The western American snowpack is nature’s reservoir, providing 60-70% of the region’s water supply. Winter precipitation is stored there and is released slowly during the spring and summer. The snowpack feeds the region’s rivers, fills reservoirs, supports irrigation for agriculture, enables hydropower, and sustains ecosystems. After the warmest winter on record for many states and a major heat wave in March that left almost no snow in many places, there is real trouble ahead.
Most of the Mountain West won’t be able to rely on melting snow because there is hardly any there. Almost the whole region is affected, not just isolated pockets. California’s Sierra Nevada has only traces of snow. Parts of western Colorado that typically have at least 6 inches of snow are virtually snowless.
The situation is the result of a record-warm winter for many western states. Much of the time, temperatures were too warm for it to snow, resulting in rain instead. A March heat wave broke monthly temperature records in more than a dozen states, wiping out much of whatever snow there was.
As a result, very little fresh water will flow out of the mountains this spring and summer, meaning that vital reservoirs like Lake Powell will see very low water levels.
Water agencies in the region are seeking to cut usage and are imposing water restrictions earlier than usual. The conditions have already elevated fire dangers across the region, including much of Nevada, California, Utah, Colorado, Arizona, Wyoming, and Montana.
The realities of warmer temperatures that come with climate change are forcing changes in how the West manages water.
