The days of millions of Sin City residents and visitors who love swimming in, boating on, and drinking water siphoned from Lake Mead could be numbered.

After 14 years of drought in the Southwest, the water reservoir created by the Hoover Dam has officially dipped to its lowest water level since it began filling up with water from the Colorado River in the 1930s.

On Sunday, the lake’s water level dropped to 1,081.7 feet above sea level, leaving the reservoir only 39 percent full. The body of water hasn’t been full since 1998, when it was about 1,296 feet above sea level. As the hot, dry summer months continue, the water level is expected to recede even more.