Lowry Avenue Bridge over the Mississippi River - Improving Water Quality
City of Minneapolis, Department of Public Works
SRF Consulting Group, Inc.
Minneapolis Park and Recreation Board
Minnesota Department of Transportation
Rani Engineering, Inc.
T.Y. Lin International Group
The Lowry Avenue Bridge over the Mississippi River in Minnesota includes an innovative water treatment design, developed by Hennepin County and its partners. Prior to reconstruction, the existing bridge employed an open-grate deck that allowed pollutants from vehicles and runoff to drain directly into the river. A large trunk storm drain system also discharged untreated stormwater into the river at the base of the east abutment. Stormwater management practices have changed considerably since the construction of the original bridge. The new Lowry Avenue Bridge project provides the opportunity to bring the drainage system up to current standards and to incorporate new, innovative water quality practices.
To meet the unique challenges presented by Lowry Avenue's topography and existing groundwater systems, Hennepin County and its partners developed an underground sand filter system to address water quality. The resulting system removes 85 percent of total suspended solids in stormwater for 10.5 acres of the corridor and provides low-flow treatment for an additional 127 acres. Having this filtration system in place prevents over 14,000 pounds of total suspended sediment from reaching the river annually. The project serves as an exemplary model of how innovative and sustainable urban stormwater management practices help to protect valuable natural resources and improve water and ecosystem quality.
The Lowry Avenue Bridge Project integrates a landmark steel arch river span with multiple other enhancements. A bird's eye view of the bridge is shown here, as it is opened for use.
Photo: SRF Consulting Group, Inc.