Thanks again for responding Billy as I just can't see his posts. But I
did know what he meant about the inlet pipe without having to do a google.
Effectively he'd described how to obtain that drop into the ram so I knew
what he was referring to.

Harry thinks a 'normal person' wouldn't see that as a drop, but I know
that you'd know my background well enough to know that I'm quite normal in
the rural Australian sense but probably not in an urban or American sense.
Having seen so many silly questions online such as can someone drink
rainwater, or drink water collected off a roof or (grasp!!) even use it on
vegetables, I'm always stunned at such lack of awareness of water and
it's provision to house, animals and garden.

Obviously, there has to be some kind of "drop" or the stream wouldn't flow
and it would only be a long, narrow, stagnant pond.

But if it has any kind of flow it's possible to run a pipe upstream and, if
necessary, construct a small "dam" to concentrate the flow into your ram
inlet. The ""dam" would only have to be, say, 6" high!

What matters to the ram isn't necessarily the "head" (which may only be a
few inches) but the amount of the flow, and the diameter and length of the
inlet pipe.

That's the "MAGIC" of the hydralic ram: it can derive some useful work
(namely pumping water "uphill" from 6' to 20') from a so-so stream that most
folks would consider useless for power generation purposes.

Obviously, the greater the "head" at the inlet pipe entrance, the easier it
is to get a significant flow going and the large the hydralic ram can be and
the more water you can pump.

I have only seen ONE hydralic ram in actual use. It was in Western NC. I
was visiting the family home of a then girlfriend and her dad was interested
in them. He took me to the home of someone he knew and he showed off his
pump. The "stream" was small but seemed to have a good flow. I don't
remember how long the inlet pipe was. Anyway, the pump kept operating 24/7
and keep a water tank above the level of the house filled. IOW: this guy
had running water without using any electric power. The total lift was on
the order of 15' to 20' from the stream bed.

BTW: my girl friend's fanukt house was about half way up what they called a
"mountain." They got their water from a spring located some 100' up the
slope and some 20' higher in elevation. Thus, they too had running water
without needing any kind of pump. In the winter, to keep it from freezing
they simply let the water run 24/7.