil, water and timber, and, 2) an in-depthstudy of how society today adapts to a changing natural resources, namely water through theremoval of small, hydropower dams. Often in human history, societies prosper and faildepending on their ability to adapt to climate-driven shifts in natural resource availability.However, with the arrival of modern Native Americans and Euro-Americans, shifts in naturalresource availability results primarily from the exploitation of environmental services. Anillustration of the human-driven alteration of a natural resource is the building and removal ofdams along the Baraboo River. This research studies hydraulic and geomorphic responses tothe 2001 removal of the La Valle dam from the Baraboo River. Examination of longitudinalprofile adjustments and hydraulic response to a 500-year flood using stream surveys from theFlood Insurance Survey, Martin Doyle, the Sauk County Land Conservation Office, and theauthor show significant changes in channel form continued to occur several years after theremoval of the dam. Between 36-39% of stored reservoir sediments were transporteddownstream since the 500-year flood, involving incision upstream of the dam site andaggradation downstream of the dam site. These bed adjustments created a smootherlongitudinal profile; however, a grade control structure at the dam site further appears tostrongly influence stream hydraulics and may result in renewed sediment storage within theold reservoir. This research reinforces the need for more studies which examine fluvialresponse to dam removal at larger spatial and temporal scales. With a better understandingof fluvial response to dam removal, watershed managers and planners can better protect oursafety and the quality of our natural resources.