to extend their seasons and sustain their businesses in times of low snowfall. With changing climate trends, snowfall is becoming increasingly unpredictable, thus jeopardizing the economic success of ski resorts. Between 2008 and 2013, American ski and snowboard resorts experienced annual revenues of about US$3 billion. Such high levels of revenue increase the demand for predictable and adequate amounts of snow cover, which can be achieved through artificial snowmaking practices. While the economic benefit of ski resorts has been around US$3 billion in recent years (see Figure 2), the additional economic value of winter tourism in the United States is estimated to be around US$12.2 billion per year. These additional benefits come in the form of spending at hotels, restaurants, gas stations, and other local businesses. Additionally, winter tourism supports around 211,900 jobs in the United States, which amounts to a total of approximately US$7 billion paid in benefits and salaries, US$1.4 billion paid in state and local taxes, and US$1.7 billion paid in federal taxes. The economic benefits of snow sports are great, but also fragile. It is estimated that in years of lower snowfall, there is about a US$1 billion decrease in economic activity. Environmental impact and future conditions Mountain reservoirs The implementation and use of artificial snow making technologies requires the undertaking of major infrastructural projects. These projects result in significant disruptions to local ecosystems. A major infrastructural project associated with the use of artificial snowmaking technology is the mountain reservoir. Many mountain reservoirs are embankment dams that feed underground water pipelines, and pose significant safety risks to nearby populations and ecosystems. In addition to the hazards posed by conventional reservoirs and dams, mountain reservoirs are subject to a variety of mountain-specific hazards. Such hazards include avalanches, rapid flows, and landslides. Approximately 20% of mountain reservoirs are built on avalanche-prone sites, and about 50% are prone to very high hazards. Additionally, mountain reservoirs expel water very quickly, causing massive floods, and significantly jeopardizing public safety. The severity of these hazards is augmented due to their potential impact on lower populations and properties. Water and energy use Snowmaking machines generally require between 3,000 and 4,000 cubic meters of water per hectare of slope covered. Accordingly, it takes approximately 106 gallons (400 litres) of water to produce one cubic meter of snow, and snowmaking machines use about 107 gallons (405 litres) of water per minute. A significant amount of