Reclamation Confirms a Tier 1 Colorado River Shortage for 2024

Published Aug 15, 2023

The U.S. Bureau of Reclamation has released the August 24-Month Study , which determines how the Colorado River system will be managed the following year based on the levels of Lake Mead. The Study's findings can impact the water supplies used by millions of people who rely on the Colorado River, including here in Central Arizona. As anticipated, the Study confirms that we will be in a Tier 1 Shortage in 2024. So what does this all mean, and how does it impact Arizona and the AMWUA cities? We thought answering these frequently asked questions would be helpful.

What is happening with the Colorado River?

  • The Colorado River system is reaping the benefits of this winter’s above-average snowfall, at least for the short term. Recent history shows that back-to-back wet winters are a rarity, so we are not expecting one favorable winter to change the negative trajectory of the Colorado River.
  • While this year’s runoff may bring a minor reprieve, the Colorado River Basin still suffers from the consequences of over two decades of severe drought, a hotter and drier climate, and the long-term imbalance between supply and demand. All of this contributes to a river that is producing historically less water.

Why will we be in a Tier 1 Colorado River Shortage again?

  • The wet winter has temporarily prevented Lake Powell and Lake Mead from reaching critical operational levels and has lifted the elevation of Lake Mead to above 1050 feet. Under the current operating guidelines, the elevation determines that we will return to a Tier 1 Shortage for 2024.
  • A Tier 1 Shortage means Arizona will have access to slightly more Colorado River water in 2024 than under the current Tier 2a Shortage. However, it is still less water than what Arizona has historically received.  

What does this mean for the AMWUA Cities?

  • While their water portfolios and reliability on the Colorado River may vary, the AMWUA cities will be able to continue to meet the water demands of their communities.
  • The AMWUA cities will remain in the current stages of their drought and shortage preparedness plans that ensure each city is best prepared based on its own specific water resources, infrastructure, and customer needs. This level of planning ensures cities can effectively manage their water supplies despite any short-term or long-term challenges that may arise. A Colorado River Shortage is one of many scenarios the cities have planned for.
  • The AMWUA cities will take advantage of this winter's reprieve to continue preparing for a future with less Colorado River water. Their planning initiatives include investing in infrastructure, ramping up conservation programs, and exploring water resiliency projects – all of which will increase our collective sustainability in the desert.
  •  A number of AMWUA cities, along with other Colorado River users, have agreed to leave water in Lake Mead to add to the favorable hydrology and keep the elevation well above critical operational levels.

What’s next for the Colorado River?

  • The U.S. Bureau of Reclamation has initiated the process with the Basin States to develop a detailed plan on how to operate the river after the current guidelines expire in 2026. This includes developing new guidelines to protect the entire Colorado River system, which continues to produce less water.
  • Reclamation has committed to pursuing a collaborative, consensus-based approach to reduce demand, increase water use efficiency, and protect the system’s reservoirs from falling to critically low elevations that would threaten water deliveries and power production.
  • This year’s favorable hydrology will allow Reclamation and the Basin States to focus on developing the post-2026 long-term operating guidelines to ensure a stable Colorado River system for the 40 million people who rely upon it.

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For over 50 years, Arizona Municipal Water Users Association has worked to protect our member cities' ability to provide assured, safe, and sustainable water supplies to their communities. For more water information, visit .