09 esrm 311 green infrastructure student led field trip ...depts.washington.edu/esrm311/2016...
TRANSCRIPT
12/2/2016
1
Green Infrastructure: Case Studies in Seattle
Field Trip Leaders:Danielle Bogardus, Joe Puleo,
Andres Morales, Ed Nebendahl
What is Green Infrastructure?
Water management infrastructure
Goal is preserve, maintain, or improve natural hydrological cycles
Mimicking natural environments using engineered systems
Rain gardens, permeable surfaces, green roofs, and roof gardens
https://www.americanrivers.org/threats-solutions/clean-water/green-infrastructure/what-is-green-infrastructure/
Photo Credit: Jacob Dyste
12/2/2016
2
Why use Green Infrastructure?
Can be applied in small and large scales
Natural systems work better than “man-made” systems
Investment in green infrastructure can save money in the long run
Must protect quality of life, safety and health
Create jobs and stimulate the economy
Rain Gardens
“A rain garden is a planted depression or a hole that allows rainwater runoff from impervious urban areas, like roofs, driveways, parking lots, and compacted lawn areas, the opportunity to be absorbed.” -Wikipedia
A form of Bioretention
Temporarily store rainwater and runoff to clean the water of unwanted hydrocarbons, heavy metals, oil, fertilizers, and other pollutants
12/2/2016
3
Aspects to a Rain Garden
Shallow depression
Planted with native plants that have deep rootsGrasses
Native plants are adapted to the area
If a drought occurs, the deep rooted plants can reach down to access the lower water table
Located near a downspout, driveway, or runoff location
Goal is to collect the water before it enters the sewer system or watershed Natural filtration system
Slows the speed of the water
Soil in a Rain Garden
High infiltration ratesSand-Sandy loamStore some in the pores but then allows the rest to flow to the groundwater
A gravel bed is beneficial at the bottom where soil has slow infiltrationGravel allows for more storage, and prevents water pooling at the surface
Overflow structureRock lined notch in the bermGrass lined swaleDepends on if erosion from overflow is a concern
Do not build a Rain Garden in soil that has a high water table
Do not build a Rain Garden within 10 feet of infrastructure
Do not build a Rain Garden on a slope greater than 15%
12/2/2016
4
What are Green Roofs?
NOT roof gardens
Layers of waterproofing membranes, root barriers, drainage and irrigation systems
Completely or partially covered in soil or growing medium
Vegetation
Text & Image: Green Roofs for Healthy Cities website http://www.greenroofs.org/index.php/about/aboutgreenroofs
Benefits of Green Roofs
Opportunities for social, economic, and environmental benefits
Private stakeholder expendituresIncrease property valueImprove roofing material longevity
Ecosystem servicesReduce pollutants/runoff entering bodies of waterIncrease carbon sequestrationDecrease urban heat island effectImprove air quality
Improve human wellbeinghttp://www.seattle.gov/Documents/Departments/OSE/Green-Roofs-In-Seattle.pdf
12/2/2016
5
Permeable Pavement For Green Parking Lots
https://www.youtube.com/watch?v=1fKGwbpgLJg
● Permeable Paving○ Concrete
only 30% smaller than ⅜” aggregate○ Asphalt same as concrete○ Pavers
● Use in conjunction with natural drain-age landscapes like bioswales and rain gardens
● Help meet water quality and flow control requirementshttp://www.seattle.gov/DPD/Publications/CAM/CAM515.pdf
Permeable Pavement Uses
● Residential: Walks, Patios, Driveways
● Commercial: Pedestrian Plazas, City Sidewalks, Parking Lots
● Streets: Residential and Collector
● Not recommended for High Speed Highways, >35mph
●http://www.psp.wa.gov/downloads/LID/20121221_LIDmanual_FINAL_secure.pdf
12/2/2016
6
Permeable Paving Limitations
● Flat grades 2% or flatter, maximum slope 5%
● Needs to be engineered
● Avoid using where a seasonal high groundwater is near the surface
● Avoid using where there is routine sanding during winter months
● Minimize sediment from adjacent areas
● Avoid use on USDA type D soil (soils with a clayey texture) greater than 40% clay and less than 50% sand. Have a high runoff potential and a depth to water impermeable layer less than 20 inches.http://www.seattle.gov/DPD/Publications/CAM/CAM515.pdf
Urban Agriculture - Roof Gardens
→ Green spaces containing gardens and/or recreational areas constructed on roofs of commercial, residential, and industrial buildings.
Includes perennial gardens, lawns, walkways, benches, tables, putting greens, shrubs and
trees, rooftop farming, etc.
Growing in popularity due to environmental, societal, and financial benefits
12/2/2016
7
Ecological Benefits of Roof Gardens
Provides food and plants for consumption
Provides habitats for wildlife (i.e. pollination for insects, branches for birds to perch, etc.)
Improves air quality by reducing CO2 in air and producing oxygen through photosynthesis
Decreases stormwater runoff which can improve water quality
http://www.bestroofing.net/brv2/wp-content/uploads/2015/06/Benefits-of-a-Garden-Roof-1.png
Urban Benefits of Roof Gardens
Decrease pollution from stormwater runoff
Makes efficient use of limited urban space for cultivating crops
Increases life span of roof membranes
Temperature control reduces need for Air Conditioning
12/2/2016
8
Societal Benefits of Roof Gardens
Recreational activity and social health benefits
Provides shade for walking or lounging
Aesthetics
Saves money through less air conditioning/building maintenance
Green Roofs vs. Roof Gardens
Roof Garden Green Roof
Principal Use Recreation/AgricultureEnergy Efficiency/ Protective Layer
Maintenance/Cost High Low
AccessibilityWalkable and
high accessibilityLow to no accessibility
12/2/2016
9
Field Trip Sites
What to Look For?
A.B. Ernst Park
Permeable Paving
12/2/2016
10
http://bestseattleparks.com/wp-content/uploads/2009/12/IMG_1993.JPG
http://jennyheishman.com/public/img/etCetera/publicWorks/waterMover.jpg
12/2/2016
11
Up-Garden P-Patch Community Gardens
Roof Gardens
http://mediad.publicbroadcasting.net/p/kplu/files/styles/x_large/public/201206/UPGarden%20Landscape%20Plan%20Labeled%20-%20Final.jpg
12/2/2016
12
http://www.erichigbee.net/wp-content/uploads/2014/08/UpGarden1_Ehigbee_1200px-690x458.jpg
UW Biological Sciences Building
Rain Gardens
12/2/2016
13
UW Husky Union Building
Green Roof/Rain Gardens
12/2/2016
14
Husky Union Building Green Roof
Xero Flor Technology SystemPre-vegetated mat
Moss and sedum in growing medium
Retention fleeceDesigned to store and distribute water throughout the root zone
Drain matAllows excess water to drain below the vegetated layer
Root barrierPlastic layer over waterproofing membrane to prevent root damage to building
http://www.xeroflora.com/green-roof-system/xero-flor-green-roof-features/
12/2/2016
15
http://www.xeroflora.com/green-roof-system/xero-flor-green-roof-features/
Sources
1)http://www.raingardennetwork.com/blog/what-is-a-rain-garden/
2)http://www.fairfaxcounty.gov/nvswcd/raingardenbk.pdf
3)http://www.bestroofing.net/infographics/benefits-of-garden-roofs-infographic/