As hydropower reclaims centre stage in the global energy transition, few engineering consultancies are as closely associated with the sector’s technical evolution as Gruner Stucky Ltd. Founded in Switzerland and built on decades of dam and hydropower engineering expertise, the company has grown into a globally active specialist delivering complex infrastructure in some of the world’s most demanding environments. Now celebrating 100 years of activity, Gruner Stucky Ltd.’s leadership describes the current phase not as a reinvention, but as a natural continuation of a mission that has always revolved around renewable energy and sustainable infrastructure.
“Our mission has not fundamentally changed,” says Sergio Camilletti, Director of Business Area Energy. “We have always focused on sustainable infrastructure and renewable energy. What has evolved is the scale, the integration of new technologies, and the stronger emphasis on the role hydropower plays within wider energy systems.”
Hydropower’s expanding system role
While conventional hydropower generation remains central to Gruner’s portfolio, Camilletti emphasises that the company increasingly views the technology through the lens of system integration. With wind and solar capacity expanding rapidly worldwide, hydropower’s value as a stabilising force for national grids has never been more important. Pumped storage has also become a strategic growth area. “For us, pumped storage fits naturally into the energy transition,” Camilletti explains. “It connects hydropower to the modern power system and transforms reservoirs into strategic assets for balancing supply and demand.”
Alongside new development, the company sees significant opportunity in extending the operational life of existing infrastructure. Rehabilitation, refurbishment and asset modernisation projects are increasingly prioritised over greenfield construction.
“Upgrading existing dams and hydropower plants saves materials, reduces emissions associated with new construction and maximises the value of existing assets,” Camilletti notes. “Brownfield development will be one of the strongest drivers of growth in the coming years.”
This approach is particularly relevant in mature hydro markets, where installed capacity is already high but ageing assets require modern safety systems, upgraded electromechanical equipment and digital monitoring solutions. For Gruner, this provides an opportunity to improve performance while aligning legacy infrastructure with today’s sustainability expectations.
Swiss engineering heritage with global reach
Switzerland’s long hydropower tradition has profoundly shaped Gruner’s technical culture. Alpine topography, complex geology and extreme climatic conditions have historically required innovative dam solutions, particularly in high concrete and arch dam design.
This background has positioned the company as a trusted partner for utilities seeking advanced expertise in dam safety, structural optimisation and rehabilitation. Switzerland itself has become a reference market, with international clients regularly turning to Swiss engineers for specialist know-how in dam heightening and modernisation projects. Today, Gruner combines this heritage with an expanding international footprint. Engineering teams operate across Switzerland, France, Italy, Serbia, Georgia and the Philippines, enabling the company to remain close to project owners while also tapping into broader talent pools.
“Being physically present in our clients’ regions matters,” Camilletti says. “Despite digital collaboration tools, strong on-the-ground engagement remains essential for trust, training and long-term partnerships.”
This international operating model allows fully integrated project teams to work across borders using shared digital platforms, common design environments and unified project management systems. Regardless of geographic location, each project is treated as a single delivery unit, a structure that enables fast decision-making while maintaining technical consistency.
Technical excellence under extreme conditions
Gruner’s reputation has been built on its ability to deliver complex hydropower and dam projects in challenging environments. One of the most prominent recent examples is the replacement of the Spitallamm Dam at the Grimsel reservoir in Switzerland. Located at approximately 2000m above sea level, the project required the construction of a new dam immediately downstream of the existing structure while maintaining continuous reservoir operation. Alpine weather conditions, short construction seasons and logistical constraints added further complexity.
To address these challenges, Gruner employed advanced finite element modelling, 3D design tools and staged construction simulations. These digital techniques enabled engineers to optimise dam geometry, assess structural performance and coordinate construction sequencing with unprecedented precision.
Beyond engineering complexity, such projects demand close coordination between designers, contractors, plant operators and authorities. Camilletti highlights this collaborative approach as central to the company’s delivery philosophy, ensuring that design intent is maintained throughout construction and commissioning phases.
