The Alcoa Overlook Reservoirs project involved the design of two 6.0 MG (12.0 MG total) water storage tanks to replace two outdated and undersized tank facilities in the City of Alcoa water system. The study phase included field data collection, soils testing, surveying, modeling, and site analysis. Welded steel, prestressed concrete, and repair/replace options were compared for the tank design. In the final analyses of the first costs and life-cycle costs, it was verified that the prestressed concrete option was the most cost effective in both cases.

The optimum location for the tanks was established by overlaying the proposed tanks on the existing site to review alternate tank sizes and heights. In the final analysis the tanks were designed to be 190 feet in diameter with a side wall depth of 29 feet. The tanks were designed to make the most economical use of the site by having them half buried in the slope.

The project’s economical design yielded construction bids that were 15% less than the original project budget. Each tank is equipped with a solar powered mixing system that will help reduce water age and maintain overall water quality. The tanks include inlet and outlet piping as well as valving that provides a connection between the tanks. The SCADA system installed for the tanks is connected to the City’s master system located at the water treatment plant.