LAS VEGAS (KLAS) — Lake Mead has dropped below 1,050 feet, a milestone level as the Las Vegas valley’s water supply dwindles during a 22-year drought.

Overnight monitoring and levels reported through the morning show the lake fluctuating, dipping to 1,049.97 feet at around 5 a.m. before rising again.

The 1,050-foot mark is important because it marks the level at which Intake No.1 can no longer function, according to information from the Southern Nevada Water Authority (SNWA). Intake No.1 is one of three intake “straws” that take water from the lake for delivery to the valley. An animated graphic shows the interconnections of the three straws and how they send water to Las Vegas:

Water officials saw this coming years ahead, and capped the intake pipe in 2015. The pipe broke the surface of the water earlier this year, and more of the pipe has become visible as Lake Mead continues to drop.

The pump for Intake No.1 continued to operate until it was turned off on April 1,” according to Bronson Mack, spokesman for SNWA and the Las Vegas Valley Water District.

“On April 1, operations made the transition to Intake 3,” Mack said. “Almost all of our water is coming from No. 3.”

Interconnections between the intakes allowed pump No.1 to continue to operate years after the water stopped flowing.

Intake No.2 is still operating, and is capable of taking water from Lake Mead until the level drops below 1,000 feet, according to SNWA. The lake level is expressed as an altitude — Lake Mead’s surface was exactly at 1,050 feet above sea level at noon on Friday.

Water flows from Lake Mead into a 3-mile-long tunnel, filling underground caverns. Pumps deliver the water from there to treatment plants and on to the valley for use.

FILE – This April 25, 2022 photo provided by the Southern Nevada Water Authority shows the top of Lake Mead drinking water Intake No. 1 above the surface level of the Colorado River reservoir behind Hoover Dam. (Southern Nevada Water Authority via AP, File)

What’s the next milestone? An August report will determine whether water officials forecast Lake Mead to remain below 1,050 feet on Jan. 1, 2023. If so — and that appears very likely — Tier 2 water use restrictions would go into effect.

On Aug. 16, 2021, the federal government issued a water shortage declaration on the Colorado River. That declaration reduced Southern Nevada’s water allocation by 7 billion gallons in January.

Las Vegas currently gets 279,000 acre-feet of water from Lake Mead under Tier 1 restrictions, and that would be further reduced if Tier 2 restrictions come.

Last year, Mack said, the valley used 247,000 acre-feet of water.

He emphasized that all the water used indoors is returned to the system through treatment plants, but water used outdoors is gone.

That’s why there is such an emphasis put on conservation and reducing the amount of water spent on lawns and outdoor uses that waste water.