"Education is like water flowing on rocks. The effects are hard to notice immediately, but years from now the results will be unmistakeable"
- Proverb, Brown University Department of Geology
On Monday, November 19th of 2012, my students and I witnessed a historic event and a ... concrete ... reminder of the power humans have to alter our environmental surroundings. It was the first High Flow Experiment of a new series of such experiments, and we were invited to attend the event through a series of pretty lucky connections.
When I think of the Colorado River, I rarely ever say the name with out the adjective 'mighty' applied in front of it. The river simply seems so wild and so rugged - it is a symbol of the Wild West.
But the sad truth of the matter is that the modern day Colorado River, as compared to its former grandeur, is a poodle in comparison to a wild wolf. The similarities are there and the form and shape is the same, but ... well... you get the point.
Let's put it this way: the Colorado, in its natural state, had the erosive power to cut through a vertical mile of solid rocks and form the Grand Canyon over just 6 million years. Natives and explorers who saw and lived on the river in its natural state noticed the dark red color of the river (as evidenced by its name - Colorado meaning "Red" River) that was a result of the massive amounts of suspended sediment (aka chunks of broken rock chopped off from the surrounding walls by the fast flowing river).
Ask anyone who has seen the Colorado River flowing through the Grand Canyon - it is a dark blue. That color isn't quite living up to the river's name...
Why is the once-red river tinted blue? Well, the short answer is dams. These massive concrete structures - the most famous being Hoover Dam and Glen Canyon Dam - block all water in the river from flowing. The water backs up and creates a huge lake (called a reservoir) upstream from the dam. As you can imagine, water that is still cannot continue to carry sediment downriver. The sediment sinks to the bottom of the reservoir, and the water that is released from the dam continues on downstream clear, blue, and free of sediments.
According to the Glen Canyon Institute, 100 million tons of sediment is piled up behind Glen Canyon Dam annually. That's 30,000 dumptruck loads of sediment every day. That means that Lake Powell (the reservoir created by Glen Canyon Dam) could fill up completely in just 300 years - a blink of time geologically. We will eventually have to tend to this concern, and as the Glen Canyon Institute notes, the longer we wait, the more expensive it will be.
When I think of the Colorado River, I rarely ever say the name with out the adjective 'mighty' applied in front of it. The river simply seems so wild and so rugged - it is a symbol of the Wild West.
But the sad truth of the matter is that the modern day Colorado River, as compared to its former grandeur, is a poodle in comparison to a wild wolf. The similarities are there and the form and shape is the same, but ... well... you get the point.
Let's put it this way: the Colorado, in its natural state, had the erosive power to cut through a vertical mile of solid rocks and form the Grand Canyon over just 6 million years. Natives and explorers who saw and lived on the river in its natural state noticed the dark red color of the river (as evidenced by its name - Colorado meaning "Red" River) that was a result of the massive amounts of suspended sediment (aka chunks of broken rock chopped off from the surrounding walls by the fast flowing river).
Ask anyone who has seen the Colorado River flowing through the Grand Canyon - it is a dark blue. That color isn't quite living up to the river's name...
Why is the once-red river tinted blue? Well, the short answer is dams. These massive concrete structures - the most famous being Hoover Dam and Glen Canyon Dam - block all water in the river from flowing. The water backs up and creates a huge lake (called a reservoir) upstream from the dam. As you can imagine, water that is still cannot continue to carry sediment downriver. The sediment sinks to the bottom of the reservoir, and the water that is released from the dam continues on downstream clear, blue, and free of sediments.
According to the Glen Canyon Institute, 100 million tons of sediment is piled up behind Glen Canyon Dam annually. That's 30,000 dumptruck loads of sediment every day. That means that Lake Powell (the reservoir created by Glen Canyon Dam) could fill up completely in just 300 years - a blink of time geologically. We will eventually have to tend to this concern, and as the Glen Canyon Institute notes, the longer we wait, the more expensive it will be.
A few of my students peer over the edge of the dam before the beginning of the High Flow events.
The water downstream of the dam isn't just sediment-free; it's cold. Whereas the river water's temperature should naturally fluctuate with the changing seasons, the water released from the dam comes from the bottom of Lake Powell where water never sees the sun. This perennially cold water exits the dam spillways all year round just above the freezing temperatures.
One of the park rangers explains some of the characteristics of the Colorado's watershed.
Another major dam-induced change to the Colorado River is the absence of floods. Historically, springtime snowmelt and summer monsoons would cause fluctuating river levels that redistributed sediments and actually supported native fish species. Luckily, the dams along the river are capable of periodically releasing high amounts of water, which can simulate the conditions of a natural flood.
This is the reason my students and I visited Glen Canyon Dam on the 19th - it was the dawn of a new protocol in High Flow Experiments (HFE's) on the Colorado River.
This is the reason my students and I visited Glen Canyon Dam on the 19th - it was the dawn of a new protocol in High Flow Experiments (HFE's) on the Colorado River.
HFE's have been conducted on the Colorado before - first in 1996, and then again in 2004 and 2008. As you notice, the events were spread out with several years between experiments. Furthermore, the experiments were run basically when the political and monetary concerns were worked out. Under the new protocol for HFE's, the timing of the flood events will be driven by science instead of policy. This means floods will occur when we know they should based on the environmental conditions, and they will be strategically timed with the 'sediment trigger' - a time when the river will be able to most effectively capture sediments and redistribute them for the benefit of native wildlife species and recreational river users.
The event was certainly educational for us, and while we were there we got to meet the Secretary of the Interior, Ken Salazar. Even more impressive for me was meeting the Director of the National Park Service, Jon Jarvis, who was a totally down-to-earth person who LOVES his job - an inspiration!
The event was certainly educational for us, and while we were there we got to meet the Secretary of the Interior, Ken Salazar. Even more impressive for me was meeting the Director of the National Park Service, Jon Jarvis, who was a totally down-to-earth person who LOVES his job - an inspiration!
Our students meet Secretary Salazar and Director Jarvis
One of our students even got picked up by Secretary Salazar! We still haven't quite figured out why!
