The impact of the new 2008 Chicago Stormwater Management Ordinance which just took affect January 1, 2008 is already being seen in a new parking lot at U.S. Cellular Field, home of Major League Baseball’s Chicago White Sox.The new, 265,000-square-foot (more than 6 acres) permeable paving parking lot is expected to substantially reduce the amount of water entering Chicago’s stormwater system, improve overall water quality, and help reduce the urban heat island effect.  The new parking lot was put into use in April 2008.

The permeable paving system using Unilock paving stones allows water to infiltrate and collect below the paving surface, substantially reducing or eliminating the amount of water entering the city’s stormwater system and reducing localized flooding. Detained water is eventually absorbed into the subgrade below the surface and released naturally back into the environment, filtering out most contaminants.

Paving stones installed on top of a gravel bed provide a drainage capacity of over 154,000 cubic feet. Workers installed about 20,000 square feet of paving stones daily. Color variations delineate parking areas.

What aids are available for a professional civil engineer to design such a parking lot?  Unilock offers a free download of PCSWMM for Permeable Pavers-software developed for use with the U.S. Environmental Protection Agency’s Storm Water Management Model (SWMM) – to allow planners and designers to simulate the response of permeable pavements in long-term modeling applications.

More information about design of permeable pavements using interlocking pavers is available from the Interlocking Concrete Pavement Institute.  Permeable interlocking concrete pavement (PICP) is compared on their web site to pervious concrete and porous asphalt.  A comparison guide and FAQ are provided among other resources.

This entry was posted on Tuesday, April 22nd, 2008 at 2:01 pm and is filed under Civil Engineering. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.