Geist Reservoir

Geist Reservoir was named after Clarence H. Geist, a former owner of the Indianapolis Water Company, who foresaw a deficit in Indianapolis's water supply and envisioned the Geist Reservoir to preemptively address the problem. Planning for the reservoir began as early as 1913, when hydraulic engineers estimated that White River and Fall Creek would not provide enough water for the increasing needs of Indianapolis. Geist gradually bought some 5,000 acres (20 km²) in the Fall Creek Valley in the 1920s and 1930s, including the small town of Germantown, which today lies at the bottom of the reservoir. Although controversial, the reservoir was completed in 1943, five years after Clarence Geist's death. In the 1960s further controversy arose over plans for commercial and residential development in the area around the lake. A proposal in the 1970s to triple the size of the reservoir was defeated, and a housing boom began in the lake area.[1]

In recent years the Geist area has experienced rapid growth. The area is noted for its topography and the reservoir. In recent years the reservoir has experienced problems with algal blooms and invasive aquatic species.[2][3]

As the result of a series of sales, the water company and the reservoir are now owned by Citizens Energy Group.

Geist Reservoir Dam is located at the lake's southern end. Fed by Fall Creek on the north, the lake overflow is directed into the creek again at the south. The earthen dam is 40 feet (12 m) high, with an overall length of 1,900 feet (580 m). The reservoir capacity is 60,000 acre-feet (74,000,000 m³), although normal storage is 21,180 acre-feet (26,100,000 m³). The reservoir is mostly rather shallow (10 feet (3.0 m) or less); the depth at the dam is 26 feet (7.9 m) and the maximum depth is 48 feet (15 m).[4]

Geist Reservoir covers 1,900 acres (769 ha)[4] and spans three counties in Indiana (Marion, Hamilton, and Hancock), four voting precincts, three school districts (Lawrence, Hamilton Southeastern, and Mt. Vernon), and features five different ZIP codes (46037, 46256, 46236, 46040, 46055). The area has undergone rapid development and some high-valued homes now line the reservoir's waterfront.

In 2019, Citizens Energy Group began work to convert a former limestone quarry adjacent to Geist Reservoir into a supplemental reservoir named Citizens Reservoir. Situated near the southern shore of the north end of Geist, the new reservoir covers 88 acres (36 ha) and is 220 feet (67 m) deep. It will hold three billion US gallons (1.1×10¹⁰ l; 2.5×10⁹ imp gal) when construction is completed in 2020. Up to one hundred million US gallons (380,000,000 l; 83,000,000 imp gal) a day will be diverted into Citizens Reservoir when Geist Reservoir is full instead of going over the latter's spillway. When needed, up to thirty million US gallons (110,000,000 l; 25,000,000 imp gal) a day can be pumped from Citizens back into Geist.[5]

The limestone quarry was previously owned by Irving Materials Inc. and had operated for 50 years before closing in 2018. Citizens Energy is spending over $20 million on the project.[5]

• List of dams and reservoirs in Indiana

• "Geist Reservoir". Holy Cross Lutheran Church. 2007. Archived from the original on October 8, 2007. Retrieved August 27, 2007.
• "History of Geist Reservoir and Germantown". Log Cabin Animal Hospital at Geist. Archived from the original on August 9, 2007. Retrieved August 30, 2007.