Dave D. White is a deputy director in the Julie Ann Wrigley Global Futures Laboratory at Arizona State University and lead author for the Southwest Chapter of the forthcoming Fifth National Climate Assessment (NCA5).

The Colorado River is essential to the social, economic and environmental vitality of the American West — supplying water to more than 40 million people, irrigating millions of acres of farmland and providing thousands of megawatts of low-carbon energy. Thus, even though the move was widely anticipated, the federal government’s declaration this week of the first-ever official water shortage on the Colorado River marks a pivotal moment in the region’s decades-long megadrought.

The announcement by the Bureau of Reclamation came after the agency projected that Lake Mead, the nation’s largest reservoir, would fall to 1,066 feet above sea level, or just 36 percent capacity by the end of 2021 — the lowest level since the reservoir was initially filled in the 1930s. The news came just days after an alarming report by the Intergovernmental Panel on Climate Change; you could call the water-shortage declaration a “code red” for the Colorado River.

The initial round of cuts in the water supply, known as a Tier 1 shortage,will affect Arizona, Nevada and Mexico, with Arizona farmers taking the biggest cuts. Deeper and more widespread cuts are increasingly likely in coming years, affecting California as well as the upper basin states of Colorado, Wyoming, New Mexico and Utah.

Beginning next January, the shortage will reduce deliveries of Colorado River water to Arizona by about 20 percent. Although water managers and farmers have been planning for this development, following the passage of state drought contingency plans in 2019, the cuts will cause some farmers to leave fields fallow, while others will rely on unsustainable groundwater pumping. The shortage also raises public alarms about the region’s long-term water security.

Addressing the complex water issues facing the Southwest will require bold solutions that match the scale of the challenges — nothing less than a water “moonshot.” Debates over water rights and water usage are often emotional because people’s lives and livelihoods depend on this basic component of our existence. Solving the problem will demand unprecedented cooperation among competing parties, rapid technological innovation and thoughtful public engagement.

While some will fall back on divisive politics of the moment — focusing on water conflicts between states or pitting farmers against cities as rivals — it would be more productive to lean into evidence of cooperation between the federal government, the seven Colorado River basin states, Mexico and Native American tribes in recent years.

The leadership by the Gila River Indian Community in Arizona, for instance, is a promising sign of inclusivity for a group that historically has been frozen out of decision-making during water negotiations. As the states work with Interior Secretary Deb Haaland to develop a new long-term management plan for the Colorado River, due by 2026, more such work will be needed to build trust in pursuit of a common goal.

Innovation in water science and technology will be essential to addressing the water shortage. To that end, researchers at Arizona State University are working with NASA and the Central Arizona Project to use Earth-observing satellites to improve water modeling, prediction and management.

Agricultural water conservation will need to be dramatically stepped up, through technology such as drip irrigation for farms. Urban and industrial water treatment, recycling and reuse improvements will be needed to support high-wage, high-water-usage industries such as microchip manufacturing.

Through a partnership with Mexico on coastal water desalination, the region can free up Colorado River water for the United States while providing Mexico with a secure new supply. Innovative, decentralized water treatment facilities could directly benefit rural communities, including those on tribal lands.

There is evidence of a broad consensus on the importance of sustainable water management. The 2020 Gallup Arizona Project survey conducted for the Center for the Future of Arizona found that residents identified a secure water supply as a top priority for the state, with broad bipartisan support.

My own research found wide public support for water conservation, reuse and more public involvement in decision-making among residents in Phoenix, Denver and Las Vegas — all dependent on the Colorado River. While the public recognizes the challenges, and many feel a personal responsibility to contribute to solutions, most simply don’t know how to participate. Education and facilitating better engagement will be essential.

There is no single solution to these challenges; an “all of the above” approach will be vital. Arizona and its partners across the Southwest can lead the nation in developing viable ways of addressing water shortages that will only worsen as the planet warms.