Guest bloggers: Anika Knowles, Ellie White, Leo Casalini and Cheyenne Wentz
The HYDRO’26 Stream Gauging Team
Objective: On Monday, September 28th, students of the Wooster Hydrology course returned to Apple Creek for a second time. The main goals of the trip were to measure the stream velocity of Apple Creek and to determine whether Apple Creek is a gaining or losing stream by comparing discharges along a reach of the stream. A gaining stream is a stream which intersects with the water table and receives water from the groundwater system. On the other hand, a losing stream is a stream with the water level above the water table and it “loses” water to the water table. Whether a stream is gaining or losing water can be affected by the stage of the stream, the amount of clay present in the surrounding soil which can acts as an “aquitard” to keep water from flowing downwards to the water table as well as other factors. The class was joined by Peter Quent, a project manager with EnviroScience, who provided insight on how stream channels develop and change overtime, in turn, affecting a stream’s velocity. Nick Wiesenberg, the Earth Science Department technician aided students in the gathering of data and the operation of various instruments.
Two of the HYDRO ’26 Team and Nick Measuring Depth and Velocity
The HYDRO ’26 Team Collecting Clay
Methods: We split up into various teams: water gauging, well installing, and clay collection. The water gauging team had two people hold a measuring tape across the river channel, and another two took measurements of water depth and velocity each meter across a cross-section to get a total discharge at two reaches along the stream.
Measuring well levels relative to the stream level – gaining or losing?
The HYDRO ’26 Team Using the Well Probe (in the distance) and observing velocity measurements being taken. The group is perched on the point bar.
The well-probing team drove a well probe into the bottom of the stream, then measured the water level with a water level indicator relative to the stream stage. Hydraulic head is the height of the water table in this unconfined system, so looking at the head of a stream relative to the well we can determine if the stream is gaining (effluent) or losing (influent). The clay collection team dug out clay from the bank using an auger. This clay was transported back to the lab in a bag for further investigation – we suspect it is lacustrine clays similar to the confining layer in the Wooster Aquifer just downstream.
There was quite a bit of geology along the creek – here the cutbank is composed of bedrock and a fining-upward channel fill with gravels at the base and about 60% overbank silts and clays overlaying the section. Note the walnut tree behind Cheyenne that has developed adventitious roots in response to overbanck aggradation.
Results: Based on the streamflow measurements, the velocity of the stream in the wider, upstream section was much lower than the narrower, downstream section. Further calculations of the stream profile and discharge will be done by the class over the next week. In addition, the well probing measurements showed that the hydraulic head within the well probe was lower at three sites along the stream. This indicates that Apple Creek is a losing stream. Finally, the clay collection showed that there is a series of fining upward sequences, indicating flood events that increased the stream’s competence. A greater competence allowed larger grain sizes to travel farther, and smaller grain sizes to deposit on the overbank, leading to the large amount of clay deposits. The exposure of these fining upward sequences is due to the erosion of Apple Creek as it moves laterally across the floodplain and old chutes and channels are infilled.
Ellie’s notes Over the Depth and Velocity of Site 1 and Site 2
End of the day – hauling out all the equipment. We thank Nick, Peter and our bus driver Maddie for their help.
Wooster students get great outdoors lab experiences!