Broward County, Florida100 -Year Flood Elevation Map and Associated ModelingBid No. R2114367P1 September 27, 2017

Meet the AECOM Team

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Key Team – Roles and Responsibilities

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Key Benefit: AECOM has assembled a proven technical team capable of adding value with innovations.

Pradeep Nagarajan, PE Project Manager

Maria Loinaz, PhD, PE Modeling Technical Lead

Pamela AdamsStakeholder Coordination Lead

Davicka Thompson Public Education & Information Lead

Fernando Miralles-Wilhelm, PhD, PE, BCEE, DWRE/PMP

Climate Change and Sea Level Rise Technical Lead

Team Qualifications

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• Developers of current MIKE SHE / MIKE 11 model for the 100-year Flood Elevation Map

• Knowledge of all major drainage basins in the County

• Prepared 100-year Flood Elevation Maps for:- Palm Beach County, FL- Brevard County, FL- St. Lucie County, FL- Indian River County, FL- Clay County, FL

Key Benefit: Tools and team to perform this work.

AECOM Relevant Projects

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Digital Flood Insurance Rate Map and Flood Insurance Study Report, FEMA Region IV Broward County, FL

Benefit: Knowledge Transfer• Team has all internal tools used to develop County Digital Flood Insurance Rate Maps

• Team understands sensitivities of the model and how they react to events

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Benefits Relevant Projects BringKissimmee Basin Modeling and Operations StudySouth Florida Water Management District

Benefit: Continuity•Team that developed the KBMOS model also worked on the Broward County’s MIKE SHE / MIKE 11 model, will also work on the 100-year Flood Model

•Original tools and routines

Key Benefit: Ability to integrate and deliver modeling, improve CRS rating and stakeholder involvement.

Relevant Projects – Community Rating System

Sarasota County Watershed Model Maintenance and GIS Update – Lemon Bay ModelSarasota County, FL

Benefit: Proven Approach• National Flood Insurance Program and the

Community Rating System Program• Floodplain Management Plan• Model calibration utilizing data from major storm events• Hydrologic and Hydraulic modeling

National Flood Insurance Program / Community Rating System / Local Mitigation Strategy AssistanceSarasota County, FL

Benefit: Reduced Flood Insurance Rates• National Flood Insurance Program and the Community

Rating System Program• Development of Community Involvement Plan• Stormwater Regulations• Qualified for Flood Mitigation Funds

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Project Understanding and Approach

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Project Understanding

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• Consistency performed in 2014 model update and precursor models(NADA, SADA, CADA)

• Thorough understanding of the MIKE SHE/MIKE 11 model (complexities; constraints; and performance)

• Knowledge and lessons learned during the previous updates

Update Broward County 100-year Flood Elevation Map through: • Refinement of the latest County-

wide integrated MIKE SHE/MIKE 11 H&H Model that includes:

- Future climatic conditions- Sea Level Rise

The Main Objective The Team Brings

Key Benefit: Each update is unique and adaptive.

Overall Innovative Project Approach

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Public Engagement

and Stakeholder Involvement

Key Benefit: Proactive, collaborative stakeholder approach to identify and address concerns.

Development / Update ofExisting

Conditions FEMA MIKE SHE/MIKE

11 Model

Existing Conditions Model

Calibration \Validation \ and

Simulation

Development / Update of

Future Conditions FEMA MIKE SHE/MIKE

11 Model

Development ofFuture Conditions

100-Year Floodplain Delineation

Public Engagement Approach

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• Purpose- Introduce project and highlight benefits- Communicate early and often- Listen to stakeholders - Address outstanding concerns

• County Benefits- Feedback from stakeholders early in the

development process- Public education- Community support of the project

Stakeholder workshop for Kissimmee Basin project

Key Benefit: Inform and garner stakeholder support.

–Residents–Civic and Business

Organizations –Government Partners –Academia/Schools–Healthcare Systems

–Environmental Advocates–Utilities and Regulators (e.g.,

SFWMD, FPL)–Elected Officials

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Public Engagement and Key Stakeholders

Key Stakeholders

Educate and inform stakeholders on the importance of developing and delivering solutions to efficiently address flooding concerns; and work collectively to improve the Community Rating System.

• Stakeholder meetings• Traditional media outreach• Social media• Interactive webpage• Short educational video• Mobile applications• Brochures / newsletters / infographics• Utility bill inserts• Planning model simulations

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Engagement Tools and Activities

Key Benefit: Utilize as many platforms as are available and appropriate to convey messages efficiently.

