HINSDALE – It’s been more than a month since the Salt Creek at Graue Mill flooded due to storms causing road closures, evacuations and even a dead body to turn up.
On May 20, chemistry students at Hinsdale Central High School went to Salt Creek to perform tests on the creek and gather data to assess the health of the water and dam. The day consisted of eight chemistry-themed classes, with about 160 kids working together in teams to collect data.
“This could’ve been a nightmare, but it’s actually going pretty well,” chemistry teacher Julie Baker said with a laugh.
Baker was directing the students with a megaphone as teams checked in with experiments they had completed, including chemical analysis of the water, air tests, looking at different kinds of fish and bugs, assessing the soil and vegetation and measuring water depth.
The focus of the project has changed recently. In past Salt Creek outings, the students came up with the top 10 issues of the creek and how to solve them.
“Now, what they’re really focusing on here is if the dam is causing environmental issues,” Baker said. “They’re collecting data above and below the dam, and then they’re going to compare it and look at the data and make a recommendation.”
Another point of the experiment is to teach the kids how to be scientists, which means going out with teams into the field, conducting experiments, assessing the data for final results – and getting dirty.
Tom Ludovice, a chemistry and biology teacher, said Hinsdale Central has been doing this field trip on and off for about 20 years. This year, Ludovice and his teams focused on catching fish above and below the dam to survey fish vertebrates, which can be an indicator of the quality of water.
Ludovice said they’ve caught small mouth bass, crappie fish and small carp downstream.
“The crappie is the one we’re looking for because it needs pretty good water, so the fact we’re finding them and finding them in large size is an indication, based upon the vertebrate survey, that it’s in pretty good condition,” Ludovice said.
He’s noticed the quality and size of the fish have been improving over the past 20 years, too – despite that the forest preserve also has stocked the creek on and off.
“The fact they stock it and they’re still here is an indication that at least the waterway system is doing pretty good,” Ludovice said.
The recent flooding not only has a direct effect on the creek, but also on the vegetation and fish. Along the trail near the creek, walkers can see where silt carried over onto the pathway.
“What that means is there is a lot of soil and silt, and what that does is it can increase cloudiness [of the water], which has numerous other impacts,” Ludovice said.
If game fish can’t see the food because of cloudiness, that could affect the population. It also has a direct influence on photosynthetic algae, he said.
To present their projects in class this week, students created tri-fold posters, videos and PowerPoint presentations. They also had to invite parents and other adults to hear their recommendation after reviewing the data.
“The recommendation doesn’t have to be just on environmental data, it could be on history, it could be on public opinion. We’re asking them to pull everything into it,” Baker said. “Like what they would have to do if they were real scientists out here.”