The Gardiner Dam is located on the South Saskatchewan River, about 25 km downstream of the village of Elbow. The earthfill dam and associated ancillary structures were constructed from 1958 to 1968. The dam is founded on the Bearpaw Formation, measures about 4,960 m in length at the crest with a maximum embankment height of approximately 64 m, and it comprises four main zoned earth embankments.
Shortly after dam construction started, three of the main embankments experienced significant downstream movements. To control the movement rates and enable the construction of Gardiner Dam to its design elevation, the original dam slopes were flattened, and gently sloping (as flat as 85H:1V) toe berms were added.
Although the incremental displacements induced by each seasonal rise of the reservoir water levels have attenuated significantly over the last several decades, they have not ceased completely. To better understand the long-term implications of those cyclic deformations, WSA awarded to Klohn Crippen Berger Ltd. in 2018 a mandate to evaluate the stability and deformation of the embankments, abutments, and ancillary works.
The project is being carried out in four phases. Phase 1 involved a review and gap analysis of available data, and the development of a work plan. Phase 2 comprises the execution of site investigations and geotechnical laboratory testing to supplement existing data. Phases 3 and 4 involve a stability and deformation evaluation of the main dam embankments, risk assessment of the existing structures, review of geotechnical instrumentation and the development of conceptual remedial options.
- Site visit and reconnaissance
- Geotechnical instrumentation data review
- Field investigations and geotechnical laboratory testing program
- Stability and deformation evaluation of the dam embankments, abutments, and ancillary structures
- Risk assessment and instrumentation review
- Development of conceptual remedial option
- Project management