I've been to the Moffat Tunnel many times and I never realized there was a water project associated with the better known rail tunnel there. FWIW, I've also never seen any sort of security there. Besides a lone Gilpin county sheriff's deputy who lives out along that road and makes it his life's mission to ticket any vehicle parked illegally on the county road.
The big black fence around the east portal didn't used to be there, and you can see the DHS surveillance gantry right over the tracks. You can't get anywhere close enough to even read the plaque/dedication embedded on the right side of the portal. Hope you have a good telephoto lens!
On the west side, the DHS cameras are back to the left out of frame of the shot, at the very eastern edge of the Winter Park station platform. The water system is also much more visible on the west side than on the east side: https://earth.google.com/web/search/Winter+Park,+CO/@39.8871...