New Coastal Study for Puerto Rico FIRMs. Paul Weberg, FEMA RII Mat Mampara, Dewberry Jeff Gangai, Dewberry Krista Collier, Baker

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1 New Coastal Study for Puerto Rico FIRMs Paul Weberg, FEMA RII Mat Mampara, Dewberry Jeff Gangai, Dewberry Krista Collier, Baker September 2007

2 Project Team FEMA Region II Program Manager Collaboration between New York City office and Caribbean office Medina Consultants Lead IDIQ contractor Dewberry Coastal subcontractor Coastal analyses and mapping expertise Michael Baker National Service Provider Independent technical review of coastal analyses and mapping

3 Project Team Dewberry Coastal Technical Credentials Lead Coastal Advisor National expert on coastal flood hazards and FEMA coastal guidelines ines Participates on ASFPM coastal committee and FEMA coastal technical workgroups 12 years of experience in coastal flood hazards as well as coastal al structures and navigation project experience Lead Storm Surge Modeler PhD in Coastal Oceanography (dissertation evaluating coastal geomorphology for vulnerability to inundation) 9 years experience in coastal sciences and analyses Lead Wave Height Analyses/Mapping Engineer PhD in Hydraulics and Coastal Engineering 8 years experience in coastal engineering Dewberry Coastal Experience Reviewed and performed storm surge and wave height analyses nationwide since 1980 s

4 Project Team Michael Baker Coastal Technical Credentials Independent Review Lead National expert on coastal flood hazards and FEMA coastal guidelines ines Participates in FEMA coastal technical workgroups Technical Review Member PhD in Hydrology 7 years experience in coastal sciences and analyses Expert in coastal hydraulics and mathematical modeling Technical Review Member Experienced with numerical modeling of coastal processes and extreme value statistics Participates in FEMA coastal technical workgroups Baker Coastal Experience FEMA National Service Provider specializing in QA/QC and reviews of coastal flood insurance studies for past 4 yrs More than 15yrs experience with FEMA and NFIP coastal studies

5 PR Coastal Project Overview Erosion Wave Setup Wave Heights WHAFIS SWEL ADCIRC 100-year EST Field Recon Mapping Wave Runup RUNUP Primary Frontal Dune

6 PR Coastal Project Overview Puerto Rico Coastal Mapping Needs Update coastal storm surge analysis Recent Hurricanes showed the flood hazards were under predicted Update approximately 600 kilometers (375 miles) of coastal restudy in Puerto Rico Limited resolution of effective surge study (km vs. 80 meters) Large distance between effective transects (113 vs. 263) Topography over 20 years old

7 PR Coastal Project Overview What's New New Topography Analysis uses most recent storm data (25 storms) Highly detailed 2D Surge Model Erosion of dunes is considered Dense spacing of transects Updated wave analysis State of the art GIS technology utilized

8 PR Coastal Project Overview Data Acquisition Topography 2004 USACE LIDAR Bathymetry SHOALS NOAA bathymetric surveys

9 PR Coastal Project Overview Data Acquisition (cont.) Wind & Pressure Fields NOAA HURDAT Database (updated to 2006 hurricanes) Storm characteristics Planetary Boundary Layer Model (PBL), Oceanweather Inc. Climatology Model

10 Puerto Rico Storm Surge Study

11 Puerto Rico Storm Surge Study (cont.)

12 Puerto Rico Storm Surge Study (cont.) ADCIRC mesh detail of San Juan

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14 Puerto Rico Storm Surge Study (cont.) Storm Selection

