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

Fact Sheet

 

The City of Eastlake constructed two bioretention cells in September 2011 to treat and reduce stormwater runoff from the City’s Service Yard at 35150 Lakeshore Boulevard utilizing grant funds obtained through the Ohio Environmental Protection Agency’s Surface Water Improvement Fund (SWIF) program. Bioretention cells are landscaping features that store and treat stormwater runoff from impervious (hard) surfaces such as parking lots, roads and rooftops. Water can pick up dirt, oil and other pollutants as it flows across hard surfaces and washes it into storm drains, and eventually to Lake Erie.

The City removed 2,700 square feet of asphalt from their Service Yard parking lot and installed two bioretention cells in its place. Storm water from the Service Yard parking lot is directed to the bioretention cells’ shallow, landscaped depressions. During storms, water runoff temporarily ponds in the depressions and soaks into the bioretention cell’s plants, mulch, sand-compost soil mix, and gravel layers that remove pollutants from the water as it passes through. Once runoff filters through these layers, a drainage tile empties the filtered water to a nearby storm drain which eventually flows to the Chagrin River and ultimately Lake Erie. This project illustrates to local developers, residents and municipal and township service garages in Lake and surrounding counties that innovative stormwater management can easily be used in service yards and existing parking areas.

The City partnered with Chagrin River Watershed Partners, Inc. (CRWP) in securing the $64,479 Ohio EPA SWIF grant. CRWP provided input on the design and assisted with education and outreach associated with the project. The Service Yard is a high traffic area with high potential for non-point source pollution. This innovative stormwater best management project will benefit the Chagrin River for many years to come.

Each bioretention cell is created by removing the asphalt parking area and excavating the compacted underlying soils to a depth of 2.5 feet. Bioretention soil mix consisting of 70% sand and 30% leaf/compost material, which enables water to filter through the soil easily, is used to backfill the entire bioretention excavation area.

Stormwater that flows across the parking lot and enters the bioretention cell filters through the bioretention soil mix. Once the stormwater filters to the bottom of the soil mix, cleaned stormwater enters the existing storm sewer system through a 4 inch perforated underdrain pipe at the bottom of the bioretention cell illustrated in the detail above.

Bioretention cells are backfilled with specially prepared bioretention cell soil mix and planted with shrubs and flowering perennials tolerant of urban stormwater environments. During the growing season plants remove stormwater runoff by evapotranspiration. The plants and microorganisms in the soil mix also remove nutrients such as excess nitrogen and phosphorus from stormwater which can be problematic for fish and other aquatic life when found in excessive amounts.

The finished Eastlake Service Department bioretention cells contain plantings, wood mulch and a perimeter of turf grass to slow down and absorb stormwater runoff from the surrounding parking lot area and work zone.

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.