Amazing Structure. Worrisome how little water is left.

Quick Stats

Built in 1935, the Hoover dam was the tallest dam in the world at the time. Some dam fun facts:
– Used 4.3 million cubic yards of concrete
– Is 727 feet tall (60 story building)
– At the bottom, it is roughly two football fields thick
– If left to cure naturally, the concrete would take 125 years to cool
– The dam created the largest reservoir in the US holding trillions of gallons of water
If you give the US government some of your money they will take you on a very long elevator ride to the bottom of the dam and down this long hallway.
And that hallway pops out here. One of the power generating stations. The Hoover dam produces enough electricity for about 1.3 million people. Note that the third generator is missing the top blue portion. This is because it has been removed for maintenance. The Hoover dam produces less electricity today due to the low water level which means less water pressure to turn the turbines. More on that shortly.
The turbine from the generator is getting a little maintenance done.
Looking down on the power generation buildings. If you look carefully, you can see pickup trucks parked outside the buildings to get a sense of scale. The building on the right is in Nevada, the building on the left is in Arizona.
A look across the top of the dam which is wide enough for a highway to pass over with sidewalks on both sides.
In 2005 they built a bridge across the Colorado river as the highway across the dam was getting too busy. The bridge is nearly 900 feet above the river below. At 1905 feet long it is the longest concrete archway bridge in North America. Personally, I found the bridge perhaps more impressive than the dam. Semi truck on the bridge for scale.
There is a sidewalk on the bridge so of course, this is the high point, which calls for the traditional summit selfie!
Unfortunately, lake Mead behind the dam is quickly becoming depleted. Lake Mead reached its highest point in the early 2000’s and has been receding for the last 22 years. At the worst, the water level was dropping nearly 2 feet per week. The white walls on the rock are called the bathtub ring and are calcium deposits from the water, or where the water once was.
These are the water intake towers for power generation. You can see how low the water level is. As the water level of Lake Mead drops, there is less potential energy for power generation. At the current level, the output is about 36% less than usual. Lake Mead has dropped about 150 feet, so far. Another 50-foot drop and the dam will no longer be able to produce electricity. An additional 130 foot drop and the Colorado river will no longer flow past the Hoover dam, drying up everything downstream of it.
So why is Lake Mead dropping by so much? It is very simple; humans are taking more water from the Colorado River than is being replenished. There are 7 states that take water from the river and each allocated a certain amount. However, the calculations were based on data from very wet years. Recent droughts were not considered when water allocation was assigned. Of course, each state doesn’t want to give up any of it’s water allocation as it is needed for farming and cities etc…. The Colorado river provides water to 40 million people and 5.5 million acres of farmland.
There are huge spillway tunnels on both sides of the dam. They are in place so that if the water in Lake Mead gets too high, it can run down these tunnels and around the dam. Some scientists are now predicting that Lake Mead will never be refilled in our lifetime. Other predictions say it would take over 6 years of heavy rain to return to the previous levels.
Another look at Lake Mead. The islands on the right would have mostly been submerged. On the top left corner you can see the campground that was once on the lakeshore. The lake hasn’t been this low since it was first filled up in 1937 after construction of the dam. Scientists estimate that about half of the loss of river flow is due to increasing temperature. The other half is from increased water consumption from the river.
But that is everybody else’s fault, not mine! As I drive this enormous gas guzzling pickup truck around the state. In all seriousness, I reserved a compact economy car, this is what they gave me. I’m laughing at how ridiculously large this truck is.

1 Comment

ted · April 10, 2023 at 1:36 am

Dam what a good description!

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