Rain Garden

WASILLA — A new rain garden at Cottonwood Creek Elementary not only teaches students hands-on science, but it will be a watershed project for the green infrastructure throughout the borough.

That is the hope of Catherine Inman, program manager for the Wasilla Soil and Water Conservation District. Working though grants from the U.S. Fish and Wildlife Service, Inman partnered with Laura Wick’s fourth-grade class to build the first storm water run-off garden in the Valley.

At Cottonwood Creek Elementary, the parking lot drains into a grass ditch away from the school. Due to the volume of water in the past, the run-off would pool below the playground before emptying into the close by Cottonwood Creek.

Impervious surfaces like parking lots carry the oils and toxins leaked by cars into creeks and rivers along with all the sediment dumped on the roads during the winter.

Also, the storm water floods creeks and rivers when it rains rather than recharge the water table for a more sustained release. All of this can be disastrous to the salmon habitats, Inman said.

“Mitigating storm water run-off is a big deal. It is part of smart development and a big component of the borough’s plans for green infrastructure,” Inman said.

In an attempt to mitigate the run-off, Inman worked with Wick’s class to build a garden fed by the run-off from the parking lot. Gardens provide a natural way to slow run-off, and the plants prevent most of the toxins from entering the creek, Inman said.

“It’s all part of a process called bioremediation,” said Jeff Heys of the U.S. Fish and Wildlife Service.

With the help of Heys, the students measured the square footage of the parking lot and calculated what volume of water comes off it during a rain. From this, they determined what size garden would be needed to handle the run-off and where the best spot for the garden would be.

In Wick’s classroom, the students learned about Alaska’s plant habitats and what species would survive in the storm water garden. She then assigned groups of students each a sector of the garden’s grid to design. On Wednesday, their learning took root as they planted a variety of dogwoods, ferns and irises at the end of the ditch before it passed the playground.

“The students are really invested in what we’re doing,” Wick said. “It’s a big deal to get fourth-graders to do this as opposed to high schoolers.”

Inman agrees and hopes this project will encourage stewardship in the students from a young age. While this is the first project of its type in the Valley, this is an idea students can take to their home or church, she said.

“This is a positive project without being regulatory,” Inman said. “We’re trying to get out in front of the issue and get people aware.”

Contact Todd L. Disher at todd.disher@frontiersman.com or 352-2252.