Too Much Dam Hubris...Lake Powell and the Future of the Colorado River

The Colorado River is a wonder of nature. Starting from glacial cirques high in the Rocky Mountains, the river flows through one canyon after another, culminating in the grandest canyon of them all, the Grand. For 1,450 miles, the river is a corridor of life, and webs extend out in numerous directions, providing life in some unlikely locations, like Las Vegas, Los Angeles, and Phoenix. Irrigation from the Colorado grows vast amounts of crops in desert valleys throughout the southwest.

The river has exposed an incredible geological story, and has played an important part of my life in my development as a teacher and geologist. It was a catalyst in my own life as I explored a corner of it on my first geology trip, and more recently as I floated a raft through the Grand Canyon for the first time last summer. So it is that I feel a little bit of ownership of the river (along with about 35 million other people).

I first became aware of the abuse of the river system as a teen when I came into possession of a dogeared copy of On The Loose, by Terry and Renny Russell, which was in part a eulogy for the canyons that disappeared beneath the stagnant waters of Lake Powell, backed up behind Glen Canyon Dam. I had grown up learning of the giant mega-dams as the greatest achievements of mankind (did anyone else get taught "Roll on Columbia, Roll on" while in grade school?), and I was duly impressed when I saw Lake Mead and the newly completed Glen Canyon Dam when I was a child on vacation. I started to learn that there were more issues at stake in regards to these giant mega-dams. Yes, flood control. Yes, cheap renewable clean energy. But at the cost of the some of some of the most amazing scenic canyons in existence, and at the cost of an entire river ecosystem. I know that those arguments don't hold much sway in a capitalistic society that measures the value of something in dollars earned. The thing is, the main purpose of these dams is imperiled by changing climate. One has to wonder if they were a gigantic mistake in the end. Do the benefits truly outweigh the costs?

One of the most incredible stories of Glen Canyon Dam is that it came perilously close to failing during an extraordinary runoff event in 1983. I've covered this story in the past, but it bears repeating (especially if you not familiar with it). Instead of using floodgates and spillways at the top of the dam for emergency drainage, designers utilized the diversion tunnels used to channel the Colorado River around the dam site during construction. They proved woefully inadequate to the task in 1983 as cavitation caused the walls of the diversion tunnels to rip out. In places the powerful flow of water cut 32 feet (10 meters) into the soft Navajo Sandstone and threatened the structural integrity of the dam itself. The diversion tunnels had to be shut down, and the lake threatened to flow over the crest of the dam in an uncontrolled fashion. This could have led to catastrophe, as such uncontrolled flow could have eroded and weakened the sandstone abutments of the dam. Failure of Glen Canyon dam would have led to the domino-like destruction of other large dams downstream, and the decimation of the water-supply infrastructure of some thirty million people. The disaster was averted by the construction of an 8 foot high dam of wood flashboards that held back the water long enough for the flood to subside. The structural integrity and survival of the dam came down to about one inch...the distance between the water level and the top of the flashboard dam in 1983.

There is an inherent conflict between water storage for irrigation and energy production, and flood control. One requires a reservoir to be mostly full; the other requires sufficient storage space for unusual events like those of 1983. The conflict requires a balancing act on the part of the water masters. Getting the balance wrong can lead to catastrophe downstream.

The scary part is that the 1983 event was not actually all that unusual. It happened because of a lack of storage space in the reservoir at the time (it had filled for the first time ever in 1980). The flooding involved flows of over 111,500 cubic feet (3,160 m³) per second. This was statistically a 25-year flood, one that has a 4% chance of occurring in any given year. Unfortunately, the statistics that guided the design of the dam have been called into question because of analysis of flood deposits upstream near Moab, Utah. New research suggests that there have been more than 40 large floods in the last 2000 years. Of these, 34 exceeded floods expected to strike once a century (20 would be expected under the old models), and 26 were larger than the so-called 500-year flood (only four of these would be expected under the prevailing models). Two of the floods were monsters that exceeded the design standards of the dam, even with the enhancements added after 1983.

