That any land or easement therein lying outside of, but adjacent or near to any drainage district may be drained into the drainage system of such district upon such written terms and agreement as the board of directors of such district, and the owner of such land or easement may determine, and the money received for such privilege shall be paid in to the treasurer of such district to be used as other funds thereof: Provided, however, That if such land or easement therein is situated within a drainage district organized under any law of the state of Kansas, such written terms and agreement may be entered into and such money paid by the drainage district in which such land or easement therein is situated.