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Cost Effectiveness of LID Implementation
Green infrastructure can provide flood control, erosion control, and water quality benefits but the costs must be considered. A case study in Markham, Ontario found that a green infrastructure strategy was not cost-effective for flood control compared to conventional grey infrastructure strategies when considering capital and lifecycle costs. While green infrastructure provided benefits, the annual costs were much higher than the annual benefits. The study also highlighted concerns with infiltration from green infrastructure increasing risks of basement flooding and degradation of drinking water sources.
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Cost Effectiveness of LID Implementation
- 1. MECP Stormwater Designand Permissions Working Group Cost Effectiveness of LID Implementation Robert J. Muir, M.A.Sc., P.Eng. Manager, Stormwater, City of Markham June 26, 2019 - Toronto, Ontario 1
- 2. OUTLINE 1) Regulations &Policies on Cost Effective Infrastructure 2) Ontario Capital Costs for Green Infrastructure 3) Ontario Lifecycle Costs and Economic Impacts 4) Grey and Green Benefits & Costs for Flood, Water Quality and Erosion Mitigation 5) Green Infrastructure Infiltration & Flood Risk 2
- 3. Provincial Policy Statement(2014): “Infrastructure … shall be provided in a coordinated, efficient and cost-effective manner ….” Infrastructure for Jobs and Prosperity Act (2015) O. Reg. 588/17 (2017): Asset management plans must show “For each asset category, the lifecycle activities that would need to be undertaken … and the costs of providing those activities.” These activities must also consider “the lowest cost to maintain the current levels of service” Class Environmental Assessments (2015): For wastewater projects “Economic Environment includes commercial and industrial land uses and activities. It also includes the financial costs associated with the alternatives, including construction, operation, maintenance, and property costs.” Regulating Infrastructure Cost in Ontario 3 Provincial Policy Statement 2014 Infr. for Jobs and Prosperity O Reg 588/17 Municipal Class EAs
- 4. History of Cost-BenefitAnalysis (CBA) 4 • Long-standing requirement to evaluate feasibility of flood reduction projects: Eckstein 1958: “Feasibility is interpreted to mean that ‘the benefits, to whomever they may accrue, are in excess if the estimated costs’, following a requirement specified in the Flood Control Act of 1936.” Watt 1989: “It is therefore reasonable to require that all projects that provide or improve flood protection be justified economically before public funds are allocated” “benefits should exceed cost by a sufficient margin” https://files.onhttps://nparc.nrc-cnrc.gc.ca/eng/view/accepted/?id=7b18d8c9-6c5f-425f-8338-ac4a24f8170bario.ca/infrastructure_update_2017-_eng_0.pdf Watt 1989:
- 5. Ontario Green InfrastructurePolicy 5 • Ministry of Environment and Climate Change (now Ministry of Environment, Conservation and Parks) draft LID manual proposed Ontario-wide targets. Did not address costs. “Excessive costs alone shall not be considered an acceptable constraint” (first draft) Draft No. 2 LID Manual: https://drive.google.com/open?id=1NHtrjCglDgox4tYISLU5LLZYS32Ea4MN
- 6. Made-in-Ontario Environment Plan •“This plan will ensure we balance a healthy environment with a healthy economy.” • Highlights frustration of taxpayers who see “hard-earned tax-dollars being put towards policies and programs that don’t deliver results”. • Cost-benefit analysis can show where results (benefits) are achieved effectively relative to economic investment. 6 https://prod-environmental-registry.s3.amazonaws.com/2018-11/EnvironmentPlan.pdf Ontario Environment Plan:
- 7. OSPE Bill 139Comments on Green Infr. Cost • “Estimates suggest that green infrastructure adaptation costs could be as high as $400,000 per hectare, inclusive of recently tendered construction projects. This means that the long-term province-wide costs to developers and municipalities—and, ultimately, the end consumer and economy—total hundreds of billions of dollars.” (OSPE - Oct. 2017) Hectares Urban Land x Cost Per ha = Initial Capital Cost 852,000 x $390,000 = $332 B 7 https://drive.google.com/open?id=1az42-2TZrcmRm2uHVcxG6mc3LBtb8vv- https://www.cityfloodmap.com/2016/11/green-infrastructure-solution-to-urban.html OSPE Bill 139 Comments: Initial Cost Assessment :
