For purposes of the rules related to boundary of State Game Refuges, the banks of the river means the words used in Nebraska Revised Statute §§ 37-706(3), and is depicted by a line on maps produced by the Department of Natural Resources using best available technical information, best available elevation information, and past and present observations of the river and adjacent lands. The Department may update the boundary determination whenever it determines that there has been a substantial change in the location of the banks of the river used for locating such boundary. For purposes of the statute, a substantial change in the location of the banks of the river will be deemed to have occurred if a horizontal movement of greater than fifteen yards has occurred from the current river bank line, and such change in the river bank line has been maintained for a period of at least two years. Any member of the public may request the Department to review its boundary determination by submitting a petition requesting such review. Every petition must be accompanied by a representation made by the applicant that the boundary has undergone a substantial change as defined by this section. The Department shall not be required to update the boundary determination more often than once every five years.