Denver Water workers do so much more than read your meter.

A group of them recently went more than 4,000 feet underground to inspect a 23-mile concrete tunnel.

The Roberts Tunnel starts in Summit county - trucking water from Dillon reservoir - under the continental divide - and into the North Fork of the South Platte River in Park County.

The water eventually makes its way to Denver.

Denver Water drained the 54-year-old tunnel for its regular inspection - looking for cracks and shifts. None were found.

Looks like a terrifying amusement park ride.

We're glad that's not our job, and glad Denver Water is so good at theirs.