At the other extreme of dismal news is the ongoing drought, 13 years and counting. The lake is hovering around 50% of capacity, and is expected to rise only modestly this year despite good snow conditions in the Rocky Mountains. We may be at the point where we are depending on the occasional El Nino event just to maintain a usable amount of water in the reservoir. There are some who think the reservoir will never have enough runoff to ever fill again.

All in all, this calls into question the wisdom of trying to control such a variable and unpredictable river. And we haven't even dealt with the question of sediment infill. The giant mega-dams are filling with silt at an astounding rate that is shortening their useful life. Ultimately our gigantic engineering projects will give way and the river will once again be in control. It's happened before with gigantic lava flow dams and blockages like Hoover Dam and Glen Canyon Dam will also give way.

Such were my thoughts as I stood on the hilltop overlooking this "mighty work of man". We hit the road again, headed towards Grand Staircase-Escalante National Monument, the largest single park on the Colorado Plateau.

Thanks to Wayne Ranney over at Earthly Musings for the heads up on the recent Colorado River research!

A Rock Outcrop, a River, and Sand flow into a Point Bar...

And the bartender said "is this some kind of joke?"

But it's not a joke of course, it's a simply stunning example of what happens when water flows over stone for a long time. What you are seeing here Horseshoe Bend on the Colorado River a few miles downstream of Glen Canyon Dam and Lake Powell outside of Page, Arizona.

A point bar is a real thing with rivers. When a river loops back and forth as a series of meanders, point bars form as sand ridges develop on the inside of the loop where the water flows more slowly. In the most technical sense, the sand bars in the picture above can be consider an example of the feature, although they are more familiar where rivers are flowing in flat floodplain.

It's obvious that Horseshoe Bend is no longer a flat floodplain! It may have been one at one time, but uplift of the Colorado Plateau (or the subsidence of the lands around the edge of the plateau) caused the river to speed up and start to erode downwards, forming an entrenched meander.

The approach to Horseshoe Bend is a sandy trail about three-quarters of a mile up from a parking lot about five miles south of Page on Highway 89. Although views are wide-ranging along the trail, there is barely a hint of the incredible view that awaits when one arrives at the brink of the cliff and looks down nearly a thousand feet to the river. Stunning is the only word for it.

My old camera couldn't show the entirety of Horseshoe Bend, so I was thrilled I was able to get these wider angle pictures with my new one. It's almost like looking at a petrified rainbow, although it should be said, this view is not entirely natural.

When Glen Canyon Dam was completed in the 1960s, the river was changed forever in terms of a human lifetime. Instead of the normal red silt-laden water, the river flows clear and cold (almost refrigerator cold, about 46 degrees; I can attest to this as I almost drowned in the river last year). As a result, green algae grows in the unnaturally blue river. It's beautiful to look at, but is kind of sad to consider what it should have been. Many of the native species of river life are in decline and cold-loving invasive species are thriving.

A trip-planning note just in case you are headed out to the region this summer: Highway 89 between Bitter Springs and Page was closed down by a serious slope failure along the Echo Cliffs Monocline. It may be years, if ever, before the highway will be repaired. In the meantime, the Arizona Department of Transportation has constructed a newly paved highway replacing Navajo Route 20. Although the detour is supposed to be temporary, I suspect it is permanent despite any feelings of the Navajo Nation about a new busy highway in a formerly isolated part of the reservation. There are far fewer engineering problems where the new highway crosses the monocline.

Where are the Ten Most Incredible Places You've Ever Stood? My Number 1: Roads End at the Edge of the World

There's an empty quarter within the bounds of the lower 48 states. It's a vast area, a swath of land across southern Utah and northern Arizona where towns are few, and the vistas are wide. It's bounded by Blanding on the east, Mexican Hat and Kayenta to the south, and Lake Powell off to the west. Outside of these few villages there are some reservation lands and ranches. There is a national monument (Natural Bridges), and a national park off to the north (Canyonlands), but mostly it's uninhabited Bureau of Land Management land. In other words, lands held in trust for all the people of the United States.

