It’s a green urban dream: Creating community open space, but areas that also helps the environment. Many parks and playgrounds are filled with asphalt that rainwater - contaminated with dog droppings, leaked oil from cars or fertilizer from grassy areas - runs off, never to return to the ground below to be cleansed before returning to nearby waterways.

But yesterday, almost 2,500 square feet of an asphalt parking lot in Allston was transformed into a new public green space that uses sustainable landscaping to help the environment.

The St. Anthony’s Parish property along the German International School of Boston is now the Everett Street Community Green Space that includes seven new trees, a rain garden and permeable pavement. The features help collect and treat contaminated storm water runoff from the parking lot that would otherwise flow unchecked into the Charles River half a mile away. Shade trees and wooden benches invite residents to enjoy the space while educational signs describe the sustainable design.

The project is the culmination of a two year process that the Allston Brighton Community Development Corporation, Charles River Watershed Association and community members designed.

Mayor Thomas Menino dedicated the area yesterday.

It is funded by the Massachusetts Department of Conservation and Recreation Urban Forestry Fund, the Harvard-Allston Partnership Fund and the Boston College Neighborhood Fund.