Project Summary
The Springbank Reservoir was created to effectively manage floods with return period of 100 years by diverting floodwaters from diversion canal to the Unnamed Creek Floodplain zone. Formula worked with the Stoney Nakoda Tribal Council and their three Nations for this project.
Grade Control Structure
The Grade Control Structure comprises excavation, Foundation base preparation with backfill with clay, sand and gravel under structure. It features 14000 m3 of mass concrete in stepped spillway and stilling basin (30 lifts of 300mm thickness), and 1300 m3 of reinforced concrete in retaining, upper, lower and wing walls. The key strategy involved the construction of vertical bulkhead for each lift in which resulted in an additional 250 m3 of concrete on Formula's cost but optimized the construction time and efficiency.
Throughout the project Formula identified the following risks which were mitigated:
- Risk of heating and hoarding costs after October 25th, 2023
- Constructability challenges related to compaction of 3B gravel material in 2V:1H slope.
Emergency Spillway
The Emergency Spillway project involves the construction of a spillway structure with reinforced retaining walls, stilling basin, crest (2400 m3) and the mass concrete in the overflow weir structure (1000m3).
Throughout the project Formula identified the following risks which were mitigated:
- Rock excavation by outside contractor posed a potential schedule threat
- Extensive rock treatment required but outside of original scope
- Risk of heating and hoarding required
- Low slump (90mm) , heavy rebar congestion, caused massive consequent patching and repairing works in retaining walls