The Colorado River is one of the most significant rivers in the western United States. The basin includes seven states- Colorado, Wyoming, Utah, New Mexico, Nevada, Arizona and California as well as parts of Mexico. The river’s history is closely tied to the development of the American West.

Today, this 1,450-mile-long river continues to serve as a vital water source, sustaining the needs of millions of people and playing a crucial role in supporting agriculture, industry, and urban life throughout the Southwest. The challenges of finding sustainable solutions for water management, compounded by the impacts of climate change, are pushing the river to the edge of crisis.

This project explores the complex challenges facing the Colorado River basin through a visual journey using photography, informative graphics and maps. The exploration includes voices from often-overlooked Native tribes with deep connections to the basin’s water and traverses all seven basin states, extending southward to the Gulf of California in Mexico.

Water management in the seven Colorado River Basin states and Mexico are intertwined, yet each faces unique circumstances and challenges.

Scroll down or jump to a specific state: Colorado | Wyoming | New Mexico | Arizona | Utah | Nevada | California | Mexico

Read more: Highlights from The Denver Post’s ongoing Colorado River coverage, linked below.

Colorado

The Colorado River’s headwaters originate at La Poudre Pass, situated southwest of Long Draw Reservoir at an elevation exceeding 10,000 feet, spanning Larimer and Grand Counties. As the high mountain snowpack gradually melts, flowing water coalesces into the Colorado River. Containing the headwaters of the river, Colorado is a critical member of the Upper Basin states, intrinsically connected to the river. The relationship was formalized by the 1922 Colorado River Compact, which apportioned the river’s waters among seven western states.

The Upper Colorado River Basin encompasses states located above Lee’s Ferry, while the lower basin is comprised of those situated below. It’s essential to note that allocation of the river’s flow is based on a “first in time” principle, meaning that although the Colorado River originates in Colorado, the state does not automatically receive primary water rights. This, coupled with ongoing drought and water scarcity challenges, has tested the state’s ability to manage this critical resource. The Colorado River plays a significant role in the state’s economy, drawing people to the region for various recreational activities along or near the river and sustaining agriculture on the Western Slope.

It was the final trip of the year for the rangers pictured above, who go to the same locations several times throughout the snowy season to collect measurements for the snowpack records. That day the two park rangers snowshoed to different locations and took a total of 16 measurements from each marked spot. Snowpack totals in the area were above the normal average, but because of the historic megadrought in the Colorado River Basin for decades, many who have been studying the drought believe it will take years of above-average snowfall to make a significant improvement to the crisis in the basin.

Angling brings nearly 2 billion dollars to Colorado’s economy, and the Colorado River alone sees tens of millions of visitors who recreate in and near the river each year. As the Colorado River battles drought, overconsumption, and climate change, communities tied to recreation along the river worry about the future.

Wyoming

The Green River originates in the Wind River Range in western Wyoming, where snowmelt from the high Rocky Mountains combine to form this river. It eventually flows into the Colorado River, serving as its largest tributary. Wyoming’s contribution of water through tributaries like the Green River is essential to the Colorado River Basin.

New Mexico

The Colorado River serves as a source of water for agricultural irrigation and meeting the municipal and industrial needs of several New Mexico communities. The state’s allocation of Colorado River water is defined by the Colorado River Compact, the interstate agreement among basin states. However, the allocation process has posed challenges for some Native tribes in New Mexico, as they may not always have the necessary infrastructure and resources to access the water they were allocated, highlighting issues related to equitable water distribution in the state.

The compact negotiators also failed — or refused — to include the approximately 30 Native American tribes dependent on the river. Despite the claims of federal officials, many tribes still feel excluded from negotiations concerning the river’s future.

Bishop’s Lodge, at the base of the Sangre de Cristo Mountains, in Santa Fe, New Mexico is where the Colorado River Compact was negotiated in 1922. During that time leaders of the seven states in the Colorado River Basin came together to allocate how the Colorado River water would be divided. There was no seat at the table for Native American leaders during the negotiations. Tribes in the river basin had water rights but were left out of the talks at Bishop’s Lodge.

