The Great Rivers Greenway District is developing a network of greenways, parks and trails, known as the River Ring which encircles the entire St. Louis region. As part of the greenway development effort, Great Rivers Greenway commissioned a team, consisting of Intuition & Logic and Planning Design Studio, to develop preliminary plans for the Plymouth to Etzel Avenue segment of the St. Vincent Greenway. This north-south segment will extend the greenway to a neighborhood park at Plymouth and Stephen Jones Avenue adding a destination to the greenway and a connection to the trail network for the residents of Wellston.



The proposed 10 foot wide trail will widen the existing sidewalk along Etzel Avenue and provide a new trail parallel to Engelholm Creek. The proposed greenway will include landscaping and have a grass channel along the section parallel to Engelholm Creek. The channels will drain to four proposed area inlets, which will outlet into the creek. One inlet will tie into an existing outfall, the remaining will be new discharge locations.  Rock grade control structures are proposed for each new outfall and were located on existing riffles.  The grade controls will be planted with livestakes to mitigate the construction impact to Engleholm Creek. 



Intuition & Logic was the project civil engineer responsible for site development and stormwater management. As part of the preliminary plan development, we performed a conceptual plan review submittal with the Metropolitan St. Louis Sewer District to obtain concurrence for the proposed water quality treatment approach.  The water quality approach consisted of a single bioretention cell and grass swales.  The bioretention cell is located adjacent to a rest area and will be a prominent landscaping amenity along the trail. We also developed a HEC-RAS model and performed a No-Rise analysis for the proposed trail and amenities.