Broward County, Florida 100 -Year Flood Elevation Map and Associated Modeling. Bid No. R P1 September 27, 2017

Transcription

1 Broward County, Florida 100 -Year Flood Elevation Map and Associated Modeling Bid No. R P1 September 27, 2017

2 Meet the AECOM Team 2

3 Key Team Roles and Responsibilities 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 Adams Stakeholder Coordination Lead Davicka Thompson Public Education & Information Lead 3 Fernando Miralles-Wilhelm, PhD, PE, BCEE, DWRE/PMP Climate Change and Sea Level Rise Technical Lead

4 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

5 AECOM Relevant Projects 5

6 Benefits Relevant Projects Bring Kissimmee Basin Modeling and Operations Study South 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 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 Key Benefit: Ability to integrate and deliver modeling, improve CRS rating and stakeholder involvement. 6

7 Relevant Projects Community Rating System National Flood Insurance Program / Community Rating System / Local Mitigation Strategy Assistance Sarasota 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 Sarasota County Watershed Model Maintenance and GIS Update Lemon Bay Model Sarasota 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 7

8 Project Understanding and Approach 8

9 Project Understanding The Main Objective Update Broward County 100-year Flood Elevation Map through: Refinement of the latest Countywide integrated MIKE SHE/MIKE 11 H&H Model that includes: - Future climatic conditions - Sea Level Rise The Team Brings 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 Key Benefit: Each update is unique and adaptive. 9

10 Overall Innovative Project Approach Development / Update of Existing Conditions FEMA MIKE SHE/MIKE 11 Model Public Engagement and Stakeholder Involvement Key Benefit: Proactive, collaborative stakeholder approach to identify and address concerns. Existing Conditions Model Calibration \ Validation \ and Simulation Development / Update of Future Conditions FEMA MIKE SHE/MIKE 11 Model Development of Future Conditions 100-Year Floodplain Delineation 10

11 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 development process - Public education - Community support of the project Stakeholder workshop for Kissimmee Basin project Key Benefit: Inform and garner stakeholder support. 11

12 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 Civic and Business Organizations Government Partners Academia/Schools Healthcare Systems Environmental Advocates Utilities and Regulators (e.g., SFWMD, FPL) Elected Officials 12

13 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

14 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

15 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

16 Project Approach Update of Existing Conditions Model Update Model Software Version to Check against old results - Possibly re-conceptualize representation of rainfallrunoff 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

17 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

18 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 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

19 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

20 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

21 AECOM Toolbox to streamline analysis and development AECOM Forecasting Local Extremes (FLEx) Tool Stre amline Download and Analysis of His torical Station Data Fle xible Large Downscaled GCM Datasets Compute Compute Range of Pre cipitation Statis tics e.g., 95 th perc. 5 day max Anytime Epoch Diffe re nt Statis tical Te ch. Generate IDF Curves Any GCMs Time Horizon Different RCP Scenarios Key Benefit: Automated postprocessing tool to develop future IDF curves and visualize spatial variation in precipitation. GIS Toolbox Post-process and Vis ualize SpacialVariation in Pre cipitation Analyze Changes in SpacialVariation ove rtime 21

22 Unique Data Processing Tools 22

23 100-Year Flood Elevation Map and Associated Modeling Home Set Up IDF, His torical data IDF, Unde r climate change Reports & Output Home Unique Data Proce s s ing Tools Future IDF (FLEx) 23 Rainfall Conve rs ion Terrain Processing Groundwater Conversion Wis e -Floodplain 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

24 Community Rating System (CRS) 24

25 Broward s Community Rating System Score = 7 Goals Reduce flood damages to insurable property Strengthen and support the insurance aspects of the NFIP Encourage a comprehensive approach to floodplain management Activities 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 Elements Prepare and deliver presentations Hazard Disclosure Category Flood Hazard Mapping Higher Regulatory Standards Flood Data Maintenance and Stormwater Management Activity 25

26 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 26

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