- 8. Green Infrastructure CapitalCost Review • Costs from various sources have confirmed magnitude of cost issue and need to assess lifecycle costs and cost effectiveness (over 1200 projects). 8 https://www.cityfloodmap.com/2018/05/are-lids-financially-sustainable-in.html https://www.cityfloodmap.com/2018/07/green-infrastructure-capital-and.html Ontario Tenders : Philadelphia, NY Costs : Ontario Tenders Philadelphia Clean Waters $575,000 per ha $568,000 per ha $783,000 per imp. ha New York State
- 9. Higher Green Infr.Unit Costs for Flood Control • “Estimates suggest that green infrastructure adaptation costs could be as high as $400,000 per hectare, inclusive of recently tendered construction projects. This means that the long-term province-wide costs to developers and municipalities—and, ultimately, the end consumer and economy—total hundreds of billions of dollars.” (Oct. 2017) Hectares Urban Land x Cost Per ha = Initial Capital Cost 852,000 x $726,000 = $619 B 9 https://drive.google.com/open?id=1XFCCwHe8R6VQ5J4kZ-hHyZVSdnL8zuYf Unit Cost for Flood Control (2019 WEAO Paper) :
- 10. Philadelphia Clean WatersCompiled Costs • Weighted program cost $857k / hectare, $2200/m3 (2018$) 10 https://www.cityfloodmap.com/2019/06/low-impact-development-capital-costs.html Unit Cost for Philadelphia LIDs :
- 11. Philadelphia Clean WatersCosts by LID Type • Cost per drainage area & storage volume for infiltration trenches, pervious pavement, rain gardens and tree trenches (2018$). Avg. 39 mm storage. 11
- 12. OSPE Comments onLong-Term Infr. Plan 2017 • “green infrastructure must be viewed through the same lens as conventional infrastructure, adhering to established asset management principles and full cost accounting—meaning it must be addressed up-front and directly, considering system-wide costs.” (Jan. 2018) Full-cost accounting includes : Operation and maintenance costs (inspection, routine intervention /restoration), depreciation (long-term replacement). 12 https://drive.google.com/open?id=1_ehoK0opvzeBFLv1Vrc6QFIbS9B5qFA8 https://www.cityfloodmap.com/2018/07/green-infrastructure-capital-and.html LTIP Comments: Lifecycle Cost Assessment :
- 13. Lifecycle Costs forGreen Infrastructure - Concerning 13 https://www.cityfloodmap.com/2018/07/green-infrastructure-capital-and.html Lifecycle Cost Assessment : Capital cost - 860,000 / imp.ha O&M cost - $20,000/imp.ha/yr Service life – 50 years (avg.) Annual Cost – $ 15.8 B - $3,100 / household / year - 3% of household disposable income Current Ontario stormwater deficit is $6.8 B.
- 14. Damages & ROIon Infrastructure – Industry Research • Relies only on ‘meta-analysis’: – no local data or ignores published local data (e.g., Pelly L. damages) – no engineering analysis (Autocase Metrolinx TEV, Green Team Analytics) – incomplete benefit/cost assessments (omits benefits) & mixes-up one-time capital & annual costs (e.g., Oakville) – extrapolates atypical wetland settings to apply to broad urban/rural areas – ‘rebrands’ quality control projects as life and money saving flood projects – ignores environmental constraints & impacts with wetland flood control https://goo.gl/xbxvyT https://goo.gl/epVuBe Green Team Report Review: ICCA Wetland Report Review: 14 https://goo.gl/Y3vWzx IBC Wetland Report Review: :
- 15. Meta-Analysis & PressPromotion – Industry Research • Overstates ‘meta-analysis’ of benefits as real “Performance monitoring results” for flood damage reduction (e.g., Pelly L. benefits page 42) • Omits cost-effectiveness of recommended physical interventions: “cost rankings are not normalized with consideration of performance effectiveness” (Section 4.4) • However Press Release (Jan. 18, 2019) promotes recommendations as “solutions that can be deployed practically and cost- effectively within communities” 15 https://goo.gl/Y3vWzx ICCA Weathering the Storm Report Review: :
- 16. 16 National Research CouncilGuidelines • NRC is developing Guidelines on Undertaking a Comprehensive Analysis of Benefits, Costs and Uncertainties of Storm Drainage Infrastructure in a Changing Climate https://drive.google.com/open?id=1W8CT2iEs-vdE-KhT87B441k8ciQZ13SL National Research Council Guidelines Scope of Work :
- 17. 17 National Research Council Guidelines • Case studies willshow how benefit/cost ratios can be developed for city-wide strategies and projects.
