(1) The Board of Trustees of the Internal Improvement Trust Fund of this state is authorized and empowered to grant unto riparian owners as herein defined, their heirs, successors and assigns, perpetual easements and easements, licenses and leases for specified terms of years, permitting such riparian owners, their heirs, successors and assigns, to construct, maintain and operate structures and facilities on, in and under the bed of any navigable stream or any river owned in whole or in part by the state, for the purpose of providing water of a suitable quality for industrial, domestic or other use; provided, however, any instrument granting such easement, lease or license may contain provisions to the effect that such structures and facilities shall be so constructed as not to obstruct the channel of the stream or river or unreasonably interfere with navigation, commerce or fishing thereon.
(2) For the purposes of this section, the term “riparian owners” shall include the owners of uplands bounded by either the high-water or low-water mark of any stream or river and shall include lessees and licensees of any such owners or grantees in easements from such owners of such uplands or river bottoms. The term “channel” shall mean the marked, buoyed, or artificially dredged channel, if any, and if none, shall mean a space equal to 20 percent of the average width of the river or stream at the point concerned which furnishes uninterruptedly, through its course, the deepest water at mean low water.
(3) This section is cumulative and shall not restrict or limit any title, right, interest or privilege of any riparian owner under the common law.