UIX: These small gardens are keeping our watershed clean with native plants

Last summer, Southeast End resident Cora Lee spent a few days a week watering the grass between her sidewalk and Underwood Avenue, battling the hot and arid weather for a small patch of verdant grass.


This year she has much less grass growing on that patch. But, it's been supplanted by something arguably much more important.


Earlier this summer, Lee approached the Plaster Creek Stewards about digging out her verge and planting native flora in a curb cut garden, after seeing one put in at her church, Oakdale Park Christian Reformed, and years earlier in the Oakdale and Alger Heights neighborhoods. Lee wanted plants that were easy to maintain, vibrant, and a good attractant for pollinators.


"Nothing too marshy," she says. "And if it gets out of hand, I can just pull it out."


Early one day in July, a small backhoe showed up in front of Lee's house and dug out a winding ditch, while a team of local high school students helped plant black-eyed susans, milkweed, sedges, and other native plants, blanketing each with absorbent mulch.


A few days later, Lee's first purple coneflowers began to bloom.


Gardens like these are showing up around Southeast Grand Rapids, and they provide a critical service, filtering the runoff as rainwater makes its way down city streets, and into the Plaster Creek Watershed which, according to PCS Program Coordinator Deanna Geelhoed, has become one of the most polluted in the West Michigan.


Plaster Creek watershed


The waters of the Kee-No-Shay, or Ken-O-Sha, creek were once some of the cleanest in the region. More than 10,000 years before Grand Rapids was founded, the Odaawaa, or Ottawa, waded across it, swam in it, used it for transportation, and drank from it every day.


Deanna Geelhoed, PCS Program Coordinator.It wasn't long after European missionaries arrived that things started to change.


The settlers discovered gypsum and lime in and around the creek bed. An industry was built, and the creek was renamed after it. The creek that ran clear for millennia became grey and cloudy, and as the population of West Michigan boomed in the 20th Century, the Plaster Creek watershed became the most polluted in the region.


Plaster Creek is a tributary of the lower Grand River watershed, with many smaller basins within. It starts out in Caledonia, runs through commercial areas, through southeast Grand Rapids, through the Roosevelt Park neighborhood and out into the Grand River about a mile south of downtown.


Curb-cut gardens reduce effort for homeowners, reduce watering, and filter run-off as it enters the watershed. The neighboring Rush Creek watershed runs through Jenison, Buck Creek through Grandville, and to the north of Grand Rapids; the Rogue River watershed runs through Rockford and Sparta.


Plaster Creek pollution


To the earliest residents around the Grand River, rainwater fell on the woods and meadows that once covered the valley. The water soaked into the ground where it landed.


"But once you add an impervious surface, parking lots and pavement and roofs, things that don't let water soak into the ground, that's a drainage system that just kind of shunts all the water into the creek," Geelhoed says. So when it rains, Plaster Creek gets a ton of runoff, and the flows are very flashy. They rise and fall very quickly."


The curb-cut gardens can have any number of attractive flowering plants.As Plaster Creek flows northward to the Grand River, it collects runoff from many different landscapes and groups of people, including any contaminants introduced into the drainage system.


"That can be dangerous for the people that live downstream, especially the lower end of the watershed, more towards the Grand River," Geelhoed says. "They get the brunt of everything that's washed into the watershed."


High levels of E. coli have made the creek and the watershed unsafe for swimming or drinking. Centuries of added sediment have turned the once clear waters of the creek into something that looks more like chocolate milk.


"It's very cloudy," Geelhoed says. "And that can erode away at the banks and take out trees."


Heat contamination is also a problem. Rainfall warms up on hot asphalt and cement in the summertime, washes into the watershed, and disrupts aquatic life.


Plaster Creek Stewards


The Plaster Creek Stewards formed in 2009 as a group of faculty, staff, and students from Calvin University, joined by community members in West Michigan. They were concerned about the health of the Plaster Creek watershed, and have since worked to restore its once thriving ecosystem.


