Will Ski Resorts Need More Water?

Alpine snowmaking machine at work. iStock 

Ski resorts increasingly rely on artificial snowmaking and often build mountain reservoirs to supply water. Now there’s growing concern about putting such water demands on already fragile mountain hydrological systems.  

A 2025 study published in Ecological Economics examines data from 35 ski resorts over nine seasons, using modeling to assess how reservoir construction affects water withdrawals, especially during low-flow periods. The findings challenge the current assumption that reservoirs reduce environmental pressure. Instead, as temperatures warm, ski resorts may need ever greater amounts of reservoir water over time.   

The study’s findings are important because ski resort operators are seeing a reduction in natural snow cover, causing them to increasingly rely on snowmaking, which is possible down to a maximum of −2 °C (28 °F). 

Here are some key data insights from the study: 

• The seasonal natural snow reliability index for the 35 resorts ranges from 4% to 85%, with an average of 61%.   

• The French Alps have approximately 136 reservoirs, with a combined storage capacity of nearly 7.3 million m³  (19.2 billion gallons)   

• On average, ski resorts withdraw 212,113 cubic meters (56 million gallons) of water per year for snowmaking.  

• Among the 35 ski resorts studied, a 1% increase in reservoir capacity is associated with a 0.28% increase in low-flow period water withdrawals (typically from December to March).   

• Over the longer term, the effect grows. The same 1% increase in reservoir capacity corresponds to a 0.4% increase in low-flow period withdrawals. In other words, rather than alleviating stress on water sources during dry periods, expanding reservoir capacity tends to encourage increased water use—potentially exacerbating low-flow period conditions.   

• Reservoirs are often promoted by ski-lift operators as part of “environmental commitment” or climate change adaptation strategies, but the empirical evidence indicates they may contribute to future water-use conflicts.   

• Canadian ski resorts are currently estimated to use around 43.4 million cubic meters (11.4 billion gallons) of water for snowmaking per annum, with predicted increases ranging from 55% to 97% by 2050.  

• Reservoir capacity has grown: In 2010, ski resorts had a storage capacity of 2.22 million cubic meters (586 million gallons) of water, which increased to 3.54 million cubic meters (935 million gallons) in 2021.