The Morningside Neighborhood located in the City of Edina, Minnesota, had been grappling with persistent flooding, particularly in low-lying and landlocked areas. The escalating effects of climate change only intensified the flooding risks, necessitating a robust response to safeguard the community. An essential principle of this project was to ensure that the benefits were equitably distributed across the neighborhood, without worsening risks to any property.
The project's strategy involved a combination of ponds, pipes, and surface swales to safely manage and store floodwaters. Specifically, an extended pipe and swale system were designed to manage overflow from the Lynn/Kipling inundation area and the Grimes Avenue low point. Additionally, an expanded and reconfigured pipe network, coupled with minor grade adjustments, effectively directed water away from homes. As part of the plan, both Weber Pond and the Lynn/Kipling Pond underwent expansion and lowering. Notably, a portion of Weber Woods saw the removal of approximately six acres of trees to accommodate the larger ponds.
Barr, the project engineer, meticulously assessed the technical requirements and selected DuroMaxx® steel reinforced polyethylene (SRPE), a robust drainage solution from Contech Engineered Solutions. DuroMaxx® SRPE is notable for offering the structural advantages of traditional High-Density Polyethylene (HDPE) without its associated drawbacks. The steel-reinforced ribs integrated into the DuroMaxx® SRPE ensures its durability by preventing creeping or buckling. Moreover, this innovative solution is twice as stiff as non-steel-reinforced HDPE, rendering it highly resistant to the impact of temperature and sunlight.
The inclusion of a High-Performance (HP) bell and spigot joint in the DuroMaxx® SRPE enables it to withstand pressures of up to 10.8 psi. The smooth interior design of the pipe ensures hydraulic efficiency and can accommodate Manning's "n" values within the range of 0.011 to 0.013. This feature is instrumental in creating designs with minimal slope requirements and longer pipe runs.
In addition to the flood risk reduction measures, the project encompassed several other valuable components:
- Natural Resources Restoration: The project included restoration efforts in upland areas to preserve and enhance natural resources.
- Nature Trails and Bridge Crossings: Two new nature trails and bridge crossings were introduced at Weber Park, providing residents with opportunities for recreation and connection to nature.
- Improved Accessibility: The project incorporated ADA-compliant trails in Weber Park, ensuring improved pedestrian access to the park.
- Sports Field Rehabilitation: Areas impacted by the project's construction saw the revitalization of sports fields, featuring new turf and efficient irrigation systems.
The coordinated execution of this flood infrastructure project coincided with planned roadway reconstruction within the neighborhood, which took place in 2022 and 2023. This dual approach aimed to optimize efficiency and minimize disruptions for the Morningside community, ensuring a holistic enhancement of the neighborhood's infrastructure and resilience in the face of climate-induced challenges.