welcome to the asce 2016 convention€¦ · gi/lid features (best management practices) added to...

WELCOME TO THE ASCE 2016 CONVENTION

Engineering Optimal Financial, Social, and Environmental Returns

Marty Janowitz MES ENV SP

Vice President Sustainable Development

Stantec Consulting

The Implementation of the BCE, AutoCASE™ and Envision™ on Behalf of

Stormwater Projects in Arid Regions

The Rationale – AutoCASE™ and Envision™ • To make sensible comparisons between green infrastructure/low impact

development and traditional grey infrastructure

• Through a common metric

• To value the risk & benefits of sustainable projects

• Integrating engineering methods and economic methods to price options for decision-making.

• Identify optimal outcomes

• So that the project is done right and the right project is done.

Stormwater Pilot Project

Prioritizing Investments in Sustainable Stormwater Management Projects 4

Premise

• In more humid parts of the country GI/LID practices are cost-effective by enhancing the potential for reducing or eliminating the risk of sewer overflows.

• Potential contaminant migration in stormwater tends to be more limited in arid environments as water bodies are few and groundwater is deep.

• Stormwater management important because use of stormwater can offset the need for potable water.

• Vegetation watered with stormwater has potential to decrease energy use and improve the quality of life by mitigating effects from the urban heat island.



Background

• The Pima County Regional Flood Control District and the City of Tucson, have been creating a Low Impact Development and Green Infrastructure Guidance Manual to facilitate the adoption of GI/LID practices in Pima County and the City of Tucson with the Pima Association of Governments

• They completed a joint Water-Wastewater (2010) Infrastructure, Supply and Planning Study • Goal 5: Increase the use of rainwater and stormwater to reduce demands on

potable supplies”

• Subgoal 5.1: Develop design guidelines



Background 2

• Despite efficient water use, best practices in stormwater management, and water re-use, the population in Pima County is growing and renewable water resources are diminishing due to drought across the Colorado River Basin.

• Together, a working group developed a Guidance Manual to facilitate the adoption of GI/LID practices in Pima County and the City of Tucson.



Unique Regional Aspects

• The Tucson region does not have combined sanitary sewers/storm sewer systems and so does not suffer from combined sewer overflow problems that give other regions cause to implement GI/LID;

• The desert environment does experience monsoons with potential for severe flooding and also seeks the beneficial use of stormwater for irrigation.

• AutoCASE™ was made more useful to desert regions by calculating the cost and benefit based on these conditions common to the arid Southwest.



Scenarios

• The goal of this Beta Testing project is to evaluate GI/LID benefits in the Pima County environment. AutoCASETM uses economic and risk analysis to evaluate costs and multi-benefits using AutoCAD Civil3D files of GI/LID practices. Because the motivating factors for use of GI/LID are different in Pima County, there is a need to evaluate the costs and multi-benefits of these features in that environment.



GI/LID

• One reason for developing the GI/LID Guidance Manual was to provide a tool for public and private sector professional designers, including engineers, landscape architects, planners, developers and non-profit organizations, to utilize and better understand design configurations and the benefits of GI/LID.

• This comparison then provides a framework for how our community can plan and adapt to become more resilient utilizing GI/LID in stormwater-management.



Deliverables

• Deliverable 1: A beta version of AutoCASE TM software with initial parameters for GI/LID practices.

• Deliverable 2: Evaluation of two clustered GI/LID scenarios (commercial site and transportation corridor) considering a series of individual practices

• Deliverable 3: List of factors that are most important and contribute most to the two different scenarios to calculate effectiveness of the GI/LID practices with the associated probabilities.



Deliverables

• Deliverable 4: Costs and multi-benefits of each of the individual GI/LID practices (described in the LID/GI Guidance Manual) in the County’s and City’s environment.

• Deliverable 5: Evaluation of the economic and environmental returns from investing in GI/LID practices in the arid west that can be incorporated into the LID/GI Guidance Manual.

• Deliverable 6: Summary report



Objectives

• To evaluate the cost and multi-benefits of these individual GI/LID practices to determine how GI/LID creates value for the arid west

• e.g. recreational benefits, air pollution reduction, carbon reduction, water quality improvements, lower urban heat island mortality rate etc.

• To create a reference document that documents the sustainable return of relevant infrastructure projects.



GI/LID Features Evaluated

Eight green infrastructure (GI) features evaluated

Features also combined in two sites:

- A commercial site

- A roadway reach

Economic analysis used to determine which GI features provide the greatest benefits in Tucson and how they can be used to comply with:

- Commercial rainwater harvesting ordinance

- Green streets guidelines



GI/LID Practices Evaluated

Water Harvesting Basins

Bio Retention Basins

Xeriscape Swales

Cisterns

Infiltration Trenches

Detention Basins (or Extended Detention Basins)

Pervious Pavers

Curb Extensions, new & retrofit chicanes, medians, road diets with inlets to gather street water runoff, traffic circles)



Costs, Benefits and Outcomes

• A distribution of costs, benefits and possible outcomes as described by the following factors. • Direct Financial Return on Investment

• Sustainable Return on Investment



Cost-Benefit Considerations

• Water Costs (assumed to be water costs associated with irrigation reduction/potable water savings, and water pumping costs)

• Energy Savings (especially energy reduction from shading)

• Operation & Maintenance (assumed to include maintenance required for continued functionality of GI).



Methodology

• Risk Analysis Approach • Reflecting the range of uncertainty about inputs as well as their most likely

values.

• A probability distribution representing the outcome of future events, based on limited information.

• Input into a Monte Carlo risk analysis following a cost-benefit approach.



Outcomes

• Evaluation of usability and usefulness of the AutoCASE™ and applicability of the data used. • A description of Envision scoring of GI/LID features to articulate the link between

GI/LID and Envision.

