CARSON CITY, Nev. (AP) — Ornamental lawns are banned in Las Vegas, the size of new swimming pools is capped and much of the water used in homes is sent down a wash to be recycled, but Nevada is looking at another significant step to ensure the water supply for one of the driest major metropolitan areas in the U.S.

State lawmakers on Monday are scheduled to discuss granting the power to limit what comes out of residents’ taps to the Southern Nevada Water Authority, the agency managing the Colorado River supply to the city.

If lawmakers approve the bill, Nevada would be the first state to give a water agency permanent jurisdiction over the amount of residential use.

The sweeping omnibus bill is one of the most significant to go before lawmakers this year in Nevada, one of seven states that rely on the Colorado River. Deepening drought, climate change and demand have sunk key Colorado River reservoirs that depend on melting snow to their lowest levels on record.

“It’s a worst case scenario plan,” said the bill’s sponsor, Democratic Assemblyman Howard Watts of Las Vegas. “It makes sure that we prioritize the must-haves for a home. Your drinking water, your basic health and safety needs.”

The bill would give the water authority leeway to limit water usage in single-family homes to 160,000 gallons annually, incorporate homes with septic systems into the city’s sewer system and provide funding for the effort.

The average home uses about 130,000 gallons of water per year, meaning the largest water users would feel the pinch, according to the agency.

The authority hasn’t yet decided how it would implement or enforce the proposed limits, which would not automatically go into effect, spokesperson Bronson Mack said.

Water from the Colorado River largely is used for agriculture in other basin states: Arizona, California, Wyoming, Utah, New Mexico and Colorado.

Las Vegas relies on the Colorado River for 90% of its water supply. Already, Nevada has lost recycles a majority of water used indoors and doesn’t use the full allocation.

Nevada lawmakers banned new swimming pools at single-family residential homes to about the size of a three-car garage.

A state edict carries greater weight than city ordinances and more force in messaging, said Kyle Roerink, executive director of the Great Basin Water Network, which monitors western water policy.

Watts said he is hopeful other municipalities that have been hesitant to clamp down on residential water use will follow suit as “good stewards of the river” with even deeper cuts to the Colorado River supply looming.

Snow that has inundated northern Nevada and parts of California serves as only a temporary reprieve from dry conditions. Some states in the Colorado River basin have gridlocked on how to cut water usage, with many of them looking toward agriculture to shoulder the burden.

Municipal water is a relatively small percentage of overall Colorado River use. As populations grow and climate change leaves future supplies uncertain, policymakers are paying close attention to all available options to manage water supplies.

Santa Fe, New Mexico, uses a tiered cost structure where rates rise sharply when residents reach 10,000 gallons during the summer months.

Scottsdale, Arizona, recently told residents in an community outside city limits that it no longer could provide a water source for them. Scottsdale argued action was required under a drought management plan to guarantee enough water for its own residents.

Elsewhere in metro Phoenix, water agencies aren’t currently discussing capping residential use, Sheri Trap of the Arizona Municipal Water Users Association said in an email. But cities like Phoenix, Glendale and Tempe have said they will cut down on usage overall.

___ AP writer Susan Montoya Bryan contributed reporting from Albuquerque, New Mexico. Stern is a corps member for the Associated Press/Report for America Statehouse News Initiative. Report for America is a nonprofit national service program that places journalists in local newsrooms. Follow him on Twitter: @gabestern326.