Landscape Performance Benefits
- Exceeds stormwater storage requirements by 21%, managing 22,049 cu ft as compared to the 18,308 cu ft originally required by the Metropolitan Sewer District.
- Achieves plant species richness of 52 within green infrastructure plantings, as compared to 2 species in lawn areas which are comparable to the initial stormwater management feature planned for the site: a turf basin.
- Provides habitat for at least 24 observed insect species in green infrastructure and prairie plantings, 23 of which are pollinators, as compared to 4 insect species observed in lawn areas comparable to the planned turf basin.
- Attains a “high” urban pollinator score of 85 for green infrastructure and prairie plantings as compared to a “low” score of 42 for the lawn areas that are comparable to the planned turf basin, based on the Urban Pollinator Habitat and Ecological Health Assessment.
- Provides outdoor space for recreation and relaxation, with 75% of 51 surveyed site users reporting relaxing or recreating in the space from once or twice per month to multiple times per week.
- Provides educational value, with 50% of 26 people surveyed who work in Cortex Innovation Community and 56% of 27 outside visitors knowing what green infrastructure is and naming at least one element on-site. Of 52 total site users, 27% reported interacting with a feature that increased their knowledge of green infrastructure.
- Promotes innovation, with 45% of 53 surveyed site users reporting satisfaction with how Cortex Commons enhances innovation.
- Promotes use of outdoor workspaces, with 55% of 53 surveyed site users reporting working in Cortex Commons from once or twice per month to multiple times per week.
- Creates 19 subcontracted maintenance jobs along with 1 groundskeeper position that supports a person with a long-term disability in reentering the workforce.
At a Glance
Former Land Use
4270 Duncan Ave
St. Louis, Missouri 63110
Cortex Commons is a central gathering space located in the heart of the Cortex Innovation Community in St. Louis, Missouri. Originally envisioned as a research park, the Cortex Innovation Community quickly became a place for start-up biotechnologies, urban residences, and retail. The central open space was previously part of a warehouse district and originally planned as a conventional turf stormwater basin. A collaborative design process instead led to a space that would become the heart of the Cortex Innovation Community, incorporating improvements for several district streets, innovative green infrastructure technologies, and design details that create an identity for the Cortex Innovation Community. The open space also supported the development of a nearby light rail station and connected bicycle and pedestrian trails as part of the Great Rivers Greenways District. The area provides a space for gathering and collaboration for the employees of over 370 companies based in the district.
- Fulfill stormwater requirements by capturing an annual rain event of 1.14 inches for the 31.8 acres of surrounding developed area.
- Improve water quality by removing pollutants including total suspended solids, total phosphorus, total nitrogen, nitrate, and heavy metals to protect downstream water bodies.
- Support native plant diversity and wildlife species through healthy soils and diverse native plantings.
- Create an outdoor amenity and gathering space that is unique and creates an identity for the Cortex Innovation Community.
- Create a space that inspires innovation, interaction, and exchange of ideas between employees of Cortex Innovation Community businesses.
- Green infrastructure technologies including biofiltration areas, rain gardens, vegetated roadside curb inlets, modular suspended pavement systems, structural soils, and pervious paving systems provide opportunities for stormwater management and the establishment of diverse herbaceous vegetation.
- The modular suspended pavement systems help support large tree growth and provide on-site stormwater management through absorption, evapotranspiration, and interception. Structural soils provide stormwater storage volume. Tree species include bald cypress (Taxodium distichum), black gum (Nyssa sylvatica), and river birch (Betula nigra).
- Over 50 species of native plants are located within the green infrastructure technologies as well as a prairie planting (which was added later) to create a natural appearance, manage stormwater, and provide bird and pollinator habitat. Dominant species that support the character of the landscape include shining blue star (Amsonia illustris), Gray’s sedge (Carex grayi), palm sedge (Carex muskingumensis), Short’s sedge (Carex shortiana), soft rush (Juncus effusus), and black-eyed Susan (Rudbekia hirta).
- Environmental education signage informs visitors about the innovative stormwater management practices and native vegetation on-site.
- Benches and other landscape features add a sense of identity to the Cortex Innovation Community. The site paving pattern is inspired by DNA sequencing, reflecting the biotechnology companies present in the district. Corten steel retaining walls evoke the historic steel industry that once occupied the site.
