Here’s a look at the Gunnison Tunnel and the water it provides for the Uncompahgre Valley, from Peter Shelton writing for The Telluride Watch. From the article:
We live on Gunnison River water from out of the Black Canyon by way of the Gunnison Tunnel, which celebrates its 100th anniversary September 26. Turns out just about everyone in the Uncompahgre Valley, from Colona to Pea Green, shares the same fortune. Without the pioneering engineering feat of the tunnel and the concurrent development of canals and laterals by the Uncompahgre Valley Water Users Association, we wouldn’t be here. Or, at the very least, this part of the Western Slope would look different. It wouldn’t be nearly as green, or as prosperous, as it is today…
The tunnel presented myriad practical and engineering challenges. Digging from both ends simultaneously, shifts of 30 men each working 24/7 took four years to dig the six-mile long hole. And when they finally met in the middle, [Water Users’ Manager Marc Catlin] told us, “They were 18 inches off! Dug by hand! A hundred years ago! You go to Denver, you go in the Eisenhower Tunnel, which was built in the 1970s, you make that turn in the middle? … They were off by 40 feet!”
While the tunnel was being dug, other crews were gouging canals into the west-side landscape, including the main artery, the 11-mile long South Canal. “Go out and look at the canals in winter,” Catlin said. “Imagine mules and Fresno scrapers – no bulldozers! They fed sheep in the canals in winter – all those little tiny feet packing that ‘dobe clay so that the canals wouldn’t leak!” Today the Water Users take care of 575 miles of canals and lateral ditches supplying three communities, two counties, and irrigating 80,000 acres of cropland. Not to mention municipal water (by Tri County and other water districts in Project 7) delivered as far as the outskirts of Ouray.