Nature Always Wins: The Colorado River Basin’s Dam Problem - Waterkeeper

Nature Always Wins: The Colorado River Basin’s Dam Problem

By: Thomas Hynes

Lake Mead near Hoover Dam by DeltaOFF/Shutterstock.

The fight for clean and free-flowing waterways often runs up against dams. These structures once seemed like great solutions for how to provide power and water to an arid landscape. However, they have since proved themselves to be detrimental to ecosystems, wildlife, and hydrology, and the communities who depend on them. That is why Waterkeeper Alliance opposes new dams and diversions, mitigates dams where there is no other option, and removes dams wherever possible. 

Dams are a matter of contention all over the world. But, increasingly, the issue takes on heightened importance in the American West as extreme droughts and water poverty driven by climate change become more commonplace. According to Colorado Riverkeeper, John Weisheit, the Colorado River Basin is the most iconic example of contemporary water management. 

“The primary purpose of dams is flood control. The secondary purpose is regulating water for agriculture, especially in the arid west where you can grow food 12 months a year,” says Weisheit. “This is exactly what the Assyrians, Egyptians and Babylonians did. So it’s not new technology at all. These dams let us fill the empty West. But they ignore the process of nature. And we all know nature always wins in the end.”  

The Colorado River Basin runs north to south, from the great altitudes of the Rocky Mountains all the way down to the sea. The water, which is often diverted and channelized, sustains the economies of Southern California, Nevada, Central Arizona, and Northwestern Mexico. Los Angeles, Phoenix, Las Vegas, among other places would not exist as we know them without it.

Before the Boulder Canyon Project of 1928, barely one million people lived in the watershed. Today, over 40 million people depend on the Colorado River for drinking water and agriculture. 

One local flashpoint for this struggle is the Windy Gap Reservoir in Northern Colorado. Andy Miller is the President of the Upper Colorado River Watershed Group (UCRWG), a Colorado Riverkeeper Affiliate. His group opposed the Windy Gap firming project, a dam and reservoir expansion project that will take an extra 10 percent of water from Grand County and send it to Denver and other front range communities in Colorado.

“We have already over-diverted this river. It has already been overallocated. Water needs to be in the river to get downstream to LA, and to just keep the river alive,” says Miller. “We stand firmly opposed to further diversions.”

UCRWG is focused on trying to protect Grand Lake, the largest natural lake in Colorado, which is directly connected to the Shadow Mountain Reservoir, in which toxic algae, aquatic weeds and other threats persist all because of water diversions. Miller suggests an impact fee to Denver area water consumers as a way to fix infrastructure and mitigate against the increased demand on the water usage.  A recent settlement allowed the firming project to proceed, but will also provide $15 million in funds to improve water quality and riparian habitats for communities in Grand County, Colorado affected by the project. 

It’s a small consolation for the damage caused by dams and diversions. Ultimately these projects remove water from the basin and alter its natural course. That’s part of the whole dam problem. 

The reservoirs also cause problems. They raise water temperatures and reduce oxygen levels, which can be deadly to migrating fish. Of course, the physical dams themselves are also bad for migrating fish as they often block species from reaching their spawning grounds. Dams also keep silt and other nutrients trapped in place that would otherwise flow downstream to help produce phytoplankton and seagrasses. 

Dams also exacerbate freshwater evaporation. This problem is extremely acute in the arid American West. As an example, the evaporation from the two largest reservoirs in the Colorado River Basin is equivalent to five times the amount of water used by the City of Denver. The realities of climate change mean more frequent and severe droughts. In this way, many dams actually worsen the problem of water scarcity, heightening the competition for the water that they were intended to allocate. 

This problem is only made worse by the megadrought of the last 20 years. With water levels in the Colorado River reservoirs of Lake Mead and Lake Powell down to historic lows, it’s likely the problem gets worse before it gets better.   

Dams also both work against carbon sequestration, and are responsible for large releases of greenhouse gases driving climate change. Flooding large tracts of forest in river valleys and building long transmission lines destroys these crucial carbon capturing landscapes. Furthermore, it’s estimated that dams and the reservoirs they create release one gigaton, or one billion tons, of carbon dioxide equivalents annually. Furthermore, dams actually create their own methane, a greenhouse gas that is more than 80 times more powerful than carbon dioxide in accelerating climate change, by way of ongoing releases fueled by microbes decomposing flooded vegetation. 

Dams can also perpetuate environmental injustice. Far too often Native American communities, and Indigenous communities around the world, bear this burden. Whether it’s diverted waterways and negatively impacted fisheries, or culturally significant lands flooded to make a reservoir, dams do not affect all communities equally. 

And that’s when dams are in good structural condition, which very few of them are. The statistics on dam infrastructure are grim. There are nearly 2,000 state-regulated dams in the U.S. in need of repair. As of 2020, 70 percent of the dams in the U.S. are more than 50 years old.

“There are 40 million people who depend on this infrastructure, but the infrastructure is not working. We have a timetable for the day of reckoning. But we’re not doing anything about that,” says John Weisheit. ”Things don’t last forever. You can’t change physical laws.”

Given the many threats that dams, reservoirs, and diversions pose to our rivers, fish and wildlife, communities, and planet, Waterkeeper Alliance is committed to continuing to support Waterkeepers across this country and around the world in pushing back against existing and proposed dams that threaten their waterways through the Alliance’s Free Flowing Rivers Initiative.

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