Little Bow Reservoir
Lomond, Alberta, Canada
Project Details
Construction Type:
Reservoir
Project Leadership:
David Mack
The Little Bow Reservoir, located in southern Alberta, is one of three major reservoirs that make up the Carseland-Bow River Headworks (CBRH) system which supplies water to the Bow River Irrigation District. The CBRH system supplies water for irrigation and municipal and landowner water users, and provides opportunities for a variety of recreation activities.
The Little Bow Reservoir (LBR) Rehabilitation and Upgrading Project was the final phase of the Carseland-Bow River Headworks (CBRH) System Rehabilitation Project initiated by Alberta Transportation. The LBR Project involved the construction of new structures and modification of existing structures in the LBR and the Travers Reservoir connecting canal.
Challenges
- Increased storage capacity and improved flood handling capabilities required to meet dam safety guidelines
- Old outlet structure needed to be replaced while continuing water supply for downstream users
- Several challenging instream activities needed to be carried out, including replacement of riprap, construction of cofferdams, and tie in of inlet and outlet channels
Solutions
- Dam raised by 3.5 m and extended from 1200 m to 3300 m in length
- Outlet structure replaced with new structure and seamlessly transitioned while maintaining continuous water supply
- Reservoir lowering was coordinated with construction activities to facilitate instream work
- Earthfill cofferdams built upstream of new outlet structure to continue water supply during construction
- Riprap protection upgraded on upstream dam slope
Successes
- Minimized disturbance footprint with borrow areas situated in reservoir areas
- Maintained uninterrupted passage of flow to BRID canal system
- Increased water storage in the reservoir
- Reduced maintenance requirements and improved dam safety, system performance and capacity
- Constructed a New Provincial Recreation Area with camping facilities, 350 trees and shrubs planted, solar powered drip irrigation system, and a sheltered boat launch
Environmental Impact Study
In addition to engineering and design services, KCB was retained to complete a federal Comprehensive Environmental Impact Study (EIS) for the Project. Subsequently, the project was approved by Canadian Environmental Assessment Agency (CEAA).
Biophysical components assessed included terrain, soils, geology, hydrology, surface water, hydrogeology, climate, air, noise, aquatic resources, vegetation, and wildlife. Socio-economic components assessed included historical, archaeological, paleontological, and cultural resources; navigation; traditional, recreational, and commercial land and resource use; and human health.
Services included:- Gap analysis
- Aboriginal, government agency and community consultation
- Socio-environmental baseline and impact assessment
- Geophysical environment assessment
- Hydrology and surface water quality studies
- Hydrogeology and groundwater quality studies
- Fisheries and aquatic resources assessment and quantification
- Wildlife, vegetation and terrestrial habitat assessment and quantification
- Climate, climate change, air quality and noise assessments
- Heritage resources and archaeology assessments and studies
- Navigable waters review and permitting
- Mitigation, enhancement, and compensation measure strategy development
- Operation environmental monitoring program design and delivery