Ontario Society of Professional Engineers OSPE Green Infrastructure Roundtable - Green Infrastructure – Cost Effectiveness and Technical Challenges for Flood Mitigation
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Green Infrastructure – Cost Effectiveness and Technical Challenges for Flood Mitigation, Robert J. Muir, M.A.Sc., P.Eng. Manager, Stormwater, City of Markham, January 30, 2018 - Mississauga, Ontario The presentation presents regulations and policies regarding cost effective infrastructure, explores green infrastructure capital costs in Ontario based on recent project tender costs and other North American extensive program sources, explores lifecycle cost (LCC) impacts of widespread green infrastructure implementation in Ontario, including cost per household and impacts on the current infrastructure deficit, and presents benefit cost analysis for city-wide grey and green infrastructure strategies including benefit/cost ratios for flood damage reduction. Unit costs of no regret programs such as sanitary downspout disconnection and plumbing isolation programs, and wastewater and stormwater system upgrades, and green infrastructure retrofits are presented per hectare. Gaps in research relying on meta-analysis estimates of flood control benefits that do not consider local engineering or costs are presented. Impacts of green infrastructure on wastewater systems and infiltration stresses is presented, and correlation of wastewater infiltration stresses with local sewer back-up risks is shown for the City of Markham. Water supply risks of green infrastructure relying on infiltration including chloride stresses are explored. The unfavourable benefit-cost profile of green infrastructure and potential impacts on wastewater system flood risks and municipal water supplies suggests a strategic review of implementation targets and policies is warranted to identify financially sustainable and technically-appropriate requirements.
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Ontario Society of Professional Engineers OSPE Green Infrastructure Roundtable - Green Infrastructure – Cost Effectiveness and Technical Challenges for Flood Mitigation
- 1. Ontario Society of Professional Engineers – Green Infrastructure Green Infrastructure – Cost Effectiveness and Technical Challenges for Flood Mitigation Robert J. Muir, M.A.Sc., P.Eng. Manager, Stormwater, City of Markham January 30, 2018 - Mississauga, Ontario 1
- 2. OUTLINE 1) Regulations & Policies on Cost Effective Infrastructure 2) Ontario Capital Costs 3) Ontario Lifecycle Costs and Economic Impacts 4) ROI for Flood Mitigation 5) Green Infrastructure Infiltration Impacts & Flood Risk 6) Green Infrastructure Water Supply Risks 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 3Provincial Policy Statement 2014 Infr. for Jobs and Prosperity O Reg 588/17 Municipal Class EAs
- 4. History of Cost-Benefit Analysis (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. OSPE Bill 139 Comments 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 5 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 :
- 6. Green Infrastructure Capital Cost Review • Costs from various sources have confirmed magnitude of cost issue and need to assess lifecycle costs and cost effectiveness (over 1200 projects). 6 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
- 7. OSPE Bill 139 Comments 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.” (Oct. 2017) Hectares Urban Land x Cost Per ha = Initial Capital Cost 852,000 x $726,000 = $619 B 7 https://drive.google.com/open?id=1XFCCwHe8R6VQ5J4kZ-hHyZVSdnL8zuYfUnit Cost for Flood Control (2019 WEAO Paper) :
- 8. OSPE Comments on Long-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). 8 https://drive.google.com/open?id=1_ehoK0opvzeBFLv1Vrc6QFIbS9B5qFA8 https://www.cityfloodmap.com/2018/07/green-infrastructure-capital-and.html LTIP Comments: Lifecycle Cost Assessment :
- 9. Lifecycle Costs for Green Infrastructure - Concerning 9https://www.cityfloodmap.com/2018/07/green-infrastructure-capital-and.htmlLifecycle 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.
- 10. 0.1 1 10 100 1000 10000 Standards Downspout Prgm. Backwater Valve Pgm. San.Sewer Upgrades Stm. Sewer Upgrades Green Infr. Retrofit Grey Infrastructure Flood Benefit / Cost = 2.5 (Insured Losses) Green Infrastructure Flood Benefit / Cost = 0.11 (Insured Losses) Best Practices No Regrets Policies & Programs High ROI Approved Program $ 283 M $1.7 B for 25% of City = 6x Fee Increase ROI on Infrastructure – Markham Flood Control Program Cost($M) $3 M $1300/ha $27 M $11,000/ha $253 M $120,000/ha $1.7 B $726,000/ha
- 11. Damages & ROI on 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: 11 https://goo.gl/Y3vWzxIBC Wetland Report Review: :
- 12. Meta-Analysis & Press Promotion – 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” 12 https://goo.gl/Y3vWzxICCA Weathering the Storm Report Review: :
- 13. 13 Infiltration & Flood Risk 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 :
- 14. 14 Infiltration & Flood Risk 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 Insurance Back-up Risk Code 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) Sewer Back-up Risk Level Sanitary Infiltration Peak Flow Rate Sanitary Sewer Capacity Correlation of Sewer Back-up Risk Level, Sewer Hydraulic Capacity, & Normalized Infiltration Peak Flow Rate Stress at Postal Code Scale
- 15. 15 Green Infrastructure Water Supply 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 :
- 16. 16 Green Infrastructure Water Supply 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:
- 17. Conclusions • System-wide capital cost 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 • Green infrastructure infiltration stress on sanitary sewers increases basement back-up risk in older service areas - shows focused implementation should be avoided. • Benefit/cost ratio is unfavourable – increasing program fees by 6-times, up to 40% of total City tax revenue (financially unsustainable) with higher capital costs alone (Markham Case Study focused implementation). 17
- 18. Conclusions … Continued • Favourable green infrastructure benefit/cost analysis is based on unreliable ‘meta-analysis’, with incomplete engineering input, and extrapolates atypical ‘pilot’ studies to make unfounded 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) 18
- 19. Thank You Questions ? More Rob : Blog: www.CityFloodMap.com Podcast: Open During Construction on iTunes Twitter: @RobertMuir_PEng More City of Markham : Web: www.markham.ca Twitter: @CityofMarkham 19
Notes de l'éditeur
- Good morning. I’d like to review green infrastructure cost effectiveness and technical challenges for flood mitigation, and advance some of the earlier OSPE and Markham commentary on this.
