the water balance model for...
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www.waterbalance.ca
The Water Balance Model for Canada:The Water Balance Model for Canada:Improving the Urban Landscape through Improving the Urban Landscape through
InterInter--Provincial PartnershipsProvincial Partnerships
Kim Stephens, Kim Stephens, PEngPEng, Project Coordinator,, Project Coordinator,InterInter--Governmental PartnershipGovernmental Partnership
&&Bert van Duin, Bert van Duin, PEngPEng, Steering Committee, Steering CommitteeAlberta Low Impact Development PartnershipAlberta Low Impact Development Partnership
Watershed & Stormwater Management Webconference
www.waterbalance.ca
“Do you know where you really are in the shifting paradigms of
stormwater management?”
1. Run it in Ditches2. Run it in Pipes3. Run it in Stormwater Pipes4. Keep it from Stormwater Pipes5. Well, Just Don’t Cause Flooding
6. Oh, and Don’t Pollute Either
7. It’s the Ecology, Stupid
8. Water is Water is Watershed
9. Green and Bear It
10. Build the Vision, Create the Legacy
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Universal IssuesUniversal Issues
Population Population SurgeSurge
Landscape Landscape TransformedTransformed
Creeks & LowlandsCreeks & LowlandsImpactedImpacted
Natural HydrologyNatural HydrologyAlteredAltered
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1999 2010 2020 2030 2040 2050
0
10%
20%
30%
40%
50%
60%
70%
80%
Ann
ual R
ainf
all a
s R
unof
f (%
)
Year
The Watershed Picture:Without Rainfall Capture
Target Condition
+ Climate Change
Impacts from Growth
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The ScienceThe Science British ColumbiaBritish Columbia AlbertaAlberta
Mind Map
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Drainage Planning in British ColumbiaDrainage Planning in British ColumbiaHas Been Has Been Evolving Over the DecadesOver the Decades
1960s: Pipe and Remove 1970s: Detain Peak Flows 1980s: Reactive Mitigation 1990s: Stream Stewardship
(Proactive Management)
2000s: Rainwater Management (Sharing a Vision)
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The “Trickle-Down” Evolution of Watershed Management in BC
(How the Past is Influencing the Present)
1970s - society’s reaction to the “dam builders”
2000s - society’s reaction to the “pipe sizers”
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Initial ImpactInitial ImpactAt About 10%At About 10%
By 30% may be By 30% may be unable to sustainunable to sustainselfself--supporting supporting coldcold--water fishwater fish
Land Use Change and Aquatic ImpactsLand Use Change and Aquatic Impacts
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The Mean Annual Flood (MAF)is the ‘channel-forming event’
When the MAF increases, the channel erodes to convey
the additional volume
A consequence of channel instability is habitat degradation
Sedimentation
Erosion
Why Manage Volume
Volume IncreasingVolume Increasing
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The ScienceThe Science British ColumbiaBritish Columbia AlbertaAlberta
Mind Map
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www.waterbalance.ca
Water Sustainability Action Plan for British Columbia
WaterBucketWebsite
Partnership
Convening for Action:
Roundtable on
Water Sustainability
Green Infrastructure
Partnership
Water Balance Model
for BC
Water $aveTool Kit for BC
Watershed/Landscape-based Approachto Community Planning
waterbucket.ca is the communicationvehicle for the Action Plan
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CommunitiesCommunities--ofof--InterestInterest
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Inter-Governmental Partnership: Vision
To promote changes in land development practices so that:
The built environment will preserve and/or restore the natural water balance over time Performance targets will be achieved for
rainwater runoff volume and flow rate reduction at the source, where rain falls
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The Water Balance Model is…The Water Balance Model is…
A tool that quantifies the benefits A tool that quantifies the benefits ––in terms of reducing in terms of reducing rainwater runoff volumerainwater runoff volume-- of installing source controls under different of installing source controls under different
land use, soil and climate conditionsland use, soil and climate conditions
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The Water Balance Model is the result of a Building Block Process:
GVRD Report on Stormwater GVRD Report on Stormwater Source Control EvaluationSource Control Evaluation
ChilliwackChilliwack Policy & Design Manual Policy & Design Manual for Surface Water Management for Surface Water Management
Stormwater Planning: Stormwater Planning: A Guidebook for British ColumbiaA Guidebook for British Columbia
UniverCityUniverCity: : The Sustainable Community at the The Sustainable Community at the Top of Burnaby MountainTop of Burnaby Mountain
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UniverCity on Burnaby Mountain was the trigger for the Water Balance Methodology
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Key Message: Anybody with a computer
and internet connection can access the model
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Policy Evaluation Policy Evaluation Decision SupportDecision Support Scenario ModelingScenario Modeling Master PlanningMaster Planning
Detailed DesignDetailed Design
OperationsOperations
StrategicStrategic
Functional Functional PlanningPlanning
Where the Water Balance Model fits on the ‘Modeling Hierarchy’
PrePre--DesignDesign
www.waterbalance.caHow Water Moves Through Soil
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Simplifying the Technical Language in British Columbia!
