Case Study: Oregon Bioretention Cells
In the South Recreation Complex of the City of Oregon, construction has begun on a pilot project that will use bioretention cells to manage stormwater in a parking area. The area has no access to storm sewers so water must be managed where it falls. Up to now, the parking lot has used catch basins that direct rain water directly to Wolf Creek. Oregon Environmental Specialist Don Nelson wants to address the concern that the water heading to the creek will contain oils and other fluids left behind by cars in the parking lot.
The green infrastructure plan is to install bioretention cells in areas between parking lots to capture and hold stormwater. Builders are removing three feet or more of hard, impervious clay and replacing it with engineered soil made up of sand and organic material. The cells will be planted with native species that have been selected for deep roots and a tolerance for both flood and dry conditions. The water collected in the retention cells will drain gradually and some will be taken up by the plants. Many pollutants degrade naturally in the engineered soil. The system will be evaluated by researchers at the University of Toledo through a grant funded by the University of Michigan. Researchers will monitor the effectiveness of the design, collecting and testing water samples. Nelson expects that study will show that water quality is improved.
Cell one construction, Oregon.
Grants from the Great Lakes Restoration Initiative (GLRI) Surface Water Improvement Fund (SWIF) are funding the design and construction of several stormwater management projects in Lucas County. The University of Toledo is evaluating those pilot projects with the goal of providing information to developers who want to reduce the amount of stormwater entering sewer systems, remove pollutants from the water, and do so cost effectively. The TMACOG Stormwater Coalition is providing a forum for the grant recipients to discuss and collaborate on their projects. TMACOG is reporting on them as they are implemented.