"Invisible" Floodwall
Along the Red River of the North
Project Location: East Grand Forks, Minnesota
The spring flood of 997 devastated the central city of East Grand Forks with up to 8 feet of floodwater. A 12-foot high floodwall was needed to provide 100 year flood protection but the intrusion of a typical wall or levee would obstruct the open views between the downtown and the river front. The invisible floodwall design offered a creative solution that provided the protection while maintaining the views.
The invisible floodwall structure features a decorative 3-foot high brick veneer stem wall and pilasters. It extends for a distance of 1,040 feet and transitions into earthen levees at the north and south ending points of the wall.
Civil Engineering Disciplines participating in this project.
Structural Engineers:
Design of the stem and the footings of the wall and the metal
Geotechnical Engineers:
Foundation load bearing capacity and wider sepage design.
Hydraulic Engineers:
Determine river stage during flood events to determine the height the walls should be built to.
Municipal Engineers:
Design of Utilities (storm sewer, etc.) that must be gated to restrict floodwater from backing up under the wall.
Project Features:
14 foot high floodwall, 1050 feet long, utilizing a 3 foot high stem wall with aluminum stop logs and supports.
Gateway entrance to City.
Architectural Brick Veneer and pilasters.
Flood protection while maintaining visibility to river from downtown retail/restaurant businesses.
3 closures for streets to pass through wall.
Project Awards:
Minnesota Society of Professional Engineers. Winner of the " 7 Wonders of Engineering " Award for the year 2000.
Owner:
City of East Grand Forks
Civil Engineering Firms or Agencies participating in project:
SEH Inc., St. Paul, Minnesota.
Floan Sanders, East Grand Forks, MN
Flood Control America, Sudbury, MA
Contractors:
Swidgen Construction, Grand Forks, ND
For more information, Contact:
Jeff Johnson, PE
SEH, Inc.
651-490-2000
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