Presenter(s): Ethan Niyangoda − Geology
Faculty Mentor(s): Josh Roering
Poster 67
Research Area: Natural Science
The Eugene Millrace, a slowly-flowing 1.5 mile channel which is connected to the Willamette River and flows through East Eugene, has once again become a matter of public interest. Originally designed by Hillyard Shaw and constructed in 1851 to create a millrace for the quickly-industrializing city. Approximately half of the channel is a former side-channel of the Willamette River, and the other half was constructed by man. With the advent of the highly-publicized Knight Campus, which will be built around and possibly atop the Millrace, there has been great speculation into the future of this small but culturally-significant channel. One helpful means of understanding the nature and movement of a river system is to examine its bathymetry (the topography of its channel) and sediment accumulation pattern. In order to do this, we used six- to twelve- foot steel rods, a canoe, a GPS unit, and a tape measure to gauge sediment depth at a given location. To do this, we launched the canoe at several locations and took measurements from the center of the channel and around drainage pipes. This was done once in May 2017 and once in November 2017. We hypothesized that the channel would have mostly uniform, shallow (less than one foot) levels of sediment throughout. This hypothesis was completely wrong, as we discovered that the Millrace in fact has sediment ranging from less than a foot to meters in depth depending on the location measured. This finding could potentially have significant implications for channel dredging during the building and design associated with the Knight Campus.