But pump math is very sensitive the difference in elevation from input to output. This pump's specs claim "pump lifts to 91.9 feet - suction height 26.3 feet - pump delivery volume 264 g.p.m." I think the model here is:
Intake side, full rated volume at 0 net lift, declining to 0 volume at 26.3 ft suction lift from the creek to the pump inlet. Output side, full rated volume at 0 net lift, declining to 0 volume at 91.3 ft elevation above the pump.
Charting those ratios will give theoretical volume for a given setup. Then subtract something for friction loss, proportional to the length of the hoses.
Marimus examined the photo and said that output stream looks like 30 to maybe 60
gpm. I agree. Using CharlieTR's math that pump capacity means 1 to 2 days per final inch of fill. Using slowzuki's math gives 1 to 2 weeks.