- So I’ll review the legislation that compels us to consider cost. Look at what widespread green infrastructure costs would mean in Ontario. What lifecycle costs would mean in terms of funding requirements and tax impacts. Then look at the return on investment of green infrastructure … compare that to grey infrastructure. Then look at the adverse impacts of green infrstructure on flooding in urban areas and water supply risks.
- There are many drivers for assessing infrastructure cost efficiency in Ontario from high level PPS goals to regulations surrounding asset management plans and within Eas. Any infrastructure investment must consider costs and cost effectiveness. For green infrastructure, that has not received a lot of attention in Ontario when considering whole systems. We need to look at whole systems to understand the cost challenges.
- Why assess costs and benefits (that is the technical effectiveness to solve specific problems) for flood control? This is a long standing principle in water resource management where we accept that flood protection must be justified economically, benefits exceeding costs. This goes back to the 1930’s in the US. In the past cost benefit analysis was done for large projects and the US Army Corp of Engineers produced guidance for it and encouraged system-wide analysis. Watt in Hydrology of Floods in Canada reminds us that flood protection must be economically justified. XXX Green infrastructure has never had that guidance on cost or a system-wide assessment on cost effectiveness for flooding.
- Are green infrastructure costs a big thing? Yes. OSPE flagged this in late 2017 using some initial projects costs. The Ontario GDP is 825 billion so 300 billion is a big number which warrants a closer look.
- A closer look. I’ve compiled 24 Ontario project costs, reviewed details for Philadelphia’s Clean Water Pilot – that’s over 1100 projects, and over a hundred New York projects and the overall cost of $800,000 per impervious hectare or 5-600,000 are justified so we are looking at half a trillion dollar in Ontario capital cost.
- So that is a staggering cost across the province if green infrastructure is applied wherever water balance and at source quality controls are not in place, say pre year 2000 development. There is a link to the background behind the higher $726 thousand per hectare unit cost which factors up Philadelphia CSO control costs for higher flood control volumes. That will be in my WEAO paper this year.
- Why is that important to recognize that cost can be high? Because there is a narrative out there that green infrastructure saves money. OSPE comments that a careful look at lifecycle costs is need.
- This chart shows lifecycle costs for initial capital, O&M and rebuilds assuming we implement green infrastructure over 50 year. We would level out at an annual cost of $15.8B. W 5,169,170 private households in Ontario that’s $3100 / household / year or over 3% of disposable household income 15.8 B is a Big number – current stormwater deficit is 6.8B https://globalnews.ca/news/3981337/ontario-household-debt-rising/ Ontario Debt to income 171%, Debt 154k/household, disposable income = 154/1.71 = 90k Aside: To fund this would increase municipal taxes in Markham by 3100/6762 = 46% based on average property taxes in Markham in 2018 http://torontostoreys.com/2018/07/gta-cities-highest-lowest-property-taxes/
- How infrastructure about the cost effectiveness of infrastructure investments – we can look at this with Markham’s Flood Control Program and green we examined This has the costs of all Markham’s Flood Control activities (list them). We can break these down into Best Practices – the No Regrets Policies and Programs, a million dollars each – they have high benefit cost ratio, maybe cost a less that 1500 per hectare. CLICK Grey infrastructure, those are sanitary and storm sewer upgrades – 283 millions with a benefit-cost ratio of 2 considering insured or higher with total losses. 11 thousand and 120 thousand per hectare respectively – the benefit cost or flood reduction considering insured losses is 2.5 – spend a dollar get 2.5 dollars of benefit CLICK – then Green infrastructure, if we converted a quarter of the city, we would have a benefit cost ratio of 0.11 for insured losses – spend a dollar, get 11 cents of benefit CLICK – We have 283 million approved in the overall program. An we consider green infrastructure only in the most strategic locations, as part of park revitalization and for one large naturalized pond retrofit costing 10’s of millions. CLICK – But we cannot justify spending over 1.7 B in capital across the city, raising taxes 30%, to add rain gardens and bioswales in all old areas, along all the streets. Today in a boardroom in Markham these costs, excluding green infrastructure, are being used to set the Flood Control Program fee for the next 5 years – it is a non-starter to suggest that we would adopt green infrastructure, increase costs and fees 6 times to $300 a year which is about 30% of Markham’s total tax intake. Unrealistic. We must focus on the most cost effective grey infrastructure solutions for flood control. We look at other benefits in the WEOA paper – green infrastructure benefits do not exceed costs
- Besides cost there are technical reasons to avoid green infrastructure in old areas.