need to write energy equation, considering pump and you have to guess your volumetric flow rate by using chart (b) and equation found. Then you can find the pump power requirement by using efficiency of pump, stated in chart (b).
Output power (Pout)
Pout = ṁgH = ρgQH
where: ρ is fluid density, g is the acceleration due to gravity, Q is the volumetric flow rate, H is the pump head, ṁ is the mass flow rate.