9415 public works stormwater summit (day two) …envision™ on behalf of stormwater projects in...

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APWA Stormwater Management Symposium

EnvisionTM Business Case Evaluator (BCE) Companion Tool: Prioritizing Investments for Sustainable Stormwater Management Projects

Moderator: Vicki Quiram, Assistant Commission, New Hampshire Dept. of Environmental Services

Leaders: John Williams, Impact InfrastructureRyan Meyers, Impact Infrastructure John Parker, Impact InfrastructureMarty Janowitz, StantecBrian Young, Autodesk

Introductions

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Introductions

Panelists and Symposium Participants

Names

Affiliations

Interests

EnvisionTM and Business Case Evaluation

Prioritizing Investments for Sustainable Stormwater Management Projects 2

Learning Objectives

Review emerging competition for financial resources and data demands

Examine new sources and paths to performance data

Make the connection between EnvisionTM, business case analysis, and project funding

Learn about automating the process through the BCE and CBA‐BIM tools

See the tools in action

Look into future developments

Prioritizing Investments for Sustainable Stormwater Management Projects3

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Ground Rules

One speaker at a time

All questions welcome

Keep answers short

Participate in active discussion

Stay within time frames

Prioritizing Investments in Sustainable Stormwater Management Projects 4

Modules

Connecting the DOTs

Envision, the BCE, and Comprehensive Business Case Analysis

Automating the Process to Save Time, Reduce Costs, and Tune Outcomes

Pima County – City of Tucson Case Study

Future Enhancements – the Ultimate “Shown and Tell”


Impact Infrastructure

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Connecting the DOTs

John F. WilliamsChairman & CEO, Impact Infrastructure

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Matching Funding Demand with Supply of Capital

Aligning community interests

Addressing data needs – merit funding

Tapping private Impact capital

Making the case for value and risk

Competing for Resources


What’s In It for Me?

Mayors – election cycle?

Service Commissioners – keeping the lights on?

Sustainability Managers – is it green?

Resiliency Officers – extreme events?

Budget Directors –transparency and priorities?

Stakeholders within the community –what’s in it for me?

Aligning Interests


Revealing Value and Risk for Merit Programs

Cost Benefit Analysis (CBA)

Comprehensive sector specific metrics

Translate tangible and intangible costs and benefits to monetary units

Assign value by stakeholder group

Data Needs


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Tapping information via the planning and design phases

Financial ROI and Sustainable ROI

Balancing preventative and responsive resilience strategy

Enabling project bundling

Informing Due DiligenceTapping Impact Capital


Early assessment

Consistent metrics and analysis

Throughout the development process

Post commissioning monitoring and reporting

Transparent, Objective, Comparability

Making the Case



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Pointing to the Future

THE ENVISION RATING SYSTEM

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EnvisionTM, the BCE, and Comprehensive Business Case Analysis

Ryan MeyersAutoCASETM Product Manager, Impact Infrastructure, Toronto


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Automation

Prioritizing Investments in Sustainable Public Infrastructure 14

The Business Case EvaluatorOverview

Produces business case for green stormwaterinfrastructure projects

Excel‐based

Allows for uncertainty around the inputs

Inputs and outputs mapped to Envision Credits

Automation


Mapping to the Envision Rating System

LEED : Buildings

Envision : Infrastructure

Points‐based

BCE maps economic value to Envision Credit categories

Answers the question: How is the value distributed?

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Automation


Themes of our Approach

Transparency

Extensive research

- Meta‐analyses

- Sources

Customization

Automation


The Business Case EvaluatorDemo

Automation


The Business Case EvaluatorUse and Documentation

http://sustainableinfrastructure.org – “Resources”http://Impactinfrastructurellc.com – “Tools”

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Automation


The Business Case Evaluator in Brief The Business Case Evaluator allows users to:

- Understand how changes to design can affect value

- Risk Adjusted Dollar Value- Communicate the value of a project for different stakeholders and Envision Credit categories

The Business Case Evaluator Uses:

- The standard cost‐benefit analysis approach

- The large body of research that is available to quantify costs and benefits of projects

- A transparent and customizable approach

- Excel, so anyone can use it!

