I love the detail in these old USBR photos. If you zoom in on them, you can see some pretty cool stuff. This one is no exception. It gives us a good downstream look at the temporary coffer dam. You are looking upstream toward what would eventually become Lake Powell. The coffer dam was built to divert the Colorado River water into the two spillway tunnels that routed the water through the canyon walls to the downstream side of the dam site. The right side tunnel (the Visitor Center side) was the primary tunnel and it handled most of the diversion water.
The excavation going on in this picture is prep work for laying the base of the dam. I remember reading or hearing somewhere that the base concrete for Glen Canyon Dam was poured 135 feet below bedrock. This picture captures that excavation. Some of the dirt and rock that was removed was used for the coffer dam and temporary roadways along the base of the canyon walls.
The rock face on the right side of the picture is part of the left side (Page side) key-way, where Glen Canyon Dam would be imbedded into the canyon wall. There was another key-way on the other side, but it’s not visible from this angle. If you look at the top right of the picture, you’ll see the rock has been (or is being) removed for the left spillway. Also very noticeable is the infamous footbridge that provided a way to cross the canyon by foot, motorcycle, or evidently, VW Beetle, prior to the completion of the US 89 bridge.
Also notice the electrical substation near the base of the coffer dam. I have some other photos I’ll be showing you that give different views of that substation. Don’t miss the two climbers on the canyon wall on the left side of the picture.
Here’s a trivia question to see if anyone reads this far down on my blogs. Does anyone remember the mummified remains of a child that were found during this excavation and put on display in one of the buildings in town? Weird, I know. But do you remember that? I do. It was sometime during the 1960-62 school years. Our elementary class went on a field trip downtown (it didn’t take long) to the corner business near Babbit’s. (it must have been a little museum at the time) behind the Gulf station, and the mummified remains were in a little glass case. I remember filing past it. That seems creepy now. But it’s true. If you remember that, or if you read this far, leave a comment and let me know.
2 thoughts on “Below The Coffer Dam”
The pictures of the Water Treatment Plant are great. Don David (’62) worked down there after he came back from the Navy. He was the Day operator in 1965-1966. This was while we were dating and just after we were married in 1966. I remember him always talking about how hot it was down there.
When they were near the bottom of the footing they came upon an erosion that appeared to be when the mighty Colorado River was just a small stream. In the eroded channel, not more than 5 feet across, there was a log jammed in it. Richard Aman & I went down the eroded channel by ropes and retrieved the log. The channel was about 60-80 feet down. I sent a piece of the log to UCLA for dating and they determined it was ~5 million years old. The log completely disintegrated very quickly after being exposed to air.