2.1 Background
The Sheerness-Blowdown Canal was built in 1983-84 by Alberta Environment. This canal accepts the water discharge from the Sheerness-Blowdown Power Plant cooling pond. This water is used for irrigation and stock water replenishment downstream before terminating into Carolside reservoir. Sheerness-Blowdown Canal has 22.2 km of concrete lined canal, 1.6 km of cobble armoured canal and 4.0 km of natural channel above Carolside Dam. The concrete-lined canal has experienced many problems including failure and loss of bitumen joint sealant, (Photo 2.1.1) concrete spalling and cracking, exposure of the welded wire reinforcement and displacement of concrete panels. The bed of the natural channel downstream in the canal has degraded and the channel banks have eroded. The drop structures show some signs of scour.
The inlet of Sheerness-Blowdown Canal is located approximately 25km south of Hanna on the west side of Highway 36. It crosses Highway 36 before turning east and ultimately terminates upstream of the Carolside Dam. Sheerness-Blowdown Canal has 19 road crossings, 6 drop structures, 15 turnout structures, 4 cross drains, one drain inlet and a Parshall flume.
3.0 SCOPE OF WORK
Alberta Agriculture and Irrigation requires the services of an Engineering Consultant to undertake a comprehensive assessment of Sheerness-Blowdown Canal. The services to be provided shall include:
1. Review previous studies, information, drawings, and technical reports including construction records, previous geotechnical investigations, structural design and structural assessments of the infrastructure.
2. Conduct a site inspection, as necessary, to become familiar with and assess the current canal condition.
3. Provide an assessment of the remaining service life of the culverts crossings indicated in Figure 3.1. Provide recommendations for the possible replacement or rehabilitation of the three culvert crossings.
4. Assess the structural condition and integrity of the Sheerness-Blowdown Canal structure and all associated structures. Also assess the risks and their consequence of the continued deterioration of the canal and structures and the anticipated further rate of deterioration.
5. Review issues and potential options with stakeholders of the project.
6. Evaluate the current design criteria for the existing project and propose design criteria for the project.
7. Propose options for rehabilitation and replacement of the Sheerness-Blowdown Canal and structures that meet operational requirements. Provide conceptual design, design, A level cost estimates, drawings, constructability assessment, advantages and disadvantages for each of the alternatives considered. One of the alternatives for consideration must be a pipeline.
8. Consult with the stakeholder and select a preferred option for the rehabilitation and replacement of the Sheerness-Blowdown Canal and structures. Provide a preliminary design of the selected option including detailed site plans; plans and various sections of each structure with enough detail to cost the components, borrow, lay down and waste disposal areas and care of water options. Specify materials for major project components including but not limited to rip rap, concrete and fill materials. Prepare a “B” estimate and life cycle cost for the preferred option.
9. Recommend the course of actions and timeline for implementation for the preferred option.
