LAS VEGAS (KLAS) — The Southern Nevada Water Authority has new power to limit how much water you can use at home.

On Tuesday, when all the news out of Carson City was swirling around a special session to finish the state budget, Gov. Joe Lombardo signed Assembly Bill 220. It wasn’t a surprise, but AB220 wasn’t the biggest story of the day.

And it likely won’t be a hot topic of conversation this year as Lake Mead is expected to refill to 26% capacity on the strength of a heavy snowpack that’s feeding the Colorado River.

But AB220 is an important step, putting some teeth into SNWA’s steady message of the critical need for water conservation. If drought conditions trigger more severe cuts to Nevada’s allocation of water from the Colorado River — which supplies about 90% of the water used in the Las Vegas valley — SNWA can use its new power to restrict residential water use.

Who would be affected?

SNWA has been proactive in the fight for water conservation. Programs to eliminate grass in favor of desert landscaping have been successful. Many residents have taken advantage of rebates that pay $3 per square foot for turf removal.

But some residential users haven’t budged.

SNWA estimates that 80% of the homes are already hitting the goal that’s specified in AB220 — using a half acre-foot of water per year (or less), about 163,000 gallons.

It’s the other 20% that could face restrictions. SNWA estimates nearly half of the water used in the valley — about 45% — is used by those customers. And the top 10% use an estimated 30% of the water.

Colby Pellegrino, SNWA Deputy General Manager of Resources.

“The intent is an emergency management nature, So if we had to reduce our use below our existing use or reduce our use in a very rapid fashion, that it’s a tool to use in our toolbox temporarily, not a permanent management strategy,” Colby Pellegrino, Deputy General Manager of Resources for SNWA, said at a May hearing.

A 2021 report by showed that the five biggest residential water users in the valley used a combined 52 million gallons — equal to 319 homes that used 163,000 gallons. Spanish Gate Holdings Inc. was at the top of that list, using more than 12 million gallons.

“This is not about singling out and punishing residential users,” Democratic Assemblyman Howard Watts said. “If we end up in this scenario, we’re going to be asking everyone to tighten their belts to make sure that the critical uses for our community are protected.”

The new law

AB220 says: “If the federal government reduces Nevada’s allocation of the Colorado River for the upcoming year to 270,000 acre-feet or less, the Board of Directors may limit each single-family residence that uses the waters of the Colorado River distributed by the Southern Nevada Water Authority or a member agency of the Southern Nevada Water Authority to not more than 0.5 acre-feet of water for that upcoming year. Any limitation imposed by the Board of Directors may not go into effect before Dec. 31 of the year before the year for which the federal government has reduced Nevada’s allocation of the Colorado River to 270,000 acre-feet or less.”

A notice would have to go out on Oct. 1 of the year before residential water use is limited.

Lake Mead is shown in a photo taken in late March, 2023. (Duncan Phenix / 8NewsNow)

Currently, Nevada gets 300,000 acre-feet of water from the river. Tier 2 water shortage conditions are in effect.

Lake Mead is currently at 1,054 feet, and it would have to drop below 1,025 feet before restrictions would be possible under AB220.

Septic systems

When the bill went through hearings in the Nevada Legislature, attention was almost entirely on requirements that residents using septic tanks get connected to the municipal sewer system. Many of the homes on septic tanks were built before sewer systems were available in their area.

Water lost to septic systems could be treated and recycled if homes were connected to the sewer system. But the cost of that conversion can be very high. Some residents estimated it would cost them around $40,000. Initial versions of the bill would have paid 50% of the cost.

By the time the bill was approved in the Legislature, lawmakers eliminated the requirement. It was changed to “optional” — with the lure of 100% funding if the connection is made by the year 2054.