Basic Source Control Types in GVRD Guidelines: Absorbent Landscape Rain Gardens Infiltration Swales Pervious Paving Green Roof
Planners: Tool for Better Use of Space Engineers: Tool for Pre-Design Landscape Architects: Tool for Green Solutions Ecologists: Tool for Watershed Function Educators: Tool for Social Marketing
Water Balance Model promotes Water Balance Model promotes Integration of PerspectivesIntegration of Perspectives
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Integration of Perspectives
Left-handed engineer
Right-handed planner
Key Message:Key Message:Integrate Actions at Three Scales: Integrate Actions at Three Scales:
Improve Site Practices to Improve Site Practices to Enhance Community LivabilityEnhance Community Livability
Site
Building sizeBuilding size
Hard surfaceHard surface
LandscapingLandscaping
Watershed:
ZoningZoning
Road DesignRoad Design
Green spaceGreen space
LandscapingLandscaping
‘‘BMPsBMPs’’
Neighbourhood:Neighbourhood:
Lot sizeLot sizeRoad DesignRoad DesignGreen spaceGreen spaceLandscapingLandscaping
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How the Water Balance Model is being used to make better decisions:
Local Governments -when communicating with the public
Planners and Engineers –when setting performance targets
Developers and their Consultants -when testing scenarios
Environmental Agencies -when monitoring watershed health
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Practical Site Level Solutionsare Typically Landscape-based
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Key Messages
‘Break the connection’ Encourage ‘rain gardens’
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‘Break the Connection’ with a Rain Garden
Simple Infiltration + Reservoir+ Overflow
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The first ‘Engineered Rain Garden’ in British Columbiahas been constructed by Westbild as a Demonstration Project
on the Westwood Plateau in Coquitlam
Roof Drainage DischargesInto Rain Garden
High Level Overflow
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Performance Monitoring Results During November 2004 Wet Weather Period
Total Rainfall for 2-day period = 80mm Total Rainfall Volume = ~11.3m3
Total Outflow Volume = ~8.2m3 (i.e. 73%) Total Volume Absorbed = ~ 3.1m3 (i.e. 27%)
(This is equivalent to the first ~22mm rainfall)
Performance Monitoring Results During the period Nov/04 Mar/05
Rainfall Volume vs Discharge
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2
4
6
8
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11/2
3/20
04
11/3
0/20
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12/7
/200
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12/1
4/20
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12/2
1/20
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12/2
8/20
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1/4/
2005
1/11
/200
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1/18
/200
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1/25
/200
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2/1/
2005
2/8/
2005
2/15
/200
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2/22
/200
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3/1/
2005
3/8/
2005
3/15
/200
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Date
cubi
c m
etre
s of
rai
n
Rainfall Runoff (m3)Overflow Discharge
28% rain volume
absorbed (22 mm)
40% rain volume
absorbed (41 mm)
39% rain volume
absorbed (37 mm)
f low me te r ins ta l led
42% rain volume
absorbed (48 mm)
44.5% overall rainfall absorbed
93% rain volume
absorbed (23.4 mm)
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1999 2010 2020 2030 2040 2050
0
Ann
ual R
ainf
all a
s R
unof
f (%
)
Year
The Watershed Picture:With Rainfall Capture
Target is Specific to Target is Specific to each Watershed as each Watershed as determined in each determined in each
Watershed PlanWatershed Plan
Watershed Target (varies)
10%
20%
30%
40%
50%
60%
70%
80%
The ScienceThe Science British ColumbiaBritish Columbia AlbertaAlberta
Mind Map
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Infrastructure Standards
Decision Support
ToolPlanning Philosophy
Alberta Low Impact Development PartnershipAlberta Low Impact Development Partnership
Promoting Sustainable Promoting Sustainable DevelopmentDevelopment
Alberta Challenges Alberta Challenges
Population and urban growth are leading to deterioration of our environmentFor instance, Calgary has grown by over 25% in the last decade
Differences in servicing strategiesEdmonton has combined and separated drainage systems
Other communities have fully separated drainage systems
Urban development is altering the hydrological balance of our watersheds
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Alberta challengesAlberta challenges
Little is known about the interaction between surface and sub-surface conditions
Increased volumes of stormwater are changing stream morphologyExample: West Nose Creek watershed in Calgary region
The biggest impact is on smaller streams and urban wetlandsCalgary has a very progressive Wetland Protection Policy
Alberta Challenges Alberta Challenges
Alberta Environment is encouraging sustainable infrastructure, resource conservation and pollution prevention
Alberta Water for Life Strategy – goals:Safe and secure drinking water supply
Healthy aquatic systems
Reliable water quality for a sustainable economy
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Alberta ChallengesAlberta Challenges
Alberta is susceptible to drought conditions and future availability of water may be threatenedResearch by Prairie Adaptation Research Collaborative (PARC) cautions for reduced flows in late summer and greater variability
Residential land development can generate 10 to 100 times more storm runoff when compared to pre-development conditions
Stormwater ponds attenuate peak flows, but they do not reduce the volume of runoffIn addition, they may worsen thermal ‘pollution’ and are questionable with respect to finer sediments, nutrients and operation during winter months
Benefits of Low Impact DevelopmentBenefits of Low Impact Development
Need for a complete, integrated approach to water management (water-centric or water-sensitive)
Stormwater source controls and LID strategies reduce the runoff peak flows AND volumes
Reducing the discharged volumes results in reduced pollutant loadings and improved hydrological balance in the watershed
Through stormwater collection and reuse, the demand on potable water supplies is lessened
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Alberta Low Impact Development PartnershipAlberta Low Impact Development Partnership
The Alberta LID Partnership was formed in November 2004, after aLID workshop organized by the Alberta chapter of ALMS
Initial reactions were mixed – planners and architects are open minded (past experience with LEED) while engineers are cautious until they realize that they need each other to implement change
The invitation by the BC IGP to participate in the evolution of the Water Balance Model brought people together who share a common vision
By March 2005, The Terms of Reference for ALIDP were finalized, and a Steering Committee was elected.
