Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in...
Transcript of Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in...
![Page 1: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/1.jpg)
Development of LID Design Guidein Edmonton
Xiangfei Li and Fayi Zhou, the City of EdmontonDan Healy, AMEC Earth and Environmental
Philadelphia LID SymposiumSeptember 26, 2011
![Page 2: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/2.jpg)
1Drainage Planning
Outline
• Why LID
• Why develop LID Design Guide
• Development of LID Design Guide
• Lessons learned
• Next steps
![Page 3: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/3.jpg)
2Drainage Planning
Where is Edmonton
• 6th largest city in Canada, population ~ 780 thousand (2009)
• Located within a cold climate zone (53° 33' 0" N / 113° 30' 0" W)
• Soil predominately are silt loam and silty clay loam
![Page 4: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/4.jpg)
3Drainage Planning
Why LID?
• Corporate strategic direction– The Way We Green
• Regulatory requirements– Municipal Policies and Procedures Manual (Alberta Environment 2001)
• 85% removal for TSS >75 μm– City of Edmonton Drainage Approval-to-Operate
• Total Loading Plan– AENV Water for Life Strategy
![Page 5: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/5.jpg)
4Drainage Planning
LID Applications
Green roof
(Terwillegar Rec Centre, Edmonton, AB)
Bioswale
(Terwillegar Rec Centre, Edmonton, AB)
![Page 6: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/6.jpg)
5Drainage Planning
LID Applications
Rain garden(Trumpeter Neighbourhood, Edmonton, AB)
Rain water harvesting for plant irrigation at green house
(Enjoy Centre, St. Alberta, AB)
Bioswale(Trumpeter Neighbourhood, Edmonton, AB)
![Page 7: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/7.jpg)
6Drainage Planning
Why Develop LID Design Guide
• Technical guidance is needed– LID application continuously increasing
• Local challenges– Cold climate
– Tight soils
– Suitable vegetations
![Page 8: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/8.jpg)
7Drainage Planning
Key Project Components
Data Collection &
Review
Community Model Comparison
Stakeholder Engagement
Cost-Benefit AnalysisLID Research
![Page 9: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/9.jpg)
8Drainage Planning
Community Model Comparison
• Compare LID neighbourhood design with conventional neighbourhood design
• Assess benefits of LID neighbourhood design
• Illustrate how a “community” of LID features function together
• Provide an hydrologic modelling example
Conventional LID
![Page 10: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/10.jpg)
9Drainage Planning
Stakeholder Engagement
… towards a “made in Edmonton” solution.
• Stakeholder identification
• Advocacy sessions– Objective: to educate, inform and gather information from
stakeholders
• Roundtables– Objective: to gather technical inputs into LID Design Guide
![Page 11: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/11.jpg)
10Drainage Planning
General Guidelines
• Relevant regulatory requirements
• Overview of LID BMPs– Description and performance
– Facility selection
– Cost, benefit, cost-benefit analysis
– Monitoring and maintenance
• Local characteristics and considerations– Physical and climatic conditions, hydrology
– Size for cold climate, manage and design for salt/sand application etc.
• Site planning and design
Bioretention
Bioswale
Green roof
Permeable pavement
Box planters
Naturalized drainage way
Rainwater harvesting
![Page 12: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/12.jpg)
11Drainage Planning
Hydrological design
~90% events (duration ≤ 5 hr) are less than 26mm
Rainfall capture distribution for 26mm capture volume
Rain point diagram for Edmonton area rainfall
![Page 13: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/13.jpg)
12Drainage Planning
7 LID BMPs
• Application• Design considerations
– Design parameters and guidelines– Deign drawing requirements
• Operation and maintenance scheduling
Cross section view of a basic bioretention area
![Page 14: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/14.jpg)
13Drainage Planning
Reported Parameters Description
Sub-Soil Infiltration Rate >13 mm/hr, under-drain required in tighter soils; for design and modeling, use 50% of specified or measured rate
Inlet design 0.5 m to 3 m grass filter buffer for non-point source inlet; erosion control at point source inlet; filter strips to buffer salt impacts are required as follows: 3-5 m width along collectors (may use sidewalk) and 5-35 m width along arterials
Design Discharge Max overflow or under-drain flow rate in design events (2-year, 5-year, 10-year, 25-year and 100-year)
Surface Area 3%-30% of contributing impervious area, several small facilities provide better treatment than one large facility; facilities to be sized by designer based on snowmelt volumes and salt loadings as required
Contributing Impervious Area <4 ha; pretreatment (grass filter with level spreader, etc) to facility required if imperviousness <75%
Facility Flow Velocity <0.3 m/s in planted areas and <0.9 m/s in mulched zones, to prevent erosion
Outlet Release Rate From under-drain or catchbasin lead; less than or equal to on-site release rates defined in Master Stormwater Drainage Plan
Ponding Depth < 0.3 m during a 2 year design event; max. 0.35 m depth per City of Edmonton standards
