Ramshorn Creek Subwatershed
Area Summary: Ramshorn Creek is a tributary to the Ruby River. It runs for approximately 14.7 miles from its headwaters in the Southern Tobacco Root Mountains to its confluence with the Ruby River above Silver Springs. Currant Creek is a 3.6 mile tributary to Ramshorn Creek. The upper reaches of Ramshorn Creek hold remnant westslope cutthroat trout populations. This remnant population holds potential for fishery restoration but is also vulnerable to downstream introductions of non-native fish.
Impairments: Ramshorn Creek accounts for half of the roadway sediment contribution into the Ruby River watershed. Additional sediment sources include historical and current grazing management practices. In addition to having major impairments from sediment loading, the stream has also had issues with temperature, de-watering, and loss of functioning riparian area.
Irrigation withdrawals have at times caused dewatering and periodic loss of connectivity with the main stem of the Ruby River. Floodplain alterations keep the stream from accessing many side channels where it would then water and revitalize riparian vegetation. Lead concentrations were found to exceed chronic aquatic life standards at higher flows during runoff events. A combination of abandoned mine sites in the Ramshorn Creek watershed above the Currant Creek confluence are likely contributing metals to the stream during runoff events.
Ramshorn Creek has been straightened and placed into ditches throughout much of its length. Straightening has led to high levels of incision, disconnection from the stream’s historic floodplain, and the presence of many active headcuts. An estimated total of ~75% of the stream’s length is incised meaning that the channel is 1) actively producing excessive sediment through bank or bed erosion and 2) the current channel dimensions allow for very little long -term sediment storage in the stream or its floodplain.
Ramshorn Creek has high potential to implement projects that would decrease sediment loading into the stream, improve riparian habitat, and reconnect the stream with its floodplain. These measures benefit water quality by reducing sediment inputs, dissipating energy in high flow events, decreasing water temperatures, and ultimately restoring function to the stream and its floodplain. Examples of projects include:
- Installation of vegetative buffer between the stream and sediment loading sources to reduce sediment inputs.
- Reconnecting the stream to its floodplain to allow energy dissipation which would reduce bank erosion, increase shallow aquifer recharge, assist riparian vegetation recruitment, and allow sediment to deposit in the floodplain during high flow events (increase stream sediment transport function).
- Bank stabilization projects including but not limited to bio-engineered treatments to allow natural stream channel evolution and vegetation recruitment.
- In-stream structures that use the stream’s own power to cause its channel to become more sinuous.