Karun III is a high‑performance, double-curvature concrete arch dam on the Karun River in Khuzestan Province, Iran. Standing about 205 m tall, it creates a reservoir of roughly 2.97 billion m³, which serves multiple purposes: large-scale hydropower generation (~ 2,280 MW), flood control, and water regulation for downstream needs. Built between the mid‑1990s and early 2000s, the dam includes a complex underground powerhouse, extensive tunnels, and engineered plunge pool structures. The project was designed not only to address Iran’s energy shortage by contributing large amounts of electricity to the national grid but also to help manage seasonal flooding in the Karun River and provide regulated water flow for irrigation and other uses.
Concrete double‑arch dam, 205 m high.
Installed hydropower capacity: ~2,280 MW (8 × Francis turbines).
Reservoir capacity: ~2,970 million m³.
Spillway capacity: up to 15,000 m³/s.
Designed for flood control in addition to power.
Seismic‑resistant design; dam can withstand earthquakes up to magnitude ~7.
Iran Water and Power Resources Development Co
Khuzestan
Iran
The Challenge
Karun III faced several formidable technical and environmental challenges. The narrow gorge and mountainous terrain of the Karun River required a precise double-arch concrete structure to safely and efficiently transfer immense hydrostatic loads to the bedrock. Seismic risks were significant, given regional tectonics, demanding a design that could reliably withstand large earthquakes. Hydrologically, the river has large seasonal flow fluctuations and very high flood peaks, so the dam had to provide robust flood control while retaining large water volumes for power generation. Additionally, integrating an underground powerhouse with extensive tunnels (intake, tailrace, transformer cavern) under high hydraulic pressures required complex civil works and high-precision tunneling. Finally, ensuring long-term seepage control and durability of the dam under extreme water pressure, combined with operational management of the reservoir and generation, posed a major engineering and operational challenge.
What did RMTEC do
We supported the project with advanced geotechnical and structural engineering expertise, optimizing the arch dam geometry to efficiently transfer loads into the rocky gorge and ensuring seismic resilience. Our hydraulic engineering teams designed the inlet, tailrace, and transformer tunnels, as well as the plunge pool, to handle the high-pressure flows while minimizing energy losses. For flood control, we contributed to modelling flood scenarios and defining operational protocols that balance water retention for generation and controlled discharges during peak floods. To manage seepage and long-term stability, we implemented monitoring systems and high-quality concrete mix designs, ensuring that the dam remains safe and durable under its full hydraulic load.
The Results
- Major boost in national clean energy production with ~2,280 MW capacity.
- Enhanced flood control, reducing downstream flood risk.
- Creation of a large reservoir that stabilizes water flow for downstream uses (irrigation, water supply).
- Improved regional infrastructure resilience, supporting sustainable development in Khuzestan.
