To the end that the waters of the several stream systems of the state may be conserved and utilized so as to prevent erosion, waste and damage caused by torrential floods, and in order that the benefits of the use of such waters may be distributed among the inhabitants and landowners of the country along said streams as equitably as possible without interfering with vested rights, the natural right of the people living in the upper valleys of the several stream systems to impound and utilize a reasonable share of the waters which are precipitated upon and have their source in such valleys and superadjacent mountains, is hereby recognized, the exercise of such right, however, to be subject to the provisions of this article.