Arizona River Map

About Arizona River Map

Explore map of Arizona with rivers and lakes, geographical / physical features clearly marked on map.

List of Major Rivers in Arizona

Major Rivers of Arizona

The rivers in Arizona are some of the most important hydrological and ecological features in the American Southwest. For thousands of years, these rivers have shaped the state's landscape, kept its ecosystems alive, and helped human civilizations grow. Arizona's rivers tell a story of water scarcity, adaptation, and the constant struggle between human development and protecting the environment. The Colorado River runs through the Grand Canyon, while smaller tributaries feed desert valleys. To understand these river systems, you need to look at where they come from, how they work, how they are used now, and the many problems they face in the 21st century.

The state's rivers flow through two main drainage basins: the Colorado River Basin, which includes the northern and western parts of Arizona, and the Sonoran Desert Basin, which includes the southern and southeastern parts. This geographic difference has a big impact on how much water is available and how it is used across the state. The Colorado River Basin is Arizona's main source of water, providing about 80% of the state's water. The Sonoran Desert Basin, on the other hand, has a smaller but just as important hydrological system that works well in dry areas.

The Colorado River: Arizona's Primary Water Source

The Colorado River is the most important body of water in Arizona and the whole southwestern United States. The Colorado River is about 1,450 miles long, from its source in the San Juan Mountains of Colorado to its end in the Gulf of California. It is the lifeblood of the American Southwest. The river goes 301 miles through Arizona, starting in the northeast corner of the state, going through the famous Grand Canyon, and ending up in Lake Mead and Lake Havasu before leaving for California and Mexico.

The Colorado River's average annual discharge changes a lot depending on where and when it is measured. The river's flow at its mouth near Yuma, Arizona, is usually between 12,600 and 14,500 cubic feet per second during normal water years. However, this number can change a lot depending on how much rain falls in the upper basin. The river starts at about 14,100 feet above sea level and ends at sea level at the Gulf of California. This is a huge drop that has made it possible for a lot of hydroelectric power to be generated along its course.

One of the most complicated water allocation agreements in North America is how the Colorado River is managed. The Colorado River Compact of 1922 set up the basic rules for how water would be shared between seven states and Mexico. Arizona gets 2.8 million acre-feet of water every year from the Lower Colorado River Basin as part of this agreement. This makes it one of the main users of the river's flow. This allocation has helped Phoenix and other Arizona cities grow, as well as farms all over the state.

Building many dams along the Colorado River in Arizona has changed the river's shape and how it works with water. Lake Mead was made by the Hoover Dam, which was finished in 1936. The dam also made a huge amount of water storage possible. The Parker Dam and other water management structures built later created more reservoirs that control the flow of water and make it available all year round. These engineering changes have been very important for controlling the river's flows, which can change a lot from season to season and year to year. In the past, the river's flows have gone from very high to very low.

In Arizona, the Colorado River is used for three main things: providing water to cities, irrigating crops, and making electricity. The Central Arizona Project, which was finished in 1985, is one of the most ambitious water transfer systems ever built. It moves water 336 miles from Lake Havasu to the Phoenix metropolitan area and Tucson through a network of aqueducts and canals. This engineering feat changed the way Arizona could grow by making sure that cities in the state's interior had a steady supply of water.

The Salt River: Phoenix's Primary Water Supply

The Salt River is much smaller than the Colorado River, but it is very important to the Phoenix metropolitan area and central Arizona. This 200-mile river starts in the Apache-Sitgreaves National Forest in the mountains of east-central Arizona. It flows southwest through rough terrain before joining the Colorado River near Tempe, Arizona. The entire 200 miles of the river are in Arizona, so it is only an Arizona resource, unlike the interstate Colorado River.

The average flow of the Salt River is between 400 and 500 cubic feet per second, but this number hides a lot of seasonal and yearly changes. Winter rain and spring snowmelt from the White Mountains usually cause higher flows, but in the summer, the river often has less flow. The river's elevation profile drops from about 11,000 feet in its source mountains to 1,000 feet where it meets the Colorado River. This means that there is a lot of potential for hydroelectric generation along its path.

