Funded by Ohio EPA Surface Water Improvement Fund (SWIF) Grant

Rain Garden
Permeable Parking Area
Forested Parking

Mayfield Heights received a $231,900 SWIF grant to retrofit their municipal complex with stormwater BMPs to showcase green infrastructure practices for residential, commercial, and light industrial use. Construction was completed in July 2011 and the site was monitored for stormwater quantity capture through fall of 2012. The project was featured in the Northeast Ohio Stormwater Training Council’s Urban Stormwater Retrofit Tour in September 2011 and includes three components:

  • Rain Garden: The rain garden collects and filters stormwater from a portion of the City Hall roof equal to about half the size of a typical residential roof (1,500 square feet). The rain garden is designed to drain within 24-48 hours of a rain event and features native plants selected to withstand large amounts of water, de-icing salt, pollution, and periods of dry weather.
  • Permeable Parking Area: Nineteen parking lot spaces were converted to permeable concrete that collects and infiltrates runoff from an area similar in size to a small business or commercial area. The surface can be plowed and only requires annual vacuuming to work at peak infiltration capacity.
  • Forested Parking Lot: A combination of tree vaults, bioretention, and permeable pavement treats stormwater and provides shade to over 85 parking lot spaces. Tree shade reduces the overall heat of the lot and helps prevent heated stormwater from entering local streams. The stormwater is filtered by the permeable pavement and used by the trees, while the bioretention islands collect, treat, and infiltrate stormwater into the underlying soils. Native plantings within the bioretention cell provide additional pollutant removal.

As this project is a demonstration of a redevelopment retrofit, the redevelopment guidelines of the Ohio Department of Natural Resources Rainwater and Land Development Manual, 2006 and the Ohio EPA NPDES Permit No. OHC000003 renewed until April 20, 2013 were applied as a minimum for this project. These guidelines require a 20% reduction of site impervious area, treatment of 20% of Water Quality Volume or a combination of both criteria. The grant received by Ohio EPA hypothesized that this project would have a 4% decrease in impervious surfaces and a 20% reduction in overall stormwater runoff. To check these calculations, flow monitoring was performed on the Forested Parking Lot and Pervious Pavement Area A. Monitoring results are published in Mayfield Heights: Green Infrastructure Projects at City Hall Water Quantity Monitoring Memorandum.

This product or publication was financed in part or totally through a grant from the Ohio Environmental Protection Agency under the provisions of the Surface Water Improvement Fund. The contents and views, including any opinions, findings, or conclusions or recommendations, contained in this product or publication are those of the authors and have not been subject to any Ohio EPA peer or administrative review and may not necessarily reflect the views of the Agency, and no official endorsement should be inferred.