The Bataan Water Loading Station in Gallup, New Mexico is open 24 hours and coin-operated. A quarter will buy 50 gallons of water. For many Navajos in the area, the water station is the only place to access clean drinking water. People fill tanks or drums in the beds of their pickups or on trailers to bring home for drinking water.

Arizona

Water from the Colorado River enables agriculture in one of the nation’s most parched regions. The 1922 Colorado River Compact, which allocated water rights to Arizona and the rest of the basin, laid the foundation for the construction of the Central Arizona Project (CAP). Comprising an extensive network of canals, aqueducts, and pumping stations, CAP transports vital Colorado River water across Arizona’s arid terrain to provide for rapidly expanding urban centers and agriculture.

Supported by this water in the Yuma area, approximately 170 million servings of lettuce are produced daily from November through April. Roughly 90 percent of all leafy vegetables grown in the U.S. during this period originate in and around Yuma. As Arizona participates in the Lower Basin Drought Contingency Plan, the state is grappling with water scarcity, ecological stewardship, and responsible resource management within its arid landscape.

As depicted in the illustration above, one acre-foot of water would fill one average American home, six train tankers, six 50-gallon barrels, one delivery truck, the box container behind an 18-wheeler semi-truck, and the volume of a large cement mixing truck. When each of these items is filled with water, the combined volume equates to approximately 1 acre-foot of water.

Living in Rio Verde Foothills, an unincorporated development in Maricopa County, Leigh Harris started facing water restrictions imposed after the Department of the Interior issued the first-ever formal water-shortage declaration for the Colorado River in 2021. As a result, the City of Scottsdale ceased providing water to Rio Verde Foothills. In response to the water scarcity, Harris invested $14,000 in a rainwater harvesting system installed at her home. This system, coupled with additional measures such as strategically placed buckets and small pools, allows her to capture rainwater efficiently. Harris and her husband mostly use the collected rainwater to flush toilets in their home. Each gallon they capture serves as one flush.

Utah

Striking a balance between human development and natural preservation is a central tension in the state of Utah’s relationship with the Colorado River. Tectonic forces sculpted deep canyons and river channels in this region. Before modern Utah’s establishment by white settlers, the land was home to various Native American tribes, such as the Ute, Paiute, and Navajo, for thousands of years. European explorers arrived in the 18th century, paving the way for Mormon pioneers in 1847, who founded settlements and harnessed the river’s waters for agriculture.

The construction of the Glen Canyon Dam in 1966, which created Lake Powell, had profound impacts on ecosystems and ignited environmental debates. U.S. Bureau of Reclamation officials worry that continuing drought conditions at Lake Powell may someday soon drop water levels below the point where the Glen Canyon Dam can generate electricity, although a wet winter in 2023 likely staved off that worse-case scenario for at least three more years.

The twin challenges of climate change and growing demand face water management leaders in Utah as they try to balance human needs with long-term ecological preservation.

The U.S. Geological Survey shows that Washington County, Utah, where St. George is located, residents uses an average of 306 gallons per day. In Phoenix, the average per resident is 111 gallons per day.

Nevada

The Hoover Dam retains the waters of the Colorado River, creating Lake Mead Reservoir, which stretches into Nevada, providing fresh water for the Las Vegas metropolitan area and its neighboring communities. The hydroelectric power generated at the Hoover Dam illuminates not only Las Vegas but also much of the surrounding region. In a city often associated with excess, Las Vegas has emerged as an unlikely leader in conservation, primarily because its existence is intrinsically linked to the Colorado River.

To safeguard this vital resource, Las Vegas has taken pioneering steps in water recycling and conservation. A significant portion of the water used by the Southern Nevada Water Authority is treated before being returned to Lake Mead. This treated wastewater flows through the Las Vegas Wash before re-entering the reservoir, earning Nevada valuable return-flow credits.

