Doug Miller wrote:

...3/4" is awfully small for a hundred yard run.

The Hazen-Williams equation says 300' of 0.75" smooth pipe with a 5 gpm
flow has a 0.0004227x300x5^1.852x0.75^-4.871 = 10 psi pressure loss...
1" makes 2.5 psi, 1.25 makes 0.84, and 1.5 makes 0.347.

If one end of the pipe is always under lake water and the flow is shut off
while the pipe is full and the pump runs every week or two, this might work
fine with a leaky foot valve.

Nick