Such districts, when established, shall have full power to erect, construct, maintain, repair and reconstruct dams, bulkheads, jetties, locks, gates, or any other character of improvement or construction necessary to the accomplishment of any such purpose, and to make such construction without the boundaries of the district, where same may be deemed necessary to the preservation, or the improvement of the purity and irrigable quality of such waters; and may issue bonds in payment therefor.