- 18. Markham Case Study– Grey/Green Benefits & Costs • Analysis of city-wide Flood Control Program costs and benefits initiated to: i) estimate DMAF project Return on Investment for flood control ii) evaluate green infrastructure (LID) cost- effectiveness for: • Flood control • Watercourse erosion repair mitigation • Water quality improvements (based on willingness to pay) 18 https://www.markham.ca/wps/portal/home/neighbourhood-services/water-sewer/projects-and-programs/06-projects-and-programs Markham Flood Control : https://www.cityfloodmap.com/2019/02/an-economic-analysis-of-green-v-grey.html WEAO paper :
- 19. Markham Case Study– Strategies (Flood Control) • Focus on 25% of city (pre-1980s areas) (brown shaded areas in image) 19 • Strategy A grey infrastructure (current program incl. one central wetland) • Strategy C green infrastructure • Strategy D 90% grey 10% green West Thornhill Unionville Markham Village Steeles Ave. E Hwy 407 Pre-1978 Subdivision Registration – No Major Drainage Design, No Water Quality or Erosion Control
- 20. Markham Case Study– Strategies (Erosion Control) • Erosion restoration priorities are within pre-1980’s servicing areas: – sanitary trunk risks along tributaries – no upstream SWM controls • Erosion stress reduction (water balance) not a priority in post-80’s areas. 20 West Thornhill Unionville Markham Village City Wide Erosion Prioritization Study and 5 Year Capital Plan April 2019
- 21. Markham Case Study- Benefits • Flood control benefits – Deferred damages based on scaled regional reported claims • Erosion control benefits – Lower creek repairs based on lifecycle costs (green only) • Watershed quality benefits – Willingness-to-pay for water quality improvements based on Rouge R. source control study (green only) 21 https://www.cityfloodmap.com/2019/02/an-economic-analysis-of-green-v-grey.html WEAO paper :
- 22. Markham Case Study- Costs • Grey infrastructure – Capital - completed, tendered, & designed projects, Class EA estimates, program costs – O&M – equivalent to existing lifecycle program costs • Green infrastructure – Capital – average of unit cost for all LID types (excl. green roof) – O&M – per Philadelphia clean waters pilot lifecycle costs 22
- 23. 1 10 100 1000 10000 Downspout Program. Backwater Valve Pgm. Sanitary Upgrades Storm Upgrades Green Infr. RetrofitOption Markham Flood Control Program Activities and Costs Cost ($M) $3 M $1300/ha $27 M $11,000/ha $253 M $120,000/ha $1.7 B $726,000/ha
- 24. 1 10 100 1000 10000 Downspout Program. Backwater Valve Pgm. Sanitary Upgrades Storm Upgrades Green Infr. RetrofitOption Flood Control Strategies - 50 Shades of Grey to Green Cost ($M) Strategy A (grey) Strategy C (green) Strategy D (grey + green)
- 25. Annual Costs andBenefits 25 -70 -60 -50 -40 -30 -20 -10 0 10 20 -70 -60 -50 -40 -30 -20 -10 0 10 20 Strategy C Strategy B Strategy A Flood Benefit Erosion Benefit Quality Benefit Cost Strategy A (grey) Strategy C (green) Strategy D (grey + green) Benefits/year $M Cost/year $M (insured losses only) (“willingness to pay”)
- 26. Annual Costs andBenefits 26 -70 -60 -50 -40 -30 -20 -10 0 10 20 -70 -60 -50 -40 -30 -20 -10 0 10 20 Strategy C Strategy B Strategy A Flood Benefit Erosion Benefit Quality Benefit Cost Strategy A (grey) Strategy C (green) Strategy D (grey + green) Benefits/year $M Cost/year $M Benefit / Cost = 2.52 (100% flood) Benefit / Cost = 0.27 (41% flood) Benefit / Cost = 0.91 (88% flood) Residential Stormwater Fee = $ 3,800 /yr Residential Stormwater Fee = $ 47 / yr (insured losses only) (“willingness to pay”) Residential Stormwater Fee = $ 150 /yr
- 27. 27 Infiltration & FloodRisk from Green Infrastructure • Source control BMP infiltration risks on sewer systems were identified in 1992 • Workshop of Ontario experts reviewed 1991 Interim Guidelines that first introduced green infrastructure for new development water quality control. https://drive.google.com/open?id=1dNFzxZxlzxUx-g9DzvVHSvwceXhddkCq https://www.slideshare.net/RobertMuir3/robert-muir-green-infrastructure-for-climate-adaptation-nrc-workshop-on-urban-rural-storm-flooding-february-27-2018-ottawa OSPE Watershed Planning Guidance Comments : National Research Council Workshop Feb 2018 : https://drive.google.com/open?id=0B9bXiDM6h5ViNkN1NTVweGZZMG8 1992 Workshop Summary :
