Porous paving materials allow water to pass through their surface reducing the negative impact of stormwater runoff. Most porous surfaces can function structurally as well as impervious surfaces without the damaging ecological effects. Porous materials range from structural grass to paving stones and concrete. All of these methods are used at Bayview Corner.



SUSTAINABLE FOR THE EARTH

• Added filtration protects aquifers, streams, lakes
  
• Reduce or eliminate stormwater run-off
  
• Supports heavy loads without expansive asphalt surfaces
  
• More efficient use of land without need for detention and treatment
• Replicates natural systems
  

SUSTAINABLE FOR THE WALLET

• Offsets cost of expensive conventional systems
  
• Maintenance no more costly than conventional systems
  
• Potentially utilize land that would otherwise be used for detention ponds and other conventional systems
  
• Eliminates cracking typical to conventional paving
• Grass surface doubles as entertainment/play areas while meeting fire lane requirements
  

How does it work?
Reinforced Grass (“Geogrid”): a durable plastic grid is placed over a porous base and filled with a mixture of sand, compost, and a moisture retaining additive such as Soil Moist. The area is then planted with grass. Similar to natural conditions, grass paving allows stormwater penetration and filtration rather than run-off. The grass parking lot at Bayview is Geogird.

Porous Paving Blocks:
Individual paving stones are placed over a compacted sand base allowing the penetration of rainwater through remaining voids. The paving blocks around the Half Link Bicycle Shop are an example.

Porous Concrete:
Similar to conventional concrete, but mixed without fines. This lack of fine particles leaves a network of pores through which rainwater can pass. The parking lot at the Sears House at Bayview is Porous Concrete.

What about maintenance?
Reinforced Grass: same as typical lawn surface. Not intended for heavy traffic areas. Porous Paving Blocks: same as conventional paving stones. Check voids periodically to avoid clogging. Porous Concrete: same as conventional concrete including: street sweeping, vacuuming, removal of large debris that could cause clogging.