What does the water from your tap have to do with trees in Arizona forests? The two are more connected than you might think.
In fact, the water that we use every day in the Valley comes from 8.3 million acres of forest in northern and eastern Arizona. Protecting these forests is the key to making our water supplies last.
Water’s journey from the forest floor to your front door
Your water begins its journey in the forests and through a system of watersheds. A watershed is an area of land where rainfall and snowmelt all drain to a stream or reservoir. You might know our reservoirs as lakes.
Water flow from the watersheds fills SRP reservoirs, or lakes, on the Salt and Verde rivers. It then flows into canals and, eventually, is delivered to homes, schools and businesses in the Valley.
SRP manages seven reservoirs that are fed from the Salt and Verde river watersheds.
Healthy forests create a lasting water supply
The health of these forests directly affects our water supply. Healthy forests allow more snow and rain to soak into the soil. Ultimately, this helps improve the health of streams and the ecosystem.
A forest also filters the water that flows into SRP reservoirs so it’s cleaner. Unfortunately, our forests are unhealthy. Consequently, the watersheds are at risk.

Our forests and water are at risk
Although, a recent study shows that our water supply can withstand climate change, there are still some risks.
Related read: AZ Central’s story “Study says Phoenix reservoirs are resilient to warming, scientists warn risks remain.“
When large wildfires burned through forests in the early 1900s, the U.S. Forest Service created policies to put out any fire that started, regardless of whether it happened naturally or was man-made.
As a result, the small, natural fires that once thinned and healed forests were put out.
That policy, and the lack of timber harvesting in the 1980s and ’90s, allowed Arizona’s forests to become overgrown. In other words, they’re unhealthy with too many trees and thick brush.
Right now, it’s likely that 80% of Arizona’s forests are too dense, putting them – and our water supply – at risk.
Overgrown forests create a threat
We understand now that forest overgrowth is not a natural or safe condition.
Thick brush and overcrowded trees can lead to intense wildfires that hurt forest ecosystems and are hard to control. Wildfires can contaminate our water supply with ash and debris.
In the last 18 years, Arizona has experienced six megafires (wildfires that burn more than 100,000 acres). Five of these fires have been on the Salt and Verde river watersheds.
To protect the forests and the water supply, we teamed up with the federal government, businesses and others to support the strategic thinning of overgrown areas. In this case, strategic thinning means removing small trees and thick brush.
Restoring Arizona’s forests through strategic thinning
To help restore forests in northern and eastern Arizona, we’ve partnered with the:
- U.S. Forest Service
- U.S. Bureau of Reclamation
- Arizona Commerce Authority
- Arizona Department of Forestry and Fire Management
- Nature Conservancy
- National Forest Foundation
- Local governments and many other organizations
When it comes to restoring a forest, cutting down trees may not seem to make sense. However, selectively removing small trees reduces the risk of fire reaching large trees. It slows the fire from moving over larger areas.
Our goal is to support the strategic thinning of 50,000 acres of overgrown forest per year – 500,000 acres total by 2035.
It’s a big goal, and we could use your help to reach it.

Stay informed
You can learn more about how we plan to prevent large, harsh wildfires, and protect the water that comes to your faucet. As a starting point, see this helpful infographic about where your water comes from.
Read on to understand more about our forests, water supply and the progress we’re making to protect it.
Help us restore Arizona forests.
Through SRP Healthy Forest Initiative™, you can help us keep prevent wildfires and keep our watershed healthy for as little as $3 a month.
The email titled “Discover Tempe’s water efficiency education resources” was a wonderful and educational. I volunteer for the Desert Botanical Garden and multiple guests I have interacted with ask about where water comes from and water sustainability.
We’ll be sure to pass this feedback along, Bonnie, thank you.
While I appreciate the value of this initiative, the major reason Arizona’s forests are overgrown is due to regulations and controls by the Federal Government. For example, you rarely see issues on Indian Reservations because they do not fall under the same regulations as national forests and parks. Therefore, the Tribal folks do proper forest management to ensure healthy forests and reduce the risk of wildfires.
If the mission of your initiatives is to prevent catastrophic wildfires, then what are you doing from a political and legislative perspective to return forest management control from the Federal Government to the States?
Hi Isaac, thank you for reaching out and for the interest in SRP’s Healthy Forest Initiative. SRP has built strong partnerships with the U.S. Forest Service (USFS) and the Arizona Department of Forestry and Fire Management (DFFM) over the last five years to really push the pace and scale of forest restoration in Arizona, especially on federal lands. We have been able to identify a number of key issues that prevent us from reaching the 4FRI goal of 50,000 acres/ year. Lack of forest industry in Arizona is one of those issues, which is why we have worked with USFS to issue a request for a proposal for a 20-year contract to thin 520,000 acres and with the Legislature to create a tax credit that incentivizes industry to process more wood, therefore restoring more acres. Finally, SRP and DFFM have created a new partnership that allows the State to manage forest thinning projects on National Forest lands and for SRP to bring funding to the projects. These are just a few examples of how we are trying to make a difference. Please visit srpnet.com/forest to learn more.