Streamflow and sediment transport responses to snow fencing a rangeland watershed

Abstract

The effects of snow fencing a big sagebrush rangeland watershed were evaluated within a paired watershed study framework. The fence, 3.8 m tall and 800 m long, increased snow water storage 78% and snowmelt runoff 129%. Flow duration was lengthened 33 days. An average of 39% of channel snow appeared as Streamflow while 54% of additional snow deposited by the snow fence appeared as streamflow. The proportion of the snowpack appearing as Streamflow was directly related to the size of the snowpack. Placement of the fence 38 m upwind of an incised channel that was the primary source of streamflow maximized the water yield increase. The concentration of filtrable sediment and bed load transport were unaffected by treatment. Discharge of filtrable sediment increased in proportion to the increase in water yield. Filtrable sediment content averaged 6 mg L−1, and about 25% of sediment weight was contributed by organic matter. Sediment transport after fencing averaged 0.275×103 kg km −2 yr−l, with filtrable sediment accounting for most of the transport.