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Western Rivers

By the Numbers

  • 9: Number of Western rivers defended including the Colorado, Gila, Green, Gunnison, Cache la Poudre, San Pedro, Verde, White & Yampa
  • 30: stream miles protected (along Big and Little Dominguez Creeks) inside the 66,000 acre Dominguez Canyon Wilderness
  • 6,200: Rate, in cubic feet per second, of average year water flows protected for Black Canyon of the Gunnison National Park

From the mighty Colorado to the smallest ephemeral streams, these waterways have supported Arizona's people and places for thousands of years.

Learn more about Arizona's Rivers below:

The Colorado River (.pdf)

The Salt River (.pdf)

The Little Colorado River (.pdf)

The Santa Cruz River (.pdf)

The Bill Williams River (.pdf)

The Gila River (pdf)

The Verde River (pdf)

San Pedro River (pdf)

San Francisco River (pdf)

Fossil Creek (pdf)

Aravaipa Creek (pdf)

Agua Fria (pdf)

Arizona Rivers In Peril

Salt River

Arizona's rivers are part of the state's rich cultural and natural history. They support communities, agricultural and mining uses, and are "ribbons of life" for plants and animals. For example, it's estimated that almost half the bird species in the U.S. use the San Pedro River in southeast Arizona at some point in their lives. Arizonans visit their rivers for fishing, swimming, and relaxation. Wildlife-based recreation alone brings more than a billion dollars to the state's economy every year.

However, many of Arizona's rivers and river habitat have been destroyed or altered by human activity and climate change. An estimated 35 percent of Arizona's rivers have disappeared. The ones that remain are critical to both wildlife and to Arizona's citizens.

Instream Flow Rights: A Legal Means to Protect Our Rivers

Under Arizona's surface water law, farmers, ranchers and others can apply to the Arizona Department of Water Resources (ADWR) for a water right to remove water from rivers and streams to: irrigate fields, water cattle, meet domestic needs(i.e take a shower, water your garden), and meet other "beneficial uses." A surface water right applies to water in rivers and streams as opposed to water in underground aquifers.

For a long time there was no legal way to keep surface water in rivers and streams because the courts only protected water rights that took water out of rivers and put it to "beneficial use." But in 1979 that changed with the addition of the instream flow water right program, which lets landowners apply for a right to keep water in the stream for recreation, wildlife and fish. This relatively new program finally gave river flows legal protection.

Water Drop

During times of drought or water shortages, water is given to those who have the oldest or most senior water right first - this concept is known as priority. Since the instream flow program is relatively new most river flows are protected by a junior right. Senior water rightholders must be satisfied before more junior water right holders. This can be problematic because there is no requirement that some water must be left in the stream. Still, instream flow water rights provide an opportunity to maintain and protect flows, and generally the law prevents harm to all rights (regardless of their seniority).

Arizona water law allows surface water rights to be transferred from one water user to another. Surface water rights can be transferred for irrigation, municipal use, stock watering, power and mining purposes and for instream uses without losing priority. However, for instream uses the right must be transferred to the state or a political subdivision of the state, such as a state agency or irrigation district to maintain the original priority date. A transfer from a diversionary use like irrigating a farm field to an instream use like protecting a river's flow is still untested but two applications have been made to "sever and transfer" rights on the San Pedro River and Aravaipa Creek in southeast Arizona. If these transfers are approved by ADWR it will represent a major milestone in river protection because of the older priority dates and the removal of a historic water diversion.

Applicants for an instream flow water right must show the streamflow volume requirements before ADWR will issue an interim permit and eventually a Certificate of Water Right (CWR) with a priority date of the initial application. As of May, 2013 there were 38 CWRs, one permit and 88 applications.

Changes to state law in 2012 (SB 1236) now require instream flow water right applicants to submit at least five years of continuous stream flow measurement data at the time of application - a higher standard than previous application requirements. This change also led to an ADWR decision to complete the processing of pending, incomplete applications, not all of which could be completed by applicants within the timeframe provided. As a result, 55 applications were withdrawn or dismissed in nine watersheds, representing almost 340 miles of stream reach.

Status of Instream Flow Water Right Applications

Status of Instream Flow Water Right Applications
Watershed Permits/Certificates Active Applications Withdrawn/Dismissed Applications Withdrawn/Dismissed Application Stream Miles
Agua Fria


2 2


Bill Williams


4 0


Little Colorado River 1 8 2 5.6
Lower Gila 1 0 0 0
Salt River 5 12 13 100.6
San Pedro River 14 13 8 33
Santa Cruz 1 13 8 64.8
Upper Gila River 2 14 8 45.2
Verde River 10 15 10 45.8
Virgin River 0 7 0 0
Whitewater Draw 1 0 1 10.9
Willcox Playa 0 0 3 0
Total 39 88 55 337.6

*Last updated: July 2013

Click to download a .pdf map of the applications

Keeping Arizona's instream flow water right program intact is a critical tool to keep water in rivers. You can help protect Arizona's rivers by participating in restoration, monitoring or advocacy activities and by telling your state legislator how important rivers and their protection are to you.

