Dam raising, roller compacted concrete practice reach new heights
Colorado’s Gross Reservoir serves as a combination storage and regulating facility for water that flows under the North America Continental Divide. New Jersey-based Doka USA has supplied formwork to raise the reservoir’s dam from 340 ft. to 471 ft., nearly tripling its 42,000-acre-ft. capacity to 119,000-acre-ft. Construction over a 2024-2027 schedule entails placement of 118 steps from the existing structure to the new dam crest. The material schedule spans 725,000 yd. of roller compacted and 90,000 yd. of conventional concrete mixes. Synonymous with water resources structures, roller compacted concrete entails zero slump mixes placed and finished with asphalt paving equipment.
The Doka Infrastructure Group worked with the Kiewit and Barnard joint venture team to develop a custom engineered solution addressing the project’s unique challenges. The formwork system incorporates horizontal adjustment to maintain tie spacing as the dam face steps back with each lift, ensuring both aesthetic alignment and structural integrity. Custom and standard girder forms create a flexible, easy-to-move system that supports 24/7 progress on the jobsite. The formwork solutions include Xclimb 60 for the training wall girder formwork, Framax S Xlife panels on the lower training walls, plus trailing platforms constructed from WS10 and H20 Beams T. The formwork is designed to be assembled in a way that allows four 1-ft. lifts per 24 hours. As the project progresses, crews will install DokaXact Load and Pressure sensors for real-time concrete monitoring.
“The challenges the dam’s stepped design pose and the need for precise alignment with the existing structure required us to engineer a formwork solution that could adapt to varying pressures while maintaining efficiency and safety,” says Doka USA CEO Michael Kennedy. “By combining custom and standard girder forms, our team delivered a system that not only supports the massive volumes of roller compacted concrete but also helps ensure the structural integrity of the dam as it rises.”
The project is reportedly the largest dam raise in the United States and the largest roller compacted concrete dam raise worldwide.
MOVING FIRST ON SCIENCE BASED TARGETS INITIATIVE COMMITMENT
Through a sustainability strategy dubbed “Net Zero 2040,” global concrete formwork and scaffolding provider Doka has aligned its carbon dioxide emissions reduction goals with Science Based Targets initiative terms. London-based SBTi provides producers, suppliers or manufacturers with auditing services and guidance aimed at limiting CO2 emissions volumes sufficient to cap the rise of global temperatures at1.5°C above pre-industrial levels.
SBTi clients focus especially on GHG Protocol-defined Scope 1, 2 and 3 emissions. They respectively indicate CO2 or equivalent greenhouse gas volumes associated with raw materials production and delivery; material processing or product manufacturing; and, cradle to gate phase power consumption. Doka’s move follows similar SBTi commitments from global counterparts upstream in portland cement production, including Cemex S.A.B. de C.V., CRH Plc, Heidelberg Materials and Holcim Group.
“The transition to net zero is a complex challenge that requires both ambition and resilience. By committing to SBTi, we are demonstrating that sustainability is not just a buzzword for us—it’s serious business,” says Doka CEO Robert Hauser. “We believe that sustainable practices and solutions are the key to helping our customers thrive in a futureproof, competitive construction industry.”
The industry faces increasing pressure to adopt more sustainable practices, driven by both rising regulatory demands and the need to mitigate its substantial environmental impact. Doka views the challenge not only as an environmental responsibility but as a catalyst for building more resilient and sustainable business models that can drive long-term success in the evolving construction market.
The company is committed to reducing its Scope 1, 2, and 3 emissions in line with the SBTi absolute reduction methodology, or 42 percent in each category by 2030. “We are constantly collaborating with our customers and suppliers to develop safer, more efficient, and climate-friendly solutions,” Hauser affirms. “Commitment to SBTi solidifies our dedication to cutting greenhouse gas emissions, not just within Doka but across our entire supply chain.”
Doka has already implemented significant emissions reduction measures, increasing the use of renewable energy across global operations among them. At Austrian headquarters, it has transitioned to 100 percent renewable electricity, supported by the expansion of photovoltaic systems and a green energy switch. By refurbishing formwork after every use in dedicated North American or overseas service centers, moreover, Doka USA ensures that material and resource consumption is minimized, keeping products in circulation for extended periods. The company is also exploring the use of low-carbon materials in formwork systems, further reducing construction project environmental impact.