November 13, 2008
The Johnson Reservoir is actually two (2) separate concrete circular reservoirs (shown at right), the majority of which is buried underground. The first of the Johnson Reservoirs was completed in 1962 and holds 5 million gallons (MG). In 1967, as Erie’s water demands increased, a 10 MG reservoir was constructed. A number of years ago, following an intensive study and investigation, it was determined that the concrete roof of the 5 MG reservoir was failing and structurally unsound and the 10 MG reservoir was in need of extensive repairs.
After many alternative replacement options were evaluated, it was decided to install a self supporting (no interior columns) Aluminum Geodesic Dome. The existing 5 MG Reservoir is 170-feet in diameter and 30-feet deep.
The project design was awarded to KLH Engineers, Inc. at the February 2007 Board Meeting. The 5 MG Roof Replacement and Site Work contract was awarded to E.E. Austin & Son of Erie, PA. The majority of the dome construction took place inside of the empty reservoir as shown in the picture on the left.
When construction was nearly complete the dome structure was lifted from the bottom of the reservoir with the assistance of three large cranes and remained suspended while the last portion of the perimeter was constructed. It was then anchored into place (shown at right). The existing walls support the 170-ft wide dome and no interior columns are needed. The roof is 30-feet tall at its highest point.
Allegheny Restoration, Inc. of Greensburg, PA. was awarded a contract for Concrete Repair and Restoration. The concrete work includes sealing cracks on the roof of the 10 MG Reservoir, and installation of an interior sealing system in the 5 MG Reservoir.
Demolition of the existing roof (shown above and at right) on the 5MG reservoir began on May 27, 2008 and was completed in April 2008. The roof was cut apart and removed piece by piece as illustrated above. Shown in the picture to the right are the columns that were used to support the original concrete roof. Other work included leveling of the walls, which was needed to provide a flat and uniform surface upon which the Aluminum Geodesic Dome was placed and anchored. The project is scheduled for completion in November of 2008.