it was a 102 year old tunnel. I wonder how it was maintained by these cowboys, if ever...

I read that the "temporary" repairs for the tunnel of the Fort Laramie-Gering irrigation canal made. The bad news is that the diameter of the tunnel got smaller as a result of the repeairs (use of steel ribs & concrete). Farmers get less water with all the consequences.

They are now working on planning the permanent repairs. They considered "lots of options, including drilling a new tunnel, putting a new pipe within the existing tunnel, lining the tunnel with a steel liner, and 'permeation grouting' ".

They are going for an in-between solution

http://netnebraska.org/article/news/1238981/tunnel-repairs-show-vulnerability-old-infrastructure