I've been going through a list of the ten most incredible places I've ever stood, and so far in this series we have explored the Alaka'i Swamp of Kaua'i, Hawai'i, the lava flows at Pu'u O'o on the Big Island, Frame Arch in Arches National Park, the moment of global death in Gubbio, Italy, and the Burgess Shale of British Columbia. There was Siccar Point in Scotland, Kartchner Caverns of Arizona, Dante's View in Death Valley, and Hance Rapids on the Colorado River in the Grand Canyon. I also cheated a little and insinuated that Glacier Point in Yosemite was one of the ten (which it is, even if all of these add up to eleven; didn't you all see "This is Spinal Tap"?). Some of these I chose because of their geological significance, and some because of their incredible scenery. A few were chosen from sheer emotion and personal spiritual reasons, and that is also the motivation for my number one choice. Not many people know of the place. It's not a national park or monument, and the geology, while interesting, is not exceptional. It's in the center of the empty quarter of Utah on the edge of Cedar Mesa. It's called Muley Point.

Standing on the edge of the world at Muley Point, one looks down several thousand feet into the mysterious gorge of the San Juan River, one of the major tributaries of the Colorado River. The canyon is an intricate twisting maze of curving gorges called entrenched meanders. The river once flowed as a meandering stream channel over a flat plain relatively close to sea level. When the land rose, the gradient of the river increased, but the water was trapped in the meandering channel, so the curve was preserved as the river cut ever deeper (below).

The rocks making up the cliffs are part of the Cedar Mesa Sandstone, a Permian-aged unit that preserves some coastal sand dunes, and the occasional bone or track of some pre-dinosaurian reptile like Dimetrodon.

Entrenched meanders of the San Juan River below Muley Point

In the distance beyond the canyon of the San Juan stand the buttes and mesas of Monument Valley, the scene of so many iconic western movies (below). The valley is administered as a tribal park of the Navajo people. The farthest horizon reveals the margin of Black Mesa, the heart of the Navajo Reservation and the home of the Hopi Nation as well. The spiky monument in the far distance just left of center is Agathla's Needle, the core of a deeply eroded volcano. This volcanic neck, or diatreme, is similar in age and composition to the better known Shiprock a few miles away in New Mexico.

The view to the east extends across the Raplee Anticline to the Chuska Mountains of New Mexico, and the Rocky Mountains of southeastern Colorado. The scene below is taken from the top of the Moki Dugway on Utah Highway 261, the precarious road that provides access to Cedar Mesa and Muley Point.

The view east from the top of the Moki Dugway, the spectular road that provides access to Muley Point

North from the Moki Dugway one can see the deeply incised edges of Cedar Mesa. Looking at this barren desert landscape, it is hard to accept that Cedar Mesa was once part of the "fertile crescent" of the American Southwest. An arc of land extending from Mesa Verde to Cedar Mesa was in the "sweet spot" elevation of being not too hot and not too cold and having just enough precipitation to produce high yields of maize, squash and beans. It was a thriving agricultural region for the Ancestral Puebloan people for hundreds of years. Most of the surface of Cedar Mesa was under cultivation, and thousands of archaeological sites dot the region (unfortunately making it a target for illegal pothunters). The Puebloans moved on eight hundred years ago, and the mesa has been more or less deserted since then. The juniper and pinyon trees sprouted and covered the ancient corn fields.

Years ago I learned the craft of leading field studies with the staff and crew of Santa Barbara City College, days I remember fondly. We used to take a one-day raft trip down the San Juan River from Bluff to Mexican Hat, and the night before we would spend the night at Sand Island on the river. We would spend a few moments at Muley Point before descending to the hot, humid, and buggy campsite. One year someone pointed out that we were fully equipped to camp anywhere, so why not stay on the rim of Cedar Mesa where the view was indescribable, and the air was fresh and clean, and gloriously free of biting deerflies and mosquitoes? From that time on we camped on the edge of the world. What had been just another spot with a nice view became for me a yearly pilgrimage.

