Corporal White's Journal
It can be found in Cpl. White's locker in the Camp McCarran concourse.
I pulled the log from the East Pump Station computer for the last week. Looking back over the past several weeks, the times are roughly consistent. There's definitely something going on - water shouldn't even be going over to the Westside and yet the log says otherwise. I know I'm on to something.
Westside, South Cistern:
Westside, North Cistern: