By Suha Augenstein, 2025 Watershed Science and Outreach Intern
Each summer, around the summer solstice, the Glen Lake Association (GLA) conducts its Annual Inlet Study, a cornerstone of its water quality monitoring efforts. This study focuses on the 11-12 primary inlets feeding Big Glen and Fisher Lakes. As the GLA’s intern, I assisted Rob Karner and Laura Wiesen with this year’s inlet study.
We used a Hydrolab–a multiparameter water-quality sonde that measures temperature, pH, dissolved oxygen, conductivity, turbidity, and depth. Hydrolab’s are most widely used in rivers, lakes, estuaries, and groundwater for both short-term sampling and long-term deployments. These devices are modular, allowing users to attach a range of sensors depending on monitoring needs, and include features like self-cleaning probes, automated calibration reminders, and data logging.
Above: Assistant Scientist, Laura Wiesen with the Hydrolab
These readings help us better understand the condition of water entering the lakes. By comparing inlet data with samples from the deep basins of the lakes, we can detect signs of nutrient loading, pollutants, or other changes in water chemistry.
Our work began in Little Fisher Lake at the first inlet. To collect the samples, we used clean buckets that we rinsed three times to avoid contamination. We repeated this rinsing process for the Hydrolab’s sample cup as well. Once prepared, we tested the water for the key parameters listed above. At some sites, where inlets weren’t accessible by boat, I retrieved samples from the shore.
For over a decade, this consistent annual sampling has confirmed that the inlet water is as good as, or even better than, the lake’s deep water, signaling excellent watershed health. By tracking variation over time, this study helps the GLA detect subtle changes, address potential threats early, and maintain public awareness of their efforts to preserve the lakes’ pristine condition, reflecting a proactive, science-based approach to watershed stewardship and maintain public awareness of our efforts to preserve the lakes’ pristine condition, reflecting a proactive, science-based approach to watershed stewardship.
About the GLA’s Internship Program
The GLA Watershed Science and Outreach Internship is an eight-week, hands-on learning experience where interns engage directly in field research, environmental monitoring, community outreach, and communications. This year, Suha Augenstein is the 2025 Watershed Science and Outreach Intern.
Our internship program began in 2017 and is made possible by generous annual donations from Jim and Susan Dutmers, Tom and Monica Dutmers, and Bill and Rita Witler, in honor of their mothers, Patricia Johnson Dutmers and Elva Witler. We are so grateful for their support.