Silver Basin Dam and Reservoir


Ames constructed the first asphalt core dam to be completed in the U.S. along with a leach pad with supporting collection ponds for a major mining company in Arizona. Replacing an existing reservoir, the new Silver Basin Reservoir dam and leach pad were constructed concurrently.

Crews established a quarry site to load, haul, and place material for the dam embankment. An aggressive schedule for crushing and processing operations helped to maintain daily project demands as the dam was raised from the foundation to the ultimate crest height elevation. Multiple crushing spreads were used, and more than 1 million cubic yards of material were crushed and placed in the dam.

During placement, crews were prohibited from crossing the core. To manage this challenge efficiently, placing operations were hopscotched upstream and downstream every two to three days to allow concurrent asphalt and embankment placements while maintaining a level surface.

Additional project features included an intake tower, steel conduit feed line, reservoir inlet structure, overflow spillway, bifurcation structures, and main pump station. Ames also constructed a new bypass pipeline to allow the existing reservoir to continue to operate during construction, providing the town with an ongoing water supply. During decommissioning of the existing reservoir, Ames installed a temporary pipeline to transfer water upstream to the new reservoir and collaborated with a fish recovery specialist to relocate the fish with care and caution.

When the project scope expanded with no adjustments to the schedule, Ames adapted by adding more personnel and equipment and resequencing work fronts. The stockpile work was delivered five months early, opening up the mining area, and leaching began three months ahead of schedule.

The finished facility supports the client’s expansion of operations while maintaining a consistent water supply for its industrial needs and for the community.

Markets: Mining, Water Resources, Dams, Leach Pads, Reservoirs

Location: Arizona

Completion: November 2018


  • Earthwork
  • Aggregate processing and placement
  • Piping


  • 1 million cubic yards of material crushed and placed

2020 Build Arizona Award
Category: Private - Heavy Industrial/New Construction
Associated General Contractors, Arizona Chapter