In Kansas City, the private sector is helping pick up the tab for green infrastructure in a new residential development.

By Zach Mortice

Since 2010, Kansas City, Missouri, has been subject to a federal consent decree, to begin properly capturing sewage and stormwater before it flows into rivers and streams. It’s a consequence of the city’s overwhelmed combined sewer system, which covers 58 square miles. From 2002 to 2010, the system produced 1,300 illegal overflows, putting approximately 6.4 billion gallons of untreated sewage into waterways annually.

Notably, this is the first time a municipal water federal consent decree has allowed the use of green infrastructure, according to Andy Shively, a special assistant to the City Manager Troy Schulte, who works on issues relating to the consent decree. And the developer-driven West Bottoms Flats mixed-use residential complex designed by Kansas City-based BNIM is shaping up to be an influential test case for ways the private sector can grapple with public sector failure toward water quality goals.

Landscape architects at BNIM have designed the flats’ green infrastructure capacity to absorb excess stormwater as a series of placemaking amenities “in order to prevent it from being [value-engineered] from the project,” says Cheryl Lough, the director of BNIM’s landscape architecture studio.

Typical residential amenities often encompass a co-working space, a roof deck, and a pool (West Bottoms Flats includes rain gardens in this category)—all of which require investment from the developer. At West Bottoms Flats, the developer is Cleveland’s MCM, a redeveloper of historic buildings in neighborhoods it deems newly fit for residential development. The company has put up $500,000 for permeable pavement alleys, rain gardens, courtyards, and a stormwater cistern to collect rainfall from the nearly four-acre site, keeping it out of the city’s beleaguered sewer system.

All watershed drainage systems work at a metropolitan scale across municipal boundaries. In Kansas City, it’s a process that also works across state lines. So how much can one complex of four buildings really do to lessen the burden on the sewer system?

“Honestly, I don’t know,” says Greg DeNicola, a senior project manager with MCM. “But it’s like any other large problem, whether it’s pollution or climate change—every bit helps. Somebody has to take the first steps.” West Bottoms Flats aims to absorb all the water that falls on the site, but also to build in excess storage capacity for other parcels to plug into. This should give “everyone that comes in after us an easy leg up,” he says.

Lough says the flats won’t make a large difference on their own, “but it does create a precedent to work from.” She hopes this project’s success will “lead to new codes and restrictions. That’s when you start to see a change across the board.”

The consent decree’s goal is 88 percent capture and containment of sewage flow, up to 96 percent containment in some neighborhood streams. This is a decades-long process: The consent decree’s deadline is the end of 2035.

“You don’t find a lot of smoking guns,” Shively says. “It’s the cumulative effect of over 140 years of wastewater infrastructure that brings us to where we are today.”

Shively says the city needs to rely on the private sector to share the burden of restorative green infrastructure. “It’s most cost-effective if we’re working with the private side to achieve the requirements of the consent decree,” he says.

The $1 million price tag for green infrastructure splits evenly between private developers and the city. BNIM is converting a group of century-old historic warehouses (part of a furniture and burlap sack factory complex) into three apartment buildings and a parking garage. The buildings lie in the flood-prone West Bottoms neighborhood, at the confluence of the Missouri and Kansas Rivers. It’s currently home to antique shops and artist studios, but the flats complex has been largely vacant. (Accordingly, BNIM pledges to preserve some of its graffiti.) Construction on the brick, timber, and concrete buildings is to start late this year. Completion is scheduled toward the end of 2019, at a cost of more than $60 million. The 265 market-rate apartments will sit on 10,000 square feet of ground-level retail, one of the first new residential projects in the area.

The four-building complex is bisected by a landscaped, intimate public street that feels more like an alley, crossed by an elevated corridor that leads to its parking structure. The three apartment buildings are huddled around a courtyard that Adam Wiechman, an associate at BNIM’s landscape architecture studio, calls the “heart of the whole design.” It’s stocked with trees, landscaping, and pervious pavers. At the courtyard’s southern tip, a rain garden is fed by a network of runnels that collect water that’s fallen on impervious surfaces.

“Making stormwater visible is one of the biggest issues,” Wiechman says, which the runnels (at three feet wide) will help with. The theory is that if people consciously engage with stormwater infrastructure, they’ll understand its dynamics and insist developments take it into account. The question remains: Who is best positioned to bring it into people’s awareness? The private sector, which has more opportunities to artfully and engagingly insert it, but can’t be compelled as yet to do so? Or the public sector, with a broad mandate, but few resources?

Zach Mortice is a Chicago-based design journalist who focuses on landscape architecture and architecture. You can follow him on Twitter and Instagram.