• An evaluation on the possible use by the City and County for the Envision™ System to assess GI/LID practices.



Findings

GI/LID features (best management practices) added to the conventional design provide multiple high impact social benefits on both sites analyzed

- Commercial Site

- Road Re-Design



Envision Results – Road Re-Design Site

Quality of Life

Leadership Resource Allocation

Natural World

Climate

Other

Envision Category Breakdown of Value – Road Re-Design

“…most of the value is attributed to increased pedestrian safety due to traffic calming (Quality of Life), reduced heat mortality (Quality of Life), reduced social cost of water (Natural World), and lower carbon and air pollution (Climate).” -AutoCASE Beta Testing Project, Final Report



Road Re-Design Results

Summary Results Net Present Value of

Benefits - Silverbell Road Capital Expenditures -$42,125 O&M Costs -$3,897 Reduced Electricity Costs $20,331 Reduced Natural Gas Costs $57 Direct Financial NPV -$26,634 Reduced Flood Risk $25,645 Change in Property Values $1,592 Reduced Heat Stress Mortality $84,634 Value of Reduced CO2 Emissions $12,095 Value of Reduced Air Pollution $17,588 Reduced Direct Costs of Water $43,823 Reduced Marginal Social Costs of Water Use $39,868 Increased Pavement Longevity Benefit $1,763 Traffic Calming - Roundabouts and Curb

Extension $117,737

Other Benefits $3,412 Sustainable NPV $322,523

0%

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-$2,000 -$1,000 $0 $1,000 $2,000 $3,000

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Net Present Value of Net Benefits (Benefits - Costs)

Thousands

Base Case - DirectFinancial NPV

Base Case -Sustainable NPV

Direct Financial NPV(Includes GI/LIDFeatures)

Total SustainableNPV (Includes GI/LIDFeatures)


Net Present Value of Net Benefits (Benefits


Road Re-Design Benefits

Reduced Electricity Costs 6%

Reduced Flood Risk 7%

Reduced Heat Stress Mortality

23%

Value of Reduced CO2 Emissions

3% Value of Reduced

Air Pollution 5%

Reduced Direct

Costs of Water 12%

Reduced Marginal Social Costs of Water Use

11%

Traffic Calming - Roundabouts and Curb

Extension 32%

Other Benefits 1%

Net Present Value of Benefits – Road Re-Design



Road Re-Design Benefits

Direct Financial Value 9%

Government or Taxpayer 20%

User / Target-Beneficiary or Customer Service

1%

Economic or Business Activity

22%

Environmental 10%

Community or Other 38%

Stakeholder Breakdown of Value – Road Re-Design



GI/LID Results Net Present Values – Median (50th Percentile) Costs Benefits

CapEx Cost O&M Costs Flood Risk Reduction Property Value

Uplift Heat Mortality Risk

Reduction Reduced CO2 Emissions Reduced Other

Costs Direct Financial NPV Total SNPV

Bioretention -$2,096 -$377 $169 $49 $515 $0 $0 -$2,473 -$1,740

Pervious Pavers,

relative to asphalt -$2,496 -$834 $168 $51 $513 $0 $0 -$3,330 -$2,597

Detention Basin /

Extended Detention-$1,215 -$194 $234 $50 $514 $0 $0 -$1,409 -$612

Water Harvesting

Basin* -$132 -$7 $200 $52 $518 $0 $0 -$139 $631

Cistern -$2,685 $0 $95 $0 $0 $0 $448 -$2,685 -$2,142

Xeriscape Swale -$383 -$173 $159 $51 $512 $0 $0 -$556 $167

Infiltration Trench -$701 -$167 $200 $50 $515 $0 $0 -$868 -$102

Pavement -$10,817 $0 -$424 $0 $0 $0 $0 -$10,817 -$11,241 Concrete -$14,106 $0 -$379 $0 $0 -$1,346 $0 -$14,106 -$15,831 *Entered as Infiltration Basin



GI/LID Results

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-$18,000 -$13,000 -$8,000 -$3,000 $2,000

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Bioretention

Pervious Pavers/PorousPavement

Detention Basin

Water Harvesting Basin

Cistern

Xeriscape Swale

Infiltration Trench

Pavement/Ashphalt

Concrete



Highlights • Benefits of GI/LID features quantified and

monetized:

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$(1,000) $(500) $- $500 $1,000 $1,500 $2,000 $2,500 $3,000

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Thousands

Commercial Site DirectNPV - No GI/LID

Commercial Site SNPV -GI/LID Included

"Road Re-Design DriectNPV - No GI/LID"

Road Re-Design SNPV -GI/LID Included

• Adding GI/LID features to the commercial and road re-design sites provides net benefits to the Tucson region

• Largest benefits: heat related mortality, traffic calming, flooding, reduced water costs and reduced air pollution


Net Present Value of Net Benefits (Benefits


GI/LID features have a payback to governments, the environment, the economy and the community

This approach allows all stakeholder groups to understand how they are affected by a project

- “What’s in it for me?”

Ignoring benefits of GI/LID features can lead to incorrect decisions

Overall Findings Stormwater Pilot Project


Recommendations

The City of Tucson, Pima County, should continue to use this approach to demonstrate the full value of its GI/LID initiatives

This information should be used to help make the best decisions as projects are planned and designs are modified

The Tucson region should consider the use of Envision to communicate project benefits to outside stakeholders



THANK YOU FOR ATTENDING ASCE 2016!

Reminder: WE LOOK FORWARD TO SEEING YOU NEXT

YEAR AT ASCE 2017 IN NEW ORLEANS, LOUISIANA!

welcome to the asce 2016 convention€¦ · gi/lid features (best management practices) added to...

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