Automating the Process to Save Time, Reduce Costs and Tune Outcomes

John ParkerChief Economist Impact Infrastructure, Toronto


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CBA-BIM/si‐bä‐bim/ ‐ noun

1. The process of combining the costs, benefits and risks of infrastructure with digital representations of physical and functional characteristics of places to answer the question “what is in it for me?”

Cost Benefit Analysis & Building Information Modeling Be Consistent

- Methodology & Data

Be Realistic- Accounting for Risk

Be Sensible- Stakeholders Matter

AutoCASE- CBA‐BIM in Action

STANDARDIZATIONBeing Consistent

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Cost Benefit Analysis (CBA) –Useful, Expensive, Answering the Wrong Questions CBA is the “gold standard” for

decision‐support

It has been used and refined for over a hundred years

- Key concepts of valuation, consumer surplus, discounting, and externalities

CBA is expensive, does not capture risk, and is focused on the wrong things

The French economist and civil engineerJules Dupuit(1804‐1866), credited with the creation of consumer surplus in 1864. Benefit of bridges is greater than toll paid.

“Sir William Petty (1623–1687) English economist, scientist and philosopher. The Economist credits Petty with three ideas: valuation, discounting, and the transparent use of data.

Arthur Pigou(1877–1959) was an English economist. In the 1920s, he developed “the concept of externality citing externalities associated with child labour, alcohol, war, and pollution.

A Brief History of CBA ‐ 1 CBA took on a significant role with the US Flood Control

Act of 1936

- APWA founded on January 1, 1937

“Owing to the lack of specific and concrete guidelines, inconsistent sets of standards and procedures were developed and implemented by the various agencies involved in the development of water resources. This gave the impression that each agency’s main objective of the CBA was to justify the projects that each agency wanted to carry out instead of providing critical evaluations of the merits of the projects.” (Mishan & Quah ‐ Cost‐Benefit Analysis)

A Brief History of CBA ‐ 2

To ensure consistent and standardized practices, an inter‐agency group was formed in 1946. Called the US Federal Inter‐Agency River Basin Committee’s Subcommittee on Benefits and Costs, it produced the Proposed Practices for Economic Analysis of River Basin Projects (1950; revised 1958) or more commonly known as the U.S. Army Corp of Engineers Green Book.”

Since then, most national governments have standardized the methodology and many publish recommended input data values to use

Institute for Sustainable Infrastructure (ISI) EnvisionTM

Rating System ‐ http://impactinfrastructurellc.com/tools.html

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Cost Benefit Analysis (CBA) – Old Dog, New Tricks Three innovations in CBA have led to the ability to include CBA in Building Information Modelling (BIM) :

1. CBA’s methodology, input data, and outputs have been standardized.

2. Risk analysis and meta‐analyses mean that uncertain or controversial inputs can be used.

3. Multiple account CBA accounts allow for an understanding of all stakeholders’ positions.

CBA is becoming standard and cheap. At the same time, open data initiatives have allowed powerful BIM models to be populated easily and cheaply.

Building Information Modeling ‐ BIMBIM is a process that uses a integrated model with consistent data across project phases to facilitate project coordination, collaboration, and analysis. BIM models:

Manage relationships between objects

Track design codes, standards constraints

Visually enables better analysis, simulation and communication

Integrated model view showing the complexities of subgrade utilities.

Image courtesy of Stantec, Inc.

Feasibility

Plan

Design

Consult

Construct

Operate

150 km2 3D model of Manhattan – terrain, buildings, roads, waterways, transit etc. Time to build – 15 min.