WSE1 in Design Storms Show that HWL during 5-year, 10-year and 100-year design events does not compromise adjacent structures
Captured Volume Volume of water retained through ponding and surface infiltration during the 2 year design event; additional volume captured during larger events if applicable
Emptying Time Duration of ponded water following a 2-year design event is <48 hrs
Media Layers
Mulch: 70-80 mm depth
Growing media: (amended topsoil with infiltration rate 15-50 mm/hr) 500-1000 mm depth
Filter layer: (16-25 mm washed rock <0.1% silt) 100 mm depth
Drainage / infiltration: (>40 mm washed rock <0.1% silt) 300-1000 mm depth
Surface Geometry Flat bottom, recommended length / width = 2:1
Side Slopes 4:1 (H:V) preferred (max 2:1)
Infiltration Trench (optional) 0.5 m to 1 m depth (dependent on native soils infiltration rate); 1 m to 6 m width, through length of facility; bottom slope 0%
Groundwater Buffer Groundwater must be >1.8 m below final surface grade; facility base must be 0.6 m to 1 m above groundwater level
Structural Buffer Facility located 3 m (significant clay content) to 5 m (heavy clay soils) from building foundations
Vegetation Species selected for contaminant removal, aesthetics and inundation / drought resistance (see Appendix A)
Parameter Plan Detail Profile Description
Location x Areal extent shown on plan view (bump-outs, municipal reserves, private lots, parks)
Surface area x Outlined on plan view drawings and stated in report
Inlet x x Shown on plan view and typical detail provided (curb cut, flow spreader, ribbon curb)
Materials x x Material specs (soil, drainage layer), depth, hydraulic conductivity, porosity
Vegetation x x Planting plan and vegetation details (species, mature density, succession plan)
Outlet x x Under-drain spec & slope, spill elevation, catchbasin type and grate, weir type and location, inlet control device details
Catchment x Delineated catchment area directed to bioretention facility
Flow Arrows xFrom contributing area and overflow route
Water Depth x Ponding depth and water surface elevation during design storm and maximum prior to spill
Inundation x Extent of inundation during design storms
Erosion control x x Located at inlet, outlet if overland spill
Operation Activities Scheduling
Inspect for sedimentation, erosion, plant health, mulch condition Semi-annually (spring, fall), quarterly during establishment (2 yrs)
Avoid use as snow storage facility unless specifically designed for this purpose Winter
Strategic application of de-icing and anti-skid material on roadways contributing to facility Winter
Street sweeping to prevent sedimentation Semi-annually (spring, fall)Soil contamination testing in areas with high levels of contaminants AnnuallySoil infiltration (empty time <36hrs) and pH (5.2-7.0) testing Bi-annually
Maintenance Activities
Weed control MonthlyMow grass and remove clippings, minimum length (50-250 mm) no shorter than maximum flow depth Monthly (May-October)
Prune vegetation when access or operation limited AnnuallyLitter and debris removal from inlets, outlets, vegetation and flow paths Bi-monthlyTilling or deep raking Bi-annually, prior to infiltration testing
Sand and sediment removal Annually (spring) or when sediment depth >100 mm
Under-drain flush Annually (spring)
Erosion repair of soils, mulch, splash pad, rip rap As indicated by inspection, annually (spring)
Replacement Activities
Grass/plants (unhealthy or dead >10%) As indicated in inspection (1-10 years)Mulch, replenish or replace As indicated by inspection (1-3 years)
Soils As indicated by contaminant / infiltration testing (2-20 years)
Gravel drainage layer As indicated by infiltration testing (25-50 years)
Under-drain When flushing indicates irreparable clogging (25-50 years)
Design Parameters and Guidelines
Drawing Detail Requirements
Operation, Maintenance, and Replacement Schedule
![Page 15: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/15.jpg)
14Drainage Planning
Tools & Examples
• Recommended native and ornamental plants
• Soil amendment tools
• Cold climate facility sizing example
• Salt application example
• LID modelling example
![Page 16: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/16.jpg)
15Drainage Planning
Lessons Learned
• Local considerations– The Guide is tailored for its local climate and geographical conditions
– Update of the Guide requires further research
• Stakeholder engagement – Prepare user-oriented LID BMP fact sheets, approval checklists etc.
– Use demonstration projects
• Team collaboration
• Education– Home owners, government staff, and private industry should all be educated
on the benefits along with the development Design Guide
![Page 17: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/17.jpg)
16Drainage Planning
Next Steps
• LID research– Cold climate issues: snowmelt runoff treatment etc.
– Pollutant mass balance study
• Develop and implement long term monitoring program
• Develop local project database
• Develop LID implementation plan
![Page 18: Development of LID Design Guide in Edmonton · 2020-03-17 · Development of LID Design Guide in Edmonton Xiangfei Li and Fayi Zhou, the City of Edmonton Dan Healy, ... Rain garden](https://reader031.fdocuments.in/reader031/viewer/2022011819/5e9330f14c864a39a20feb8f/html5/thumbnails/18.jpg)
17Drainage Planning
Thank You
Questions?