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Calls to Rethink the Colorado River’s Iconic Dams Grow Louder
With two major reservoirs on the Colorado River, Lake Powell and Lake Mead, sitting half empty, will a new hydrologic reality be enough to push for big management changes? One conservation group hopes so.
Written by Tara Lohan
The Colorado River through the Grand Canyon has been ecologically impacted by the Glen Canyon Dam, prompting calls for a change in strategy that is made more urgent by the impacts of climate change.Tara Lohan
LEE’S FERRY, Ariz. – Tens of thousands of rafters paddle down the Colorado River through Grand Canyon National Park each year, though most don’t scan the Redwall Limestone canyon sides for bore holes around River Mile 39.
But one group of rafters that launched in mid-March was keen to see those holes and the ashy looking sediment piled beneath them. The holes mark the exploratory tinkering of those who were itching to build another dam on the Colorado decades ago. It’s a rare sign of engineering in this remote section of the park known as Marble Canyon, where it is nature’s handiwork that usually takes center stage.
This group of about 30 boaters consisted of graduate students from the University of California, Davis, with expertise in geology, hydrology, ecology and other subjects related to watersheds. On a journey of more than just whitewater excitement, they were enrolled in an ecogeomorphology class, taking a multidisciplinary look at the canyon while rafting through it.
Each night they gathered in a circle to discuss how the canyon has evolved and changed. They recited the stratigraphy out loud – memorizing the layers of rock that started at the put-in at Lee’s Ferry with Kaibab Limestone from 270 million years ago. And then as they rowed deeper and the rocks rose higher, each layer revealed was like rowing further back in time and they called out, Toroweap, Coconino Sandstone, Hermit Shale, Supai Group – all the way back to Vishnu Schist, “the basement rocks,” which formed nearly 2 billion years ago.
They discussed the slow passage of geologic time that each layer of rock revealed but they also contemplated much faster changes that have happened to this ecosystem since Grand Canyon was bookended by the Hoover Dam in 1936 and the Glen Canyon Dam in 1964.
Lee’s Ferry, Arizona, is the dividing line between the upper and lower basins of the Colorado River. (Tara Lohan)
The canyon that they traveled is now a vastly altered landscape since Glen Canyon Dam changed water temperature, volume and sediment load in the river, creating an environment foreign to the one in which native species evolved. For some of these species, the changes have already been too much. A few others, listed as endangered, now cling precariously to existence.
Problems stretch to outside the canyon, where the entire 1,400-mile-long Colorado River, provider to nearly 40 million people, is so overallocated it’s known to be in a “structural deficit” of 1.5 million acre-feet (489 billion gallons) a year. More water is claimed than nature can deliver most years, which has drawn down the bank account of water savings stashed in Lake Powell behind Glen Canyon Dam and 300 miles downstream in Lake Mead behind Hoover Dam.
How to solve the problem is a source of political and legal wrangling that’s been going on for years among the seven U.S. states that share the river and Mexico. And it’s exacerbated by climate change: rising temperatures are expected to further shrink runoff in the basin, tightening the belt even more.
So what’s to be done? The Glen Canyon Institute, a small nonprofit that advocates restoration for Glen Canyon, put forth a seemingly radical plan a few years ago to “Fill Mead First,” which is another way of saying “drain Lake Powell.” It’s an idea that was rebuked by some environmental groups and state water agencies, and dismissed by federal agencies that manage the water resources and dams. It might have stayed that way, but last fall Fill Mead First was given serious scientific examination in a study by researchers at Utah State University, led by John (Jack) C. Schmidt, a watershed sciences professor.
The scrutiny has catapulted Fill Mead First back into Western water discourse and in doing so, it has revealed some key problems in the Colorado River Basin that can’t be ignored much longer.
Even Schmidt admitted that while crazy, the idea in theory was not necessarily bad.
Dam Nation
Lee’s Ferry, Arizona, where the U.C. Davis students began their rafting trip, is known as River Mile Zero in Grand Canyon parlance. As they lined up their gear on the beach – diligently counting helmets and life jackets, while rigging food and gear to their boats – the students straddled an important divide.
When the Colorado River Compact was signed in 1922 it divvied up the river among seven states by splitting the share in two between the upper basin (which includes Wyoming, Colorado, Utah and New Mexico) and the lower basin (consisting of Arizona, Nevada and California).
A line stretching across the river at Lee’s Ferry marks this dividing point between the basins and it is also a point of reckoning. This is where a gauge measures the official flow of the river – and lately it has largely failed to live up to expectations.
But things could have been worse.
