This graphic shows just how little water the West has left

The American West, not just California, is experiencing a long-term drought.

As drought conditions drag on, the region’s water reservoirs are getting drained.

Dean Farrell of the University of North Carolina Chapel Hill made a stunning (and frightening) interactive graphic illustrating how empty the West’s water reservoirs are becoming. The reservoirs at less than 50% of their capacity are represented by the red dots in this map (the larger the dot, the bigger the reservoir):

Water resevoir mapWestern Water / Dean FarrellRed dots are reservoirs less than 50% full, yellow ones are 50-75% full, and green are over 75% full.

The huge red dot straddling the Utah and Arizona border is Lake Powell, which was 45.4% full in May. The other big red dot at the southern tip of Nevada, Lake Mead, was only 37.6% full.

On Farrell’s website you can click reservoirs and see how their water level has changed over time.

Take, for example, Trinity Lake, California’s third-largest reservoir, which has been low since the summer of 2014.

California trinity lake skitchWestern Water / Dean FarrellThe arrow points to Trinity Lake, California’s third-largest reservoir.

Trinity Lake’s water level has fluctuated pretty wildly, presumably because of scheduled water releases, Farrell says.

But you can clearly see a major dip from 2008 to 2010, and water levels haven’t recovered from their tumble in 2013:

Trinity lake reservoir water levelWestern Water / Dean FarrellTrinity Lake’s water level is below average, and much below its capacity.

In May, Trinity Lake was only 41.8% full, coming down from a peak of 48.4% in March after heavy December rains recharged it.

Overall, in May California’s reservoirs were at only 46% of their full capacity, and 72% of their historical average.

Surface water reservoirs aren’t the only source of water in the West — people also take water from underground aquifers, rivers, and desalination plants — but as they dwindle less and less water is available for people to use.

Check out and play with the graphic on Dean Farrell’s website.

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