The City of Phoenix has agreed to participate in a drought mitigation plan that will require the city to voluntarily give up a large part of its entitled Colorado River water shares in order to keep Lake Mead, the nation’s largest reservoir, from falling to dangerously low elevation levels in 2022.
500+ Plan is a collaborative regional effort amongst the three lower basin states of Arizona, California and Nevada. These regions all heavily rely on the Colorado River water stored in the Lake Mead reservoir as a main water source.
The 500+ plan ultimately seeks to leave behind 500,000 acre-feet of water per year in the Lake Mead reservoir every year until 2026. This number is believed to keep the reservoir from falling to a dangerously low elevation level of 1,020 feet in the coming years, a point that would force painful cuts in Colorado River water supply to all three of the lower basin states.
“The initial feeling of the lower basin states was certainly anything below 1020 is a dangerous area, and so we were going to prevent it from even getting there,” said Cynthia Campbell, the water resource management advisor for the City of Phoenix. “It’s a short-term, immediate reaction to what we saw was coming. I certainly don’t think it’s sustainable over too many years because it’s a lot of money, and it’s a lot of water.”
Campbell predicts the 500+ Plan will keep the Lake Mead reservoir above an elevation of 1,020 feet, but not by much. For Phoenix residents, this means they could see an increase in water bills and property tax rates as Colorado River water becomes more expensive in the coming years.
“It’s not going to turn the situation around,” Campbell said. “The water will probably cost more in the future, it is certainly not going to get cheaper,” she continued
The plan comes as a direct response to rapidly declining water levels in Lake Mead that were the direct result of climate change, two decades of intense drought and a significant over-allocation of Colorado River water resources.
The Colorado river system currently supplies water to 40 million people in seven western states and Mexico and irrigates more than 5 million acres of farmland, according to the Kyl Center for Water Policy at Arizona State University’s Morrison Center.
“Right off the bat, the amount of water that’s being divided up is greater than the amount of water that actually exists in the river in most years,” said James Leenhouts, a hydrologist for the United States Geological Survey. “On top of that, the reservoirs, Lake Mead and Lake Powell, evaporate about another million and a half acre-feet, so the river is way over-allocated,” he continued.
The over-allocation of the Colorado River water has been further compounded by climate change and drought in recent years, resulting in a shortage of about 1.2 million acre-feet per year, according to the Kyl Center for Water Policy.
“I think it transcends the problem of over-allocation. They are taking out more water than they are putting in, and only over the last ten years or so have they really acknowledged the existence of this structural deficit,” said Tony Davis, an environmental reporter for the Arizona Daily Star.
The 500+ Plan works by offering its participants money in exchange for leaving their allocated water shares in the Lake Mead reservoir.
“We are forgoing delivery of water that we were entitled to take, we were scheduled to take, we had taken in the past. In the case of Phoenix, we decided to contribute 15,977 acre-feet,” Campbell said. “It might seem like a random number, but it actually represents the volume of water that we were due to receive in 2022 based upon the Drought Contingency mitigation plan,” Campbell continued.
The Drought Contingency Mitigation plan was a set of agreements established in 2019 among the seven Colorado River Basin states. These agreements were meant to offset the impacts of the drought on the Lake Mead reservoir and established the precedents used to cement the 500+ Plan.
The City of Phoenix will receive compensation in the amount of $4,163,765.97 in exchange for its 2022 contribution of 15,977 acre-feet of water to the reservoir. The funding, which will come from the Central Arizona Water Conservation district, will be put towards new water conservation and sustainability efforts.
The City of Phoenix has not yet made concrete plans for the allocation of the funding, but is looking at using it for multiple water conservation efforts across the city.
These efforts will include hiring new staff positions in water conservation, expanding ways to reduce home owners association water usage, expanding toilet retrofit programs and making irrigation systems more sustainable, according to Campbell.
Campbell says the city will also increase its efforts to become engaged with citizens regarding water conservation efforts.
“People really do want to do the right thing, they want to do what is best for everyone and we just need to give them more opportunities to do their best on that,” Campbell said.
The implementation of the 500+ Plan will last through the year 2026, which is when current operating guidelines for the Colorado River will expire and the seven basin states will re-negotiate new terms.
“That’s a re-negotiation that we’ve been anticipating for quite some time,” Campbell said. “There’s just not enough to go around for everybody to get what they think they need. So that is going to be a difficult conversation,” she continued.
Official re-negotiations of the Colorado River Operating guidelines have not yet started amongst all seven basin states, but the lower three basin states and 500+ Plan participants are already preparing for when that time comes.