Holes in the canyon wall in Marble Canyon are the result of exploration work when officials were considering building a dam here – before this stretch of canyon was part of the Grand Canyon National Park. (Tara Lohan)
The holes in the rock the students saw at River Mile 39 were at the location of one of two proposed sites for a Marble Canyon dam. If built, the dam would have flooded everything this group (and countless others before them) had just passed through – inundating the beaches where they slept; flooding beautiful Redwall Cavern, an eye-shaped limestone amphitheater where they ate lunch; and swamping Vasey’s Paradise, where water springs from the rocks hundreds of feet up and cascades down to the river, providing a faucet of fresh drinking water amid a garden of hanging plants. And it would have slowed the entire Colorado River to a “scenic trickle” through Grand Canyon National Park, where more than 4 million people each year travel to the canyon’s edge to peer into the abyss.
After much public outcry in the early 1960s, the dam proposal was eventually abandoned and the idea forever extinguished when President Lyndon Johnson made Marble Canyon a National Monument in 1969 and the Grand Canyon Enlargement Act annexed it to Grand Canyon National Park in 1975.
To these rafters now, the idea of a dam here seems almost unfathomable. It’s the same thought admirers of Glen Canyon had when their beloved stretch of the river was sacrificed to build Lake Powell, fueling the West’s ambition for cheap power, bigger cities and more farms.
From the moment Glen Canyon was flooded onward, there have been passionate arguments to remove the dam. The project drowned numerous archeological sites, petroglyphs and areas of importance to Native American tribes and submerged what many have called one of the most beautiful canyons in the world, rivaling its downstream neighbor, the Grand Canyon.
For some, there has always been a cultural and ecological reason to restore Glen Canyon, but Fill Mead First gives a scientific reason, according to the Glen Canyon Institute’s executive director, Eric Balken.
Hoover Dam and Glen Canyon Dam were built with the prevailing mindset of controlling the abundance of the river and providing storage for the Upper Basin in Lake Powell and the Lower Basin in Lake Mead. Under current policy the two reservoirs have been managed under a plan of equalization – aiming to keep roughly equal amounts of water in each reservoir.
But lately that equal water level is low – so low in fact that in the next few years Lake Mead could slip below an elevation that would deem the lake in shortage, triggering cuts to water supply for its users, with Arizona figuring to take the biggest hit.
“Let’s rethink this,” said Balken. “Assume you don’t have a full Colorado River anymore, do you really need to have two less than half-full reservoirs? Let’s put the water downstream in Lake Mead and give Glen Canyon a chance to come back.”
Calls to Rethink the Colorado River’s Iconic Dams Grow Louder
With two major reservoirs on the Colorado River, Lake Powell and Lake Mead, sitting half empty, will a new hydrologic reality be enough to push for big management changes? One conservation group hopes so.
Written by Tara Lohan
The Colorado River through the Grand Canyon has been ecologically impacted by the Glen Canyon Dam, prompting calls for a change in strategy that is made more urgent by the impacts of climate change.Tara Lohan
LEE’S FERRY, Ariz. – Tens of thousands of rafters paddle down the Colorado River through Grand Canyon National Park each year, though most don’t scan the Redwall Limestone canyon sides for bore holes around River Mile 39.
But one group of rafters that launched in mid-March was keen to see those holes and the ashy looking sediment piled beneath them. The holes mark the exploratory tinkering of those who were itching to build another dam on the Colorado decades ago. It’s a rare sign of engineering in this remote section of the park known as Marble Canyon, where it is nature’s handiwork that usually takes center stage.
This group of about 30 boaters consisted of graduate students from the University of California, Davis, with expertise in geology, hydrology, ecology and other subjects related to watersheds. On a journey of more than just whitewater excitement, they were enrolled in an ecogeomorphology class, taking a multidisciplinary look at the canyon while rafting through it.
Each night they gathered in a circle to discuss how the canyon has evolved and changed. They recited the stratigraphy out loud – memorizing the layers of rock that started at the put-in at Lee’s Ferry with Kaibab Limestone from 270 million years ago. And then as they rowed deeper and the rocks rose higher, each layer revealed was like rowing further back in time and they called out, Toroweap, Coconino Sandstone, Hermit Shale, Supai Group – all the way back to Vishnu Schist, “the basement rocks,” which formed nearly 2 billion years ago.
They discussed the slow passage of geologic time that each layer of rock revealed but they also contemplated much faster changes that have happened to this ecosystem since Grand Canyon was bookended by the Hoover Dam in 1936 and the Glen Canyon Dam in 1964.
Lee’s Ferry, Arizona, is the dividing line between the upper and lower basins of the Colorado River. (Tara Lohan)
The canyon that they traveled is now a vastly altered landscape since Glen Canyon Dam changed water temperature, volume and sediment load in the river, creating an environment foreign to the one in which native species evolved. For some of these species, the changes have already been too much. A few others, listed as endangered, now cling precariously to existence.
