Clearwell Reservoir Rehabilitation

Clearwell Reservoir Rehabilitation

Clearwell Reservoir Rehabilitation

Tucson Water’s 60-million-gallon Clearwell Reservoir is Arizona’s largest potable concrete reservoir and conveys two-thirds of the City’s water supply each day. The HDR team rehabbed the two-cell facility over three years by constructing shear walls, adding carbon fiber wrapping, modifying structural steel to upgrade its seismic performance and installing a new liner and roofing system.  

We used drones to find imperfections and deflection in existing structural steel members, which accelerated shop drawing and procurement processes; allowed the structural team a safe and effective inspection method; and eliminated the need to cut and field-fit steel during installation.  

To minimize environmental effects, the team moved several large Saguaro cacti and constructed a specialized animal fence around the construction site. Located near a luxury resort, the team worked with the community to avoid complaints and concerns, and added amenities for a popular trail as a gesture of goodwill.  

We overcame the project site’s mountainous location, uncertain foundation and Arizona’s blistering temperatures. We overlapped several construction trades at once, using a unique sequencing effort to complete the project within the low system demand months. Conducted like a symphony, careful management and scheduling were orchestrated to keep the project moving forward.  

Completed on time and under budget, the new, water-tight Clearwell Reservoir will provide Tucson with clean drinking water for decades to come. 

Clearwell Reservoir Rehabilitation
Tucson Water

Tucson, AZ
United States

60 million gallons


National Recognition Award (2020)
Engineering Excellence Awards
American Council of Engineering Companies
Grand Award (2020)
American Council of Engineering Companies of Arizona