In anticipation of and to provide for the carrying away and the safe disposal of natural storm and flood waters, the county may remove any obstacle from any natural channels within the county and the incorporated municipalities in the county. For the same purpose the county may plan for and construct new channels, storm sewers, and drains to serve as though they were natural channels. The county may cause such channels, storm sewers, and drains to be surveyed, and the county legislative body may, by ordinance, establish their location and dimensions. The county legislative body may promulgate regulations to prevent the destruction or obstruction of these channels, storm sewers, and drains, and may provide for the enforcement of those regulations. The county legislative body may also provide for the maintenance, improvement, and fencing of all such channels, including covering or replacement with buried conduits. To implement the establishment, clearing, protection, and continued use of such channels, storm sewers, and drains, the county may acquire, by right of eminent domain necessary easements and rights of way. All laws and sanitary regulations against the pollution of water in natural streams, canals, and lakes shall be enforced by the county executives in their respective counties, or, by the state, through the attorney general and in co-operation with the state board of health, state fish and game commission, and the several county legislative bodies.