(a) The authority shall prepare a master plan for the maximum development of the soil and water resources of the Red River watershed inside the authority.
(b) The master plan must include plans for the complete use of the water resources of the watershed for all economically beneficial purposes.
(c) A soil and water conservation district in the Red River watershed shall prepare the portion of the master plan and amendments to the plan relating to soil conservation, upstream flood prevention, and watershed protection works in aid of soil conservation and upstream flood prevention, subject to the approval of the State Soil and Water Conservation Board.
(d) The master plan must be filed with and approved by the commission.