FYI with my little squirt stream, during really dry times, it's only flowing maybe 5 GPM. But so what. If I only get 1 GPM into the pool and it takes a 6 hours per inch with a 1/6 HP Flotec sump pump...so what. When I do fill from the stream I dump it into the skimmer so it's filtered before it hits the pool. Last year I was chasing a leak and had to use an old 1 HP Jacuzzi pool pump in the stream. Flow was good in the Spring. Ran the flow backwards thru the sand filter....put the filter in Backwash mode, fed the waste, clean filtered water came out the skimmer. Another trick.
Al