Stabilization of Fivemile and Muddy Creeks

Steady waste flows from the Riverton Project in central Wyoming increased the annual discharge of two ephemeral streams from 5,000 acre-ft to over 90,000 acre-ft on Fivemile Creek and over 20,000 acre-ft on Muddy Creek. Accelerated erosion resulted with Fivemile Creek losing its natural meander pattern, becoming wide and braided. The deterioration was so severe that it was contributing 49% of the sediment entering Boysen Reservoir. Muddy Creek still retained its meander pattern because it has only recently carried waste water. As a result of investigations, comprehensive plans were made for control of both creeks. Fivemile Creek was controlled by providing continuity of flow, while Muddy Creek was controlled by protecting the meander pattern. Both creeks were stabilized with jacks, groins, and jetties. Willow and Russian olive seedlings were planted behind the control works. Both channels are now essentially stabilized. Sediment inflow into Boysen Reservoir is now only 10% of the inflow prior to stabilization.