Glen Canyon Dam nears completion in the early 1960s - Click for larger image (https://jamesmcgillis.com)

The Historical Saga of Glen Canyon Dam and Wahweap Bay

Any visit to Glen Canyon Dam and Lake Powell is a memorable event. The surreal nature of a giant concrete plug embedded in soft Arizona sandstone, while holding back the second largest reservoir in America is a site to behold. Visitors can walk across the bridge that spans the 800-foot chasm just downstream of the dam. As large trucks rumble across the bridge at well over the twenty-five mile per hour speed limit, the whole structure resonates at a low pitch. Many of the smaller vehicles flagrantly violate the speed limit. There are no automated “Slow Down” signs and little actual enforcement of the speed limit.

On a recent visit, I trained my camera lens between the chain links that make up the safety fencing along the bridge. Looking down at the dam, which registers 710-foot tall, I noticed a strange anomaly. Where the canyon wall abuts the lower-right portion of the dam, steel rods and plates had been installed to keep the sandstone from crumbling. To make the scene even more startling, water had seeped from behind the dam and along a horizontal seam. The result was a large, horizontal mosey patch leading downstream from the dam itself. Apparently, the dam was weeping around its eastern edge, and engineers had installed protective bolts and plates. Their intent was to keep the lower canyon wall from crumbling away and exposing more of the concrete dam.

If you have ever observed a concrete patch on an asphalt road or an asphalt patch on a concrete road, you know that the hard concrete and the softer asphalt to not make for a happy marriage. Concrete and asphalt expand and contract deferentially under pressure, heat or moisture. The result is that sooner or later the two will separate and create a greater problem than before the patch was made. Likewise, the 4,901,000 cubic yards of ever-hardening concrete within Glen Canyon Dam are embedded in the soft and porous sandstone of Glen Canyon itself.

When fully stressed by an overfilled condition in 1983, Lake Powell contained over 27-million acre-feet of water. To avoid spilling water over the front of the dam and possibly losing it all together, water managers were forced to run both spillway tunnels at their designed maximum of 208,000 cubic feet per second. Anonymous sources later revealed that as the extended water release activity continued, the entire dam resonated and thrummed. Since parts of the twin spillway tunnels were bored through sandstone, huge chunks of that natural formation broke loose and swept out into the Colorado River.

How much lasting damage was done during the 1983 water release event will never be known. Large public agencies like the United States Bureau of Reclamation (USBR), which runs Glen Canyon Dam, have a habit of hiding as much controversial information as they can. What they cannot hide is the thermal stress on the dam. In January the average high temperature at nearby Page, Arizona is 44F degrees. In July, the average high temperature is 97F degrees, or 57F degrees higher.

Daily temperature cycles should also be considered. Each day throughout the year, the high and low air temperatures vary by up to 24F degrees. Although the concrete in the dam does not thermally cycle as dramatically, the face of the dam is shaped like a parabola thus concentrating the sun on its southeastern exposure. With cold water behind the dam and hot sun shining on the front of it, how does the dam dissipate that energy into the sedimentary rock in which it stands? Maybe that differential stress is why the unmentioned grout, steel bolts and plates have been installed in the sandstone canyon wall along the lower right face of the dam.

After traveling over the Glen Canyon Dam Bridge, I proceeded west on Highway 89 to the Wahweap Overlook turnoff. The directional signage from Highway 89 West is minimal, so the obscure turnoff is easy to miss. The paved road up the hill to the overlook is adequate, but the unpaved parking area at the top has no traffic markings or designated parking spots. Since the inception of the dam, the Wahweap Overlook has defined how an “overlooked” overlook might look. Given the popularity of the site and its status as a senior citizen, authorities should have paved the parking area and installed a restroom facility sixty years ago. Perhaps it is a moot point, since the drying of Lake Powell could soon leave Wahweap Overlook as just another dry knoll in the Arizona desert.

In May 2021, from Wahweap Overlook I could still see Wahweap Marina on the near shore of Wahweap Bay. In the middle distance lay Castle Rock, which looks as much like a castle as any other “Castle Rock” in the Western U.S. Farther north and east stands the eroded volcanic shape of Navajo Mountain (elevation 10,387’). With some effort and a short hike down the hill, I could look downstream and see the top portion of Glen Canyon Dam. Ironically, the water level was about the same as I remembered it from my first visit to Lake Powell in 1965. Keep in mind that Lake Powell was then still receiving its initial fill of once abundant Colorado River water.

