Green Infrastructure Modeling

8/9/2019 Green Infrastructure Modeling

1/17

Green Infrastructure Modeling

Andrew Parker

Water Resources Modeling Group Director

2010 Regional Water Quality and

Green Infrastructure ConferenceMay 13-14, 2010

Dallas, Texas

Presentation Overview

Modeling basics

Models and calculators

applied to green

infrastructure

BMP design

Site developmentWatershed

management Applications


2/17

Input Model Output

Others

Factor 1

Rainfall Event

Pollutant Buildup

Land use

System

Soil

Stream

Pt. Source

Factor 2

Factor 3

Response

What is a model? A theoretical construct,

together with assignment of numerical

values to model parameters,

incorporating some prior observations

drawn from field and laboratory data,

and relating external inputs or forcing

functions to system variable responses

* Definition from: Thomann and Mueller, 1987

What constitutes a model?


3/17

Why use a model or calculator?

Applications

Multiple scales of planning site to watershed

Other TMDLs, permitting, remediation, design

Purpose

Determine stormwater runoff quantity (total and

peak)

Determine pollutant load reductions and water

quality benefits

Monetize costs and benefits Facilitate design

Model Categories Landscape models

Runoff of water and materials on and through the

land surface

Receiving water models

Crops

Pastu

re

Urban

Flow of water through streams and into lakes and

estuaries

Transport, deposition, and transformation in receiving

waters

Watershed models Combination of landscape and receiving water

models

Site-scale models

Detailed representation of local processes, for

example Best Management Practices (BMPs)


4/17

Model Basis Empirical formulations

mathematical relationship

based on observed data

rather than theoretical

relationships

Deterministic models mathematical models

designed to produce system

responses or outputs to

temporal and spatial inputs

(process-based)

Model Selection

Utility

Ability to answer key management questions and convey results

Relevance

Representation of key processes

Assumptions and limitations

Scale of application

Credibility

Peer-reviewed

Public domain Usability

Availability of documentation, training, and support

Availability and accessibility of data to run model

Model and user interface is reliable and tested


5/17

Typical Modeling Process

(simple models may skip or leave out steps)

Phase I

Phase II

Phase III

Modeling Approach Development

Data Collection (historic, field monitoring)

Model Input Preparation and Configuration

Calibration

Validation

Verification

Follow-up Monitoring OptionalPost-audit

Analysis of Alternatives/Scenarios

Simple Models and Calculators Common Calculation

Methods

Runoff Volume

Runoff Curve Number

Method (TR-55)

Small Storm

Hydrology Method

Infiltration Models

Peak Runoff Rate

NRCS Unit

Hydrograph Method

Rational Method

Pollutant Loading

Simple Method

Typical DataNeeds Land use

Soil types

Rainfall data


6/17

More Complicated Models

Uses

Can evaluate site scale to watershed scale

impacts of land use decisions

More accurately estimate stormwater benefits

of green infrastructure

Can be used for single-event or continuous

simulation

Limitations

Data intensive

Require specific expertise to apply

Models for Green Infrastructure

BMP design Properly size and configure practices

Evaluate effectiveness of BMP after design and construction

Site development Evaluate effectiveness of multiple practices for

hydrology and water quality Optimize selection and placement of practices

Watershed management Analyze watershed-wide implementation

Program evaluation

CSO reduction

TMDL compliance


7/17

BMP Design RECARGA (University of Wisconsin-

Madison Bioretention/Rain Gardens)

Green Save Calculator (Green Roofs)

CityGreen (Tree Canopy and Green

Space)

RECARGAUniversity of Wisconsin-Madison

MATLAB application Design tool for

evaluating

performance of

bioretention facilities

and infiltration

basins

Model can simulate

continuous rainfall, a

single-event, or user

specified volume

User inputs

Rainfall and evaporation file

Drainage area characteristics

Layer characteristics


8/17

GreenSave CalculatorGreen Roofs for Healthy Cities

Web-enabled tool (registrationrequired)

Life-cycle costing tool used to

compare cost of green roof

with conventional roof

Option to publish data to Case

Study database

Modules with minimum and

optional detailed data inputs

Roof durability

Energy use

Stormwater

Heat island

Development fees

Sale-ability/rent-ability

Tenant health and productivity

CityGreenAmerican Forests

ArcGIS extension (not free)

Analyzes ecological and economic

benefits of tree canopy and other green

space

Stormwater Runoff

Runoff volume for 2-year, 24-

hour storm

Based on Runoff Curve

Number (TR-55)

Air Pollution Removal

Pollutant removal capacity of

tree canopy and financial

benefit

Based on US Forest Service air

pollution model

Carbon Storage andSequestration

Amount of carbon stored in

trees and annual carbon

removal

Based on US Forest Service

model


9/17

Site Development Green Values Stormwater Management Calculator

(Center for Neighborhood Technology)

IncreasedComplexity

LID Quicksheet (Milwaukee, WI MSD)

LTHIA (Local Government Environmental Assistance

Networks Long-Term Hydrologic Impact Assessment

Model)

BMP-DSS (Prince Georges County, MDs Best

Management Practice Decision Support System)

SUSTAIN (EPAs System for Urban Stormwater

Treatment and Analysis Integration)

Green Values StormwaterManagement CalculatorCenter for Neighborhood Technology

Web-enabled application

Planning tool with lot and

neighborhood level

calculations

Hydrologic

Financial

Evaluates range of green

infrastructure practices

Pre-defined or custominputs

Landscape details

Cost elements

Integrated pop-up help

screens


10/17

LID QuicksheetMilwaukee Metropolitan Sewerage District

Excel spreadsheet

Evaluates various green

infrastructure features on a

development site to reduce

detention requirements

Can evaluate 2-year and

100-year, 24 hour storm

events

Practices include:

