Green City Market: Blending A Park And A Farmer’s Market

In these two aerial photographs you can see how the site was initially laid out and, once the tents are removed, the effects of market traffic on the land.

Our first step was to define the challenges at the existing site. The panoramic photograph below shows the initial conditions on-site and calls out our major goals for the redesign.

Once we had a clear picture of what the location needed, we created a plan to revamp the site. First, we wanted to tackle pedestrian traffic jams by straightening and widening the paths that visitors use to traverse the site. We also needed to address the issue of drainage, which the lack thereof had turned the site into a muddy mess. The solution called for a system of underdrainage – a layering of perforated plumbing pipe, landscape filter fabric and permeable gravel buried just below the surface. This simple construction assembly allows rainfall to percolate rapidly through the soil to eliminate surface water build-up, known more commonly as puddles. We also wanted to provide the Market with an improved tent layout, expanding the number of vendors that can fit within the space while protecting the trees of our urban park – accommodating future growth in two very different ways!

The site plan above illustrates new areas of mulch (in orange), reorganized tent layout (in yellow), the widening and paving of the Park’s existing path at the north end of the site (in light gray) and the addition of a new asphalt path (in dark gray). This new path connects visitors with a route from the parking lot to the south and also serves as a walkway along Stockton Drive – which currently along this stretch has no sidewalk – thus drawing pedestrians into the park for a safer and more enjoyable outing.

Prior to installation this spring, we visited the site to spray out the routes of paths, walking via them in their imaginary form as though we were visitors ourselves experiencing their ultimate configuration in the physical reality of the space. Here’s a great before and after shot – the existing north path the day we painted its centerline and the same path this week on Market opening day.

Site visits also helped us discover unexpected challenges to our original design. On one visit I noticed the tree below was located dangerously close to a planned asphalt path. The image on the left is what I sent to our project team upon returning to the office that day, asking for everyone’s thoughts on how the pathway might affect the health of this particular tree.

This simple diagram on the right was used to study the extent to which the proposed path would intersect with the tree’s “drip line”, essentially the expanse of leafy canopy above that generally reflects the extent of the tree’s root system below. We determined the path as planned would better serve the health of the tree by not running over its “critical root zone” and causing soil compaction that would inevitably deprive the tree of much needed oxygen. The final solution, to curve the path around the tree, is shown below.

Note the undrainage in the image on the left – the white material is the pervious gravel; the vertical turquoise pipe is connected to a subsurface horizontal pipe buried within the trenches of gravel, all of which discharge into an existing city storm sewer on site.

After spending the month of May at a temporary location immediately north of this site, the market has returned to its improved permanent home. The image below shows the site enhancements now in place.

Five months after the Green City Market organizers came to us with their dream for an improved site, I finally got a chance to see it all in action. This past Wednesday, without a cloud in the sky, families, farmers and Chicagoans from all walks of life filled the new paths of the Market, enjoying the bounty of the season and soaking up the sun…and the shade.