Problems stretch to outside the canyon, where the entire 1,400-mile-long Colorado River, provider to nearly 40 million people, is so overallocated it’s known to be in a “structural deficit” of 1.5 million acre-feet (489 billion gallons) a year. More water is claimed than nature can deliver most years, which has drawn down the bank account of water savings stashed in Lake Powell behind Glen Canyon Dam and 300 miles downstream in Lake Mead behind Hoover Dam.
How to solve the problem is a source of political and legal wrangling that’s been going on for years among the seven U.S. states that share the river and Mexico. And it’s exacerbated by climate change: rising temperatures are expected to further shrink runoff in the basin, tightening the belt even more.
So what’s to be done? The Glen Canyon Institute, a small nonprofit that advocates restoration for Glen Canyon, put forth a seemingly radical plan a few years ago to “Fill Mead First,” which is another way of saying “drain Lake Powell.” It’s an idea that was rebuked by some environmental groups and state water agencies, and dismissed by federal agencies that manage the water resources and dams. It might have stayed that way, but last fall Fill Mead First was given serious scientific examination in a study by researchers at Utah State University, led by John (Jack) C. Schmidt, a watershed sciences professor.
The scrutiny has catapulted Fill Mead First back into Western water discourse and in doing so, it has revealed some key problems in the Colorado River Basin that can’t be ignored much longer.
Even Schmidt admitted that while crazy, the idea in theory was not necessarily bad.
Dam Nation
Lee’s Ferry, Arizona, where the U.C. Davis students began their rafting trip, is known as River Mile Zero in Grand Canyon parlance. As they lined up their gear on the beach – diligently counting helmets and life jackets, while rigging food and gear to their boats – the students straddled an important divide.
When the Colorado River Compact was signed in 1922 it divvied up the river among seven states by splitting the share in two between the upper basin (which includes Wyoming, Colorado, Utah and New Mexico) and the lower basin (consisting of Arizona, Nevada and California).
A line stretching across the river at Lee’s Ferry marks this dividing point between the basins and it is also a point of reckoning. This is where a gauge measures the official flow of the river – and lately it has largely failed to live up to expectations.
But things could have been worse.
Holes in the canyon wall in Marble Canyon are the result of exploration work when officials were considering building a dam here – before this stretch of canyon was part of the Grand Canyon National Park. (Tara Lohan)
The holes in the rock the students saw at River Mile 39 were at the location of one of two proposed sites for a Marble Canyon dam. If built, the dam would have flooded everything this group (and countless others before them) had just passed through – inundating the beaches where they slept; flooding beautiful Redwall Cavern, an eye-shaped limestone amphitheater where they ate lunch; and swamping Vasey’s Paradise, where water springs from the rocks hundreds of feet up and cascades down to the river, providing a faucet of fresh drinking water amid a garden of hanging plants. And it would have slowed the entire Colorado River to a “scenic trickle” through Grand Canyon National Park, where more than 4 million people each year travel to the canyon’s edge to peer into the abyss.
After much public outcry in the early 1960s, the dam proposal was eventually abandoned and the idea forever extinguished when President Lyndon Johnson made Marble Canyon a National Monument in 1969 and the Grand Canyon Enlargement Act annexed it to Grand Canyon National Park in 1975.
To these rafters now, the idea of a dam here seems almost unfathomable. It’s the same thought admirers of Glen Canyon had when their beloved stretch of the river was sacrificed to build Lake Powell, fueling the West’s ambition for cheap power, bigger cities and more farms.
From the moment Glen Canyon was flooded onward, there have been passionate arguments to remove the dam. The project drowned numerous archeological sites, petroglyphs and areas of importance to Native American tribes and submerged what many have called one of the most beautiful canyons in the world, rivaling its downstream neighbor, the Grand Canyon.
For some, there has always been a cultural and ecological reason to restore Glen Canyon, but Fill Mead First gives a scientific reason, according to the Glen Canyon Institute’s executive director, Eric Balken.
Hoover Dam and Glen Canyon Dam were built with the prevailing mindset of controlling the abundance of the river and providing storage for the Upper Basin in Lake Powell and the Lower Basin in Lake Mead. Under current policy the two reservoirs have been managed under a plan of equalization – aiming to keep roughly equal amounts of water in each reservoir.
But lately that equal water level is low – so low in fact that in the next few years Lake Mead could slip below an elevation that would deem the lake in shortage, triggering cuts to water supply for its users, with Arizona figuring to take the biggest hit.
“Let’s rethink this,” said Balken. “Assume you don’t have a full Colorado River anymore, do you really need to have two less than half-full reservoirs? Let’s put the water downstream in Lake Mead and give Glen Canyon a chance to come back.”
