Completion Form

2020

The Middle Bear River and Cutler Reservoir Total Maximum Daily Load (TMDL), February 2010, mentions the need for streambank rehabilitation on 10 miles of streambank in the Little Bear to reduce total phosphorus (page 14) and in the discussion in 4.1.2 NONPOINT SOURCES, says: "Fertilizer applications from urban and agricultural areas, erosion from cultivated fields and disturbed soils, and streambank erosion all contribute phosphorus to the surface waters" (page 132). The TMDL notes "Streambank vegetation serves to stabilize bank sediments and reduces the erosional force of flowing water. It also serves as a depositional area for sediment already in the stream. Related impacts include increased water temperatures in the tributaries due to removal of stream-side vegetation." (Page 139). Second stream stabilization is one of the steps outlined in the Lower Bear River Conservation Action Plan (CAP), a process developed by local, state and federal agencies, nonprofits, research scientists, and others, to identify goals for specific "targets," and implementation steps to achieve those goals on the lower Bear River downstream of the Idaho state line in Cache and Box Elder counties. This CAP began in 2009 and targeted aquatic, riparian and wetland systems. It assessed current conditions and causes of degradation, and specified activities to improve degraded conditions. Sedimentation from riverbank sloughing was identified in the CAP as affecting all three targets and as a source of nutrient loading, which in turn was identified as a major contributor to algal growth that results in low dissolved oxygen in Cutler Reservoir. The streambanks selected in this project are representative of large portions of the lower Bear River. It is the intent of this project to demonstrate the feasibility of restoration using mechanical and vegetative means on 600 feet of streambank on the Bear River bottoms. If successful not only will this project help to mitigate some of the issues relayed above, but the means by which this project is constructed can readily be transferred to additional sites within the lower Bear. Second, Russian Olive (Elaeagnus angustifolia) and Tamarisk (Tamarix ramosissima) are highly invasive nonnative woody plant species that consume large amounts of water, displace native plant species, reduce the habitat available to native bird and animal species, and increase the salinity of soils through the depositing of salts along the Bear River. Both Tamarisk and Russian Olive have been identified as state noxious weeds. Tamarisk has been classified as a Class 3 weed and the Utah Department of Agriculture and Food has recommended that weed control efforts may be directed at reducing or eliminating new or expanding weed populations and that these weeds pose a threat to the agricultural industry and agricultural products. Russian Olive has been classified as a Class 4 Weed and that is is known to be detrimental to human or animal health, the environment, public roads, crops, or other property.These species are also extremely difficult to remove and require a combination of mechanical removal and timely herbicide application to be successful. Like many sites on the lower Bear, the Bear River Bottoms has been largely overrun by these invasive species. In order to restore this and similar sites along the Bear to their original ecological condition these nonnative trees and shrubs must be removed.

Through the implementation of these projects sediment loading was reduced and new techniques to hold back the bank were identified. A future project will occur on site in the fall of 2020. Second the project has curtailed the amount of non-native russian olive in the area. Future projects will need to be implemented to remove existing stands of the tree outside of the project area to curtail future seed dispersal.

Casey Snider

08/28/2020 08:59:52