Wednesday, February 6, 2013

Today In Wyoming's History: February 4: The Dams

Recently the Today In Wyoming's History blog ran this item:
Today In Wyoming's History: February 4:
1905  Construction starts on Pathfinder Dam.


Presently construction is undergoing to raise the height of the dam to take into account a century of silting.

 Walkway on the top of the dam, soon to be removed due to dam being heightened.

View from the top of the dam, on one of the rare occasions that water is released through a tunnel from it.
It occurred to me that this illustrates a massive physical change in our region.  One we're so used to that we hardly even recognize it.

Pathfinder Dam is on the North Platte River, a river that runs from northern Colorado, north into Wyoming, before turning East and Southeast and flowing to Nebraska.  It's one of the most controlled rivers in the world.  I honestly do not know the most upstream of the dams on the river, but I believe there's some sort of small such structure in Colorado.

In Wyoming, the most upstream dam is Seminoe Dam, which was completed in 1939.  Below that, just a few miles downstream, is Cortez Dam, a dam apparently so obscure that it doesn't get much mention anywhere, except by locals, even though its a pretty impressive structure.  It likely was built about the same time.  Below that is Pathfinder Dam, depicted above, the only dam of its particular vintage and necessarily the first of the dams on the river.  Below Pathfinder is Alcova Dam, which started impounding water in 1938.  A couple of miles below that is the very small dam, Grey Reef.  Miles downstream is Glendo, and then Guernsey.  All of these dams, except for Pathfinder, were part of the Kendrick project, a project designed to bring irrigation to Central Wyoming.

Prior to the dams, the North Platte River flooded every spring, and then was a trickle by fall.  Paintings of Ft. Caspar from the 1860s show the river in flood stage as being absolutely massive, something that would surprise people in the area today, but which squares with contemporary accounts.  In the Fall it was the opposite.  Very clearly the river as we know it today was not the river that existed at least prior to 1910.  It isn't even the river as it was known in the 1940s, as at that time the Bureau of Reclamation didn't worry about choking the river off in Fall to impound water.  Now it does, as that's a pretty destructive process.

The difference between having water all year long and not is too great to really expound on.  We're used to having it all year round, and its part of the background to our lives.  It wasn't always that way.

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