Storm water ponds act as instructional tool
Dan Hebl, a life science teacher at Two Harbors High School, has been taking seventh-grade classes outside to observe ecosystems for more than a decade. Historically, he has chosen a body of water for the kids to study, which until a few years ago was Skunk Creek in Two Harbors.
When the new high school was built just off Lake County Highway 2, however, the grounds plan included storm water detention ponds. So now, instead of a bus ride, the students can walk to the small bodies of water and observe plant, animal and insect life within view of their school's own backyard.
"It gives us a place to go nearby. We can get there quickly," he said.
Hebl and his class were at the pond last week. A group of boys perched on the edge of the floating dock, netted a frog and deposited it into a bucket of water. Three girls closely inspected some bugs they had caught earlier, measuring them and checking a guidebook for identification.
"Seventh-graders love being outside. They're amazed by what lives in a pond," Hebl said.
The ponds weren't built for aesthetic or teaching purposes, though. They are wet detention ponds designed to lessen the school's impact on the environment. The campus has lots of parking lots, which means that when it rains, runoff that ordinarily would be absorbed into the ground pours directly into streams, which empty into Lake Superior.
"The whole idea of improving storm water quality is to remove the sediment in the storm water flow," said Dan Shaw, engineering department manager at LHB, the firm that designed the school.
He said that most pollutants, such as particles in the air and vehicle emissions, latch on to sediment. With the wet detention ponds at THHS, some water stays in the pond after a rain storm and some flows out. The ponds are designed to mimic what might have happened to the water had the site remained untouched.
The pond where Hebl has taken his students to is a little different from the rest. The school received a grant that allowed them to personalize it. Instead of the cattails that were planted in the rest of the ponds, more diverse grasses and aquatic plants were rooted in the observation pond. A simple floating dock was installed and benches line the edge. A large, dead tree was anchored at one end to provide a habitat for creatures.
"The whole grounds are unique. We're lucky," Hebl said, recalling when a Twin Cities colleague visited and was amazed by the campus.
In addition to science classes, he said that other teachers take their students out to enjoy the pond, too. Art classes sometimes use it for inspiration, and other teachers might take their students out there for a break from the monotonous classroom regimen.
The kids appear to like it. Hebl asked one of his students last week if they preferred classroom work or being outside, observing the pond.
"Outside," he answered emphatically.