A system for pumping liquid having a first reservoir at a first elevation, which stores a first liquid, a second reservoir at a second elevation, where the second elevation is substantially lower than the first elevation, the second reservoir stores a second liquid, a third reservoir at a third elevation, where the third elevation is substantially lower than the first elevation, the second elevation is higher than the third elevation, the third reservoir arranged to store the second liquid, and, at least one hydraulic pump connected to the first reservoir via a first conduit, connected to the second reservoir via a second conduit, connected to the third reservoir via a third conduit, the pump arranged to be powered by the first liquid when the first liquid is permitted to fall due to gravity, the pump arranged to pump the second liquid from the third reservoir to the second reservoir.