One of the ways to manage stormwater runoff, and add a bit of natural beauty, is the creation of bioretention cells (biocells). One has been established in the City of Muscatine and more are in the planning stages.
Biocells have become one of the most widely used green infrastructure practices for managing stormwater. A landscaped depression that captures and infiltrates stormwater runoff from impervious surfaces, biocells are most notably found in settings such as parking lots and residential areas where soils do not adequately drain.
To the resident or visitor these cells look like flower gardens. Underneath, however, is an engineered subgrade that is designed to filter pollutants out of stormwater runoff. Native plants are widely used in these “gardens” since these plants have deep roots while maintaining soil quality and soil pore spaces (the liquid and gas phases of soil).
One such cell is located just off Sycamore Street between the #1 Alley and the City of Muscatine parking lot.
Jon Koch, Director of the Water and Resource Recovery Facility (WRRF), and his staff have spearheaded the creation and maintenance of biocells within the City of Muscatine.
“The Stormwater Department took over care of this biocell last year and after Public Works repaired the intake and put in a stone walkway, we teamed with the Muscatine Pollinator Project to bring this biocell to life,” Koch said.
The Sycamore Alley biocell was constructed in 2016 but problems were encountered that allowed more weeds than native plants to grow. With the combined effort of the City of Muscatine and the Muscatine Pollinator Project, those problems were corrected and the biocell replanted.
After years of painstaking nurturing and months of being under water from the flooding Mississippi River, the Sycamore Street biocell is producing a brilliance of color as the plantings take hold, mature, and spread across the cell.
“We had to do a lot of weeding, replanting, and mulching this year,” Koch said. “Then the flood came and we were worried if the plantings would survive. But go look at it now … just beautiful.”
The use of plants native to this area of Iowa was key not only for their survival but also to benefit the many pollinators that migrate through this area.
“The orange flowers of the Butterfly Milkweed and the purple flowers of the Swamp Milkweed are important elements to the cell as they are the only kind of plant that Monarch butterflies will lay their eggs on,” Koch said.
Also included in the biocell are Heath Asters, Prairie Blazing Star, Blackeyed Susan, Bottle Gentian, and Blue Flag Iris.
It is a splash of color against the sea of concrete bleakness that permeates urban landscapes. And this is just the beginning. The Sycamore Alley biocell is serving as a proving ground for the biocell that will be built in the City Hall parking lot between Cedar and Sycamore. That project should begin within the next two months.
This is not the only project that the City has been involved with recently as a grass detention basin (Mulberry Native Habitat Basin) was established at the intersection of Mulberry Avenue and Baton Rouge Road. Again the Stormwater Department teamed up with the Muscatine Pollinator Project to add native plantings that were excellent for pollinators and loved the wet conditions.
“These basins are different than biocells and can be kind of tricky,” Koch said. “It is a larger area and we added rock to the bottom to aid in the filtration of stormwater.”
Native plants are ideal not only for greenscape projects like biocells but also great plantings for individual home owner flower beds.
“Native plants are a great way to beautify your landscape and provide a home and food for vital pollinators,” Koch said. “But you need to make sure that the native plants you purchase are ones native to this area. These plants are more beneficial to bees and butterflies than any other plants.”
The Butterfly Milkweed is a long-lived perennial with clusters of small, bright orange-red flowers. Caterpillars of the Monarch butterfly rely on milkweed leaves as their sole source of food. Butterflies and hummingbird are attracted to the plant throughout the growing season.
Swamp Milkweed is a perennial with rounded clusters of pink/red flowers. Pollinated by bees, insects, moths, and butterflies, the plant is one of the favorite host plants for the Monarch butterfly caterpillar. Several species of butterflies can be found feeding on the nectar at the same time.
Heath Aster, a native perennial aster, has clusters of small flowers typically in white but can be pink, yellow or blue. The plant attracts large numbers of native bees including honeybees and bumblebees. Butterflies, skippers, and moths are also attracted to the plant.
Prairie Blazing Star, a member of the sunflower family, is a tall, upright, clump-forming native prairie perennial with violet-lavender to rosy purple flower heads that is a magnet for butterflies, birds, and honeybees.
Probably the most commonly grown of American wildflowers, Blackeyed Susan is another native North American plant used in a variety of landscapes. This wildflower is in the Aster family with cheerful blossoms that attract a variety of butterflies, birds, and other insects.
Bottle Gentian is a native plant that is slow growing but long lived, requiring little care once established. The main pollinators are large bees, such as bumblebees, who are the only insect strong enough to force open the closed petals, crawl inside to sip nectar, and deposit pollen.
The Blue Flag Iris is a showy native plant with several violet-blue flowers that attracts a variety of insects including butterflies, skippers, bumblebees, and long-horned bees, as well as hummingbirds.