Mormon Island Axiliary Dam Overlay
Suulutaaq completed the $49M Mormon Island Auxiliary Dam (MIAD) Overlay project for the Bureau of Reclamation – Department of the Interior (BOR) to upgrade the Mormon Island Auxiliary Dam. This project utilized onsite production of filter sand and rock allowing the project to be completed three months ahead of schedule.
The construction for the MIAD project included the overlay of four distinct material zones with 10 different zone configurations to be placed on the downstream side of the dam. The materials consisted of sand, filter rock, and processed embankment, all produced onsite to meet the Bureau of Reclamation’s stringent specifications.
Major Scope Items:
- Process the 1.8M CY onsite stockpile to produce the 1.7M CY of zone products needed
- Production and placement of 942,000 CY of Zone A Material (18” minus)
- Production and placement of 369,000 CY of Zone B Material (4” minus)
- Production and placement of 166,700 CY of Coarse Filter Material
- Production and placement of 262,000 CY of Fine Filter Material
- Foundation excavation of 35,000 CY
- Toe Drain installation of 4,500 LF of 24” HDPE in Coarse Filter Envelope
- Three cast-in-place Wier Box outlets
- Remove and replace 46,200 CY of Cobble Slope Protection
- SWPPP protection and maintenance of the 115 Acre site through three winters
- Dewatering for Toe Drain installation
- Protection and raising of 21 piezometers and casings
It was a large excavation project involving innovative and critical equipment. The site, while spanning 115 acres, was tight and compact with regard to equipment placement, haul routes, and stockpile management. Conveyors were strategically placed to provide maximum stockpile size; haul routes were frequently moved and material processing methods were frequently changed to ensure material produced from a changing stockpile stayed within specification.
It required a team effort from Suulutaaq, the Bureau of Reclamation, and all subcontractors to ensure timely completion. Suulutaaq, through mandatory weekly meetings, was able to coordinate, control, and effectively manage the project to maintain a safe, ahead of schedule, and successful project.