Delhi Dam, also known as Hartwick Dam, is an embankment dam on the Maquoketa River 2.5 km 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. It was rebuilt in 2016. The dam and lake are part of the Turtle Creek Recreation Area, and is owned by a local community group. 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 turbine 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. 2010 failure The southern embankment of the Delhi Dam failed on July 24, due to a period of about of rainfall in twelve hours. Before the breach, river levels upstream of the dam had reached , above flood stage and breaking the May 2004 record of . However, the stream flow at the time was less than the 2004 record peak stream flow of . Only two of the dam's three spillway gates were fully open. Water eventually overtopped the dam, causing a 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