Rogun: redefining the limits of dam engineering
At the global scale, one of Gruner’s most significant current involvements is the Rogun hydropower project in Tajikistan. Once completed, the Rogun Dam will reach a height of 335m, making it the tallest dam in the world. Originally initiated during the Soviet era, the Rogun project combines legacy infrastructure with newly designed powerhouse extensions and modern safety systems. Construction is progressing while power generation is already partially operational, requiring complex sequencing and high levels of coordination between engineering teams and plant operators.
“Rogun represents the type of integrated challenge that defines modern hydropower engineering,” Camilletti explains. “It involves geology, hydraulics, structural design, operational continuity and long-term system planning – all at an exceptional scale.”
Digital engineering
Digitalisation is reshaping every phase of infrastructure delivery, and Gruner has placed digital tools at the centre of its engineering workflow. Building Information Modelling (BIM) is now widely applied across hydropower and dam projects, incorporating 4D and 5D. Digital twins are increasingly requested by clients, particularly for electrical installations and hydropower plants, enabling asset owners to improve operational planning, predictive maintenance and performance optimisation. Beyond modelling, the company is investing heavily in artificial intelligence and advanced data analytics. Hydrology, flood forecasting and sediment transport modelling are key application areas where machine learning techniques are delivering new insights.
The company has a number of tools it utilises. The Tethys inflow forecasting platform supports basin-scale hydrological prediction, while CRUEX++ enables improved estimation of extreme flood events under changing climate conditions. Meanwhile, the HYPOS sediment management framework helps operators optimise reservoir performance and extend asset lifespan.
“These tools allow us to move from static design towards adaptive infrastructure management,” Camilletti says. “They also support climate resilience by improving decision-making under uncertainty.”
Basin-scale collaboration
A further example of Gruner’s systems-based approach is its involvement in the Enguri Hydrology Initiative in Georgia. Working alongside hydropower operators and academic partners, the programme focuses on improving understanding of river basin behaviour, sediment transport and hydrological forecasting across a major hydropower cascade. By combining operational data, advanced modelling and stakeholder collaboration, the initiative supports better reservoir management and long-term plant performance. According to Camilletti, such basin-scale projects are becoming increasingly important as climate variability intensifies and water resource management becomes more complex.
Sustainability embedded in design
For Gruner, sustainability extends far beyond carbon-free electricity generation. Environmental protection, community engagement and material efficiency are increasingly embedded within project design.
In dam engineering, structural optimisation plays a crucial role in reducing embodied carbon. By designing thinner concrete sections and more efficient geometries, engineers can significantly reduce material use while maintaining the highest safety standards.
“Historically, these optimisations were driven by cost,” Camilletti explains. “Today, sustainability is an equally important driver.”
Sediment management, ecological flows and river system continuity are also growing priorities. Gruner supports clients in adapting hydropower assets to stricter environmental regulations, including sediment flushing systems, fish passage facilities and adaptive reservoir operation strategies.
Long-term partnerships
Hydropower infrastructure is built to last decades and Gruner applies the same long-term thinking to client relationships. The company frequently works with the same utilities and authorities across multiple project cycles, spanning rehabilitation, expansion and new development phases.
“We operate in a conservative, safety-critical sector,” Camilletti says. “Reputation and trust are fundamental. We view every project as a partnership rather than a transaction.”
This philosophy extends across political cycles and national boundaries, allowing the company to maintain continuity on major infrastructure programmes regardless of changing external conditions.
Strong links with academic institutions remain central to Gruner’s innovation strategy. Collaboration with Swiss research centres, including EPFL in Lausanne, allows advanced research in hydrology, geotechnics and structural mechanics to be translated into applied engineering solutions. Internally, structured training programmes ensure staff remain up to date with digital tools, modelling techniques and project management practices. These efforts are supported by ISO 9001-certified quality management systems, structured technical peer reviews and dedicated leadership oversight, reinforcing the company’s long-standing reputation for reliability and safety-critical engineering.
Looking ahead, Camilletti believes the demand for resilient infrastructure, grid stabilisation and climate-adaptive water management will continue to grow.
“Our opportunity lies in combining engineering heritage with digital innovation and sustainability,” he concludes. “Hydropower will remain essential – not just for power generation, but as the backbone of integrated, low-carbon energy systems.”
