About this project
client
City of Saint Paul, Capitol Region Watershed District, and Ryan Companies US, Inc.
location
Saint Paul, Minnesota
cost
$13.5 M (construction)
completion date
2021 Innovative stormwater planning and design for a new Saint Paul community
With the closure of Ford Motor Company’s assembly plant in 2011—and the opportunity to redevelop the 135-acre riverfront property as a sustainability-focused, mixed-use community—the City of Saint Paul and Capitol Region Watershed District worked with Barr to develop and analyze alternative concepts for low-impact stormwater management for the property that aligned with sustainability and place-making goals. Barr compared the tradeoffs, costs, and benefits of the alternatives using stormwater modeling as well as sustainable return-on-investment and life-cycle assessment tools. The analysis led to Barr’s development of a district stormwater management plan and design that harnesses green infrastructure and a new, central water feature on the former assembly plant property—the future Highland Bridge community. The city adopted the district plan into its master plan, and developer Ryan Companies, Inc. hired Barr to complete the final design and provide construction administration services.
Construction of the stormwater management infrastructure completed in 2021. Five rain gardens, planted with native plants and equipped with iron-enhanced filters, and five underground storage and filtration systems collect, treat, and route stormwater into a nearly half-mile-long recreational pond. The pond conveys treated stormwater into the reimagined Hidden Falls Creek—buried long ago during construction of the assembly plant—before entering the Mississippi River. The stormwater management system serves as a recreational amenity while reducing intense creek flows by 98% in a two-year storm event, helping to mitigate erosion downstream. The system captures and cleans an estimated 64 million gallons of stormwater annually, preventing an estimated 28 tons of total suspended solids and 147 pounds of phosphorus from entering the Mississippi River each year. We are now assisting the city with day-to-day system operation and maintenance.