The construction activities for the modular Hydroshaft Power Solution (HSPS) in At‑Bashy, Kyrgyzstan, began in August 2024. The contractor is Orion, a local Kyrgyz construction company. ILF Consulting Engineers, a partner in Hydro4U, played a key role in the design phase and supervision of this demonstration hydropower plant. ILF Austria (ILF‑AUT) was responsible for the detailed design of the civil works and for the structural calculations, while ILF Kazakhstan (ILF‑KAZ) conducted the site supervision during construction.

Between September and December 2024, ILF‑KAZ carried out several site visits, each lasting between 6 and 14 days. These visits were essential for monitoring the construction progress, identifying challenges and ensuring compliance with the design. Site supervision was further supported by a visit from the Project Coordinator of the Technical University of Munich (TUM), underlining the collaborative and interdisciplinary nature of the project.

Despite the remote location and harsh environmental conditions, significant progress was made during Phase 1 of construction. The construction of key structural components – including foundation slabs, vertical walls and beams – was successfully completed. Reinforcement and concrete works were carried out across multiple sections of the hydropower plant, with adjustments made to account for site-specific constraints and unforeseen challenges.

During the construction process, several obstacles had to be overcome, which were addressed through collaborative efforts and adaptive measures:

• The project faced several logistical and technical challenges. The existing structure proved to be stronger than anticipated, leading to breakdowns of equipment and minor delays during demolition. Issues such as inconsistent fuel and electrical power availability also contributed to minor delays in the initial stages of construction.

• The remote project area and limited access to specialized subcontractors made it difficult to implement certain technologies.
  Although jet grouting technology was planned during the initial design phase for securing the existing weir structure, it was later found to be unavailable and replaced with a traditional underpinning method with concrete.

• The timely procurement of essential construction materials, such as swelling tapes, was a challenge at times, leading to adaptive decisions on site.

• Several structural elements displayed dimensional deviations and misalignments. These misalignments were critical for the subsequent installation of hydraulic steel structures and the turbine. Therefore, corrective measures were essential to ensure smooth progress in Phase 2. These issues were addressed through corrective actions in the geometry of the walls, reinforcement adjustments, and the employment of a permanent surveyor by Orion.

• A construction schedule was not provided by Orion, which required the spontaneous coordination of the on-site visits.

Quality control remained a priority throughout Phase 1 of construction. Instances of insufficient concrete vibration led to surface defects, which required subsequent concrete repair measures. Cold joints were observed, caused by premature concrete setting due to low temperatures during placement. Safety concerns such as unstable slopes and eroded retaining structures were identified early and addressed through temporary protective measures.

As winter approached, construction activities were further complicated by freezing temperatures, snowfall and icy roads. Emergency heating measures – including gas and electric heat guns, wood-fired stoves and protective tents – were employed to maintain suitable conditions for concrete curing. These pragmatic measures, while not ideal, were necessary to prevent further delays and to ensure structural integrity. They proved to be sufficient and eventually helped the construction progress to reach a state that could be paused during the following winter months.

Due to worsening weather conditions, construction activities had to be suspended as scheduled in December 2024. The remaining scope of work is scheduled to start in August 2025, including the pouring of second stage concrete after the installation of hydraulic steel structures and the turbine unit, the construction of the operational building as well as the construction of the fish passage.

Although it was not always possible to use standard European construction methods, due to the above mentioned restrictions, the work has progressed very positively so far thanks to intensive construction supervision, and good contact with both the owner and the construction site personnel. The engagement and linguistic proximity of our colleagues at ILF‑KAZ were also crucial. The Hydro4U partners are therefore optimistic about the upcoming completion of construction works and the commissioning of this innovative power plant.

ILF remains committed to continued supervision and collaboration with all stakeholders to ensure the successful completion of the remaining project phases while upholding both quality and safety standards.

Authors: Gabriel Pojer, ILF; Bertalan Alapfy, TUM

Picture credits: Bertalan Alapfy, TUM