Press Release Apr 26, 2011

New Colorado River Study Finds Water Uses Impair the Health of National Parks in the Southwest

NPCA report finds alterations to natural water flows damage national parks

WASHINGTON, D.C. - The nonprofit National Parks Conservation Association (NPCA) today released a new report about water management in the Colorado River Basin and its impact on five national parks that lie along the Colorado River and its tributaries. The report finds that alterations to the natural state of the river, such as the long-term presence of major dams and non-native species, and changes in water flow is altering the natural landscapes and cultural heritage found in national parks in the southwest.

The report examines the relationship between regulation of the Colorado River and Grand Canyon National Park, Glen Canyon National Recreation Area, Canyonlands National Park, Dinosaur National Monument, and Black Canyon of the Gunnison National Park. Key findings concerning the current state of resources associated with the rivers in these parks:

• Dams along the Colorado River have fundamentally changed ecological and environmental processes in these parks by destroying natural habitats in some areas, creating highly unnatural flow regimes, trapping sediments that are critical for building and maintaining aquatic and riparian habitats and altering natural water temperatures that foster native fish communities.

• Reintroducing more natural water flows in the rivers can protect park resources. In addition, any further alterations to the natural flow of the river must not compromise these treasured parks, which receive a total of more than 8.5 million visitors annually. Recent proposals to divert water from the River for municipal and agricultural uses would likely be detrimental to the parks.

• Climate change scenarios predict the western United States will become drier and warmer, which increases the likelihood that the volume of water in the river annually will decrease and releases from reservoirs like Lake Powell will be reduced.

• Non-native fish have been introduced; causing issues for native species through predatory and competitive behavior and the non-native tamarisk has altered the river channel, further restricting river flows.

“Without proper management, the landscapes that make the national parks located on its banks and its tributaries so incredible will be severely diminished, irreparably damaging in about a century’s time iconic ecosystems that was slowly formed over a period of six million years,” said Nimkin. “This report looks at how the river and changes to it impact the parks, and it forms a dialogue for coming up with solutions to the biggest challenges facing the river.”

The report outlines steps that can be taken to reverse or mitigate some of the challenges facing the river, including:

• Changes to dam operations to reduce impacts on endangered species and other resources, which would have relatively minor effects on hydropower revenues.

• Climate change research to clearly understand and ensure that its effects on the River are taken into account for all future policies and decisions impacting water flow in the river.

• Additional research on costs and benefits of restoring more natural flows so that the value of the parks along the River can be properly assessed.

To view a full copy of the report, please click here.


About National Parks Conservation Association
Since 1919, the nonpartisan National Parks Conservation Association (NPCA) has been the leading voice in safeguarding our national parks. NPCA and its more than one million members and supporters work together to protect and preserve our nation’s natural, historical, and cultural heritage for future generations. For more information, visit

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