They knew how to make water run uphill without any mechanical aids..............
Depends on the Drop 125 feet would give you about 52# not to shabby.
Not exactly. They (the Romans) simply used the same kind of “siphon” that are used today in routing irrigation canals and even toilet bowls. The pipe making up the siphon does need to be water-tight though, and most Dark Age Europe didn't have the technical skills to maintain the aqueducts the Romans left. Also, the attacks from the Vandals, Goths, Franks, etc destroyed many city water supplies as a way to force the city to surrender during a siege.
When I climbed around the Roman aqueduct ar Merida, Spain, this spring for several hours - tracing its source canal back across the sides of the hills above Merida and into the brush, and, at the “town end” above and through the town into the plaza fountain, I was surprised at how small the actual water-bearing pipes were.
I expected an open canal-type ditch, maybe lines when it got into the dirt and off the aqueduct itself, but that wasn't the case.
In the stone and brick and tile aqueduct - the “bridge” always seen in the photos - the water flowed in three tile pipes near the top. Each was 6 - 10 inches in dia, (No, the Romans didn't use the metric system.) There were siphons going under the roads, a few caves cutting under hills, but most of the in-ground aqueduct was stone-lined, covered with a larger flat rock. Not sure why it was covered - dust and dirt falling in wouldn't seem to be a problem since the sides were built of stone, and I don't figure that animals drinking from the flowing water would be that much of a bother. The Romans themselves used urine as a clothes cleaner and as soap, so hygiene certainly wasn't an issue.
Flow was by gravity from the source. At Merida, that was a hillside lake and dam about 15 miles (I think) from the town. )