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BIM Makes CBA Relevant Again Standardized CBA, integrated it into BIM makes it useful from early planning through to operation

Linking of economic valuation methodologies to GIS gives architects, engineers, designers, and planners access to decision‐making tools that help them decide what to build, how to build it, what the risks are, and who benefits

META‐ANALYSIS

Being Realistic – Including Risk

Value of Crops, Wetlands and Meadow

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Peer Reviewed Meta‐Analysis In, Quality, Defensible, Useful Out CBA’s input data, methodology, and outputs have been standardized.

- The Environmental Valuation Reference InventoryTM. EVRI is a searchable storehouse of empirical studies on the economic value of environmental benefits and human health effects.

- US department of Transportation (2014 and 2014a)

- US Federal Highway Administration (2013)

- European Commission (2008)

- Treasury Board of Canada Secretariat (2013)

- Australia Department of Finance and Deregulation, Office of Best Practice Regulation (2013)

Wetland Value Can Be Determined Based on Size, Geography, Type and Function

• Meta‐Analyses–Allows for aggregation of different methods, geographies, features, or filtering of these to find the closet match to your project–By using dozens of studies from many different situations, value per acre can be determined –In this case 3 meta‐analyses with 152 studies and 339 observations

Where Do the Values Come From?

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Uncertain, Risky, Contentious Inputs –Wetland Value3 meta‐analyses of wetland valuation

1. 39 studies (1969‐1996), 65 world observations

2. 80 studies (1969‐2000), 202 world observations

3. 33 studies (1969‐2002),72 US observations

Recognize Uncertainty and Allow for Uncertain Inputs

Inputs with risk ranges

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The first curve is the Direct Financial NPV (i.e. only including direct costs and benefits such as capital expenditures, revenues, etc., and not including other costs and benefits such as air pollution, carbon emissions, water quality benefits, etc.).

The second curve incorporates all costs and benefits in the model, including impacts on the local economy, society, and the environment.

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An example of the probability curve output of a planned project.

Risk‐Adjusted Output

A steeper the curve means lower risk.

A more stretched out curve means more risk.

The difference between the curves is the (net) non‐market or societal benefits (externalities) such as lower carbon emissions, reduced pollution and less urban heat island effect.

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Risk‐Adjusted Output

MULTIPLE ACCOUNT CBABeing Sensible – Stakeholders Matter

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Multiple account/stakeholder CBA

Multiple account/stakeholder CBA

Winners, Losers & Risk Bearers Increased job opportunities, better health‐care, more neighbourhood connectivity, and better local air quality answer the “what's in it for me?” question of low‐income households, cyclists, environmentalists etc.

BIM allows people to see the project CBA allows sponsors to identify those likely to block project

CBA allows stakeholders to know how they benefit

With CBA cheap and answering the right questions – it is relevant again

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MA‐RA‐CBA accounting for risk, differing stakeholder perspectives, is now available to all

Planning level regional default data included

Integrated into BIM for detailed design stage

AUTOCASE

CBA‐BIM in Action

CAD System

3D Drawing AutoCASE

Web Service

Calculations

Data

Web Pages

Analytical Engine

ArchitectureAutoCASE

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Web‐only version projects – admin. & sharing

ii Stormwater Ribbon inside Civil 3D

Cloud‐linked results

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Pima County – City of Tucson Case Study

Marty Janowitz, MES ENV SPVP, Discipline Leader Sustainable Development, Stantec

The implementation of the BCE, AutoCASE™ and Envision™ on behalf of stormwater projects in arid regions

Prioritizing Investments in Sustainable Stormwater Management Projects52

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


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.



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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.



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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.



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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



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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).



