Inside the Sayano-Shushenskoye Reservoir: history, risks, and resilience

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The Sayano-Shushenskoye Reservoir is often described as one of the Soviet era’s most unusual undertakings. For some, it stands as a symbol of technical progress; for others, a contentious intrusion into nature. Yet the fate of what many liken to a sea among the mountains turns out far more layered than a neat boon-or-blunder verdict.

A river that carved its own way

The reservoir’s vast bowl emerged where the Yenisei spent centuries cutting through rocky massifs. Over more than 300 kilometers, the river shaped a channel that was narrow and deep. That natural bottleneck made a high-power dam feasible: a flow squeezed by mountains is easier to harness for energy. Even today the river widens here to no more than 6–9 kilometers, and the steep walls still hold back the immense pressure of the water.

A long road to filling

Work on the dam began in 1963, but completion took nearly four decades, slowed by complex engineering challenges and surprises along the way. High loads caused cracks, water-handling components failed, and fixes had to be made on the fly. The reservoir began filling only in 1978, right after the first unit was launched. The basin was scarcely cleared: authorities deemed large-scale shoreline cleanup uneconomical, and heavy equipment simply could not operate in the hardest-to-reach places.

Thousands of trees went under. By the 1980s they began to surface and kept causing trouble for years. Specialists estimate the last submerged trunks may rise only around 2030.

Depths on a skyscraper scale

The Sayano-Shushenskaya dam is the tallest in Russia, at 242 meters. Up to 31 cubic kilometers of water gather behind its concrete wall, with depths reaching 220 meters in places. With pressure like that, there is no room for complacency. In 2009, a tragedy claimed the lives of 75 station employees, and recovery took ten years. It is no surprise that stories swirl around the dam; workers sometimes say that at night they seem to hear echoes of the past.

The clarity of a never-freezing sea

Despite its scale, the water here is strikingly clear. The Yenisei feeds it with clean mountain flows, and local soils have long been washed out. The reservoir’s bed is stony and largely free of silt, which helps keep the water transparent even at great depths. That is why the reservoir is considered a strategic reserve of fresh water, expected to supply vast areas if required.

A reserve created to give wildlife a chance

In 1976, before the valley was flooded, the Sayano-Shushensky Nature Reserve was established to help wildlife cope with the upheaval. Wolves adapted first, followed by hoofed mammals, and later birds. Rare species occur in the area, including the snow leopard. For the mountain region, it became an important example of how ecosystems can adjust to a major project, a reminder that resilience often reveals itself step by step.

Logistics that does not forgive mistakes

Reaching the dam is no simple task. There are few good roads, and the nearest settlement, the village of Cheryomushki, lies in a cramped valley. Steep banks, sharp gradients, and scarce flat land set strict limits. Floating hotels appeared as a practical solution: they operate on the water in summer, then are moved toward the ice-free center of the reservoir in winter so shore ice does not crush their hulls.

How underwater life changed

Underwater life changed markedly. Taimen, lenok, and grayling once dominated here; their numbers fell sharply after the reservoir was created, though in the 21st century populations were partially restored. Less demanding species such as perch, pike, and bream, by contrast, found room to expand. In 2006, the reservoir was added to the federal list of fisheries. The shift reshaped the food web but did not erase it, showing how the system settled into a new balance.