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LAKE DELHI DAM
Delhi DamFrom Wikipedia, the free encyclopedia Jump to: navigation, search
Delhi Dam, also known as Hartwick Dam, was an embankment dam on the Maquoketa River 2.5km southwest of Delhi, Iowa that created Lake Delhi. The dam was over-topped and subsequently failed on July 24, 2010 after a period of heavy rain. The dam and lake are part of the Turtle Creek Recreation Area.
[edit] HistoryThe dam was built between 1922 and 1929 by the Interstate Power Company for hydroelectric power production, but its generators ceased operating in 1973 shortly before the Lake Delhi Recreation Association took ownership.[2][3] Since then, it has been used for recreation. Several floods in 2008 caused an estimated $500,000 in damages to the dam and its floodgates. In October 2008, the Association signed a partnership with Modern Hydro to have the power plant's turbines refurbished and recommissioned.[4] The new power plant was to have two turbine generators with a 1.5 MW capacity able to produce 3 GWh of electricity annually for sale to the local power utility.[5] $1.5 million in funding was sought by the Iowa Power Fund and power production was expected as early as 2010.[4] The dam was cited for minor problems during a 2009 Iowa Department of Natural Resources safety inspection.[6] [edit] 2010 failureThe southern embankment of the Delhi Dam failed on July 24, 2010 following the failure of the upstream Quaker Mill dam in Manchester Iowa, due to a period of about 10 inches (250 mm) of rainfall in twelve hours.[7] Before the breach, river levels upstream of the dam had reached 24.53 ft (7.48 m), 10 feet (3 m) above flood stage and well above the 2004 record of 21.66 ft (6.60 m). Despite having at least two of dam's three floodgates fully open in its concrete outlet works, the river overwhelmed and over-topped the roadway next to the dam. [8] This caused a 200 ft (61 m) long portion of the embankment and roadway to erode away and the lake to empty.[9] Around 8,000 people in downstream areas like Hopkinton and Monticello had to be evacuated.[10] The breach caused damage estimated in the millions of dollars thus far. In Monticello, 50 homes and 20 businesses received major flood damage among other damaged structures. The city's sewage treatment plant was also flooded, leaving residents without sewer services. Property owners that live near the lake pay special taxes to have the Lake Delhi Recreation Association maintain it, and replacement of the dam is uncertain, as the association is in debt from previous lake-dredging costs.[9] Engineers believe that a failure of one of the dam's floodgates to fully open may have contributed to failure.[8] At the public annual meeting of the Lake Delhi Recreation Association, on August 1st, 2010, Jim Willey indicated that the dam was flowing beyond 108% design capacity. The third gate was scheduled to be capped with stoplogs on July 28th, and removed for repairs due to damage suffered in the 2008 floods, after nearly two years of planning. The building erected to house the flood gate during repairs was located below the roadway and washed away as well. Had the flood happened 4 days later, these stoplogs wouldn't have been able to be removed, and the failure of the dam may have been more catastrophic. [edit] See also[edit] References
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Location of Delhi Dam
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