From research I conducted during my thread "Hydropower... is the idea feesable" hydropower plants can be set up anywhere...
I live in the N/W corner of Arizona at 3300' altitude.
The area is primarily desert country.
I encourage you to set up a hydro facility here.
No major rivers, no major lakes and minimal rainfall.
Next, low rainfall can be compensated by using other sources of water, or other liquids (which I am sure would be more efficient.
There is no compensation for lack of rainfall.
In the wet years you generate all you can.
In dry years, hydro is used when they can, usually during peak hours at some facilities and at others, water is retained so some generation can be
done through the dry season.
Discounting to an extent requirements to maintain lake levels for the benefit of wildlife etc.
These all have greater problems than hydropower plants. Ecological effects aside, all these sources are dependable on resources. 70% of the world is
covered in water. One hydropower plant can be equal to "15 power plants", so I think any argument against hydropower on its lack of production is
unsupported.
One hydro plant being equal to 15 power plants would only be true if the hydro plant in question had, say, 1500mw capacity and you compared it to 15
fuel burning plants of 100 mw capacity each.
The Southern California utility I worked at has about 1200-1400 mw hydro generation capacity with all hydro plants on line and system load during a
hot summer day - a few years back - equalled 18,000mw.
Some of the generation methods I listed do require resources in the form of constantly burning fuels.
Others require resources in the form of manufacturing components etc. but once those are in place use of resources is minimized to an extent.
Keep in mind that efficient hydro units require a high hydraulic pressure and that's derived from water delivered from an altitude considerably
higher than the generating plant.
I'm not knocking hydro, on the contrary I like it and wish we had more hydro capable areas, but in the USA we don't.
Power companies like hydro generation, in a small way it's almost free power and once the plant is paid for, the only real cost is maintenance and
operating costs which are minimal compared to the revenues gained.
I read your links and the one recommended in your last post is about adding small generating low-head units downstream from the big plants.
A good idea, but not sufficient to power the entire US.
As far as other countries that generate all of, or the great majority of electricity from hydro, the answer there is their population densityprobably
doesn't equal the population density of the US, but they have a lot of hydro sites as well as a lot of precipitation in the form of snow and rain.
I did read your other hydro oriented post and it seems what your friends dad demonstrated was a siphon.
For liquid to flow in a hose the outlet has to be lower than the inlet.
Raise the hose end and the siphon stops.
You're having a nice dream about powering the US via hydro . . . nevertheless, it's still a dream....
. Anyway, the Owens Valley was a dispute about water rights, so I don't understand the reason you bring
that up. 
