Sun Coverage Ask Mr. Sun

Hi Mr. Sun,

How much water evaporates during each Bellagio fountain show? How many gallons evaporate during hot summer days?

— Alexander

•••

The fountains dancing above Las Vegas’ version of Lake Como consume about 12 million gallons of water a year, according to resort officials.

The Bellagio’s 8.5-acre lake holds 22 million gallons and is replenished annually with another 12 million, representing the amount lost to evaporation, leaky pipes or really thirsty ducks.

Assuming evaporation is responsible for that entire amount, that would break down to 1,200 gallons lost in each of the roughly 10,000-plus fountain shows performed throughout the year.

The amount lost, of course, would vary depending on temperatures and wind speeds. (Mr. Sun was told there would be no math on this exam and therefore did not attempt to calculate that.)

It’s worth noting though that the lake is equipped with sensors that shut off the fountains when winds would blow water beyond its borders.

The fountains are always Exhibit A for critics of the metropolitan area’s water use and the equity of conservation requirements. While there are legitimate questions about the logic of building a city of 2 million souls in North America’s driest desert, singling out the fountains as representative of the region’s water problems isn’t entirely fair.

The Bellagio uses water from a private well beneath the property — the water source for the old Dunes golf course — and thus does not further strain the Colorado River, the primary source of water for the Las Vegas Valley.

Still, no matter how many green lawns are replaced with rock or how far water here is stretched and recycled, the sight of those fountains seems to overshadow it. That is probably inevitable when a desert resort brags about operating “the most ambitious, choreographically complex water feature ever conceived.”

Questions for Mr. Sun can be sent to [email protected].