The City of Garrison had two side-by-side 50,000-gallon elevated water storage tanks providing water storage for the entire city and a large rural water customer. The older elevated tank was constructed in 1916, and the newer tank was built in the late 1940s.
To maintain a minimum required fire flow storage of 60,000 gallons, the actual available storage for operation was only about 40,000 gallons. Although the City of Garrison maintained operations with limited storage for many years, there were growing concerns with the system because of steadily increasing demand from the rural water customer and the age of the towers.
A preliminary estimate indicated the tanks had less than two years of useful life remaining. In a 2011 evaluation, Bartlett and West Engineers, Inc. concluded that the cost to improve the safety, operations, and coating work necessary to rehabilitate the towers may be high enough to consider replacement of the towers.
The City of Garrison worked with Moore Engineering in the removal of the two 50,000-gallon tanks and the design of a new tower at a new location near the existing tower. The project required keeping one 50,000 gallon tower active and in service while they removed the second tower and replaced it with a new 400,000 gallon tower adjacent to the old tower left in service. After the new 400,000 gallon tower was in service, they removed the second 50,000-gallon tower. The new tower has a unique painting scheme to highlight fishing and Lake Sakakawea, two of Garrison’s main attractions.
The tower was complete in 2016 and currently serves 805 users within the City of Garrison and 550 users outside of the City as part of the rural water system. The area has grown and is projected to continue to grow. With its 400,000-gallon tower, the city is now well-equipped for that growth.