All persons owning lands on any watercourses are authorized to ditch and embank their lands in order to protect the lands from freshets and overflows in the watercourses, provided that the ditching and embanking does not divert the watercourse from its ordinary channel; but nothing in this Code section shall be so construed as to prevent the owners of lands from diverting nonnavigable watercourses through their own lands.
OCGA § 44-8-9