An “inflatable” dam maintains a constant water elevation under variable river flows by automatically raising or lowering the crest gates. Aside from hydroelectric turbines, the gates were the only way of controlling upstream pool levels. The city's mass-concrete ogee-shaped dam was 310 feet long and 12 feet high and since it had no gates was considered “uncontrolled.” A 36-foot-long level control gate section included four 12圆-foot vertical timber gates. An inflatable dam, on the other hand, would maintain recreational opportunities and hydroelectric functions while also preserving the community's historical look and feel. Despite the hardship it has caused, most embrace the Cedar River as a recreational and aesthetic asset and feel their city should be “one with the river.” They considered levees to be the equivalent of turning their back on this resource and creating a visual obstruction that would put the community at odds with it. Surprisingly, at public forums the inflatable dam concept held the popular appeal with residents. The engineering firm identified two methods of flood protection: levees or an “inflatable” dam. A 100-year flood hit in 1999 and a 500-year flood struck in 2008, destroying hundreds of homes and businesses.Īfter the 100-year flood of 1999, Waverly's Department of Public Works retained Stanley Consultants Inc., which had designed improvements to the dam in the 1940s, to perform a flood protection study. Unfortunately, the new structure plagued residents with decades of persistent and regular flooding. In 1915, the original crib dam was replaced with a concrete dam and elevated spillway. Over the years the river's value to the city's industrial and economic development led to extended development on the adjacent floodplain and a need for more power. Waverly boasts the oldest operating hydroelectric plant in the state (circa 1908), which annually saves the city $100,000 on electricity. The crib dam was constructed using large timbers connected with steel spikes to form “cribs,” then hand-filled with stone to add weight. By the 1880s entrepreneurs had built a more uniform and durable crib dam to harness the river's power for industrial use. Additional water-powered mills followed, including a flour mill and a woolen mill. In 1853 city founder William Harmon built his family a cabin on the Cedar River's heavily wooded east side and a dam of stone and timbers to power his sawmill, which would provide lumber for the growing town. Economic Development Administration (75%) Community Development Block Grant (25%)įor more than 150 years, the Waverly Dam has been an integral part of picturesque Waverly, Iowa population 10,000. Gate supplier: Obermeyer Hydro Inc., Fort Collins, Colo.Ĭontractor: Peterson Contractors Inc., Reinbeck, Iowaįunding: U.S. Owner: City of Waverly, Iowa, Public WorksĮngineering and design: Stanley Consultants Inc., Des Moines, Iowa
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