For now, here’s a brief explanation of why “Lej Nair Pitschen”—which translates to “little black lake”—is being built.

100 Percent Snowmelt Water RecyclingThanks to the Nair Pitschen natural reservoir, which serves as an additional reservoir to the existing Lej Alv natural reservoir, the slopes can be covered with snow exclusively using meltwater.

Greater predictability and snow reliabilityMeltwater is available on the mountain at all times, which shortens the time it takes to make the slopes skiable and helps ensure that snow sports activities are available as scheduled.

Conservation of ResourcesThe meltwater is collected on the mountain and no longer needs to be pumped up from the valley, which saves electricity, groundwater, and money.

Added Value for Summer VisitorsThe natural reservoir will be developed as a local recreation area and made accessible to provide another mountain experience.

SustainabilityThe project investment helps secure the livelihoods of the people of the Engadin.

SOMMER 2024

In mid-June 2024, construction of the Nair Pitschen natural reservoir began successfully with excavation work. Most of the excavated material was used to build the dam that will enclose the lake in the future.

Special emphasis was also placed on preserving the existing flora and fauna. To this end, the layers of grass were carefully removed and temporarily stored on large metal plates—reminiscent of baking sheets—at the appropriate locations along the dam. On the same day, the layers of grass were carefully reinstalled at their designated locations. This process can be compared to putting together a large jigsaw puzzle.

The stones of various sizes that were removed were also carefully replaced, so that once the work is complete, it is barely noticeable that the landscape has been altered. Thanks to these measures, the natural environment remains largely untouched, and the local flora and fauna are protected as much as possible.

SOMMER 2025

First, the dam construction was completed, and the interior of the natural reservoir was “lined” with a layer of gravel. A layer of special liner was then applied to prevent meltwater from seeping away. Finally, another layer of gravel was spread over the membrane, creating a natural lake bed. The Lej Nair Pitschen was then filled so that snowmaking could begin in the fall.

The Nair Pitschen natural reservoir on Corviglia in St. Moritz is a pioneering project in the Alpine region; by recycling meltwater, it ensures winter tourism for future generations.

What is Mountains' vision for the Nair Pitschen Natural Reservoir project?

The driving force behind this project is our desire to continue offering these fantastic snow sports opportunities on Corviglia in the future—in a more sustainable and efficient way, and with even greater planning certainty. In addition, thanks to the two natural reservoirs, we’ll be able to make the slopes entirely with recycled snowmelt in the future. In short: The Nair Pitschen natural reservoir is a crucial piece of the puzzle for the long-term, sustainable development of the ski resort.

Let's talk briefly about snowmelt recycling. What does that mean?

In winter, we have snow on the mountain, which melts in the spring. We collect the meltwater in the reservoirs of the two natural storage lakes, store it over the summer, and use it the following winter to make artificial snow for the ski resort. Snowmelt recycling thus forms a cycle: the water circulates on the mountain. By way of comparison: in past decades, we had to pump all the water up the mountain for snowmaking and did not have such a cycle.

The construction of the second natural retention pond is a holistic project that addresses the three pillars of sustainability: the ecological, economic, and social dimensions. Let’s first take a closer look at the ecological aspects: What impact does the project have on the other resources used to provide the mountain adventure activities?

In terms of resource use, the second natural reservoir offers several advantages: Since the water is already stored on the mountain, there is no longer a need to pump groundwater up from the valley—the pumping systems are being dismantled. All the water needed is available on the mountain at all times, which means we spend fewer operating hours on snowmaking; in other words, we save electricity, water, and money. Moreover, the second natural reservoir offers added value for guests, as we are designing it so that it can also be used as a local recreation area—similar to the Lej Alv natural reservoir. The Nair Pitschen natural reservoir is a true win-win project: It’s a good example of how a tourism region can combine the goal of sustainable resource use with benefits for guests.

From an economic standpoint, the project is intended to ensure the long-term viability of the mountain adventure activities offered at Corviglia. How will this be achieved?

The project gives us even greater reliability in terms of snow and planning—two factors that are crucial for us as a tourism region. Thanks to the two natural reservoirs, we’ll have all the water we need for artificial snowmaking right on the mountain in the future. As soon as a cold spell sets in, we can begin snowmaking. In this context, we also refer to the so-called “snowmaking period”—that is, the time we need to cover the ski area with snow. A great deal depends on this snowmaking period—including the scheduled opening of the ski resort, which is extremely important not only for us but also for service providers in the valley. In the past, when we didn’t have any natural reservoirs at all, the snowmaking period for the entire Corviglia area lasted several weeks—depending on the amount of water that could be pumped up, the availability of electricity, and other factors. With our first natural reservoir, Lej Alv, we were able to significantly shorten the snowmaking period. With the second natural reservoir, Nair Pitschen, we’re making even better use of the cold periods, allowing us to shorten the snowmaking period even further. Ultimately, this gives us greater planning certainty and more reliable snow conditions. In light of climate change, this is a decisive advantage for us as a snow sports destination.

What other savings will be achieved through the Nair Pitschen Natural Reservoir project?

Since we no longer have to pump groundwater up the mountain, we’ll save an additional approximately one gigawatt-hour of electricity per year, which corresponds to just under 10 percent of our total energy needs as a company. To put this into perspective: One gigawatt-hour is equivalent to the annual electricity consumption of about 250 four-person households. With this second natural reservoir, we are thus achieving a dramatic reduction in electricity consumption that we could not achieve through conservation measures alone. In addition, we will no longer need groundwater for artificial snowmaking in the future.

As part of the project’s social dimension, let’s look to the future: What will the natural reservoir offer future generations?

Our Corviglia ski resort spans 155 kilometers of slopes, ranging from 1,730 meters to 3,057 meters above sea level. Various studies using climate scenarios indicate that ski resorts at our altitude have good to very good snow reliability, supported by snowmaking systems, for at least the next 60 years. The second natural reservoir is another key project in our long-term snow sports strategy aimed at enhancing the experience for our guests. The Upper Engadin, with its approximately 17,000 residents, is largely dependent on tourism. With this investment in the new natural reservoir, we are making a contribution—one that should not be underestimated—to preserving the livelihoods of thousands of people living in the Engadin who depend directly or indirectly on snow sports tourism.

The groundbreaking ceremony for the Nair Pitschen natural reservoir took place in June. What challenges does the construction project present?

The biggest challenge is the weather: We’re building the natural reservoir at an elevation of about 2,600 meters. At such a high altitude, we have to expect snowfall at any time. Weather conditions can significantly impact the construction schedule. That’s why we’re hoping for good weather—largely free of precipitation—so we can make progress as quickly as possible.

And what has been your personal highlight so far in this project?

I was overwhelmed by the overwhelming support the people of St. Moritz showed for this forward-looking project. 87 percent of those who voted believe that the construction of the second natural reservoir is an important project that should be carried out. That’s fantastic and really motivates us.