Adopting a storm drain was a big responsibility, the kindergartners knew.

There was a winter’s worth of gunk clogging the drains outside Eden Prairie’s Cedar Ridge Elementary.

Unless somebody did something, that gunk could flow into the nearby creek where the kindergartners liked to explore and play.

Their teacher, Jen Heyer spent a lot of time with them in that creek, letting them get muddy and climb trees and weave what they saw in the natural world into their math, reading and science lessons.

After the children splashed around the creek, Heyer explained how storm drains work and where stormwater ends up.

“What sort of things would you not want in the creek?” she asked them, explaining how pollutants, even dirt and rotting leaves, can harm the creek and its creatures.

The students could stop pollution from washing out of the school parking lot and into the creek, she told them. But to do it, they’d have to stop it at the storm sewers.

“There were kids that cheered,” Heyer said with a laugh. “And kids that said ‘yuck.’ ”

But a few weeks ago, as the snow melted and revealed all the yuck that was about to go down the drain, students pulled on their galoshes, gathered up the kid-sized rakes and rubber gloves the Home Depot had donated, and got ready to clean.

First, though, they needed to name the drains they’d just adopted. Naming and claiming is a cornerstone of Hamline University’s Adopt-a-Drain program.

Thousands of volunteers have visited adopt-a-drain.org, clicking around a searchable map of 300,000 regional storm drains until they find one or two they’re willing to maintain.

To date, almost 4,000 Minnesotans have spent more than 4,000 hours tidying metro storm grates.

“People may ask, ‘Isn’t this the city’s job?’ ” said Jenni Abere, who coordinates the program at Hamline’s Center for Global Environmental Education. “But there’s only so much the city can do.”

Instead of waiting for street sweepers to come along, volunteers spend maybe 15 minutes, once a month or so, raking debris out of the gutters and storm sewer grates. Bit by bit, grate by grate, they’ve kept an estimated 103,000 pounds of gunk out of Minnesota lakes, rivers and creeks.

These grate volunteers have also given thousands of storm drains a name: Splishy, Stormy McStorm Drain, Bubblesworth, Singin’ in the Drain and about as many references to murderous Stephen King sewer clowns as you’d expect.

The Cedar Ridge kindergartners had four parking lot storm sewers to name. After some debate they settled on: Stormy, Storm Trooper, Cleany McCleaner Face and The Abyss. The final vote narrowly edged out Cupcake and Sweety Pie, but some of the students went home and persuaded their parents to adopt more drains, so we can only hope there’s a Cupcake storm drain out there somewhere.

Then the kindergartners and teachers Heyer and Carol Reno went to work.

“We filled two trash cans” that day, Heyer said. If you follow @heyerlearning on Twitter, you can see pictures of her students getting muddy and throwing themselves into her Wilderness Wednesday outdoor learning lessons.

After the next rain, the students gathered around their storm drains and listened as the water flowed down the drains like underground waterfalls.

“They could see it and they could hear it,” Heyer said. “They were making a difference.”

The students will keep the drains clear through the end of the school year. Next year, Heyer will have a new class of kindergartners, who will pull on their galoshes, pick out some new storm drain names, and carry on the work.