For 10 years, the PCS has organized stream testing projects and collected information on the state of the watershed at different times throughout the year. A Research Methods class added to the curriculum at what was then Calvin College and began concentrating on the watershed in 2011. Students in the 60-member class regularly check Plaster Creek for E. coli with the goal of pinpointing its source, monitoring water flow and stormwater impact, and identifying the most vulnerable areas in the stream, where restoration efforts could make the biggest difference.


At a community level, PCS' advocacy and educational programs have helped the residents of the Plaster Creek watershed understand much more about the impact of their own habits on the local water supply than their ancestors may have ever known. According to Calvin University, over 1,500 people show up at Plaster Creek-focused educational events each year. As well, stakeholders include local students, faith communities, businesses, a local golf course, homeowners, local governments, and nonprofit organizations.


Outside of educational programs, the PCS have helped build many different large scale bioswales, which treat and slow stormwater from large parking lots, preserved close to 500 native species in local greenhouses, and facilitated savanna prairie and floodplain restoration projects near the southern headwaters of Plaster Creek.


The group took on another initiative in 2015: building its first curb-cut rain garden.


"Since then, we've done at least 70 around the Alger Heights, Oakdale, and Roosevelt Park neighborhoods," Geelhoed says.


Curb-cut rain gardens


The gardens begin as basins cut into the city-owned areas between homeowners' sidewalks and lawn. Compost, mulch, and native plants whose local residence predate European colonization are added to the slopes, and about two feet of the curb is removed to divert streetside runoff.


Just walking by, it seems like a quaint landscaping feature. On closer inspection, the real work is being done by the plants.


"They're used to [the] Michigan climate," Geelhoed says. "They have really deep roots that help them survive cold winters and hot summers. These deep roots act like straws, essentially sucking up all the excess rainwater."


The result is a filtration system that cleans and cools the water far better than drainage pipes. The plants hold the soil in place, attracting critical pollinators along the way: native butterflies, bees, and birds.


Science behind the stewards


Every fall, Geelhoed visits different natural areas in West Michigan and collects native plant seeds. The seeds are brought to Calvin University's greenhouses, sprouted, and nurtured by student researchers. It's only the shorter species, about 30 different types of plants commonly found on Michigan prairies, which are transplanted into the curb-cut rain gardens.


"Purple coneflower. blazing star, like black-eyed susans, and butterfly weed. Those are things that people naturally use in their landscaping," Geelhoed says. "You might not always realize they're native, but native plants can be really showy and beautiful, too."


The Stewards have intentionally chosen some areas for the gardens where such restoration would make the most impact, typically commercial districts. In residential areas, where PCS advocates may be in shorter supply, the Stewards will leave informational flyers with homeowners on specific blocks.


In addition, an engineer helps the PCS evaluate each site for viability. The soil needs to contain enough sand to encourage good drainage, and the sites cannot be too far from a storm drain. Any rainwater that falls down slope of the garden will not be diverted.


That makes a street corner at the bottom of a hill the ideal location.


Local roots


At the corner of Adams and Underwood, Cora Lee has been walking her garden hose out to the garden each evening, just after the sun sets. Adding the rain garden to her verge came at the cost of the underground sprinkling system that previously ran through her front lawn.


Lee has been a resident of the Southeast End for nearly 50 years. This summer, she had the pleasure of introducing her grandchildren to the new garden, and with it, the responsibility of keeping it well maintained.


Along with information about the different native plants that can be found in the gardens, the Rain Garden Maintenance booklet distributed by PCS to each homeowner shows residents just what they've signed up for. There's weeding and watering to be done, mulching, pruning, and occasionally some leaves and litter to remove.


After three seasons of successful maintenance, the perennials will have dug their roots deep enough to come back without the frequent attention they need in the first few.


Lee doesn't think she will be walking down to the bottom of the basin and pulling every weed as often as they sprout, but she is looking forward to seeing her flowers return each spring.


This writer is looking forward to the same. And when Lee needs help with weeding, will be walking across the street to help.


Urban Innovation Exchange highlights the people and projects transforming West Michigan through sustainable efforts. Matthew Russell is the editor for UIX Grand Rapids. Contact him at [email protected].


Photography by Adam Bird of Bird + Bird Studio.
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