Martin County, Florida Consultation Coordination Officer (CCO) Meeting. March 22, 2018 Stuart, Florida

Transcription

1 Martin County, Florida Consultation Coordination Officer (CCO) Meeting March 22, 2018 Stuart, Florida

2 Agenda Introductions Coastal Flood Risk Study Review Data Collected Storm Surge Modeling Overland Wave Modeling Mapping Milestones & Schedule Moving Forward Map Update Options Flood Insurance Implications Flood Risk Open House Information Questions & Answers Now & Later Hobe Sound Melbourne Beach 2

3 FEMA Coastal Flood Risk Study Is Not an Evacuation Study 3

4 Project Area East Coast Central Florida (ECCFL) Study Brevard County Indian River County Martin County St Lucie County 4

5 Why the Coastal Flood Risk Study Is Being Updated Flood risk changes over time Effective study based on outdated hurricane modeling and topographic data Ability to more accurately define risk and account for significant development in project area To gain a complete and current picture of coastal flood risks, which helps the community: Plan for the risk. Communicate the risk to citizens. Take action to reduce flood risk to lives and property. Build smarter and safer. 5

6 Why the Study Is Being Updated (Cont d) Current surge analysis is 30 to 40+ years old SURGE FEMA Coastal Flood Storm Surge Model, last updated1988 Climate data from 1975, 1978, and 1979 NOAA reports Your risk is better defined through Updated elevation data (topographic data and aerial imagery) New climatological data based on recent storms Computing resources a lot has changed in 30 years! Updated coastal hazard methodologies/modeling Improvement in Geographic Information System technologies to improve coastal mapping accuracy 6

7 Outreach Meetings Discovery Meeting May 16, 2012 Technical Update Meeting June 17, 2013 Storm Surge Analysis Update Meeting November 20, 2014 Flood Risk Review Meeting March 29, 2017 CCO Meeting March 22, 2018 Flood Risk Open House March 22, 2018 Resilience Meeting - TBD 7

8 ECCFL Coastal Flood Risk Study Phases 8

9 Basic Elements of a Coastal Flood Risk Study Base Flood Elevation (BFE) on FIRM includes four components: 1. Storm surge stillwater elevation (SWEL) Determined from storm surge model 2. Amount of wave setup 3. Wave height above storm surge (SWEL) elevation 4. Wave runup above storm surge elevation (where present) 9

10 Basic Elements of a Coastal Flood Risk Study (Cont d) 10

11 Gathered Field Data Coordinated with community officials and stakeholders regarding available data Conducted thorough data investigation Conducted field investigations for surge and overland wave modeling efforts 11

12 Gathered LIDAR, Topographic Data Light Detection and Ranging System (LIDAR) systemgenerated data Gathered bathymetric data 12

13 Gathered Bathymetric Data 13

14 Hurricane Model Mesh Development 14

15 Seamless Digital Elevation Model Mesh resolution 1,406,658 Nodes Complex Terrain/ Developed Areas: m ( feet) Nearshore: m ( feet) Offshore Boundary: 1 5 km (3,000 16,000 feet) 15

16 Hurricane Model Mesh Atlantic Basin 16

17 Hurricane Model Mesh Martin County St. Lucie Inlet, FL Sewall s Point ICWW St. Lucie River 17

18 Comparison of Old and New Mesh 18

19 Hurricane Modeling Validated tidal elevation modeling Reviewed historical storms Picked five storms to validate the hurricane/ surge model Generated hundreds of hypothetical storms 19

20 Validation Storm Selection: Tidal Elevations Astronomical tides simulated based on eight tidal constituents Modeled tides compared to 10 NOAA stations Agreement based on amplitude and phase 20

21 Storm Climatology: In Study Area Tropical storms: Passing within 175 NM of Melbourne, FL Limited data before

22 Validation Storm Selection: Significant Surge Events, Landfalling, bypassing, and exiting storms that passed near study area 22

23 Validation Storm Selection: Significant Surge Events 23

24 Validation Storm Selection: Significant Surge Events (Cont d) Five validation storms selected 1. Hurricane Irene (1999) 2. Hurricane Frances (2004) 3. Hurricane Jeanne (2004) 4. Tropical Storm Tammy (2005) 5. Hurricane Wilma (2005) 24

25 Validation Storm Selection: Significant Surge Events (Cont d) 25

26 Validation: Summary Validation completed for tides and five historical storms Demonstrated model capability to reproduce water levels and waves in project area Comparisons to available data showed reasonable agreement for water levels and waves 26

