I'm curious if I'm out to lunch or if this is feasible.
I live on a large lake which is the headwaters for the Yukon River. It has a strong, constant current running from south to north. The Yukon River itself runs at about 5 to 10 km/h. I'm guessing that Tagish Lake - my home - runs about 4 to 6 km/h.
My cabin is situated approx 100' from the water's edge, and from the water to the front door is approx 25' of elevation gain.
Currently I have a gasoline water pump which I use to fill 3x 200 liter drums. These sit atop a 10' high 'water tower', which is used for watering gardens, filling the wringer washer and for supplying the shower/sauna house. I run the pump for approx 15 minutes every week or two in order to keep the drums full. The gas pump works perfectly well, but I'm curious if a ram pump would do the job.
Would the lake current work? Obviously at lake-level there is no possibility of elevation gain in order to harness energy from falling water. But if I were to use a large diameter pipe for the inlet and then neck it down for the check valve, do you think that I would see enough pumping action to get a ram pump to function?