Bioretention Beyond Rain Gardensdepts.washington.edu/uwbg/docs/stormwater/Bioretention07.pdf-...
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Bioretention Beyond Rain Gardens
Transcript of Bioretention Beyond Rain Gardensdepts.washington.edu/uwbg/docs/stormwater/Bioretention07.pdf-...
BioretentionBeyond Rain Gardens
•Bioretention components-Conveyance Ideas- Overflow Ideas
•Bioretention Design Examples - Stormwater Planters- Linear Bioretention in Parking Lots- Linear Bioretention in the Street
•Rules in the Rights-of-Way•Design Notes
Presentation Outline
Tracy Tackett, PE Low Impact Development Program Manager
•Bioretention components-Conveyance Ideas- Overflow Ideas
•Bioretention Design Examples - Stormwater Planters- Linear Bioretention in Parking Lots- Linear Bioretention in the Street
•Rules in the Rights-of-Way•Design Notes
Presentation Outline
Design Components –same as raingarden
-Conveyance Zone
-Bioretention
-Overflow Zone
Design Components –Conveyance Zone
Design Components –Conveyance Zone
Pipes
Sheet Flow
Portland’s SW 12th Avenue Green Street
Design Components –Conveyance Zone
Trench Drains
Photos courtesy of Portland BES
Design Components - Bioretention
Vegetation, Mulch/compost, Surface Storage, and Infiltration area, Soil Storage, sometimes subsurface pipe
Design Components – Overflows/Surface Storage
Pipe
Trench Drain
Overflows/Surface Storage
Beehive Grate
Overflows/Surface Storage
Weir
Overflows/ Surface Storage
Cast In-Place Concrete Weir
Surface Storage
Earth BermsPhotos courtesy of SvR
Overflows/Surface Storage
Grading – overflow by directing of Sheet flow
•Bioretention components-Conveyance Ideas- Overflow Ideas
•Bioretention Design Examples - Stormwater Planters- Linear Bioretention in Parking Lots- Linear Bioretention in the Street
•Rules in the Rights-of-Way•Design Notes
Presentation Outline
Conveyance
Overflow
Design Ideas:Stormwater Planters
Design Ideas: Parking Lots
Combining Conveyance with Bioretention
Greenlake? Elementary, Seattle
Space optimization at Northgate Mall, Seattle
Design Ideas: Parking Lots
Telescope Swale Details Design Ideas:Parking Lots
Curb Cut Inflow
Beehive Structure Overflow
Private Property: parking lots
• Parking lot CAM
www.seattle.gov/dpd/GreenBuildingwww.seattle.gov/dpd/publications/cam/CAM515.pdf
Coupeville High School, Coupeville, WA
Design Ideas: Parking Lots
Wheel stop curbs allowing sheet flow
Combining Landscape Rqmts with Bioretention
? Park, Bellevue
Photos courtesy of Kevin Perry, BESApril 27, 2005
PortlandPortland’’s Green Streetss Green Streets
NE Siskiyou Green Street
SW 12th Avenue Green Street
Others…
Design Ideas: Street Right-of-Way
SeattleSeattle’’s Natural s Natural Drainage System StreetsDrainage System Streets
Offset Template
Block Scale Template Cost/Benefit Comparison
0
200
400
600
800
1000
1200
1400
1600
Template I: Curvalinear Template II: Offset Template III: Existing
Con
stru
ctio
n C
ost p
er B
lock
($10
00)
cost
infiltration surfacearea
Pot
entia
l In
fitlra
tion
Surfa
ce A
rea
(SF/
Bloc
k)
$141,000 $139,000 $109,000
863 SF
1465 SF
440 SF
Construction Costs
$280,000 for 660’ block42% Stormwater elements (including soil)45% Street improvements (road, curb, sidewalk)13% LandscapingNote: correlates to approximate $200/ LF for stormwater elements
Offset with Cascade Design
•Bioretention components-Conveyance Ideas- Overflow Ideas
•Bioretention Design Examples - Stormwater Planters- Linear Bioretention in Parking Lots- Linear Bioretention in the Street
•Rules in the Rights-of-Way•Design Notes
Presentation Outline
Working in the Street ROW
- 2-foot shoulder
- Grade down 3H:1V (4:1 at intersections)
Working in the Street ROW
-Rockery 10-feet min from curb/edge of road
-1-foot high rockery 5-foot min
P. Gaynor, 2004
Design note – Space for Grading
Leave room for grading
Design note – Space for Grading
Design Note: Soil Compaction
For road (or parking lot) stability, need heavily compacted from road prism (2H:1V from edge)
Design Note: Native Soils Variable
Native Soils in Seattle Vary Widely
Broadview Green Grid, Seattle, WA
Modified FullScale Field Testing
(PIT)
Native Soil Infiltration Rates
Subsurface Pipe
Design Note: Large Projects, if construction will be through wet season, likely to need imported soil
Technical Note: Have TESC Enforcement Procedures in place prior to construction
Raingardens in the Right of Way
SPU LID Information:www.seattle.gov/util/naturalsystems