27 Hypothetical Storms Developed using five parameters 1. Central pressure 2. Radius to maximum winds 3. Forward speed 4. Storm heading 5. Holland s B (shape parameter) Simulated whole range of possible storms for FL (based on historical data for area) Ran storms on high-speed computer Performed quality control reviews of results 27

28 Surge Modeling Gives 1-Percent Annual- Chance SWELs, Martin County Set up mesh for hurricane/ surge model Validated hurricane/surge model Ran hundreds of hypothetical storms Computed return periods for study area Storm surge SWELs for 1-percent-annual-chance event resulted 28

29 Overland Wave Analysis 29

30 Overland Wave Analysis (Cont d) 30

31 Martin County Transects 31

32 WHAFIS Modeling and Mapping 32

33 Primary Frontal Dune (PFD) a continuous or nearly continuous mound or ridge of sand with relatively steep seaward and landward slopes immediately landward and adjacent to the beach and subject to erosion and overtopping from high tides and waves during major coastal storms NFIP regulations 33

34 Wave Runup Modeling and Mapping 34

35 Limit of Moderate Wave Action (LiMWA) FEMA Procedure Memorandum No. 50, 2008 Not an NFIP regulatory requirement (at present) No Federal insurance requirements tied to LiMWA CRS benefit for communities requiring VE zone construction standards in areas defined by LiMWA (coastal A zone areas subject to waves greater then 1.5 feet, but less than 3 feet) 36

36 Combined Probability Mapping Coastal Riverine 37

37 Combined Probability Mapping (Cont d) 38

38 Combined Probability Mapping (Cont d) 39

39 Example FIRM 40

40 Example FIRM (Cont d) 41

41 Preliminary Map Package Sent to each community (CEOs and FPAs) on July 12, 2017 Package included: Updated Martin County FIRM Index panel Updated FIRM panels for community Updated Flood Insurance Study (FIS) report Preliminary Summary of Map Actions (SOMA) Digital data 42

42 Updated FIRM Panels 43

43 Post-Preliminary Processing Milestones Preliminary Flood Insurance Rate Map (FIRM) Issued CCO Meeting and Flood Risk Open House Held Notices Published; Appeal Period Started Appeal Period Ends Letter of Final Determination Issued FIRM Effective Preliminary Phase Community Review 90-Day Appeal Period Administered Appeals Resolved & Map Products Finalized 6-Month Adoption/ Compliance Period Administereed 44

44 Schedule Moving Forward Preliminary FIRM Issued July 12, 2017 CCO Meeting/Flood Risk Open Houses Held March 22, 2018 Appeal Period Administered June-September 2018* Letter of Final Determination Issued December 2018* Adoption/Compliance Period Administered December 2018 June 2019* FIRM Effective June 2019* *estimated times 45

45 Appeal Period Martin County and incorporated communities will have a 90-day period to appeal new or revised flood hazard information shown on the FIRM and FIS report. Notice of changes published in the FEDERAL REGISTER, on the FEMA website, and twice in local newspapers within 10-day period Second newspaper publication begins 90-day appeal period Appeals are for new or revised flood hazard information. 46

46 What Is an Appeal? Appellant believes the new or revised flood hazard information is scientifically or technically incorrect. The information is scientifically incorrect if: The methodology used and assumptions made in the determination of the information are inappropriate or incorrect. The information is technically incorrect if: The methodology was not applied correctly or was based on insufficient or poor-quality data. The methodology did not account for the effects of physical changes that have occurred in the floodplain. 47

47 Data Submission Examples - Coastal Study Areas Storm surge and wave analysis (i.e., revised ADCIRC/SWAN model or other model) Revised WHAFIS transects/ analysis Revised PFD delineation Revised BFEs and flood hazard zones Newer topographic or bathymetric data Data certifications from Professional Land Surveyors/ Engineers 48

48 Comments During Appeal Period Martin County and incorporated communities also will have an opportunity to comment during the appeal period. Comments do not involve flood hazard information (BFEs, floodplain boundaries, etc.). Comments include, but are not limited to, the following: Channel name and location changes Road name and location changes Corporate limit changes Comments are change requests that do not involve hazard information. 49

49 Where to Submit Appeals and Comments Please have appeals and comments directed to your local floodplain administrator. Your local floodplain administrator can submit all appeals and comments to: Christopher Mack AECOM 4016 Salt Pointe Parkway North Charleston, SC FEMA will not move forward until your appeals and comments are resolved. 50

