Bechtel is the majority partner (45%) in the BBE joint venture bringing Keeyask to fruition – working with the Montana-based Barnard Construction Company (35%) and Canadian contractor EllisDon (20%). BBE is responsible for all major civil works on the project commissioned by the Keeyask Hydropower Limited Partnership (KHLP) – a partnership between the crown corporation Manitoba Hydro and four Manitoba First Nations (Tataskweyak Cree Nation, War Lake First Nation, York Factory First Nation, and Fox Lake Cree Nation). A daily workforce of 2,500-strong integrates talent from across Manitoba and North America, including many workers recruited locally from the neighbouring Indigenous communities who are trained in valuable industry skills.
Scaling up within the Nelson river system
The generating station is located on the Nelson River. It includes a seven-unit powerhouse/service bay complex on the north side of Gull Rapids with a seven-bay spillway to the south. Other key elements include 23km of dykes and three dams – ranging from 99m to 1,600m long – plus numerous ‘cofferdams’ that create the essential dry work areas that make construction possible. Alongside rock excavation and all concrete for the powerhouse and spillway, BBE is also accountable for the project’s balance of plant electrical and mechanical work.
The Keeyask Generating Station follows on from Bechtel’s previous involvement in shaping Manitoba’s power infrastructure. In the early 1990s, the company delivered the ten-unit, 1,330 MW Limestone hydroelectric station under budget and ahead of schedule. It was this success that gave Manitoba Hydro the confidence to turn to a Bechtel-led joint venture again almost 25 years later. Keeyask will ultimately form part of a six-station system on the Upper and Lower Nelson rivers.
A unique location demands unique solutions
If the sheer size of the Keeyask Project is a challenge, then its remote northern setting and harsh topography represent another. In this Canadian Arctic climate south of Hudson Bay, temperatures can drop to minus 45ºC over the long winter – dictating that a year’s work must be completed in half the time.
The complex river system featuring thousands of channels and sandbanks, is located 58 kilometres east of the community of Split Lake and 30 kilometres west of Gillam in the Split Lake Resource Management Area, within the ancestral homeland of all four partner First Nations. Sustainable project delivery and robust environmental management is therefore a priority, with extensive plans in place to mitigate, manage and monitor the project’s environmental and social footprint. Special measures have been taken to reduce impacts on fish, particularly Lake Sturgeon, and other important aquatic and terrestrial species and habitats affected by Project development – just one example of the monitoring studies being done in the Project area. Efforts are also being made to enhance the benefits of the Project for local First Nations and Manitoba’s northern Indigenous population.
Critically, Keeyask’s remoteness has meant that a ‘self-perform’ materials strategy was essential from project commencement. All the materials used – including aggregates and sand for the cofferdams, dams and road, plus the 340,000m3 of concrete BBE will have placed by completion – are drilled and blasted to specification at the site itself. In 2018, they will aim to place 105,000 cubic meters.
By focusing on efficiency and adaptability, BBE has been able to make timely use of these materials so that they can work through the winter and rapidly ramp up productivity in the compressed summer season.
Concrete is at the heart of this construction project – in 2017 alone, more than 510 concrete placements were completed at the Powerhouse. The project’s strategy to place concrete in sub-zero temperatures is simple - smart planning, state of the art on-site batching facilities and skilled placement crews. This straightforward approach is paying off. More than 15,000 cubic meters of concrete were placed during the current winter season, despite temperatures regularly dropping as low as minus 40C.
Technology also plays a leading role in all work planning and sequencing on the job– including the use of 4D synchronised modelling, machine automation, drone cameras for surveys, 3D model printing, equipment telematics and GPS. Technology allows for more detailed planning and risk management. Complex geometry requirements for the water passages called for the use of sophisticated formwork planning and installation techniques. To ensure precision, the team turned to automated tools to carry out self-performed repetitive formwork tasks. The process was widely used to design and fabricate the formwork needed for the concrete placements – eliminating mistakes and minimising delays.
Marking the milestones
The successful on-time mobilisation to the site and the placement of first cofferdams in 2014 meant permanent structures could then be built in dry conditions. With all major engineering drawings complete by May 2015, rock excavation for the powerhouse and spillway continued throughout the 2015/16 construction seasons, making way for the start of concrete placement in 2016.
2017 was a critical season for the Keeyask team. Despite many hurdles they accomplished three critical project milestones by the end of the year– ready for installation of the permanent powerhouse crane; the completion of all spillway concrete and successful turnover to the gates contractor; and the enclosure of the Service Bay and Units 1, 2 & 3 (meaning the completion of the complex superstructure, roof and progress on the cladding).
Coming up next
BBE takes on its biggest, most ambitious construction season ever in in 2018. The team is pressing hard towards its critical path milestones this year, including diverting the river through the Spillway and the completion of the South Dam Cofferdam.
They will also place more than 105,000 cubic metres of concrete– roughly a third of the project’s total concrete needs; complete the North Dam, second 1/3 of the Central Dam and progress the South Dyke, all while enclosing Powerhouse Units 4&5 by the end of the year.
July 2020 will then lay down a major marker. That’s when ‘impounding’ finally takes place and water is let into the completed dam in anticipation of the first generator unit coming into service by August 2021. The last turbine will then be made ready to turn in time for project completion one year later.
Once complete, the Keeyask Project will provide generations of Manitobans with a source of reliable and sustainable electricity – a future this Bechtel-led venture is proud to be part of.