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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



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Envision Results – Road Re‐Design Site

Quality of Life

LeadershipResource 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 ‐$26,634Reduced 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 $322,5230%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

‐$2,000 ‐$1,000 $0 $1,000 $2,000 $3,000

Probability of Not Exceed

ing

Net Present Value of Net Benefits (Benefits ‐ Costs)

Thousands

Base Case ‐DirectFinancial NPV

Base Case ‐SustainableNPV

DirectFinancial NPV(IncludesGI/LIDFeatures)

TotalSustainableNPV (IncludesGI/LIDFeatures)



Road Re‐Design Benefits

Reduced Electricity Costs6%

Reduced Flood Risk7%

Reduced Heat Stress Mortality

23%

Value of Reduced CO2 Emissions

3%Value of

Reduced Air Pollution

%

Reduced Direct Costs of Water12%

Reduced Marginal Social Costs of Water

Use11%

Traffic Calming ‐Roundabouts and Curb Extension

32%

Other Benefits1%

Net Present Value of Benefits – Road Re‐Design



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Road Re‐Design Benefits

Direct Financial Value9%

Government or Taxpayer20%

User / Target‐Beneficiary or

Customer Service1%

Economic or Business Activity22%

Environmental10%

Community or Other38%

Stakeholder Breakdown of Value – Road Re‐Design



GI/LID Results

Net Present Values – Median (50th Percentile)

Costs Benefits

CapEx Cost O&M CostsFlood Risk

Reduction

Property Value

Uplift

Heat Mortality

Risk Reduction

Reduced CO2

Emissions

Reduced Other

Costs

Direct Financial

NPVTotal 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

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

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

Probab

ilty of Not Exceeding


Bioretention

PerviousPavers/PorousPavement

Detention Basin

Water HarvestingBasin

Cistern

Xeriscape Swale

Infiltration Trench

Pavement/Ashphalt

Concrete



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Highlights• Benefits of GI/LID features

quantified and monetized:

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

$(1,000) $‐ $1,000 $2,000 $3,000

Probab

ility of Not Exceeding


Thousands

Commercial SiteDirect NPV ‐ NoGI/LID

Commercial SiteSNPV ‐ GI/LIDIncluded

"Road Re‐Design DriectNPV ‐ NoGI/LID"

Road Re‐DesignSNPV ‐ GI/LIDIncluded

• 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



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 FindingsStormwater 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



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Future Enhancements – the Ultimate “Shown and Tell”

Brian YoungSustainable Infrastructure Program Manager, Autodesk

Autodesk

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The New Infrastructure Tools


Courtesy: Parsons Brinkerhoff

Plan


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Plan


Design


Build


Courtesy: VTA Consulting

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Manage


Courtesy: City of Vancouver

Show


Courtesy: Parsons Brinkerhoff

Show


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Envision Business Case Evaluator (BCE) Companion Tool: Prioritizing Investments for Sustainable Stormwater Management Projects

Questions & Answers


APWA Stormwater Management Symposium

Envision Business Case Evaluator (BCE) Companion Tool: Prioritizing Investments for Sustainable Stormwater Management Projects

Moderator: Vicki Quiram, Assistant Commission, New Hampshire Dept. of Environmental Services

Leaders: John Williams, Impact Infrastructure, Inc.Ryan Meyers, Impact Infrastructure, Inc. John Parker, Impact Infrastructure, Inc.Marty Janowitz, StantecBrian Young, Autodesk

Conclusions

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References Australia Department of Finance and Deregulation, Office of Best Practice Regulation (2013). “Best Practice Regulation

Handbook ‐ Appendix E. Cost‐benefit analysis” http://www.finance.gov.au/obpr/proposal/handbook/appendix‐E‐cost‐benefit‐analysis.html

Congress, U. S. "Flood control act of 1936." Public Law 738 (1936): 49.