ALIDP MembershipALIDP Membership
The City of Calgary The City of Edmonton The City of Red Deer The City of Lethbridge The City of Airdrie The Town of Cochrane The Town of Okotoks The Towns of Black Diamond and
Turner Valley MD of Rocky View
Alberta Environment
Bow River Basin Council
North Saskatchewan Watershed Alliance
Elbow River Watershed Partnership
University of Calgary
UDI Alberta
Alberta Real Estate Foundation
Alberta Chapter of CMHC
Alberta Lake Management Society
The membership is open to all Alberta municipalities, individualThe membership is open to all Alberta municipalities, individuals and s and organizations with interest in land development and environmentaorganizations with interest in land development and environmental l protectionprotection
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ALIDP GoalsALIDP Goals
1. Facilitate development of an Alberta LID strategy to promote changes in land development practices: Sites will be designed to mimic the natural hydrologic
conditions to the extent possible
Adequate stormwater source controls will be implemented where suitable
Performance targets for stormwater runoff volume and rate reduction will be achieved
ALIDP Goals ALIDP Goals
2. Coordinate the regulatory, technical and communication aspects of LID strategy
3. Develop an outreach and education program to enhance public understanding of LID
4. Anticipate future issues related to sustainable development, watershed protection, and climate change
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Early Challenges and DiscussionsEarly Challenges and Discussions
ALIDP and national initiatives allow for exchange of ideas and information
Universality with local variations (e.g. cold climate)
Do not get stuck on particular methods but look at the entire toolbox available, and allow it to evolve
Need regulatory framework and clear information on why we would be interested in doing this
Early Challenges and DiscussionsEarly Challenges and Discussions
Need first of all public education and outreach
Provides impetus for further research, pilot projects, etc. by pooling resources
ALIDP is more than just a model
Commitments to partnership, not to any tool. But need tools to demonstrate impacts and what practically could be done
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ALIDP Action PlanALIDP Action Plan
Formalizing the ALIDP
Map out the process – what is needed to make LID a reality in Alberta
Identify stakeholder needs
Develop public education and outreach programs
Promote further research through demonstration projects
Examples of onExamples of on--going and new LID initiativesgoing and new LID initiatives
Stormwater re-use for irrigation
Full-scale test sites of green roof system, swale, bioretention area and permeable pavement
Bioretention and permeable pavement at University of Calgary
Experimental constructed wetland (69th Street SW, Calgary)
Land-use bylaw template
Nose Creek Basin Instream Flow Needs Initiative
Preparation of BMP Scoping Study (Calgary)
Preparation of BMP and Source Control Manual (Calgary)
Conceptual design of LID subdivisions minimizing impacts on streams and wetlands
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Alberta Alberta –– British Columbia British Columbia
After ALIDP is formalized, the ALIDP is expected to enter into an inter-provincial partnership with the BC IGP
Synergies between 1998 British Columbia Strategy & Alberta’s Water for Life initiative
BC IGP has already created Alberta page on national portal
Joint presentations being done by BC IGP and ALIDP
Feed-back from ALIDP led to evolution of QUALHYMO
From BC to Alberta to Canada to ???
The Mission is to The Mission is to Create a LegacyCreate a Legacy
Influence choices by individuals and organizationsInfluence choices by individuals and organizations
Use the term “sustainability” as a lens for Use the term “sustainability” as a lens for considering approaches that influence choicesconsidering approaches that influence choices