Lunch & Learn
The INsite team recently had a lunch reviewing Sustainable and Permeable Pavement Systems (1) presented by Jamie Jenkins, a Commercial Hardscapes consultant for Jewell, an Oldcastle company. Permeable interlocking concrete pavement (PICP) is a sustainable system that can eliminate the need for detention creating more useable area on a property. Although there are other systems available for permeable surfaces, such as grasscrete (2) the PICP create a look that is aesthetically pleasing as pavers.
The PICP system is very similar to traditional pavers system and has the same structural integrity as pavers, but there are small gaps between the pavers that are filled with gravel (similar to a grout in tiling). These small gaps allow the water to penetrate though three layers of stone and aggregate where the water is retained until flowing into a drain or directly into the ground.
The system can be used to channel water into a tank for water harvesting, which can earn you LEED credits. For example, in a residential project the Owner used the PICP system and drained the water underneath the paver system to a detention tank with permeable lid. The Owner then used a solar powered pump use the harvested water for irrigation.
Reduces Urban Heat Islands
Also the lighter color pavers have a solar reflective index of 29, which means it absorbs less heat and reduces the amount of urban heat islands, which means it prevents the rise in atmospheric temperatures that many parking lots create with heat retention because of their dark surface.
Recharge Ground Water
If water detention or retention is not needed and only mitigation is required, you can allow the water to drain into the ground to recharge the ground water (depending on site and local code requirements).
The paver system is also cost effective for long term use because it is cheaper to re-level a paver system than it is to remove and replace a concrete drive or parking lot. The only down side of the system is that it requires regular maintenance with a leave blower or sweeper truck to remove debris that can block the flow of water through the pavers. However, that kind of maintenance is typical for concrete and asphalt systems for certain Owners. If there is a project dealing with limited amount land where the profits on developments are contingent upon the amount of square feet and parking this may be a viable solution if detention and mitigation requirements are consuming a significant portion of the land. However, within the City of Houston it may be difficult to get this system permitted and until they allow these systems to be used this system may be best suited for something outside the city limits, but in the county.
Demonstration: 500 gallons per minute
Belgard Permeable Pavement Systems