On Sun, 4 Aug 2019 20:17:45 +0100, newshound wrote:

I don't know how far they need to deliver the water, but the flow rate
is dependent on the frictional losses. The pumped system still recovers
available potential energy. To get the same flow rate from a syphon will
require *much* larger hoses, especially if they are long.

See, for instance, the syphons on the Thirlmere - Manchester route.
Not much pumping there!