Our new pervious pavement parking lot has just been installed! It has all the great features we all expect from a parking lot, but in addition, it also absorbs rainfall runoff. That means it is one of the ways we are acting as responsible stewards of our "piece of the Earth." Because our stormwater can be absorbed by the soil under the parking lot, we are helping to restore the natural hydrology in our watershed. That means better water quality downstream, less runoff for our city infrastructure to manage, and happier fish in our rivers.
We used two different kinds of pervious pavement in our parking lot.
For the main driving surface we installed pervious concrete. It is just like normal concrete, except that the sand particles have been removed from the cement mixture. Some people describe the texture as like a "rice crispy treat". That means when it cures, it has tiny holes in it that allow the water to flow through. So, it helps us recharge the groundwater underneath our property, and...when it rains, our feet don't get wet!
The parking stalls were paved with pervious pavers. They look just like normal pavers, but they are spaced so there are small gaps that allow rainfall to pass through.
We were also careful to make sure we selected pervious products that are light in color. That way in the summer when the sun is shining, our parking lot absorbs less heat from the sun. This helps us reduce the amount of heat our site contributes to Portland's urban heat island effect. That keeps us all cooler and reduces our need for air conditioning and energy usage.