Information from the CONCRETE NETWORK
In general, initial costs for pervious concrete pavements are higher than those for conventional concrete or asphalt paving. But total costs can be substantially lower.
The material itself is only a little more expensive, but we tend to install pervious concrete thicker than regular concrete, says Youngs. The reason is that we know the water is going to go through and saturate the subgrade underneath. So we have to design for a weaker subgrade. With a pervious parking lot, we may go 6 inches thick versus 4 inches for conventional concrete.
But he adds that when you compare overall installation and life-cycle costs, pervious concrete is the clear winner. You just cant look at per square foot costs. You have to look at overall system costs, he says. For parking lot owners, pervious concrete is a sustainable product that actually saves them money. It ends up being less expensive than a conventional parking lot.
Among the reasons why:
- Lower installation costs
According to the Center for Watershed Protection, installing traditional curbs, gutters, storm drain inlets, piping, and retention basins can cost two to three times more than low-impact strategies for handling water runoff, such as pervious concrete. Projects that use pervious concrete typically don’t need storm sewer ties-ins, which eliminates the cost of installing underground piping and storm drains. Grading requirements for the pavement are also reduced because there is no need to slope the parking area to storm drains.
- Permits the use of existing sewer systems
Pervious concrete may also reduce the need for municipalities to increase the size of existing storm sewer systems to accommodate new residential and commercial developments. Cities love pervious concrete because it reduces the need to rebuild storm sewer systems when new developments go up, says Youngs.
- Increased land utilization
Because a pervious concrete pavement doubles as a stormwater management system, there is no need to purchase additional land for installing large retention ponds and other water-retention and filtering systems. That means developers and property owners can use land more efficiently and maximize the return on their investment.
- Lower life-cycle costs
Pervious concrete is a sustainable paving material, with a life expectancy equal to that of regular concrete. Most parking areas, when properly constructed, will last 20 to 40 years, according to the Southern California Ready Mixed Concrete Association.