After more than two decades of drought, water utilities serving the largest urban regions in the arid Southwest are embracing a drought-proof source of drinking water long considered a supply of last resort: purified sewage.

Water supplies have tightened to the point that Phoenix and the water supplier for 19 million Southern California residents are racing to adopt an expensive technology called “direct potable reuse” or “advanced purification” to reduce their reliance on imported water from the dwindling Colorado River.

When the Colorado River Compact was signed 100 years ago, the negotiators for seven Western states bet that the river they were dividing would have ample water to meet everyone’s needs – even those not seated around the table.

A century later, it’s clear the water they bet on is not there. More than two decades of drought, lake evaporation and overuse of water have nearly drained the river’s two anchor reservoirs, Lake Powell on the Arizona-Utah border and Lake Mead near Las Vegas. Climate change is rendering the basin drier, shrinking spring runoff that’s vital for river flows, farms, tribes and cities across the basin – and essential for refilling reservoirs.

The states that endorsed the Colorado River Compact in 1922 – and the tribes and nation of Mexico that were excluded from the table – are now straining to find, and perhaps more importantly accept, solutions on a river that may offer just half of the water that the Compact assumed would be available. And not only are solutions not coming easily, the relationships essential for compromise are getting more frayed.

Momentum is building for a unique interstate deal that aims to transform wastewater from Southern California homes and business into relief for the stressed Colorado River. The collaborative effort to add resiliency to a river suffering from overuse, drought and climate change is being shaped across state lines by some of the West’s largest water agencies.  

For more than 20 years, Tanya Trujillo has been immersed in the many challenges of the Colorado River, the drought-stressed lifeline for 40 million people from Denver to Los Angeles and the source of irrigation water for more than 5 million acres of winter lettuce, supermarket melons and other crops.

Trujillo has experience working in both the Upper and Lower Basins of the Colorado River, basins that split the river’s water evenly but are sometimes at odds with each other. She was a lawyer for the state of New Mexico, one of four states in the Upper Colorado River Basin, when key operating guidelines for sharing shortages on the river were negotiated in 2007. She later worked as executive director for the Colorado River Board of California, exposing her to the different perspectives and challenges facing California and the other states in the river’s Lower Basin.

Managing water resources in the Colorado River Basin is not for the timid or those unaccustomed to big challenges. Careers are devoted to responding to all the demands put upon the river: water supply, hydropower, recreation and environmental protection.

All of this while the Basin endures a seemingly endless drought and forecasts of increasing dryness in the future.

Colorado is home to the headwaters of the Colorado River and the water policy decisions made in the Centennial State reverberate throughout the river’s sprawling basin that stretches south to Mexico. The stakes are huge in a basin that serves 40 million people, and responding to the water needs of the economy, productive agriculture, a robust recreational industry and environmental protection takes expertise, leadership and a steady hand.

The Colorado River is arguably one of the hardest working rivers on the planet, supplying water to 40 million people and a large agricultural economy in the West. But it’s under duress from two decades of drought and decisions made about its management will have exceptional ramifications for the future, especially as impacts from climate change are felt.

High in the headwaters of the Colorado River, around the hamlet of Kremmling, Colorado, generations of families have made ranching and farming a way of life, their hay fields and cattle sustained by the river’s flow. But as more water was pulled from the river and sent over the Continental Divide to meet the needs of Denver and other cities on the Front Range, less was left behind to meet the needs of ranchers and fish.

“What used to be a very large river that inundated the land has really become a trickle,” said Mely Whiting, Colorado counsel for Trout Unlimited. “We estimate that 70 percent of the flow on an annual average goes across the Continental Divide and never comes back.”

For the bulk of her career, Jayne Harkins has devoted her energy to issues associated with the management of the Colorado River, both with the U.S. Bureau of Reclamation and with the Colorado River Commission of Nevada.

Now her career is taking a different direction. Harkins, 58, was appointed by President Trump last August to take the helm of the United States section of the U.S.-Mexico agency that oversees myriad water matters between the two countries as they seek to sustainably manage the supply and water quality of the Colorado River, including its once-thriving Delta in Mexico, and other rivers the two countries share. She is the first woman to be named the U.S. Commissioner of the International Boundary and Water Commission for either the United States or Mexico in the commission’s 129-year history.

As the Colorado River Basin becomes drier and shortage conditions loom, one great variable remains: How much of the river’s water belongs to Native American tribes?

Native Americans already use water from the Colorado River and its tributaries for a variety of purposes, including leasing it to non-Indian users. But some tribes aren’t using their full federal Indian reserved water right and others have water rights claims that have yet to be resolved. Combined, tribes have rights to more water than some states in the Colorado River Basin.

Nowhere is the domino effect in Western water policy played out more than on the Colorado River, and specifically when it involves the Lower Basin states of California, Nevada and Arizona. We are seeing that play out now as the three states strive to forge a Drought Contingency Plan. Yet that plan can’t be finalized until Arizona finds a unifying voice between its major water players, an effort you can read more about in the latest in-depth article of Western Water.

Even then, there are some issues to resolve just within California.

Most people see the Grand Canyon from the rim, thousands of feet above where the Colorado River winds through it for almost 300 miles.

But to travel it afloat a raft is to experience the wondrous majesty of the canyon and the river itself while gaining perspective about geology, natural beauty and the passage of time.

Beginning at Lees Ferry, some 30,000 people each year launch downriver on commercial or private trips. Before leaving, they are dutifully briefed by a National Park Service ranger who explains to them about the unique environment that awaits them, how to keep it protected and, most importantly, how to protect themselves.

They also are told about the pair of ravens that will inevitably follow them through the canyon, seizing every opportunity to scrounge food.