Rain gardens

Rain barrels

Green roofs

Cisterns

Permeable pavement

Long-Term Hydrologic Impact Assessment ModelLocal Government Environmental Assistance Network

Web-enabled tool

Quantifies impact of land use change

on water quantity and quality

Runoff Curve Number approach

30 years of precipitation data topredict yearly runoff

Event Mean Concentrations forpollutant loading estimation

Provides graphical and tabular runoff

volumes and associated pollutant

loads Five versions:

Basic L-THIA

Impervious L-THIA

GIS L-THIA

Detailed Input L-THIA

Advanced Input L-THIA


11/17

BMP-DSSPrince Georges County, MD

Developed for detailedsite-scale planning andBMP modeling

Considers hydrology andwater quality

Models individual BMPsor groups of BMPs (e.g.,at watershed scale)

Includes post-processingcapabilities

Watershed Management

STEPL (EPAs Spreadsheet Tool for

Estimating Pollutant Load)IncreasedC

omplexity

BMP-DSS

SWMM (EPAs Storm Water Management

Model)

SUSTAIN

Multiple models used collectively


12/17

STEPL Spreadsheet Model Spreadsheet Tool forEstimating Pollutant Load (STEPL)

Used at the watershed level for nutrients (nitrogen andphosphorus), sediments, and organic compounds (e.g. biochemical oxygen demand)

U.S. EPA Office of Wetlands, Oceans, and Watersheds - Nonpoint

Source Control Branch, Washington, DC

Automatically customized Microsoft Excel application

Easy-to-follow graphical interfaces

Online STEPL input data server

BMP calculator

Assisting federal, state, and local organizations in reportingestimated pollutant reductions of 319 projects to the Grants

Reporting and Tracking System (GRTS)

SWMM

Often used toestimate existingloads

Different BMPscenarios modeled todetermine loadreductions

Considerations

Street sweeping Flow detention and

pollutant removal

Varying hydrologic

and pollutant loading

assumptions


13/17

Fairfax County, VA

SWMM Application

Creating countywide SWMM

watershed models

Representing hydrology

Simulating stormwater BMPs

Creating prioritization strategy to

maximize stormwater and

environmental benefits

Also linking SWMM to HEC-RASmodels for flood analysis

Prince Georges County, MD BMP-DSS Application

Applied to Anacostia Sewershed (Washington, D.C.) to

support CSO alternative analyses

Identified potential LID configuration scenarios

Tested BMP selection

and placement

optimization

Summarized the effectof potential LID

configurations on runoff

volume and CSO inflow

reduction


14/17

Los Angeles County, CA

Multiple Models Developing comprehensive

watershed management decision

support system Dynamic HSPF/LSPC models for watershed

hydrology and transport of multiple pollutants Evaluation of storm size and return frequencies

for identification of management targets Dynamic simulation of BMP processes, including

both distributed LID and centralized facilities Optimization of the most cost-effective

combination and designs of BMPs to meetmanagement objectives

Load reduction quantification to support TMDLimplementation efforts

Cost estimates for County-wide water qualityimprovement planning

System forUrban StormwaterTreatment andAnalysis INtegrationSUSTAIN

U.S. EPA ORD - Edison

A GIS-based framework designed to support decision-

making

Evaluate and select BMPs to achieve loading targets set by a

TMDL

Identify protective management practices and evaluate pollutant

loadings forSource Water Protection

Develop cost-effective management options for a municipal MS4

program

Determine a cost-effective mix of green infrastructure measures to

help meet optimal flow reduction goals in a CSO control study

Released in November 09

http://www.epa.gov/ednnrmrl/models/sustain/index.html
http://www.epa.gov/ednnrmrl/models/sustain/index.htmlhttp://www.epa.gov/ednnrmrl/models/sustain/index.html


15/17

BMP criteria GIS data Suitable area for BMP placement

SUSTAIN Advantages Multi-scale application

Detailed BMP simulation

Cost consideration

Optimization

Siting Tool


16/17

Background InfiltrationMedia F iltrationSettlingOrifice OutflowBypass Flow

Small Medium

Untreated

Bypass

Attenuated

Orifice Outflow

Media Filtration

(Underdrain

Outflow)

Large

100%

(% Treated)

50%

(% Treated)

10%

(% Treated)

Continuous BMP Simulation

Optimization What is

optimum?

Minimize cost

Maximize pollutant flow and/or load reduction

Subject to BMP size, selection, and placement constraints


17/17

55%24%0%21%

$4.5DRYPOND

RAINBARREL

Selected Simulation

55%24%

0%

21%

BIORETENTION

POROUSPAVEMENT

CostDistribution($Million)

$4.0

$3.5

$3.0

$2.5

$2.0

$1.5

$1.0

$0.5

$0.0

9.9

%

14.1

%

16.6

%

18.4

%

20.3

%

22.1

%

23.4

%

24.2

%

24.8

%

25.7

%

26.6

%

27.3

%

27.9

%

28.5

%

29.6

%

30.2

%

30.6

%

30.8

%

31.1

%

31.6

%

31.8

%

32.1

%

32.4

%

32.9

%

Effectiveness (% Reduction)

Thank you!

Contact Information:

Andrew Parker

[email protected]

(703)385-6000

Optimization

Documents

Green Infrastructure Modeling