137 MW with 100 m High RCC gravity dam
In November 1994, a Klohn Crippen Berger joint venture was awarded the contract to carry out a comprehensive engineering and environmental feasibility study for a new hydroelectric project on the Lower Larona River, Sulawesi, Indonesia. Options for partial and full development of the Lower Larona River were studied and the decision was made to develop the hydro potential at a dam site upstream of the village of Balambano. KCB continued to work on the project through the detailed design and construction of the project, with special emphasis on the geotechnical and RCC dam design. KCB provided full time staff on site during construction for design compliance QA/QC services. KCB has stayed involved with this project since its completion with various inspections and a dam safety review and risk assessment currently on-going and scheduled to be completed by the end of 2022.
- An important design issue for the proposed Balambano plant was the requirement to respond rapidly to the extreme load and frequency swings in the P.T. Inco generating system resulting from normal operation of the arc furnaces used in the nickel processing operation.
- Availability of quality concrete aggregate and placement schedule.
- The design minimized flow velocities, utilized short power conduits with rapid water starting times and incorporated high inertia generators with long mechanical start times to allow rapid response to extreme changes in load on the generating system.
- A Roller Compacted Concrete (RCC) dam was selected as the best alternative with both the lowest cost and shortest possible construction schedule for this dam site. This was possible due the site configuration and access conditions.
- The Balambano facility was designed and built providing a rapid, yet stable power delivery for a highly variable smelter demand.
- Project was commissioned and is still performing well and delivering reliable power after more than 25 years of operation.