The Metropolitan Sewer District (MSD) created a program called the “MSD Green Infrastructure Program – Early Action Projects.” As part of a consent decree with the Environmental Protection Agency, MSD agreed to spend $100 million on green infrastructure investments over the course of 23 years. In 2012, MSD approved funding for the Cortex District’s best management practice (BMP) investments of $5.1 million over the course of 15 years to accomplish the district’s goal of combining the sewer in Duncan Avenue between Sarah Street and Vandeventer Avenue, in addition to the implementation of infrastructure practices. All BMP investments within the district completed after October 2012 have qualified towards the program.
A full-time Cortex Landscape Maintenance Manager was being considered to manage the grounds at the Cortex Commons. This dedicated position would initially cost the Cortex Innovation Community $87,057, as compared to the current overall maintenance costs of subcontractors at $106,680. The initial cost to hire a full-time employee would cost the Cortex Innovation Community 18% less than continuing the current subcontracting system and would provide improved care and ongoing planning for the site.
- The environmental, social, and economic benefits of this project were the result of strong collaboration between the Cortex Innovation Community, Metropolitan Sewer District, Metro St. Louis, professional design consultants, and the general contractor. This collaborative approach allowed for improvements for several district streets, incorporation of innovative green infrastructure technologies, transportation improvements, and a level of design detail that creates an identity for the district. Collaboration with the Metropolitan Sewer District led to the installation of varied types of stormwater management technoologies.
- Each type of green infrastructure at Cortex Commons plays a unique role in treating stormwater pollutants. This combination of practices, which include biofiltration areas, rain gardens, vegetated roadside curb inlets, modular suspended pavement systems, structural soils, and pervious paving systems, improve water quality while also providing wildlife habitat – adding significant value in contrast to the previously existing asphalt parking surface as well as the originally planned turf basin.
- Businesses that are part of the Cortex Commons Community contribute funding for the maintenance of the park. This is a unique model and has resulted in a high level of maintenance and high-functioning green infrastructure within the park and streetscapes.
- Pervious paving was used for some areas of street parking along the edge of Cortex Commons. Sediment transported in stormwater from the street quickly filled the pores of the pervious paving, preventing it from infiltrating water. To be successful, previous paving requires frequent street sweeping to remove sediment, or it should be located in areas where there is very little sediment transport. Proper maintenance of pervious paving by vacuum is also essential, as well as providing protection for green infrastructure during construction.
- Use of the site has changed over time, with the most significant changes caused by the COVID-19 pandemic and an increased number of professionals working remotely. This remote work has resulted in fewer park users during the week. It is anticipated that having a higher percentage of residential housing included as part of upcoming planned development will lead to increased park use.
- There was a decrease in vegetation management during the beginning of the COVID-19 pandemic, which led to an increase in aggressive weedy species within the biofiltration basins, influencing aesthetics and plant diversity on-site. More recently, regular maintenance led by experienced staff has resulted in attractive plantings and high plant diversity.
- Cortex Commons provides a high level of plant diversity for an urban park, which can be attributed to the different types of green infrastructure plantings, carefully considered planting plan, newly established area of prairie, and proper maintenance of plantings.
Bike Rack: Forms+Surfaces
Escofet Lungo Mare Seat: Landscape Forms
Fences/Gates/Walls: Custom Corten Steel Wall
Interpretive Signage: Design Communications Ltd. (DCL)
Irrigation: Hunter Products
Larkspur Planters: Landscape Forms
Modular Suspended Pavement System: SilvaCells by DeepRoot
Lighting: BEGA, Tokistar Lighting, and Erco LED
Trash Receptacles: Landscape Forms
Parc Centre Table and Chairs: Landscape Forms
Pavers: Wausau Tile
Permeable Pavers: Belgard Aqua-Roc
ADA-compliant Pavers: Pavestone ADA
Shade Structure: Fabritec
Soils: Cornell University structural soil supplied by Buchheit Supply Inc. and BMP soils by St. Louis Composting
Lead Landscape Architect: SWT Design
Landscape Architect: Lawrence Group
Civil Engineer: David Madison & Associates
Stormwater Modeling: Stock & Associates Consulting Engineers
Electrical Engineering: Kai Design & Build
Structural Engineer: Cowell Engineering
Lighting Designer: Randy Burkett Lighting Design
Signage and Wayfinding: Ten8
Public Art Consultant: Via Partnership
Role of the Landscape Architect
The lead landscape architect was the project lead for improving the open space of the Cortex Innovation District and played a key role in advocating for innovative green infrastructure practices. A key responsibility was to lead improvements of several district streets and a central park that was intended to be the heart of the district. The landscape architect also helped to bring in other stakeholders to promote greenway development, public transportation, and bike infrastructure.