Colorado River Protection

Dominguez Canyon Wilderness

On March 30, 2009 Congress passed legislation designating the Dominguez Canyon Wilderness Area. The new 66,000-acre wilderness lies in the heart of the Dominguez-Escalante National Conservation Area, west of the Gunnison River and south of Grand Junction, Colorado. The wilderness designation provides a unique and important opportunity for the State of Colorado to use its instream flow program to protect federal wilderness values. As a process unfolds to determine how much water is needed to protect this new wilderness area, it's important that the water rights established be adequate, not only to keep the streams flowing, but to insure the health of the aquatic and riparian ecosystems that rely on them. Read more on issues facing Domingues Canyon here.

Protecting Water in Dominguez Canyon

Dominguez CreekCongress passed the Omnibus Public Land Management Act of 2009. This legislation will protect and conserve public lands across the nation. The newly designated Dominguez-Escalante National Conservation Area and Dominguez Canyon Wilderness Area will benefit from the Act.

Western Resource Advocates helped craft a unique water rights solution for the legislation that established the Dominguez-Escalante National Conservation Area and Dominguez Canyon Wilderness Area. Working closely with state agencies and Western Slope water interests in 2007 and 2008 we helped reach a compromise on federal legislation that calls upon the state’s instream flow program to secure flows in the new federal wilderness. The legislation, which passed both chambers of Congress in March 2009 provides that if the state fails to secure appropriate flows, the Secretary of the Interior can file for a federal water right to protect a wide array of wilderness values.

Water Agreement to Protect the Black Canyon of the Gunnison National Park

Decades of negotiations, legal wrangling and involvement by WRA have finally produced more water for the Gunnison River. A Water Court judge finalized the water rights decree for the Black Canyon of the Gunnison National Park returning healthier streamflows back to a river beginning this year that has been long controlled by three upstream dams. Learn more

Carved over the millennia by the Gunnison River, the Black Canyon is recognized as a national treasure for its spectacular gorges, wildlife habitat, and unique scientific value. It is home to a world-class trout fishery and mesmerizes visitors with its wild roar of cascading water, especially when it reaches its peak flow each spring. The Black Canyon became a national monument in 1933 and was elevated to National Park status in 1999.
Western Resource Advocates has actively sought protection of the Black Canyon and Gunnison River for years, representing five conservation organizations in the Black Canyon water rights case—the largest, and one of the most important, water cases in Colorado’s history.  On June 6, 2008, a proposed settlement signaled an end to more than 30 years of contentious water rights battles.

Restoring the Ecological Balance: A New Flow Regime

Interested parties in the Black Canyon water rights case presented a settlement of the federal reserved water right, which includes annual peak flows and shoulder flows—tied to natural inflow—plus a year-round base flow of 300 cubic feet per second. Collectively, these elements are critical to the health of the Park and the Gunnison River.
This flow regime will protect the water-dependant resources of the Black Canyon and help restore the ecological balance in the river system disrupted by three federal dams immediately upstream of the Park. The flows will create a healthier environment for a
world class trout fishery, cleanse sediment deposits that have caused whirling disease in trout, clear woody debris, maintain the river channel, and greatly improve the aesthetics of a flowing river for hundreds of thousands of visitors from around the world each year.

Negotiating Protection for the Black Canyon

Interested parties at the negotiation table included irrigators in the Gunnison basin, hydroelectric power producers, flat water recreationists, boaters, federal agencies (including the National Park Service, Bureau of Reclamation, and Fish & Wildlife Service), the State of Colorado, towns concerned about flood control, anglers, and conservation groups.

“Considering the number of organizations and interests involved, the water settlement epitomizes the tremendous complexities of environmental negotiation,” said Andy Spielman, a partner at Hogan & Hartson, representing, on a pro bono basis, all seven conservation groups involved in the case. “What’s truly encouraging is how everyone’s needs were addressed with integrity to create a workable compromise for all.”


The protection proposed for the Black Canyon is the culmination of many years of effort by Western Resource Advocates representing five other conservation organizations and working in partnership with Trout Unlimited and the National Parks Conservation Association. 

Bart Miller, WRA’s Water Program director and attorney in the Black Canyon case, played a lead role in negotiations and collaborated closely with in-basin interests and State and federal officials.  He has organized research for the environmental groups’ hydrologist and sits on the committee that set the agenda for mediation.  Most invaluably, Bart has been the primary author of correspondence from the conservation groups to the federal agencies, and has acted as the chief point of contact between the conservation groups and other parties.  The law firm of Hogan and Hartson provided extensive pro bono assistance to us, our clients, and our partners in this litigation. 

Continuing Protection for the Black Canyon National Park 

The settlement proposed in June 2008 continues the success WRA has achieved in protecting the Black Canyon.  In September of 2006, in an historic decision, U.S. District Judge Clarence Brimmer issued a decision to protect the magnificent natural resources of the Black Canyon of the Gunnison National Park. This decision blocked the federal government from giving away the Black Canyon’s long-standing reserved water right to those who would like to use the water for development on Colorado’s Front Range. The decision also established an important precedent about governmental responsibility for protecting water resources of National Parks across the country.
With the court’s decision, the Black Canyon was saved from a 2003 agreement between the federal government and Colorado officials that would have opened the possibility of diverting Gunnison River water a hundred miles away from the park for use fueling more Front Range sprawl.

Over the past five years, the Black Canyon of the Gunnison National Park has faced numerous threats to its ecological health, recreational use, and aesthetic quality.  The series of victories to protect the Black Canyon demonstrates that with effective collaboration, unrelenting determination, and ardent supporters, WRA’s work can go far in protecting the West’s land, air, and water now and for generations to come.

Photos by MGA73bot2 & the National Park Service.