Youfang Duan
Alexandra Hall
Linnea Laux
In this intervention, I attempt to highlight flooding and sediment deposition dynamics through leaky dams in small streams. The three dams are made of different materials, have different levels of leakiness, and are in different locations. They will passively register what is being carried in the stream, and may also influence the path of the stream. The leakiest dam is made of various types of wood, and is in a place where the stream bottom is rocky and erosion is limited. The moderately leaky dam is in a small branch of the stream, where the bottom is grassy and mucky, and is made of glass and acrylic. I hope to register any sediment accumulation through the clear glass. This stream appears to be seasonally active. The final dam is made of Eastern White Cedar shingles, and is located in a heavily eroded stream where the bottom remains mucky. At this location, an empty rice container allows me to take pictures of layers of sediment as they form. The watershed of this stream does not include farmland, so heavy sediment loads are unlikely. The main source of sediments in these streams is likely currently soil being washed away from the roots of horizontal trees by rain. This suggests that the stream might offer evidence as to where and which types of trees are falling. This winter resulted in heavy tree damage, and trees have continued to fall since my first explorations of the site. I hope that these dams can help me to understand what the floodplain registers about its watershed and what it might conceal, depending on the type and location of stream. I am defining the floodplain as the area that regularly receives soil and disturbance from floods, and this intervention will help me understand how much the small streams contribute to the maintenance of the floodplain. Is the soil deposited all from the Rivanna, or does it also come from these smaller tributaries? How much do the trees that fall across the stream affect floodplain dynamics, and what might this mean in light of the recent ash tree die-off?
Dina Luo
Katherine Rossi