Dupuit, Arsène Jules Étienne Juvénal (1844): De la mesure de l’utilité des travaux publics, Annales des ponts et chaussées, Second series, 8. Translated by R.H. Barback as On the measurement of the utility of public works, International Economic Papers, 1952, 2, 83‐110 http://www.rothsteineconomics.com/On%20the%20Measurement%20of%20the%20Utility%20of%20Public%20Works.pdf

The Economist, “Petty impressive ‐Meet Sir William Petty, the man who invented economics”, Dec 21st 2013 http://www.economist.com/news/finance‐and‐economics/21591842‐meet‐sir‐william‐petty‐man‐who‐invented‐economics‐petty‐impressive

Federal Inter‐Agency River Basin Committee. "Proposed practices for economic analysis of river basin projects." Report of the Sub‐Committee on Costs and Budgets, Washington DC (1950).

Mishan, Edward J., and Euston Quah. Cost‐benefit analysis. Routledge, 2007.

Pigou, Arthur Cecil. The economics of welfare. Transaction Publishers, 1924.

Treasury Board of Canada Secretariat (2013). “Canadian Cost‐Benefit Analysis Guide: Regulatory Proposals” http://www.tbs‐sct.gc.ca/rtrap‐parfa/analys/analystb‐eng.asp

U.K. Government, Department for Environment, Food and Rural Affairs (eftec) (2010). “Valuing Environmental Impacts: Practical Guidelines for the Use of Value Transfer in Policy and Project Appraisal ‐ Case Study 7 – Using GIS in Valuing Ecosystem Impacts” https://www.cbd.int/financial/values/unitedkingdom‐case7.pdf

US Department of Transportation (2014). “Benefit‐Cost Analyses Guidance for TIGER Grant Applicants ‐ TIGER BCA Guidance” http://www.dot.gov/policy‐initiatives/tiger/tiger‐bca‐guidance‐2014

US Department of Transportation (2014a). “TIGER BCA Resource Guide” http://www.dot.gov/policy‐initiatives/tiger/tiger‐bca‐resource‐guide‐2014

US Department of Transportation, Federal Highway Administration (2013). “Benefit‐Cost Analysis ‐ Asset Management” http://www.fhwa.dot.gov/infrastructure/asstmgmt/primer05.cfm

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GREEN INFRASTRUCTURE DESIGNS FOR MULTIPLE BENEFITS

August 19, 2014

2014 APWA International Congress & Exposition

Toronto, ON, Canada

Brenda Macke, P.E.

Andy Sauer, P.E.

Today’s Presentation

• Green infrastructure implementation

• Green infrastructure evaluation

– 4 levels of scale

– 2 most typical (small distributive or large centralized)

• Small distributive

• Large centralized facilities

• Case Study 1 – Adams Park Wetland & StormwaterDetention, Omaha, Nebraska

• Case Study 2 – Target Green West Marlborough, Kansas City, MO

• Question & Answers

Green Infrastructure Implementation

• Goal: Improve water quality

– 85‐90% reduction in pollutants

– Extend the useful life of existing infrastructure

• Challenges

– Cost effective

– Aging infrastructure

– Limited or no curb capacity

– Blighted/vacant property

– Depopulation

– Requires coordination & cooperation

– Paradigm shift (gray to green)

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Green Infrastructure Scale

• Lot Level

– Rain Barrels

– Rain Gardens

• Street Level

– Bioretention

– Swales

• Subbasin Level

– Wet Pond

– Wetland

• Basin Level

– Restoration

Distributive Green Solutions

• Design Objective

– Keep initial stormwater runoff from entering pipe

– Manage stormwater on‐site

• Store in soils for plant use

• Deep infiltration for groundwater recharge

• Delayed slow release back to sewer system

• Store for reuse (irrigation or vehicle washing)

• Main Driver

– Utilizes existing infrastructure

Distributive Green Solutions

Benefits

• Uses existing pipes

• Mimic pre‐develop hydrology

• Recharging groundwater

• Provides green spaces

• Enhance neighborhoods

• Public engagement

• Re‐development standards

Challenges

• Capturingstormwater

• Requires lots of sites

• Needs to look good

• Requires maintenance

• Within ROW or on private property

• Micro designs

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Centralized Green Solutions

• Design Objective

– Strategic sewer separation to consolidate GI in one central location

– Manage stormwater with larger public operated facility

• Create public amenities

• Provide water features that promote infiltration, evaporation, & ET

• Operate with multi stage control structure to meter release back to sewer system