- 28. 28 Infiltration & FloodRisk from Green Infrastructure • Infiltration in sanitary sewers explains > 60% of sewer back-up risk at a postal code spatial scale. • Green infrastructure relies on runoff infiltration and increases core stress driving basement flooding. Sanitary Sewer Capacity Back-up Risk Sanitary Infiltration Peak Flow Rate Infiltration Drives Basement Back-Up Risks in the Most Flood- Prone, Partially-Separated Sewer Service Areas 10 Yrs Continuous Flow Modelling (all areas) All-pipe Hydraulic Model (2 Master Plans) Moderate High
- 29. 29 Green Infrastructure WaterSupply Risks • Infiltration of runoff violates MECP Procedure F-6-1 to prevent ‘sewage’ (runoff in OWRA) discharge over municipal potable water supply lines. • Journal of Toxicology and Environmental Health publication Sources, Pathways, and Relative Risks of Contaminants in Surface Water and Groundwater: A Perspective Prepared for the Walkerton Inquiry summarizes contamination types and indicates that presumably ‘clean’ runoff sources such as roof runoff can, contrary to local LID design guidelines, exhibit high contaminant loads. http://www.hydrorelief.org/frackdata/references/RisksContamWater.pdf Journal of Toxicology and Environmental Health : https://www.ontario.ca/page/f-6-1-procedures-govern-separation-sewers-and-watermains F-6-1 Procedures to Govern Separation of Sewers and Watermains : https://drive.google.com/open?id=1T3vXEJ_nBi8e30KpcawVTfFPKx7A6y_v WEAO MOECC LID Guidance review July 2017 :
- 30. 30 Green Infrastructure WaterSupply Risks • Infiltration of runoff increases chloride concentrations in aquifers. Municipal wells in Waterloo, Kitchener and Cambridge exceed Ontario objectives and are increasing. • Green infrastructure that infiltrates road, and parking lot runoff degrades drinking water source quality. https://www.therecord.com/news-story/9046980-chloride-levels-are-rising-in-waterloo-region-drinking-water/ Region of Waterloo Chloride Levels:
- 31. Conclusions • System-wide capitalcost and lifecycle cost assessment shows universal implementation of green infrastructure (e.g., retrofitting 852,000 untreated hectares in Ontario) is financially unrealistic. – > ½ trillion dollars in capital (opportunity cost for other priorities) – $3100 / household / year = significant financial impact • Benefit/cost ratio for LIDs unfavourable for flood control – Markham Case Study with focused implementation shows benefits less than costs. • Benefit/cost ratio for LIDs unfavourable for water quality improvements – ‘willingness to pay’ benefits less than costs. • Green infrastructure infiltration stress on sanitary sewers increases basement back-up risk in older service areas - shows focused implementation should be avoided. 31
- 32. Conclusions … Continued •Favourable LID green infrastructure benefit/cost analysis based only on unreliable ‘meta-analysis’, with incomplete engineering input, and atypical ‘pilot’ studies that do not support universal claims. • Green infrastructure runoff infiltration water supply impacts overlooked by proponents focused on surface water systems: – Clean runoff sources have high metals and pathogen concentrations receiving only moderate treatment (Walkerton Inquiry) – Infiltrated chlorides accelerate corrosion/deterioration of ductile iron watermains, reducing asset life and increasing break risk (high chlorides decrease soil resistivity) – Infiltrated chlorides degrade aquifer and municipal well quality (e.g., Waterloo, Kitchener, Cambridge) 32
- 33. Thank You Questions ? MoreRob : Blog: www.CityFloodMap.com Podcast: Open During Construction on iTunes Twitter: @RobertMuir_PEng More City of Markham : Web: www.markham.ca Twitter: @CityofMarkham 33