The City of Bellingham is a big fan of pervious concrete.
After all, pervious concrete provides a structural surface capable of supporting traffic loads while also allowing water infiltration into the subgrade below, according to a city flyer dedicated to pervious pavement.
Other benefits of pervious pavement, according to the City of Bellingham, include decreased runoff to adjacent areas, faster surface dry time, faster melt-off of snow, greater resistance to freeze/thaw cracking, help in meeting stormwater requirements, and the contribution of LEED® points to construction projects.
As you know, the Pacific Northwest experiences heavy annual rainfall. Because of this, it is critical that cities, counties and other jurisdictions account for stormwater runoff in construction design.
“Stormwater runoff from impervious areas, specifically roadways, is the primary source of pollutants that are found in our regional streams, rivers, and Puget Sound,” the city states in its AMM300 bulletin on porous pavements. “A porous concrete or porous asphalt surface is one effective way to treat stormwater, as it keeps larger organic matter from downstream stormwater systems while providing an infiltration facility for aquifer recharge.”
For proof of that, a quick look at another rainy area on the West Coast — San Francisco — should help.
Just a few years ago, San Francisco tested pervious concrete parking strips and bioretention planters in several areas of the city to help with runoff management. The upshot of the city’s pervious concrete installations, according to the resulting study, was a whopping 77% reduction in rainwater overflow, on average, in the five locations.
“Measured across the whole rainy season, monitored volume reduction ranged from 56%-96% with an average 77%,” the study proclaimed.
In other words: The presence of pervious concrete alongside the impervious driving surfaces dramatically lessened the burden on the city’s stormwater system. After the installation of these green infrastructure projects, the amount of stormwater entering the system was less than a quarter of what it was before.
Custom Concrete has done similar installations of pervious concrete throughout the Cascadia Region, including many in Whatcom and Skagit counties. Pervious concrete has a number of great municipal uses, including as walking paths and parking strips.
Additionally, in the City of Bellingham, the use of porous concrete can help meet criteria that could qualify a project for a 50% reduction in stormwater development charges. To chat about how Custom Concrete can help with your next pervious concrete project, please reach out. We are the pervious concrete experts in Whatcom County, and we would love to help.