What makes this place so different? It's magic, I think. It is the top of the world, and the edge of the world. One can stand and see a vast region occupied by a mere handful of people, a land that shows little of the damage (at distance anyway) that people can do to a landscape. It's colorful and ever-changing, especially in the light of dusk or twilight. There aren't many places where one can experience the full drama of the Earth through sunset, night and sunrise, and have a completely unobstructed view of the sky from horizon to horizon to horizon.

Usually when we pull into a campsite on our field trips, the students and crew jump out, unpack, and set up their tents and the cooking area. I learned long ago that Cedar Mesa and Muley Point are different. The people emerging from their vehicles disappear. I wander along the edge of the mesa and I find them, sitting alone or in small groups, just contemplating and staring at the scene before them. I often take on the task of preparing the evening's meal just to give them more time to be out there.

I've spent a total of two weeks on the mesa over the last three decades and every night is different. We've seen warm clear days and nights, we've had windstorms (equipments blows over the edge never to be seen again), thunderstorms, and rain.

Have you ever spent an entire night taking in a special place? Have you ever watched the progression of the cosmos over hours and hours of time? We constantly insulate ourselves from the darkness, but there are certain times and places where we can revel in it. There is nothing quite like watching moonlight reach deeper and deeper into canyons below the rim. What had been featureless darkness below becomes an intricate pattern of complex beauty. I've awakened in the early hours of the morning to watch the moon setting or watching the long drama of sunrise. Some nights there are thunderstorms over the Sleeping Ute or Chuska Mountains. The fire in the sky is an incredible sight.

Sometimes there are eerie things as well. Rational people can still feel the echoes of the lives that were played out on this mesa. I've been keenly aware of the spirits that exist in and around the canyons, whether real, or constructs of the imagination. We sat on the edge of the mesa one night nearly thirty years ago and saw mysterious lights. I still to this day don't know what to make of them (and you can be sure that I've watched for their return ever since!). Yet, I've never felt scared or nervous in this place. Just curious.

The morning inevitably comes, and once the sun rises high in the sky, the mesa becomes less mysterious. We are ready for a day of seeking the Ancestral Pueblo ruins that are hidden in literally every side canyon on the mesa. Spending a night exposed to the environment that they called home enlightens our explorations.

It was hard to pick the top ten of my most incredible places, and I couldn't begin to rank them, but I do know that I might not see the Burgess Shale or the Gubbio clay layer or Siccar Point again in my life. They were memorable, and I will always cherish that fact that I got to see them. But I didn't experience them, not in the way that I've experienced the Grand Canyon, Yosemite, and Cedar Mesa.

That's the thing I guess. Any place in this wide world can become the most incredible place you will ever stand. It won't be that tourist destination that is famous worldwide, because those are the places that you visit once or twice and never get to know. The special places are those which you experience in the fullest sense in all kinds of situations and conditions. That's what Cedar Mesa is to me.

So, what has me worried? I was digging through the tons of old topographic maps in the old department as we prepared for the move to the new Science Community Center. And I found a topo map of the Glen Canyon National Recreational Area, and noticed that a small corner of Cedar Mesa extends over the boundary of the GCNRA. Muley Point is "protected"! But in small print were the following words: "Slated for future development". Chilling words, but thus far unrealized. A paved road, interpretive signs, restrooms, and parking lots would ruin this incredible place. I hesitated about even making its presence known, but in the end I did, because unknown places are the easiest to destroy (just ask Glen Canyon). Such places will need friends in the future.

In the meantime, revel in the discovery of your own most incredible places, and if you are ever near the town of Mexican Hat, seek out Muley Point. It's not too hard to find, the road is okay for most cars even if a bit bumpy at times. And don't just look and drive away after a few minutes. Lay out a sleeping bag, find the appropriate rock (you'll know the right one), and let this place fill you. You won't regret it.

PS: After I posted this, Ron Schott let me know he had a 360 degree gigapan of the view from Muley Point. Check it out at  http://www.gigapan.com/gigapans/52566 !