1. Permeable Paving

2. Low Impact Development (LID)  Low impact development (LID) is an approach to managing stormwater runoff to protect water quality

3. Permeable Pavements  Permeable pavements are recognized as a Best Management Practice (BMP) by the U.S. Environmental Protection Agency  A cornerstone of low impact development (LID) design

4. Non-Permeable Pavements  Increased runoff  Deprives groundwater  Pollutants  Non-point source

5. Non-Permeable Pavements  1990s average was about 30,000 miles of paving per year  Parking lots affect microclimates of city climates

6. Non-Permeable Pavements  U.S. federal law mandates that states control water pollution in runoff through the National Pollutant Discharge Elimination System (NPDES)

7.  Increases the water quality  Increases groundwater  Reduces installation costs of drainage system  Reduces storm water runoff  Reduces flooding  Reduces erosion Advantages of Permeable Pavers

8. Permeable pavers  Initially, infiltration is over 50-75in/hr.  Reduce by around 50% in the first 5 years.  Over a 20-year period, designed to achieve and maintain a consistent 3in/hr infiltration rate

9. Permeable pavers  No sand used in joints  Clog pores

10. Permeable pavers  http://www.youtube.com/watch?v=xBTYFo2z9HY&featur e=related http://www.youtube.com/watch?v=xBTYFo2z9HY&featur e=related

41. Permeable pavers  Cleaning should be done at least once a year  Removed by a vacuum-sweeping street cleaning machine

42. Permeable interlocking concrete pavements  A North Carolina State University study has shown that the initial surface infiltration rate of PICPs can be as high as 2,000 in./hour. Other research has shown that near initial surface infiltration rates can be restored through cleaning and replacement of the initial 3/4 to 1 in. depth of small stones in the openings of PICPs.

43. Permeable interlocking concrete pavements  Ice and snow can melt into the pavement  Water does not collect on the surface and re-freeze

44. Permeable interlocking concrete pavements  Sand should not be used for traction  Deicing salts can  Adequate space for the ice to expand within the open- graded base  Minimizing the risk of heaving.

45. Pervious Asphalt and Concrete  Angular crushed stone, usually 3/8”, excluding fines that normally fill voids  Porous  http://www.youtube.com/watch?v=ScsQYHMfabU http://www.youtube.com/watch?v=ScsQYHMfabU

46. Pervious Asphalt and Concrete  Pervious paving may cost 10% more than conventional asphalt  Doubling as a stormwater system and eliminating storm drains, save 12% to 38%  Reduces retention ponds  Land area saved that would be used for basins

47. Pervious Asphalt and Concrete  Minor loss of porosity occurs in all porous materials over the first four to six years  One test, an inch of loose fine was applied  Full porosity was easily restore by a cleaning with a HydroVac

48. POROUS ASPHALT  Formulated with larger aggregate and less fine particles  “Open-graded” surface drains and supports traffic

49. POROUS ASPHALT  Asphalt version originally developed for airport runways  prevents dangerous surface ponding  Reservoir holds water until it percolates into soil

50. POROUS ASPHALT  Almost 40% of the reservoir’s total volume will be water- holding voids

51. Cool asphalt  Increase pavement reflectiveness  Albedo  Asphalt can be lightened  Asphacolor  Colored at plant

52. PERVIOUS CONCRETE  Porous concrete withstands heavier and more repeated loads than porous asphalt  Does not soften under heat

53. Grass Pave  Grass will not survive daily traffic  Grass for parking stays healthy if used not more than about one day a week, less in dry climates  http://www.youtube.com/watch?v=wx-CNC7f5xY http://www.youtube.com/watch?v=wx-CNC7f5xY

54. GRASS PAVERS  Open-cell unit paver in which the cells are filled with soil and filled with turf or gravel  Comprised of a grid system, which is made of concrete or synthetic to distribute the weight of traffic  Appropriate for  Foot traffic  Overflow parking  Driveway

55. Grass Pave

56. COST COMPARISON  Asphalt: $0.50 to $1 per square foot  Grass/Gravel Pavers: $1.50 to $5.75 per square foot  Porous Concrete: $2.00 to $6.50 per square foot  Interlocking Concrete Paver Blocks: $5.00 to $10.00 per square foot