Even with its steadily shrinking size, Wahweap Bay still looks grand, giving Lake Powell a spacious, breathtaking feel. Most visitors do not realize that prior to the construction of the dam, the flow of the Colorado River never touched what we now call Wahweap Bay. The main canyon, known as Glen Canyon, meanders northeast from the dam in a rocky trench. The containment created by that sheer cliff does not broaden out again for many miles. From the Wahweap Overlook, I could see neither Glen Canyon or the Castle Rock Cut, which once was Lake Powell’s much shorter version of the Suez Canal. As such, it was a manmade cut in the sandstone, which allowed boats to pass from Wahweap Bay upstream to Warm Creek Bay. Transiting that trench by boat bypassed a stretch of Glen Canyon, shortening the distance from Wahweap to the upper reaches of Lake Powell by twelve miles, or over one hour of travel time.

First cut into the sandstone in the 1970s, and with its bottom deepened to 3,600’ elevation in 2014, the Castle Rock Cut served boaters for decades. As of 2021, Google Maps still shows the cut as if it is operational. I suppose the map keepers at Google Maps are either too lazy to show current reality or perhaps they believe that the lake will refill itself and reactivate the cut for boat travel. An environmental assessment in 2008 had optimistically stated that the cut could be deepened to 3,580’ elevation. On July 23, 2021, the reservoir’s level fell to 3,555’ elevation, or twenty-five vertical feet below the final proposed depth of the Castle Rock Cut. In other words, the Castle Rock Cut now stands high and dry.

The iconic scene of Charlton Heston finding a destroyed Statue of Liberty in the 1968 original Planet of the Apes movie was filmed on the beach at Paradise Cove, California. However, the opening scene, which depicts his prior crash landing in a spacecraft was filmed at Lake Powell. With such Science fiction credibility already established at Lake Powell, I suggest that the “Sandcrawler”, a fictional transport vehicle in the Star Wars universe that is found on the desert planet Tatooine be redeployed to the Castle Rock Cut. There it could be utilized as a houseboat transporter. It could scoop up a boat from Wahweap Bay, and then use its many treads to crawl the Castle Rock Cut to Warm Creek Bay. There, it could disgorge the houseboat and its happy passengers, all in a matter of minutes.

Back in the reality of the twenty-first century, the Castle Rock Cut joined the Bullfrog Main Launch Ramp, Antelope Point Public Launch Ramp, Hite Launch Ramp and Stateline Launch Ramp on the list of closed Lake Powell boating facilities. As of this writing, the main launch ramp at Wahweap Marina had an expected closure date of mid-August 2021. Recently, the National Park Service (NPS) began preparing a smaller, “Auxiliary Ramp” not used since the 1960s. It will be able to launch or retrieve only two boats at a time. The NPS was also preparing the Stateline Auxiliary Launch Ramp for limited use later this year. Neither auxiliary ramp will accommodate houseboats over thirty-six feet in length.

Thinking back to the original Planet of the Apes movie, I imagined an event thousands of years from now. An errant spaceship, piloted by a descendant of Elon Musk might aim his disabled spacecraft for the dead pool of Lake Powell. Assuming a successful water landing, the survivors might hike out in the direction of what once was Wahweap Bay. There, Elon the 125th and his crew might come across the huge concrete ramp at Wahweap. With Lake Powell no longer reaching Wahweap Bay, the long concrete ramp at the former Wahweap Marina would be as mysterious as the Pyramids at Giza. The survivors might ask, “What type of spacecraft could have launched from this dry and desolate ramp?”

Throughout my own lifetime, the Glen Canyon Dam and Lake Powell have represented subterfuge, boom and bust. As I reflected on that, I knew it was time to go. Fifty-six years after my first visit to Wahweap in 1965, I wondered if this would be my last. Having photographically documented the Wahweap Overlook view for the past fifteen years, I snapped a few more pictures and then departed. What my photos revealed was the continued desiccation of Lake Powell. In the past six years alone, a large section of Wahweap Bay had gone dry.

Finished in the early 1960s, Wahweap’s concrete launch ramp extended farther and deeper into the lake than any other launch ramp. At the time no one imagined that the surface of Lake Powell would ever fall below the end of the concrete ramp. As I drove away, the question in my mind was, “Once it is reduced to a shadow of its former glory, will Wahweap Marina ever again thrive as a pleasure boating facility?” I have my doubts.

This concludes Part Four of a Five-Part Article. To read Part Five, click HERE. To return to Part One, click HERE.