One of Arizona's oldest and most important water management companies is the Salt River Project, which was founded in 1903. The Salt River project runs four big reservoirs: Salt Lake, Granite Reservoir, Mormon Lake, and Horse Mesa Lake. These reservoirs hold water during wet years and let it out during dry years, giving the Phoenix area a steady supply of about 900,000 acre-feet of water each year. The Salt River Project also makes a lot of hydroelectric power. Its system makes enough electricity to power about two million people in central Arizona.

Engineers have made a lot of changes to the Salt River, but it still provides important ecosystem services besides just water supply. The Salt River corridor has riparian habitat that is home to many different types of wildlife. The river also has many recreational opportunities, such as fishing, boating, and camping, which bring thousands of visitors each year. The lower Salt River, in particular, has become a popular place for tubing and other activities. This has helped the economies of nearby towns while also giving people access to water resources for fun.

The Gila River: The Colorado's Largest Tributary

The Gila River is the longest tributary of the Colorado River. It starts in the Mogollon Mountains of southwestern New Mexico and flows 649 miles to where it meets the Colorado River near Yuma, Arizona. About 188 miles of this total length flow through Arizona. The Gila River drainage basin covers about 59,100 square miles, making it a large hydrological system even though it is hard to keep the flow steady in dry areas.

The Gila River's average flow rate changes a lot along its course. In the upper reaches, it ranges from 100 to 300 cubic feet per second, but it drops a lot in the lower reaches. The river's elevation profile goes from about 5,000 feet at its mountain sources to only 200 feet at its mouth near Yuma. This is a big change that made navigation easier in the past and powered water wheels for grinding grain. In the last few decades, a lot of the lower Gila River has become intermittent, especially in dry years when upstream diversions for irrigation take up almost all of the flow before it reaches the Colorado River.

The Gila River used to have large riparian forests and wetland ecosystems that were home to many species that were well-suited to life in the southwestern United States. The introduction of invasive species like salt cedar and the slowing of water flow due to agricultural diversions have changed these ecosystems in very important ways. The goal of modern efforts to restore the lower Gila River is to get rid of invasive plants, bring back native cottonwood and willow stands, and make wetland areas that are home to endangered species like southwestern willow flycatchers and razorback suckers.

The Gila River is very important to the culture and history of the area. For hundreds of years, Native American groups, especially the Tohono O'odham and other tribes, have depended on the river. Spanish colonial settlements along the Gila River, like the town of Tubac, which was founded in 1752, grew because the river always had water. The Gila River Trail, which was used by American explorers and settlers in the 1800s, follows a lot of the river's path through Arizona.

The Little Colorado River: Northeastern Arizona's Water Source

Even though its name might make you think otherwise, the Little Colorado River is an important source of water for northeastern Arizona. The White Mountains in east-central Arizona are where this 315-mile river starts. It flows mostly north before joining the main Colorado River in the Grand Canyon. The Little Colorado is about 200 miles long, and about 200 of those miles flow through Arizona. It meets the Colorado River at river mile 61 in the Grand Canyon.

The Little Colorado River is easy to spot where it meets the main Colorado River because of its unique turquoise color, which comes from minerals like calcium carbonate found in limestone areas. This change in color was important for river runners in the past and still serves as a visual guide for modern river trips. The river's average discharge is between 50 and 150 cubic feet per second. This is a moderate flow volume that changes depending on how much rain and snowmelt falls in the headwater mountains.

The Little Colorado River's flow is very different from that of the regulated Colorado River below Glen Canyon Dam. The main Colorado River has flows that stay pretty steady because of dam management, but the Little Colorado's flows change naturally with the seasons. The highest flows usually happen in the spring when the snow melts in the White Mountains. In the summer and early fall, the flow is usually lower. Researchers have looked into the river's hydrological features a lot because they can tell us about how the Colorado River used to flow before dams were built.

The Hopi Nation's reservation is located in the Little Colorado River's drainage basin, which makes the river very important to them. The river supplies water for farming and community use, and it has deep spiritual and cultural significance for the Hopi people. The Sipapu, which is the name for the place where the Little Colorado and Colorado Rivers meet, is a holy place in Hopi religious cosmology. Tribal authorities must be consulted and tribal water rights and cultural needs must be taken into account when making modern decisions about how to manage the Little Colorado River.

