Realizing that thecould not continue to meet the growing city’s water demands, the had the foresight to purchase 5,727 acres of land in northern Marion, southeastern Hamilton, and northwestern Hancock counties in the 1920s. In 1941, the company built a dam across and flooded 1,900 acres of this property. The dam backed up water for 7.5 miles and covered 535 acres of woodland and 45 homesteads including the small village of Germantown, creating a reservoir capable of storing 6.9 billion gallons of water. The newly formed Geist Reservoir, named after Clarence H. Geist (president of the Indianapolis Water Company, 1913-1938), began supplying Indianapolis with water in 1943.
In addition to providing an additional water supply to the city, the reservoir became a popular recreation spot during the 1940s and 1950s. Bank fishing yielded thousands of local fishermen some of the largest crappies and catfish in the state, and the Indianapolis Sailing Club, headquartered at Geist, held races there.
In 1961, the Indianapolis Water Company announced its intention to convert the property around Geist into an exclusive subdivision. The company transferred 2,782 acres of land to its newly created subsidiary corporation, Shorewood, which proposed to close the land around the lake to bank fishing and picnicking and sell it as private lots. The Marion County Council, led by president and frequent Geist fisherman John Kitley, opposed the water company’s plan.
By May 1961, the County Board of Commissioners adopted a resolution to condemn the land around Geist for a public park. When surveyors estimated the value of the land at $3.9 million, however, the commissioners voted to rescind their resolution.
In 1970, the Indiana Public Service Commission ordered the water company to dispose of its excess reservoir land. Shorewood was made an independent, private corporation and given the land around Geist in exchange for 1,069,000 shares of its stock. Later that year, the water company bought the rights to control boating and fishing on Geist from the County Line Dock Corporation. It renovated the docking facilities and in 1971 opened Geist to water skiing and speedboats with unlimited horsepower.
In September of that year, Governor Edgar Whitcomb announced the state’s plan to participate in the Army Corps of Engineers’ $52-millon project to expand Geist. It included two new dams that would double the reservoir’s size. The proposed project delayed development for almost a decade but was eventually scrapped in 1978 when U.S. Senator Birch Bayh refused to support it.
Shorewood finally began construction of its first two housing developments, Beamreach and Masthead, in 1980. Under the ownership of the Meritor Financial Group of Philadelphia, Shorewood continued to sell lots around Geist through the early 1990s. Residential development continued expanding, and by the early 2000s, there were around 2,200 up-scale homes lining the reservoir’s banks. On January 2, 2010, Fishers annexed the unincorporated area of Geist after a four-year legal battle with the Geist United Opposition group.
The ecological health of the reservoir for recreational use became problematic through the 2000s, leading to the formation of two different groups focused on protecting it. The Geist Lake Coalition was formed in 2000 with the mission of addressing and upholding the longevity of the Geist Reservoir. During the Summer of 2007, the reservoir suffered a toxic blue‐green algal bloom. This resulted in the formation of the Geist Watershed Alliance organization which focused on the long-term improvement and protection of Geist Reservoir’s water quality.
In 2018, Fishers purchased 70 acres along the northeast area of the reservoir from Irving Materials, Inc., with plans to build a waterfront park, making the largely private lake open to the public. IMI had been mining the quarry in this area for limestone, sand, and gravel since the 1960s, and their departure left the quarry vacant. Citizens Energy Group, which took over ownership of the reservoir in 2011, made plans in 2019 to transform the now vacant quarry into the Citizens Reservoir to serve as supplemental storage of 3 billion gallons of water for Geist Reservoir.