Drainage districts created by authority of this chapter may be used as the agencies within this State for insuring watershed conservation within the districts. In addition to the general powers of the board of supervisors of the drainage district, as set out in § 49-19-1440, boards of supervisors of drainage districts shall, under the same provisions of law, authorize the development and execution of plans and programs relating to any phase of conservation of water, water usage, flood prevention, flood control, erosion prevention and control of erosion, floodwater and sediment damages, and also make provision for constructing such works and improvements as they believe necessary to insure the conservation and storage of water within the districts.