• Store for reuse (irrigation)

• Main Driver

– Consolidates operations


Benefits

• Creates water features

• Enhances public spaces

• Creates habitat

• Provides green spaces

• Enhances neighborhoods

• Increases public engagement

• Creates opportunity for multi‐benefits between City departments

Challenges

• Sewer separation

• Requires large sitein right location

• Needs to meet long range plan for the area

• Requires maintenance

• Requires more coordination

• Higher risk

Holistic watershed approach to maximize community benefits

• Evaluate Watershed Characteristics

– Public and private property

– Vacant and blighted areas

– Large tracks of impervious surface

– Large transportation corridors

• Identify Opportunity Areas to provide cost‐effective GI solutions

– Large centralized locations

– Minimize utility conflicts and new infrastructure requirements

• Potential Enhancements

– Community amenities

– Redevelopment opportunities

Large Centralized GI Solution

Linear Roadway GI Solution

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Site Suitability Criteria• Community enhancements

• Re‐development opportunities

• Connected with other CIP projects

• New infrastructure requirements

• Major utility conflicts

• Environmental issues

Evaluate: Where to install Green Infrastructure Facilities

Land Use Cover

• Public land

• Large impervious cover

• Large transportation corridor

• Vacant property

• Blighted areas

Implementation Process of Green Infrastructure

• GI controls (small storms)

• StormwaterConveyance

• Quantify capture volume

• Estimate reduction in gray solutions

• H&H modeling• Cost benefit analysis

• Adaptive designs• Meets volume capture

and water qaulity• Enhancements

CASE STUDY #1

Adams Park Wetland & Stormwater Detention, Omaha Nebraska

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• Identify locations for green solutions

• Screen sites

• Distributive GI Sites

• Centralized GI Sites

1- Adams Park

2

3

4

8

5

6

John Creighton BlvdWatershed Evaluation

1- Adams Park

9-13

2

8

Initial Screening

Distributed Green Solutions within existing right of way- Bioretention

1- Adams Park

9-13

2

8

Initial Screening


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Centralized GI Results

• Meets stormwater water quality regulation

– 0.5 inch runoff

• Significant benefit to downstream conveyance

– Reduced 10‐yr conveyance by 83%

– 60 inch pipe

– Able to meet downstream conveyance restriction

• Drainage area is 244 acres 0

100

200

300

400

500

600

700

800

900

1000

1:00 2:00 3:00 4:00 5:00 6:00

Inflow Outflow

Centralized GI ‐Wetland

1- Adams Park

9-13

2

8

Final GI Solutions

Adams ParkWetland Design Meets Master Plan Concept

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Wetland Design Features

Storm Sewer Outfall

Pool, Riffle, Reach

Road Crossing

Wetland

Outlet Structure

Inlet Structure

Outlet Structure

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Outlet Structure

Final Grading Plan

Wetland Water Budget

• Evaluated 3 Years

– Dry Year (1988)

– Avg Year (1969)

– Wet Year (2007)

• 11‐26 Days of Continuous Saturation or Inundation

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Adams Park Wetland – Rain Events

After ½ inch Rain After 2 inch Rain

Adams Park Wetland Zones

Wetland Cross‐Section

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Pre‐Treatment Channel & Play Area