15 Puerto Rico Storm Surge Study (cont.) YEAR MONTH DAY BTID NAME CAT. MAX. BASIN NOTNAMED TS North Atlantic Storm Selection NOTNAMED H2 North Atlantic NOTNAMED TS North Atlantic NOTNAMED H1 North Atlantic NOTNAMED H2 North Atlantic NONAMED H5 North Atlantic NOTNAMED H4 North Atlantic NOTNAMED TS North Atlantic NOTNAMED H1 North Atlantic NOTNAMED H1 North Atlantic NOTNAMED H1 North Atlantic BETSY H1 North Atlantic DONNA H3 North Atlantic EDITH H1 North Atlantic INEZ H4 North Atlantic BEULAH H4 North Atlantic FREDERIC TD North Atlantic GERT TS North Atlantic KLAUS TS North Atlantic Hugo H4 North Atlantic LUIS H4 North Atlantic MARILYN H2 North Atlantic HORTENSE H1 North Atlantic GEORGES H2 North Atlantic LENNY H4 North Atlantic JEANNE TS North Atlantic

16 Storm Surge Results: Tidal Calibration ADCIRC vs. NOAA Predicted Tides at San Juan Harbor Water Elevation, m Time, min Predicted Simlulated

17 Storm Validation Results Hurricane Georges Simulated vs. Observed Water Levels at Magueyes Island 0.8 ADCIRC Water Levels NOAA Verified Water Levels Water level, m Time, min

18 Maximum SWEL from 1928 Hurricane

19 1928 Hurricane

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21 Puerto Rico Storm Surge Study (cont.) Empirical Simulation Technique (EST) Statistical Program Stage-Frequency Analysis Input water levels from all storms at specified locations or stations Output return periods at each station

22 100-Year Storm Surge Elevations

23 Wave Analysis: Transect Layout

24 Wave Analysis: Field Reconnaissance, 2005 Inspect Transect location for adequacy Document each Transect with photographs Inspect composition and characteristics of beach sand Document obstructions Vegetation Buildings

25 Field Reconnaissance (cont.) Location Description : Transect Number 21 Sea Blue Place Atlantic Ocean Latitude, Longitude (decimal degrees): Building Description: None Vegetation Description: Vegetated dune with small brush and palms Palms 6-12 diameter, 20 height, 20 spacing Beach Description (sand and dune characteristics): Sandy beach with PFD present Open fetch General Comments:

26 Field Reconnaissance (cont.)

27 Puerto Rico Wave Analysis (cont.) Wave Modeling Erosion Wave setup (DIM) Wave runup (2%) Wave height analysis Special Consideration Wave setup and runup behind reefs Erosion of thin sandy beach face

28 Beach Erosion PR beaches 1. Dunes: Identification of Primary Frontal Dune (PFD); FEMA 540 sq ft rule 2. Sand veneer overlaying rocky ledges: 1-22 ft of sand removed from original profile. Shape of profile preserved

29 Wave Set-up Linear beaches => Direct Integrated Method (DIM) Hs = 27.4, Ts =11.2 s, and slope Range set-up for PR = ft Reef-protected beaches => Gourlay M.R. (1996) Method If reef plateaus at coast: wave set-up calculated at reef If reef is detached from coast and wave reforms behind reef: Wave set-up calculated at reef + Wave set-up calculated (DIM) at shore as function of H max at reef crest

30 Wave Run-up up R2% was calculated following FEMA Guidelines Methods TAW Method (van der Meer, 2002) Slopes 1:8 to 1:1 Reefs (based on maximum wave passing over reef) Runup 2.0 Model (based on composite slope method) Slopes < 1:8 Shore Protection Manual (SPM USACE 1984) Vertical Structures

31 Obstructions

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34 Mapping

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36 Effective vs. New Mapping

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38 NSP Independent Review Intermediate Submission No. 1 Scoping and Data Review Intermediate Submission No. 2 Storm-surge Model Calibration and Storm Selection Intermediate Submission No. 3 Storm-surge Runs and Flood-frequency Analysis Intermediate Submission No. 4 Nearshore Hydraulics Intermediate Submission No. 5 Draft Flood Hazard Mapping

39 Puerto Rico Wave Analysis (cont.) Results Revised stillwater elevations New coastal wave modeling New coastal flood hazard zones and mapping

40 New Coastal Study for Puerto Rico FIRMs??? QUESTIONS? Preguntas?