Everything we know about Scottsdale's wastewater swap plan

• It's latest proposal: put treated and purified wastewater into the Central Arizona Project (CAP), the main source of water for the Valley.
• In return, Scottsdale wants a larger share of Colorado River water.

Yes, but: That means other cities, like Chandler or Gilbert, may receive the recycled wastewater Scottsdale doesn't want to keep.

Why it matters: The proposed exchange could help Scottsdale protect its water supply as Colorado River cuts deepen.

Driving the news: City manager Greg Caton outlined the strategy in a Sept. 8 memo to the City Council, which Axios obtained.

• Scottsdale could also help pay for additional testing, monitoring or other costs for water users downstream.

Catch up quick: The city's 2024 water strategy included treating recycled wastewater to drinking-water standards and adding it to the city's water system.

• But this idea, dubbed the "toilet-to-tap" plan, quickly became politically contentious and was later put on hold.

While Scottsdale operates an advanced treatment facility that can purify up to 20 million gallons of recycled wastewater daily, it doesn't have the permits or infrastructure to supply it to homes.

• Instead, the city mainly relies on the treated river water from CAP, while the recycled water is put aside for golf courses and groundwater recharging.

The city's latest proposal is a "creative solution" that could give Scottsdale another way to manage water shortages, Sarah Porter, director of ASU's Kyle Center for Water Policy, tells Axios.

• "This would be a novel use of the CAP canal."

• The plan would need CAP's approval but possibly also the Bureau of Reclamation's since it oversees the federal water canal project, Porter says.

What they're saying: Councilwoman Solange Whitehead isn't fully convinced by the idea.

• The proposal could make Scottsdale residents pay twice: first to purify the city's wastewater and again to treat the raw CAP water received in return, Whitehead said in a press release Wednesday.
• "If Scottsdale puts a cup of water into the canal and takes a cup out, I don't see how the regional supply has changed," she said.

Meanwhile, the idea of providing recycled wastewater to Scottsdale hasn't been completely ruled out, but it may be an uphill battle.

• Councilman Barry Graham and council candidate Michelle Ugenti-Rita are both against the idea, citing unanswered questions about cost and public-health safeguards.
• Actor Rob Schneider, a Scottsdale resident, has also weighed in repeatedly, most recently calling the recycled water "new untried technology" in a post on X this week.

What's next: CAP told AZFamily that it received Scottsdale's proposal and is reviewing it.