California

The construction of the Hoover Dam in the 1930s provided flood control, electricity, and water storage to help meet the needs of California’s rapidly growing population. Simultaneously, the completion of the Colorado River Aqueduct facilitated the transport of Colorado River water to fuel the urban growth and agricultural development in Southern California. In the Imperial Valley, an arid desert region, Colorado River water travels through a network of irrigation systems that deliver it to fields, sustaining crops like lettuce, cotton, and various fruits. The fresh produce cultivated in the Imperial Valley plays a significant role in the United States’ food supply chain.

Within the Imperial Valley lies an accidental inland sea, known as the Salton Sea, whose water levels are predominantly regulated by inflows from agricultural runoff in the valley, primarily sourced from Colorado River water. However, as water levels in the Salton Sea decline, it presents a complex set of environmental concerns.

The Imperial Valley has rights to more than 1 trillion gallons of Colorado River water each year. The valley’s water rights to the Colorado River total as much as Arizona and Nevada put together. Their rights are twice as much as the rest of the state of California.

As water levels drop, so does tourism to Southern California’s Salton Sea, which formed in 1905 when the Colorado River broke through a canal and flowed into the Salton Basin for two years before repairs were made. Contamination from farm runoff and climate change are adding to evaporating water levels and warming water temperatures. As water levels drop, the area has seen more diseases and massive die-offs of several species of fish along with reducing tourism. The popular travel website TripAdvisor has ranked the Salton Sea as one of the worst places to swim in the nation.

Mexico

The 1944 U.S.-Mexico Water Treaty established the allocation of Colorado River water between the two nations. Under this treaty, the United States committed to providing an annual flow of water to Mexico. However, the river’s flow no longer consistently reaches the Mexican border. Reduced flows at the border can be attributed to factors such as climate change and the overallocation of the river’s water. Additionally, the construction of dams and water diversion projects upstream in the United States has significantly contributed to the diminished flow. Over time, these factors have led to ecological challenges in the Colorado River Delta, where the river meets the Gulf of California in northwestern Mexico. This once-diverse ecosystem has suffered the loss of a significant portion of its wetlands and habitat for various species.

Efforts to restore the Colorado River Delta’s ecosystem have been ongoing through the work of environmental groups. In recent years, the United States and Mexico have collaborated to address the environmental decline in the delta, marking a historic moment where two nations allocated water for the benefit of the environment. These collaborative efforts involve the release of Colorado River water stored in the United States to mimic natural flooding patterns, ultimately working to restore some of the delta’s original environmental functions.

Restauremos el Colorado works with the U.S. and Mexico governments to secure water from the Colorado River via permit or temporary solutions to restore native wetlands in the Colorado River Delta in Mexico. In May 2022, water was strategically delivered into the delta for the second consecutive year. The releases of water are designed to mimic the river’s natural spring flows. The water for the restoration site travels through irrigation canals and continues on to farms in the Mexicali Valley.

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Thanks to those who supported the efforts behind this project.

All editorial content and decisions made while producing this work were solely determined by members of the editorial department at The Denver Post. For full transparency, here is a breakdown of how this editorial work was supported by outside agencies not affiliated with The Denver Post.

LightHawk, a nonprofit based in Colorado, provided aerial support for photojournalist RJ Sangosti to undertake multiple trips along the Colorado River basin, capturing images from the air.

The Water Desk at the University of Colorado Boulder granted funds that helped cover some travel costs as photojournalist RJ Sangosti traversed over 1400 miles of the river. Part of the grant was also used to hire a local artist to make two different illustrations for the website.

Trout Unlimited funded the design of a Colorado River timeline, which was executed by New Thought Digital Agency. This design company collaborated with The Denver Post’s editorial team to create a timeline showcasing historical dates in the Colorado River’s history. All images and content for the timeline were provided by The Denver Post.

Graphics produced by the Babbitt Center for Land and Water Policy at the Lincoln Institute of Land Policy were selected by The Denver Post’s editorial staff for display on this website.