Monitoring of Water Temperature and Determining Water Budget of Keller Reservoir in the McElhattan Creek Watershed

Elaine Langone Center, Terrace Room

In the summer of 2016 the Pennsylvania Fish & Boat Commission (PFBC) conducted a study on McElhattan Creek to gauge the health of the wild trout population within the watershed. The study identified a significant problem that the watershed faces in relation to the difference in water temperature upstream and downstream of Keller Reservoir (92 Million Gallons), which is situated alongside McElhattan Creek. This discrepancy in water temperature is affecting the wild trout population, with some showing Black Spot, a parasite found when fish are combating temperature stress. Following up on the PFBC study, the focus of this project was to keep an extended record of water temperature above and below Keller Reservoir for the entire length of the summer, when the temperature discrepancies were observed to be at their highest. A series of HOBO Water Temp Pro data loggers were deployed at four locations in the watershed to obtain a broader picture of what could be influencing the previously observed temperature fluctuations. Monthly reports were then generated and compiled into a comprehensive file to examine trends in water temperature within the watershed. There was an isolated period (7/21/2017) when the temperature differential at two locations in McElhattan Creek, which are located upstream and downstream of Keller Reservoir, respectively, exhibited the highest range, which appears to be influenced by air temperature. There was a second event (7/24/2017) that displayed the smallest range in temperature differential between the same two locations following a major rain event. This event seems to be influenced by a relatively higher amount of water being discharged from Ohl Reservoir (580 Million Gallons) into the upstream segment of McElhattan Creek. Our data indicate that the surface water in Ohl Reservoir is relatively warmer than the upstream segment of McElhattan Creek. This project also investigated water budget for Keller Reservoir to asses a full view of the hydrologic controls of the area. Flow measurements were conducted at several sites within the watershed on various dates to investigate any fluctuations in the amount of water contributed by different components of water budget. The most recent data collected revealed a slight surplus in the output of water budget, which could be attributed to groundwater flow, evaporation, or direct precipitation over Keller Reservoir.