Broward County, Florida 100 -Year Flood Elevation Map and Associated Modeling Bid No. R2114367P1 September 27, 2017
Meet the AECOM Team 2
Key Team – Roles and Responsibilities Pradeep Nagarajan, PE Project Manager Key Benefit: AECOM has assembled a Maria Loinaz, PhD, PE proven technical team Modeling Technical Lead capable of adding value with innovations. Pamela Adams Stakeholder Coordination Lead Davicka Thompson Public Education & Information Lead Fernando Miralles-Wilhelm, PhD, PE, BCEE, DWRE/PMP Climate Change and Sea Level Rise Technical Lead 3
Team Qualifications • 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. 4
AECOM Relevant Projects 5
Benefits Relevant Projects Bring Digital Flood Insurance Rate Map Kissimmee Basin Modeling and Operations Study and Flood Insurance Study Report, FEMA Region IV South Florida W So a Wat ater M Man anagement Distric Di ict Broward County, Br , FL FL Benefit: Knowledge Transfer Benefit: Continuity • Team has all internal tools used •Team that developed the KBMOS to develop County Digital Flood model also worked on the Insurance Rate Maps Broward County’s MIKE SHE / MIKE 11 model, will also work on • Team understands sensitivities the 100-year Flood Model of the model and how they react to events •Original tools and routines Key Benefit: Ability to integrate and deliver modeling, improve CRS rating and stakeholder involvement. 6
Relevant Projects – Community Rating System National Flood Insurance Program / Community Rating System / Local Mitigation Strategy Assistance Sar aras asota County, F , 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 Sarasota County Watershed Model Maintenance and GIS Update – Lemon Bay Model Saras asota a County, F , 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 7
Project Understanding and Approach 8
Project Understanding The Main Objective The Team Brings Update Broward County 100-year • Consistency performed in 2014 Flood Elevation Map through: model update and precursor models(NADA, SADA, CADA) • Refinement of the latest County- wide integrated MIKE SHE/MIKE • Thorough understanding of the 11 H&H Model that includes: MIKE SHE/MIKE 11 model (complexities; constraints; and - Future climatic conditions performance) - Sea Level Rise • Knowledge and lessons learned during the previous updates Key Benefit: Each update is unique and adaptive. 9
Overall Innovative Project Approach Existing Development / Conditions Model Update of Calibration \ Existing Validation \ and Conditions FEMA Simulation MIKE SHE/MIKE 11 Model Development / Update of Future Public lic Conditions FEMA MIKE SHE/MIKE Engagem emen ent 11 Model and an Stakeh eholder er Involvem emen ent Development of Future Conditions 100-Year Floodplain Delineation Key Benefit: Proactive, collaborative stakeholder approach to identify and address concerns. 10
Public Engagement Approach • Purpose - Introduce project and highlight benefits - Communicate early and often - Listen to stakeholders - Address outstanding concerns • County Benefits - Feedback from stakeholders early in the Stakeholder workshop for development process Kissimmee Basin project - Public education - Community support of the project Key Benefit: Inform and garner stakeholder support. 11
Public Engagement and 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. Key Stakeholders – Residents – Environmental Advocates – Civic and Business – Utilities and Regulators (e.g., Organizations SFWMD, FPL) – Government Partners – Elected Officials – Academia/Schools – Healthcare Systems 12
Engagement Tools and Activities • Stakeholder meetings • Traditional media outreach • Social media • Interactive webpage • Short educational video • Mobile applications • Brochures / newsletters / infographics • Utility bill inserts • Planning model simulations Key Benefit: Utilize as many platforms as are available and appropriate to convey messages efficiently. 13
Project Approach – Data Collection Activities Development / Update of Existing FEMA MIKE SHE/MIKE 11 Model 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 14
Project Approach – Update of Existing Conditions Model Update of MIKE SHE Model 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 15
Project Approach – Update of Existing Conditions Model • 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) 16
Project Approach – Existing Conditions Model Calibration/Validation 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) 17
Project Approach – Future Conditions Model Development Model Development for Future Conditions (2060 and 2100) • 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 Key Benefit: County gains future conditions model with climate change and sea level rise factors. 18
Addressing Key Challenges – Inclusion of SLR • Tidal Boundaries - SFWMD – future tidal conditions development - Zone A Coastal modeling • Antecedent (Initial) Conditions and Groundwater Boundaries - USGS MODFLOW models 19
Addressing Key Challenges – Future Climate Conditions 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) 20
AECOM Toolbox to streamline analysis and development AECOM Forecasting Local Extremes (FLEx) Tool Streamline Download and Analysis of Historical Station Data Large Downscaled GCM Datasets Flexible Compute Compute Range of Generate IDF Curves Precipitation Statistics Any GCMs e.g., 95 th perc. – 5 day max Time Horizon Anytime Epoch Different RCP Scenarios Different Statistical Tech. GIS Toolbox Key Benefit: Automated post- Post-process and Analyze Changes in processing tool to develop future IDF Visualize Spacial Variation Spacial Variation in Precipitation overtime curves and visualize spatial variation in precipitation. 21
Unique Data Processing Tools 22
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