Asphalt Green Alleys

City Planners and Engineers are working together to find a solution to stormwater runoff and the pollution it is creating in our water. Stormwater runoff is the number one cause of stream degradation in urban areas. The need for a solution is nothing new. Since the 1960’s the EPA has been working on different possible solutions.

In the 1970s the U.S. Environmental Protection Agency (EPA) determined there was sufficient benefit to the idea of porous asphalt and to provide best management practice for stormwater runoff issue and groundwater recharge.

One of the solutions more recently has been for cities to use underutilized land such as alleys. These “Green Alley’s”  were developed to transform alleys into areas that are designed and constructed using best management practices of environmentally sustainable design. Green alleys that are properly installed have been shown to reduce annual runoff by up to 80%.

A recent article from Asphalt Magazine states that “the construction of a green alley is beneficial for many reasons, the following are four ways that replacing existing alleys with porous asphalt can improve water management.

1. Groundwater

Permeable asphalt allows water to infiltrate into the ground, this recharges the groundwater table as well as reduces runoff and improves water quality. One of the major benefits of green alleys is how it reduces the impact of stormwater on the environment. Replacing existing alleys with porous asphalt allows the stormwater to seep back into the ground rather than it adding to the load on the drainage system which eventually flows into the community’s river systems.”

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