Project Approach – Data Collection ActivitiesDevelopment / Update of Existing FEMA MIKE SHE/MIKE 11 Model

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Data Collection and Review –

Topo, Land Use and H&H

Info/Reports

Field Reconnaissance –Confirm the existence or

non-existence of data

Survey and Mapping (WSM)Sub-Consultant: Whidden

Project Approach – Update of Existing Conditions ModelUpdate of MIKE SHE Model

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Development of Rainfall Events for Existing Conditions• Existing conditions: for calibration and

validation- Review historical rainfall records (Past

10 years)- Identify storms with maximum intensity

over 3-day period, possibly Hurricane IRMA

- Evaluate rainfall patterns- Convert to the precipitation rate file in

MIKE SHE format

Project Approach – Update of Existing Conditions Model

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• Update Model Software Version to 2017 - Check against old results- Possibly re-conceptualize representation of rainfall-

runoff processes based on new options in the code.• Update Time Varying Data to Simulation Period

(based on the Selected Calibrated Event)- Rainfall- Reference evapotranspiration - Measured stages and flow (calibration and boundary

conditions)- Structure operations

• Update Input Data with the Latest Available Information- Topography with Latest LiDAR- Survey Information: canal cross-sections and

structures- Land use (if applicable)

Project Approach – Existing Conditions Model Calibration/Validation

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Quality Checks• Sub-basin Stage – Storage: LiDAR versus model topography input file• Remove numerical instabilities• Mass balance conservation in surface water - groundwater exchanges

Modify Parameters for Calibration• Horizontal and vertical hydraulic conductivity (Kh and Kv)• Surface water – groundwater exchange features (flood codes, leakage

coefficients)• Surface and sub-surface runoff parameters (drainage, paved- areas)• Manning’s n (overland flow and MIKE 11 cross sections)

Key Benefit: County gains future conditions model with climate change and sea level rise factors.

Project Approach – Future Conditions Model DevelopmentModel Development for Future Conditions (2060 and 2100)

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• Updated and approved 10-yr, 25-yr, 50-yr, 100-yr and 500-yr design storm events for Future Conditions (2060 and 2100)

- Inclusion of sea level rise from Compact 2015

- Climate change adaptation

• Key challenges:

- Tidal and groundwater boundary – Inclusion of sea level rise

- Non-Stationarity of IDF Curves – Future Climate Conditions

Addressing Key Challenges – Inclusion of SLR

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• Tidal Boundaries- SFWMD – future tidal

conditions development- Zone A Coastal modeling

• Antecedent (Initial) Conditions and Groundwater Boundaries- USGS MODFLOW models

Addressing Key Challenges – Future Climate Conditions

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Acknowledging Non-Stationarity–Current IDF curves assumes stationarity and statistics are constant

(independent of time) – Increasing/decreasing trends already observed due to lower frequency

climate variability (e.g., El Nino Southern Oscillation or Atlantic Multi-decadal Oscillation)

–Stationary assumptions potentially result in lower IDF curves (USACE 2016)

Key Benefit: Automated post-processing tool to develop future IDF curves and visualize spatial variation in precipitation.

AECOM Toolbox to streamline analysis and development

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AECOM Forecasting Local Extremes (FLEx) Tool

Streamline

Download and Analys is of

His torical Station Data

Large Downscaled GCM Datase ts

Flexible

Compute Range of

Anytime Epoch

Diffe rent Statis tical Tech.

e .g., 95th pe rc . – 5 day maxPrecipita tion Statis tics

Compute

Generate IDF Curves

Time Horizon

Diffe rent RCP Scenarios

Any GCMs

GIS Toolbox

Analyze Changes in Spacial Variation

ove rtime

Pos t-proces s and Visualize Spacial Variation

in Precipita tion

Unique Data Processing Tools

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100-Year Flood Elevation Map and Associated Modeling

IDF, His torical data IDF, Unde r climate change Reports & OutputSe t UpHome

Home

Future IDF (FLEx)

Rainfall Conve rs ion

Te rrain Proce s s ing

Groundwate r Conve rs ion

Wis e -Floodpla in

Automate the processing of rainfall data for any design event to different rainfall patterns to be utilized in MIKE SHE/MIKE 11 model

Automatically merge the changes with recent aerial photography, land cover GIS feature classes, as-built and data from survey to create a single topography file from the existing LiDAR data

This specific utility is to easily convert the updated MODFLOW output files to MIKE SHE/MIKE 11 input files to allow for future updates based on changes to the groundwater model or sea level rise projections.

The merging tool is to integrate the results from the updated MIKE SHE/MIKE 11 model and Coastal Zone A Model by comparing the elevation results within a single grid, optimize the results and finally develop a single grid file that will eventually be used to develop the 100-year Flood Elevation Map

Unique Data Proce s s ing Tools

Community Rating System (CRS)

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Broward’s Community Rating System Score = 7

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Goals ElementsActivitiesReduce flood damages to

insurable property

Strengthen and support the insurance aspects of the

NFIP

Encourage a comprehensive approach to floodplain

management

Public Information Activities (Under 300)

• Elevation certificates• Map information service• Outreach projects• Hazard disclosure

Mapping and Regulation Activities (Under 400)

• Flood hazard mapping• Higher regulatory

standards• Flood data maintenance• Stormwater management

Prepare and deliver presentations

Hazard Disclosure Category

Flood Hazard Mapping

Higher Regulatory Standards

Flood Data Maintenance and Stormwater Management

Activity

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When the County partners with Our Team, you will:

• Access to modeling resources

• Proven QA/QC program

- ISO 9001 certification for more than 10 years

• Improve your Community Rating System

• Major benefit:

- Future Planning

- Infrastructure Investments

- Development Requirements