Veolia turned to Keller to design a 2.65-million-gallon concrete tank. Unlike most water tanks, the Whistle Pig Tank would be fully buried. (Whistle pigs, or groundhogs/ground squirrels, live underground and are native to this area and prime sources of food for birds of prey.) The tank was constructed within a steep hillside to minimize visibility and impact on the existing Birds of Prey site.
The Whistle Pig Tank included many unique project elements. The tank is filled from a series of pressure-reducing valves. Bypass provisions included complex valving and controls, and the tank mixing system took advantage of high-pressure water to provide mechanical mixing without the use of a pump. A small control structure built on top of the tank included provisions for future re-chlorination. Site improvements also included steep pipeline installations, an overflow pond, and creative grading and access improvements.
Sufficient water supply is a longstanding issue of public concern. This project provides vital water supply to South Ada County residents and businesses, providing system resiliency and water storage for decades to come. By working closely with stakeholders, engineering solutions can balance the need to provide sustainable water supply to developing communities while protecting the natural environment.