Park Features

Adams Park Wetland

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CASE STUDY #2

Target Green West Marlborough, Kansas City, MO

Project Goals: Target Green Marlborough

Meet regulatory capture volume requirements

Identify cost‐effective green infrastructure (GI) solutions

Minimize community disturbance

Integrate with existing neighborhood character

ARLETA PARKPILOT AREA

RACHEL MORADO

CONTROLAREA

TOWER PARK

COLONIALPOINT

Outfall 059

Outfall069

85th St

75th St

Integrate into long‐term planning goals

• Transportation Planning

– Corridor Studies

• Parks & Rec

– Trails

– Boulevards

• Public Works

– Infrastructure needs

• Historical Preservation

• Comprehensive Planning

– Revitalization

ARLETA PARKPILOT AREA

CONTROLAREA

COLONIALPOINT

85th St

75th St

RACHEL MORADOTOWER PARK

Parks and Trail Connections

Urban Renewal Areas

Trolley Track Trail

Outfall 059

Outfall069

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Target Green West Marlborough

• Land Use Cover

– Public land

• Right‐of‐way

– Large impervious cover

– Transportation corridor

– Vacant Property

• Site Suitability

– Other infrastructure needs

• Flooding issues

– Redevelopment opportunities

Large Impervious Cover

Vacant Property

Redevelopment Opportunities

Existing Right-of-Way

Outcome of Screening Analysis

TOWER PARK

COLONIAL POINT

85th t

75th St

Outfall 059

82nd st

79th st

Total Volume Capture Requirement 1,100,000 gallons

Historic Flooding Location

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Target Green West MarlboroughDistributed GI

Distributed GI –Campus Location

• Bioretention Cells

– 3,850 sf

– 10,400 sf

• Bioswale

Distributed GI –Neighborhood

• Existing sump area• City owned

property• Utilize existing

swale/ditch collection system

• Two Bioretention Cells

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Target Green West MarlboroughCentralized GI

• Successful centralized GI is dependent on getting water tothe facility

– Stormwater collection & conveyance

• How can we do this?

– Complete street replacement or

– Utilize existing features

• Challenges for Target Green Marlborough centralized:

– Use existing features (streets; swales)

– Construction impact (Driveways; future swale maintenance)

– Pipe design stormwater design criteria (future upgrades)

Reality: There will be localized ponding (utilize existing ‘green’)

Centralized GI: Future Park Feature

Centralized GI: Park FeatureEvaluating the Site

• Environmental Site Assessments

– Phase I and II

– Dry cleaning activities

– PCE exceedance

• Geotechnical borings

– 8 Borings

– Limestone & Shale

• Existing CSO Trunk

– 42‐inch RCP

Recommendation Meeting

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Centralized GI, Park FeatureCollection system

• Improve stormwater collection

– High impervious area (with curb); major transportation corridor

– Existing Residential

• Improved sump areasT

roo

stA

ve

Centralized GI: Park Feature

Dry Weather

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Storm D Event Inundation Area

1.4” Storm

2-Year

2-Year Event Inundation Area

100-Year

100-Year Event Inundation Area

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Flood Mitigation Recommendation

• Stormwater Pipe

– 48‐inch

– Connection to existing storm sewer

– Connection to Location 5

• Mitigates flooding

• Detained stormwaterreleased within 24 hrs

• WWTP Cost Savings

– $540,000 over 25 yrs

• Flooded property value

– $625,000

Centralized GI:Neighborhood


• Conveyance Improvements

– Strategic Separation

• 24 acres Curbed Streets

– (Colonial Point apartments)

• 55 acres Swale Section Streets

– (east residential area)

– Sized for 10‐year or 25‐year with overflow in excess of WQv back to combined system

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• Bioswale

• Bioretention

Lessons Learned

• Location, Location, Location

• One size does not fit all

• Engage stakeholders

• Integrate with other projects

• Coordination is key

• More than just green infrastructure

QUESTIONS?

Andy Sauer, P.E., ENV SPCDM Smith

[email protected]

Brenda Macke, P.E., CFMCDM Smith

[email protected]

9415 public works stormwater summit (day two) …envision™ on behalf of stormwater projects in...

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