Saving Some For The Fishes And Rethinking The Future of Our Water Supply

When I first moved to Colorado, I spent my summers hiking streams and collecting aquatic insects. I visited many high mountain streams that were dammed and diverted to provide water to cities along Colorado’s Front Range. In their natural state, these rivers flowed raucously over boulders, watering streamside plants, flooding wetlands, and creating fabulous habitat for fish and other aquatic critters. Downstream of the dams, the streambeds were sometimes completely dry – other times with only a thin trickle of water.

At this very moment, there are thousands of dams in Colorado that are withdrawing water from Rocky Mountain streams. Once diverted, the water moves through networks of ditches and aqueducts, sometimes tunneling through mountains and across the Continental Divide, to distant farms and cities. But the water taken from these streams is not enough to meet growing demands. In the future, water demand will far exceed supply. In response to this need and recent drought conditions, water developers in Colorado are proposing to exercise some of the last remaining water rights – for spring snowmelt peak flows in the wettest of years.

Diverting snowmelt flows from our rivers is a controversial and complex issue, both politically and environmentally. On one hand, cities want this water to support economic growth, including new commercial and residential development. However, these flows are critical to aquatic ecosystems, rearranging sediments for fish habitat, assisting Cottonwood regeneration, recharging groundwater and flooding backwater wetland habitats. Countless plants and animals rely on these flows for their long-term survival. Many of these rivers are already anemic from water withdrawals and we are approaching a tipping point beyond which the resiliency of these ecosystems will be tested.

What are our options?

As scientists, we must apply our knowledge to better balance human needs and the needs of our rivers’ inhabitants. Various water supply and smart growth solutions are available that could maintain natural ecosystems while meeting the needs of communities. Water conservation will play an increasingly critical role in allowing for a sustainable water future. Moving forward, researching and implementing state of the art water conservation technologies is key.

Your perspective on water differs whether you live near the Great Lakes, in the arid west, or by the coast. We must all begin thinking about the sustainability of our water supplies and how we can meet our needs while also protecting our rivers, lakes and wetlands.

What do you think?

About the author: Julia McCarthy is an Environmental Scientist with the EPA Regional Office in Denver, CO. She works in the Clean Water Act regulatory program on rivers and wetlands. Her background is in aquatic ecology and freshwater conservation. She recently worked on a video titled ‘Wetlands and Wonder: Reconnecting Children With Nearby Nature.’ Check it out at

Editor's Note: The views expressed here are intended to explain EPA policy. They do not change anyone's rights or obligations. You may share this post. However, please do not change the title or the content, or remove EPA’s identity as the author. If you do make substantive changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is Some links on this page may redirect users from the EPA website to specific content on a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.