Selecting a right pump for 100ft height

Hi all,

There is small dune in our village and people have plantation on top of the dune. Water is stored on the foot hill of the dune and then it is pumped to the top of the dune using a water pump. (pls see the attached photo)

Height of the dune is 100 feet and the slope length is 900 feet. We used a water pump from Oswal 15hp with 3-2.5" heads. I measured the water flow. It provides 10 liter per second of water on top of the dune. It is a 3 phase motor. We need atleast 18 liter per second of water. Can anyone suggest which motor/brand/type should be used. This is a monoblock pump (not the vertical submersible pump).

Few people suggested three stage submersible pump should be better. Any help?