CloseMountain Dell Dam Reconstruction
Overview
Originally finished in the early 1900s, Mountain Dell Dam now stores drinking-water east of Salt Lake City. A controlled drawdown exposed the upstream face so crews could build a temporary earthen cofferdam, remove deteriorated concrete, and place a geomembrane liner that forms a watertight barrier near the toe. At the same time, the low-level outlet was replaced with corrosion-resistant steel pipe and modern flow-control valves.
CMT Services
Our specialists provided geotechnical study, construction observation, surveying, laboratory testing, materials field testing, and overall project coordination from the pre-bid phase through final acceptance. Close collaboration with the owner and regulators helped the team meet each milestone without prolonging the reservoir closure.
Technical highlights
- Cofferdam design maintained reservoir stability while isolating the work zone.
- Surface preparation involved selective removal of weathered concrete and abrasive cleaning of exposed rock.
- Geomembrane installation used factory-welded panels, reducing on-site seams and future maintenance.
- Outlet upgrade improved controllability, boosting operational reliability during seasonal releases.
Performance & community benefits
The updated outlet structure allows precise releases, reducing downstream erosion. The liner stops seepage that had been observed at the lower lift, conserving storage capacity. Because construction occurred inside the cofferdam, shoreline recreation resumed during late summer—an advantage welcomed by local visitors.
Sustainability notes
- Re-using on-site excavated material for the cofferdam cut haul-truck trips.
- All removed concrete was crushed and returned as aggregate for access-road resurfacing.
- Low-VOC adhesives secured the liner’s termination bar, limiting airborne emissions.
Learn more about dam stewardship in the United States through the Association of State Dam Safety Officials’ concise “Dams 101” primer—a helpful reference for owners, engineers, and community members.