Not sure where you got the 0.433 factor from, but I assume you must have an engineering handbook that provides estimates of the loss of head pressure due to losses attibutable to pipe diameter and length. Assuming that the 0.433 factor is good, then the velocity of water flow at the outlet would be
v = sqrt(2gh)
where 'h' is the adjusted total head height of 25 feet + 35 feet + 40 feet. This gives 'v' in feet per second. From this you can calculate flow in GPM given the area of the outlet pipe in ft^2:
GPM = v (ft/s) x 60 (s/min) x A (ft^2) x 7.48 (gal/ft^3)
