Collecting rain, cleaning up lakes
Quad Community Press - by Nicholas Backus
Raingardens have critical function and can be pleasing to the eye by Nicholas Backus Staff Writer Published: Monday, April 26, 2010 5:41 PM CDT CIRCLE PINES — Matt Percy’s neighbors often ask him when the koi fish are going in.
It’s a question repeatedly answered with “never.” Percy’s expansive front-yard raingarden wasn’t built to keep ornamental fish, although it may look like it. Besides, the sandy soil would make it hard to maintain standing water even if he tried.
“Many people ask me what it’s here for,” Percy said about his lawn depression filled with rocks and mulch. “It’s fun to explain it. I almost feel like an educator on the subject.”
What his raingarden does provide the 36-year-old East Golden Lake Road resident is a system to drain stormwater runoff from his roof and lawn while sucking up some street runoff as well. It’s an easy way to maintain an aesthetically pleasing yard while helping clean Golden Lake, which is across the street.
“Everything it captures are (pollutants) that don’t go into the lake,” Percy said. “All the water from our street goes into Golden Lake or Rice Creek.”
By catching water in a raingarden, Percy also helps recharge underground aquifers. The garden only gathers standing water after heavy rains and has a capacity of about 375 gallons. A thin layer of mulch gives way to ultra-fine sand soil and drains any water within a day.
“Some people think it’s a breeding ground for mosquitos, but the opposite is true,” he said. “They might lay their eggs in the water but the eggs die after the water is gone within 24 hours. It actually prevents mosquitos.” Percy worked with the Rice Creek Watershed District (RCWD) in planning specifications and design. Because the district encourages such residential projects, called “best management practices” (BMPs), Percy was reimbursed about 50 percent of his garden’s costs after installation was complete. That amounted to $3,400 for the $7,900 project.
Some neighborhoods north of Rice Lake are being targeted for raingarden installation this summer, according to Kyle Axtell, a resource specialist at RCWD.
“We’ll be talking to folks this summer about fall installations,” Axtell said about the Legacy amendment-funded proposals.
Axtell said Rice Lake neighborhoods are one of the highest priority areas in the Rice Creek Chain of Lakes because of an aging housing stock that pipes runoff straight into lakes.
“We’re picking water bodies where it will be the most beneficial to put the dollar,” he said. About 80 percent of the BMPs will be fully funded.
All eight major lakes in the Rice Creek Chain of Lakes carry excess amounts of algae-causing phosphorus, causing them to be listed as impaired by the Minnesota Pollution Control Agency. Lakes with high levels of phosphorus are especially susceptible to excessive late-summer algae blooms.
Percy thinks more individualized projects can substantially help clean up lakes. He decided to build his raingarden in the void left by a giant oak tree felled in a 2007 storm. Half the tree crashed through his roof. Luckily no one was hurt, but after the tree was removed, weeds and patchy grass began growing.
Wanting to make a change, Percy installed the low-maintenance raingarden in the fall of 2008. He contracted the excavation work, but built walls and did plantings with help of his wife, Jen, and his mother-in-law. He decided to add a “curb cut,” which removes a small patch of street curb and directs runoff into the garden. For all it’s aesthetic beauty, Percy’s garden is more about functionality.
“You can make (raingardens) as rough or fancy as you want,” he said.
A basic garden that performs the same function as Percy’s could cost as little as $1,000. It’s all about the location, he said.
The garden isn’t perfect despite all its benefits. It doesn’t collect driveway runoff. That would have required cutting a trench in Percy’s driveway, something that was a bit too expensive. It also doesn’t collect runoff from the second-level of roofing, which constitutes about 50 percent of Percy’s roof area. The basin is also “a magnet for leaves” in the fall, Percy said.
“The leaf-blower is a good friend of mine,” he laughed.
Percy is quite satisfied with the transformation of his yard over the last two years. The striking system of rocks and plants invites neighbors and passersby to socialize, and his two children get a kick out of it too.
“They love playing on the rocks, and we’re seeing a lot more wildlife,” he said. “Butterflies and bees love the native plants. And the maintenance isn’t too bad.”
A site visit for a professional property review can be arranged by the Rice Creek Watershed District by calling Nate Zwonitzer at 763-434-2020.
Posted: April 27, 2010