To help develop and assess new techniques for capturing stormwater runoff before it enters the combined sanitary sewer system, the Kansas City Water Services Dept. piloted a green infrastructure demonstration project that aims to reduce overflows by more than 20%. Instead of conveying stormwater runoff away from the site through underground pipes, the team designed a series of natural systems that allow runoff to nurture plant life on site and percolate into the ground naturally.

The system includes bioretention and gravel infiltration basins, a permeable paver system and a dry-well infiltration system, which collect, treat and infiltrate stormwater runoff. 

Photos courtesy HNTB

To capture stormwater from bridge decks on neighboring Interstate 70, the team designed a gravel infiltration system that soaks stormwater into the ground and a rainwater harvesting system with two above-ground cisterns that can capture 18,050 gallons of rainwater.

Stormwater is also routed to 169 modular soil cells, where tree roots grow. Overall, the project added 338 trees, 1,104 shrubs, 316 grasses, 7,063 forbs and three acres of native seeding.