The Verde River: Central Arizona's Perennial Stream

The Verde River is one of Arizona's few rivers that flows all year round, and it is 190 miles long and completely within Arizona's borders. The Verde River starts in the Black Mesa area of central Arizona and flows mostly south until it meets the Salt River near Phoenix. The river starts at about 6,500 feet above sea level and ends at about 1,100 feet above sea level when it meets the Salt River. This is a big drop through a variety of geological and ecological zones.

The Verde River flows between 150 and 250 cubic feet per second on average, making it a big source of water for central Arizona. The river flows more steadily all year round than desert rivers that only flow at certain times of the year. This is because it is higher up and flows through areas that get enough rain. The upper reaches of the Verde River, which flow through limestone canyons, are great for recreation and have beautiful scenery. They also support a wide range of ecological communities that have adapted to living near water.

In the last few decades, a lot of work has been done to protect and restore the Verde River. The Nature Conservancy and other groups have worked to protect important riparian habitat along the river's course, especially in places where invasive species have harmed native plants. The Verde River corridor has become a priority for both recreation and conservation, which has led to the creation of parks and protected areas that serve both purposes. The lower parts of the river near Phoenix have been badly damaged by urban development and water diversions, but restoration projects are trying to bring back native plant communities and make the habitat better.

The Verde River is an important source of water for the Salt River Project and helps keep the water supply in the Phoenix metropolitan area safe. Each year, about 750,000 acre-feet of water from the Verde River flows into the Salt River system, adding to the water supply from the Salt River's own drainage basin. In wet years, extra water from the Verde River helps fill up Salt River reservoirs and makes it possible to send more Colorado River water to other parts of Arizona. As long-term drought conditions in the upper basin may cause Colorado River allocations to go down, the river's importance to regional water security will probably grow.

The Gila River Basin: Southern Arizona's Water Network

The Gila River system goes far beyond the main river. It includes many smaller rivers that together drain a lot of southern Arizona. The Santa Cruz River is one of the Gila's most important tributaries. It starts in the Santa Rita Mountains in southeastern Arizona and flows 280 miles northwest to join the Gila River. Historically, the Santa Cruz River has supplied water to the Tucson metropolitan area and the farms around it. However, in the last few decades, much of its lower course has become dry because of groundwater pumping and surface water diversions.

The San Pedro River is another important tributary of the Gila system. It starts in Mexico and flows northwest through Cochise County in southeastern Arizona before joining the Gila River near Mammoth. The San Pedro Riparian National Conservation Area, which is one of the most important wildlife habitat corridors in the Southwest, runs along this 144-mile river, which is all in Arizona. The San Pedro is very important for protecting biodiversity because it flows fairly steadily in its upper reaches and passes through a wide range of ecological zones. But the river is under more and more stress because of climate change and the extraction of groundwater, which have both caused flows to drop in recent years.

Contemporary Challenges and Future Outlook

In the 21st century, Arizona's rivers are facing problems that have never happened before. Climate change has made the Colorado River's flows much lower. The river's annual discharge is now about 15 to 20 percent lower than historical averages used in water allocation agreements. Lake Mead and Lake Powell, the two biggest reservoirs in the United States, are at their lowest levels ever. This has raised concerns about how long current water allocation patterns can last. As part of its efforts to manage the shrinking resource base, the U.S. Bureau of Reclamation has put in place water conservation agreements and cuts in allocations.

Arizona's rivers must be managed in a way that balances the needs of many different groups. These include the need for water for rapidly growing cities, the need for irrigation for farming, the need to protect the environment and restore ecosystems, the need for recreational use, the need for tribal water rights and cultural needs, and the need to meet interstate commitments under various water agreements. These conflicting needs will need advanced management techniques, money spent on water-saving technologies, possible changes in how land is used, and tough choices about policies for future growth and development in the dry Southwest.

Arizona's rivers will continue to be important for the state's growth and the quality of its environment. In one of the most water-stressed areas of the United States, it is important to know what these waterways are like, what their current state is, and what problems they face in order to make smart decisions about water policy and resource management.