Impeller inserted at water pipe line

Any pump that will overcome the head difference between the top level of the water and the top level of the inlet pipe, at the required circulating flowrate, will do.

The power input required is of the order of the [head difference] times the [volumetric flowrate] divided by, say 0.8, all expressed in compatible units.

Meanwhile, this might make interesting reading......

It almost sounds like you wish to build a perpetual motion machine. The only way you can pump the water back up is with an external power supply. Your machine cannot run all by itself. Do check out PW's link!

practically you can't do execute your idea because of mechanical losses for turbine, gearbox and pump in additional to friction losses results of water flow in pipes while you can install only water pump with a small power rate to overcome friction losses in pipes . With few calculations you can select power rate of your pump.

consider total pipes length for feeding pipe lines = L₁ with diameter d₁

pipe length for return line L₂ with diameter d₂

flow rate according to your choice = Q

Friction losses in pipes = ( f _* L_{1 ^*} Q² ) / 3(d₁)⁵ ₊ ( f _* L_{2 ^*} Q² ) / 3(d₂)⁵ _---------(1)

where f is friction coefficient

now consider head different between feeding and return pipes around 0.5 bar approximately 5 meters water heat -------(2)

total pump head H_t = (1) + (2)

pump HP = µ * Q * Ht / 75 ξ

where µ water density 1000 Kg/M³ , Q in M³ / sec

H_t , d and L in meters

ξ pump efficiency