Delhi Dam
Encyclopedia
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.
generators with a 1.5 MW capacity able to produce 3 GWh of electricity annually for sale to the local power utility. $1.5 million in funding was sought by the Iowa Power Fund and power production was expected as early as 2010. The dam was cited for minor problems during a 2009 Iowa Department of Natural Resources
safety inspection.
. This may have caused the river to overwhelm and overtop the roadway next to the dam. This caused a 200 ft (61 m) long portion of the embankment and roadway to erode away and the lake to empty. Around 8,000 people in downstream areas like Hopkinton
and Monticello
had to be evacuated. 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 (LDRA) maintain it, and replacement of the dam is uncertain, as the LDRA is in debt from previous lake-dredging costs.
Embankment dam
An embankment dam is a massive artificial water barrier. It is typically created by the emplacement and compaction of a complex semi-plastic mound of various compositions of soil, sand, clay and/or rock. It has a semi-permanent waterproof natural covering for its surface, and a dense, waterproof...
on the Maquoketa River
Maquoketa River
The Maquoketa River is a tributary of the Mississippi River, approximately long, in northeastern Iowa in the United States. Its watershed covers within a rural region of rolling hills and farmland southwest of Dubuque. It is not to be confused with the Little Maquoketa River, another distinct...
2.5km southwest of Delhi
Delhi, Iowa
Delhi is a city in Delaware County, Iowa, United States. The population was 458 at the 2000 census.-Geography:Delhi is located at near the Maquoketa River. The Delhi Dam on the river in Delhi's southwest created Hartwick Lake...
, Iowa
Iowa
Iowa is a state located in the Midwestern United States, an area often referred to as the "American Heartland". It derives its name from the Ioway people, one of the many American Indian tribes that occupied the state at the time of European exploration. Iowa was a part of the French colony of New...
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.
History
The 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. 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. The new power plant was to have two turbineTurbine
A turbine is a rotary engine that extracts energy from a fluid flow and converts it into useful work.The simplest turbines have one moving part, a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades, or the blades react to the flow, so that they move and...
generators with a 1.5 MW capacity able to produce 3 GWh of electricity annually for sale to the local power utility. $1.5 million in funding was sought by the Iowa Power Fund and power production was expected as early as 2010. The dam was cited for minor problems during a 2009 Iowa Department of Natural Resources
Iowa Department of Natural Resources
The Iowa Department of Natural Resources is a department/agency of the U.S. state of Iowa charged with maintaining state parks and forests; protecting the environment; and managing energy, fish, wildlife, land resources, and water resources of Iowa.The Mission Statement: To conserve and enhance...
safety inspection.
2010 failure
The southern embankment of the Delhi Dam failed on July 24, due to a period of about 10 inches (254 mm) of rainfall in twelve hours. Before the breach, river levels upstream of the dam had reached 24.22 ft (7.4 m), 10 feet (3 m) above flood stage and breaking the May 2004 record of 21.66 ft (6.6 m). However, the stream flow at the time was 1400 ft3/s less than the 2004 record peak stream flow of 26000 ft3/s. Only two of the dam's three floodgates were fully open in their concrete outlet worksOutlet works
A set of outlet works is a device used to release and regulate water flow from a dam. Such devices usually consist of one or more pipes or tunnels through the embankment of the dam, directing water usually under high pressure to the river downstream...
. This may have caused the river to overwhelm and overtop the roadway next to the dam. This caused a 200 ft (61 m) long portion of the embankment and roadway to erode away and the lake to empty. Around 8,000 people in downstream areas like Hopkinton
Hopkinton, Iowa
Hopkinton is a city in Delaware County, Iowa, United States. The population was 681 at the 2000 census.-History:The city is the former home of Lenox College, a small school that closed in 1944. The old campus is still maintained as a museum.-Geography:...
and Monticello
Monticello, Iowa
Monticello is a city in Jones County, Iowa, United States. As of the 2010 census, the city population was 3,796. It is part of the Cedar Rapids Metropolitan Statistical Area.-Geography:Monticello is located at...
had to be evacuated. 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 (LDRA) maintain it, and replacement of the dam is uncertain, as the LDRA is in debt from previous lake-dredging costs.