Green Infrastructure Data Quantification and Assessment on Chicago’s Far North Side
The Center for Neighborhood Technology, St. Margaret Mary Church and School and the USEPA are demonstrating how local property owners can solve drainage problems and contribute to improvements at the community level.
St. Margaret Mary is a Roman Catholic parish with a grade school at its heart. The church is located in West Rogers Park, a Chicago neighborhood where flooding of streets and basements is common. For several years, the church activity center has suffered from backups of water into its first floor during periods of heavy rainfall.
Green Infrastructure is expected to significantly reduce flooding problems at St. Margaret while providing valuable data for research. Three kinds of Green Infrastructure best management practices (BMPs) were created in this project: a bioswale, two rain gardens and two patches of permeable pavement. While the ultimate goal of the project is to generate data for research, it is expected that the BMPs will re-establish natural drainage patterns and relieve the parishioners and students of their watery burden. Already, the bioswale and rain gardens have provided opportunities for school children and their parents to share the enthusiasm of creating a beautiful and functional landscape feature.
The bioswale will absorb about 130,000 gallons of stormwater runoff per year. The two raingardens will absorb another 16,000 gallons per year. The capacity of the pervious pavement needs to be measured, but perhaps another 80,000 gallons per year will be absorbed there. These total more than enough water to fill two typical high school swimming pools.
This stormwater runoff that could otherwise cause flooding and potential sewer overflows now drains back into the soil, where it can complete the natural hydrological cycle. The school community can now benefit from an on site natural laboratory for science education. And St Margaret Mary has the honor of being the vanguard of a developing “green” movement throughout the West Rogers Park and Rogers Park communities.
Background
As the most recent glaciers retreated from the basin of Lake Michigan about 13,000, one of the features that remained was a north-south beach ridge that is now about a mile west of the lake. Ridge Avenue is now the dividing line between Rogers Park and West Rogers Park. Documented settlement of West Rogers Park began in 1809 when the first tavern was built on the ridge. Philip Rogers and his brothers bought 1,600 acres of land here from the U.S. Government in 1836. Chicago’s waterworks and the Columbian Exposition of 1893 provided the impetus for annexation to Chicago: in 1893, West Rogers Park and Rogers Park became the northernmost neighborhoods for the city of Chicago.1
The area west of the ridge was characterized as swampy, consistent with the wetlands and marsh that once existed before settlement. The settlements were mostly made up of farmland, vegetable gardens and greenhouses.
St. Margaret Mary Church was built in 1921 two blocks west of Ridge Avenue—the same location that St. Margaret Mary School now occupies. The parish was founded by Luxembourg and Irish families who lived in the area. “They envisioned a parish that would be woven into the fabric of their everyday lives—not a show-place church.” Generations of families have attended (and continue to attend) the school and church.
Site description
CNT initially called the City of Chicago to find out what communities had most frequently called the 311 non-emergency number to register complaints about flooded streets and basements. Unfortunately, there are no communities that didn’t make lots of these calls. But when City staff searched for specific blocks where the calls were most frequent, the St. Margaret Mary location was among the standouts. CNT made contact with the facilities manager of the church, and found that, not only was there frequent street flooding, but water occasionally backed up into ground floor hallways in the activities building.
Most storm sewers in the streets that surround St. Margaret Mary are only one foot in diameter and thus are over-burdened by the stormwater runoff from large roofs, small building lots and parking lots. Green infrastructure is an ideal strategy for the site because there is room for a variety of BMPs that can be located throughout the church property and in nearby yards.
The siting and design of BMPs on the site were challenging, however, because CNT’s research objectives had to blend with the parish’s needs. A bioswale was at first designated for a parking lot across the street from the church campus, where it would be out of the way. But the parish priest, Father Jim Barrett suggested putting it at the front door of the church in a parking lot where traffic patterns were a problem, and where he could enjoy it from his office and the rectory porch. Thus, it is located at the center of the parking lot in the main courtyard, where it creates a beautiful entryway to the church and school campus and effectively controls foot and car traffic, as well.
Swale and Garden Design and Monitoring
The bioswale measures 18 feet by 50 feet, and receives runoff from ___ square feet of pavement. Excavation to a depth of 27 inches was followed by refilling the bioswale to a depth of 12 inches with prepared soil along with up to an additional 15 inches of soil around the edges at a 3 to 1 slope. Seventeen species of native plants (500 individual plants) were installed in the bioswale by children at the school, with the assistance of GreenCorps, a Chicago job training program. Each of the two rain gardens at St. Margaret Mary has a different soil profile in order to compare the performance of different designs. Both rain gardens are 12 by 8 feet in size, and each drains a roof area of 600 sq.ft.. Each rain garden contains six species of native plants and approximately 60 individual plants.
Rainfall data and the performance of the bioswale and rain gardens will be measured through an on-site rain gauge and two monitoring wells and a soil moisture meter in each of the three BMPs. Each piece of equipment is configured to record data at 5-minute intervals; the data will then be downloaded at least once every thirty days. Monitoring began in October 2007, but was discontinued in November when freezing threatened the electronic equipment. Quantitative monitoring results will be available during the summer of 2008 and will continue the rest of that year. Funds are being sought to maintain the monitoring for several more years as the landscapes mature.
The total cost of excavation, materials, labor, plants and fencing for the swale and raingardens was $15, 400, about half of which was for excavation and fencing. The project also incurred additional design and engineering costs of $7,500.
Public Involvement
- Talk about the Blessing of the Swale
- The cooperation of Ozinga Brothers
CNT teamed with the City of Chicago’s Green Corps, leaders at St. Margaret Mary Parish and the students and teachers of St. Margaret Mary School to install the swale and raingardens. Before the construction of the vegetated swale, a parent who was an amateur archeologist discovered some artifacts in the excavation. The school principal encouraged teachers and parents dig up buckets of dirt that the school’s fifth through eighth graders sifted through with sieves. The archeological dig revealed fragments from the farmhouse that had stood on the land prior to the founding of St. Margaret Mary: students found hundreds of artifacts, including an old pitchfork, two intact blue Depression glass jars, and pieces of dishes that could be glued back together.2
The swale was then constructed by Chicago Green Corps and completed with the help of the entire student body, who added the final touch: 500 native prairie plants and mulch. The two rain gardens were also constructed by Chicago Green Corps and the students.
In an effort to educate the public about the benefits of permeable pavement, Ozinga Bros. Inc. donated the construction of two patches of pervious pavement in a rear parking lot of the church. On October 28, 2007, the green infrastructure was blessed and officially dedicated at St. Margaret Mary’s by Father Barrett.
CNT began during the winter to work with the 49th Ward GreenCorps, a volunteer group, to identify other sites in the area to serve as demonstrations of green infrastructure. Property owners will be assisted by the group during 2008 and beyond to build rain gardens that serve the community with stormwater management benefits and spark others to gain similar benefits.
Figure 1: Students at St. Margaret Mary School plant the bioswale under the direction of Greencorps
Figure 2: Students plant the two rain gardens
Figure 3: The St. Margaret Mary site after planting was completed
Figure 4: Blessing of the St. Margaret Mary gardens
Figure 5: Construction of demonstration pervious pavement at St. Margaret Mary Church
Plans are being made for working with each of the communities to locate sites for other demonstration BMPs in the neighborhood. In the Calumet area, the Southeast Environmental Task Force is the major local partner. In Rogers Park, the 49th Ward Green Corps is the major partner.
Link to Photo Gallery.
