Sep 13, 2017

Grass Parking Lot Eliminates Runoff at California Library

Grass Parking Lot Eliminates Runoff at California Library

The new Michelle Obama Neighborhood Library is a 24,655-sq-ft single-story facility in Long Beach, Calif., that includes areas for children, teens and adults, as well as three public community meeting spaces. The library has expanded resources and programs to serve the community of north Long Beach, including assistive and adaptive technologies for people with disabilities.

The project used 4,600 sq ft of Drivable Grass in the parking areas to capture and infiltrate rainwater to reduce the runoff leaving the site. The grass helps eliminate post-development runoff, provide groundwater recharge, facilitate pollutant removal and provide for a more aesthetically pleasing site. The effective imperviousness of the project was reduced, maximizing land use.

Drivable Grass allows storm water to infiltrate into the underlying permeable base and exfiltrate to the native subgrade. By employing this in permeable parking stalls, permeable swales and other rain garden strategies, the grass eliminates the need for storm drains, plastic boxes and conventional detention basins.

It is a low impact development solution that provides opportunities for storm water containment, biofiltration, infiltration and storage. As a best management practice, it offers long-term effective solutions such as armored bio-swales and rain gardens. The low runoff coefficient helps reduce storm drain and inlet size. Its permeability reduces site runoff, promoting groundwater recharge and onsite storage. The light color and aqua rock infill reflect solar radiation, helping reduce regional heat gain. 

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