50 Appeal Resolution Process At end of 90-day appeal period, FEMA will: Acknowledge receipt of appeal(s)/comment(s) via letter(s) to CEO(s) Review appeal(s)/comment(s) and supporting data/ information Request additional data/information, if required Inform CEO(s) by letter of denial if appeal(s)/ comments not supported by data/information submitted FEMA will deny appeals and comments that are not adequately supported by data/information. 51

51 Appeal Resolution Process (Cont d) FEMA also will: Revise flood hazard information if appeal(s) adequately supported Revise other information if comment(s) adequately supported Prepare Revised Preliminary FIRM panel(s) and FIS report materials if necessary Send CEO(s) letter(s) to explain resolution of appeal(s)/ comment(s) and start review and comment period Community officials/appellants will have 30 days to review and comment on the resolution. 52

52 Letter of Final Determination (LFD) After 90-day appeal period elapses and appeals/ comments addressed, FEMA will issue LFDs. LFDs begin the 6-month adoption/ compliance periods, during which communities adopt the new FIRM into floodplain ordinances. Along with LFDs, FEMA sends Final SOMAs, informing CEOs/FPAs of Letters of Map Change (LOMCs) to be revalidated or superseded on the FIRM effective date. 53

53 Adoption/Compliance Period FDEM or FEMA Region IV staff may contact communities and offer assistance with reviewing and updating their floodplain ordinances. Ordinance may require update to adopt new FIRM, FIS report, and supporting technical data. Community may update ordinance any time after LFD is received. After adoption, communities send copies of their NFIP-compliant ordinances to FDEM and FEMA Region IV. 54

54 Adoption/Compliance Period (Cont d) FDEM and FEMA determine whether updated community ordinances are compliant. If a compliant ordinance is not received before the FIRM effective date, the community will be suspended from NFIP, so Please begin the ordinance review process as soon as you receive LFD. 55

55 Adoption/Compliance Period (Cont d) Communities can obtain technical support from FDEM staff by telephone at or by at For more information, please contact the Florida State NFIP Coordinator: Steve Martin 56

56 Effective FIRM During the adoption/compliance period, before the FIRM effective date, communities receive: Paper copies of effective FIRM Index, FIRM panels, and FIS report Digital data Revalidation Letter, effective 1 day after new FIRM effective date, informing community of LOMCs that are revalidated or superseded by new FIRM 57

57 Opportunities to Update Effective FIRM A FEMA flood hazard study update is NOT the only time the effective FIRM can be updated. The effective FIRM can be updated by LOMC: Letter of Map Amendment (LOMA) Letter of Map Revision Based on Fill (LOMR-F) Letter of Map Revision (LOMR) 58

58 LOMA and LOMR-F (MT-EZ, MT-1) Provide administrative procedures for FEMA review of information from property owners who believe property has been inadvertently included in a designated Special Flood Hazard Area (SFHA) Can be submitted using paper form (MT-EZ or MT-1) or electronically through 59

59 LOMR (MT-2) Applicable any time better data available Based on changes to hydrologic or hydraulic characteristics of flooding source that results in modification of BFEs, regulatory floodway, or SFHA Is a modification to an effective FIRM and/or FIS report; officially revises the FIRM and/or FIS report Can be submitted using paper forms (MT-2) or electronically through 60

60 Risk and Flood Insurance Determine your flood risk Nearly everyone is at some risk of flooding: High Risk SFHA, identified as Zone A, Zone AE, Zone V, or Zone VE on FIRM Moderate Risk Identified as shaded Zone X on FIRM Low Risk Identified as unshaded Zone X on FIRM 61

61 Risk and Flood Insurance (Cont d) Requirements in a high-risk zone Federally regulated lenders making new loans or modifying existing loans secured by buildings in SFHAs must require borrowers to purchase flood insurance for the term of the loan. 62

62 Flood Risk Open House Date: March 22, 2018 Venue: Time: Indian River State College Chastain Campus Wolf High-Technology Center 2400 SE Salerno Road Stuart, FL :00 p.m. 7:00 p.m. EST 63

63 Flood Risk Open House Layout 64

64 Questions & Answers Now & Later Mark A. Vieira, PE Henrietta Williams, CFM Danon Lucas Steve Martin, CFM Michael (Mike) DeRuntz, CFM Shannon Riess, CFM Jason Hunter, CFM Janice Mitchell 65

65 Questions & Answers Now & Later (Cont d) Chris Mack, PE, PMP Paul Carroll, PE, PMP Richard (Dick) Wild 66