Porous Pavements for Stormwater Restoration in Urban Environments

Transcription

1 Porous Pavements for Stormwater Restoration in Urban Environments Cliff Aichinger Ramsey-Washington Metro Watershed District 1

2 Porous Pavements Why am I talking about this topic: I am not an engineer. I am a water resources planner and watershed administrator. I have a specific interest in the problems and solutions to urban water management. Stormwater runoff volume reduction and infiltration is a key to solving urban stormwater issues and meeting new volume reduction rules. Porous pavement is one of a relative few BMPs that address stormwater volume reduction. I have a specific experience with porous asphalt and have been monitoring research for about 5 years. 2

3 Why Look at New Pavement Approaches? Effects of Impervious Surfaces! Pavement covers about twice the area covered by buildings! Impervious surfaces account for about 40% of our land cover, but 70% of our stormwater runoff volume and Phosphorus loading! Impervious surfaces account for about two-thirds of surface water temperature increases! Volume reduction is now required by many City and Watershed rules and may become a requirement of state rules Benefits of Porous Pavement & Other Volume Reduction BMPs:! Keep stormwater at its source! Reduce or eliminate dissolved Phosphorus! Reduces infrastructure needs and land costs! Provides improved traction! Winter performance benefits 3

4 Alternative porous materials Each has distinctive advantages & disadvantages For any specific application Porous aggregate Very inexpensive & very permeable Porous turf Living & dynamic Open-jointed blocks Sturdy, attractive & reliable Porous concrete Quality depends on installer Porous asphalt Established Technology still advancing Costs! Vary considerably depending on contractor and project conditions! Getting more inexpensive with more local competition, more local experience, and some innovation and use of local materials 4

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6 Base Course (Reservoir) 6

7 Where Infiltration is Not Recommended! Over contaminated soils! Near steep slopes! Within 20 feet of building foundations! Near water supply wells (see DOH Guidelines) 7

8 Examples Porous Pavement! Ramsey-Washington Metro Watershed District parking lot (2005)! City of Minneapolis - numerous sidewalks, curb lines and parking (2006)! Woodbury paver cul-de-sacs (2004)! MnROAD test section (2006)! St. Peter s Catholic Church No. St. Paul (2008)! Maplewood Public Works (2007)! White Bear Lake Unitarian Church - Parking Lot (2007)! Bielenberg Sports Center, Woodbury - Parking lot (2008)! Farmington Schools - Parking lot! Mound Commercial Center - Parking lot! Park Rapids Mixed Use Development - 1/2 mile roadway and parking lots! North St. Paul Public Works Building (2009)! Maplewood Park parking lot (2008)! Shoreview Porous Concrete Street project (2009)! Troy Burne Golf Course and Stillwater Funeral Home (Porous Turf)! Others 8

9 RWMWD Parking Lot Installation Porous Bituminous Volume Reduction & Test of New Method 9

10 RWMWD Parking Lot Installation Porous Bituminous 1 to 3 feet of Clear Rock 10

11 RWMWD Parking Lot Installation Porous Bituminous Clear Rock 11

12 RWMWD Parking Lot Installation Porous Bituminous 1 Choker Course 12

13 RWMWD Parking Lot Installation Porous Bituminous Ð 1Ó Choker Course 13

14 RWMWD Parking Lot Installation Porous Bituminous 3 Pavement 14

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16 RWMWD Parking Lot Installation Porous Bituminous Pavement 16

17 RWMWD Parking Lot Installation Porous Bituminous Pavement Maintenance:! Vacuum sweep twice per year! No sanding or salting none has been required! Remove any dumped debris or dirt Results:! Some sloughing of surface rocks do to plowing or tire turning! Some tracking of sand from adjacent street and reduced infiltration rate is evident in the drive lane but doesn t reduce total infiltration capacity! Experienced several 3-5 inch rainfalls with no discharge! No surface flow no splash no icing! We are monitoring surface infiltration rates, storage bed infiltration rate, surface condition and discharge volume 17

18 Carver Subwatershed Infiltration Project Uni Eco Stone Cul-de-sac Installation! Installed 2004! Two cul-de-sacs in Woodbury! Removed asphalt and replaced with Eco Stone! Monitored for volume and nutrient reduction 18

19 Carver Subwatershed Infiltration Project Uni Eco Stone Cul-de-sac Installation Juliet Court Macbeth Court Before Before After After 19

20 National Examples 20

21 National Examples 21

22 National Examples 22

23 National Examples 23

24 Local Examples Schmelz Volkswagon New Vehicle Parking, Maplewood 2002 Uni Eco Stone Netpave 50-Rehbein 24

25 City of Minneapolis Porous Concrete Local Examples Commercial Cul-de-sac Residential Alley Edge Treatment 25

26 Local Examples White Bear Unitarian Church - Mahtomedi Porous Asphalt Church Parking Lot 26

27 Local Examples St. Peter s Catholic Church - No. St. Paul Porous Asphalt Church Parking Lot - with porous parking bays 27

28 Local Examples Maplewood Ferndale Park Porous Asphalt Parking Lot 28

29 Porous Pavement Cautions You have to select, design, and build it right. You can design it to succeed or fail.! Need quality control of the entire process and pavement mix. It requires owner knowledge & care. Every installation is site-specific.! Protection from compaction of the native soil is critical.! Erosion control around porous pavement is critical - every effort must be made to keep fines off the surface after installation. 29

30 QUESTIONS? 30