Natural Hazard Migaon Plan 2016-2021 Update for the South
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Natural Hazard Migaon Plan 2016-2021 Update for the South Western Region Prepared by the Western Conneccut Council of Governments (WCCOG) February 2016 3.0 Hazard Idenficaon and Risk Assessment .... 29 Table of Contents 3.1 Avalanche ........................................................................... 32 Execuve Summary ............................... ES.1 - ES.16 3.2 Dam Failure ........................................................................ 32 3.3 Drought ............................................................................... 36 1.0 Introducon ...................................................... 1 3.4 Earthquake ......................................................................... 39 1.1 Background and Purpose ..................................................... 2 3.5 Erosion ................................................................................ 43 1.2 Hazard Migaon Goals ...................................................... 3 3.6 Expansive Soils ................................................................... 44 1.3 Regional Overview ............................................................... 3 3.7 Extreme Cold ...................................................................... 44 1.4 Climate and Weather ......................................................... 11 3.8 Extreme Heat ..................................................................... 46 2.0 Planning Process ............................................. 13 3.9 Flood ................................................................................... 49 2.1 Building the Planning Team ............................................... 14 3.10 Hail .................................................................................... 55 2.1.1 Determining the Planning Area and Resources ...................... 14 3.11 Hurricane & Tropical Storms ........................................... 56 2.1.2 The Planning Team ................................................................. 14 3.12 Landslide........................................................................... 60 2.1.3 Project Meengs...................................................................... 15 2.2 Outreach Strategy ............................................................. 18 3.13 Severe Storms .................................................................. 61 2.2.1 Advisory Commiee and Municipalies ................................. 18 3.14 Severe Winter Weather ................................................... 64 2.2.2 Stakeholders and Public Involvement .................................... 19 3.15 Storm Surge ...................................................................... 68 3.16 Subsidence ....................................................................... 70 3.17 Tornado ............................................................................ 70 3.18 Tsunami ............................................................................ 71 3.19 Wildfire ............................................................................. 72 3.20 Climate Change ................................................................ 75 Pg i - HMP 2016 Update 4.0 Migaon Strategies ...................................... 85 4.3.3.1 Regional 2016 Migaon Strategies ............................... 217 4.1 Capabilies and Available Resources................................ 86 5.0 Plan Implementaon and Maintenance ....... 221 4.2 Municipal Capabilies ....................................................... 92 5.1 Connued Public Parcipaon ........................................ 222 4.3 Migaon Strategies ....................................................... 105 5.1.1 Plan Monitoring and 4.3.1 Overview ............................................................................... 105 Migaon Strategy Implementaon .............................................. 222 4.3.2 Goals to Reduce/Avoid Long Term Vulnerabilies ............... 105 5.1.2 Incorporaon/Implementaon through Exisng Programs ............................................................. 224 4.3.3 Progress and Changes to Migaon Efforts .......................... 105 5.1.3 Schedule ................................................................................ 225 4.3.3.1 Darien Update to 2011 Migaon Strategies ....................106 4.3.3.1 Greenwich Update to 2011 Migaon Strategies .............113 5.2 Plan Availability and Connued Public Parcipaon ...... 225 4.3.3.1 New Canaan Update to 2011 Migaon Strategies ...........120 4.3.3.1 Norwalk Update to 2011 Migaon Strategies .................121 Appendices 4.3.3.1 Stamford Update to 2011 Migaon Strategies ................124 Appendix A 4.3.3.1 Weston Update to 2011 Migaon Strategies ..................129 4.3.3.1 Westport Update to 2011 Migaon Strategies................134 A-0 Plan Adopon 4.3.3.1 Wilton Update to 2011 Migaon Strategies ....................149 A-1 Memorandums of Agreement 4.3.3.1 Regional Update to 2011 Migaon Strategies .................155 A-2 Project Development Meengs 4.4 Specific Migaon Acons and Projects ........................ 157 A-3 Outreach Strategy 4.4.1 Acon Priorizaon .............................................................. 157 A-4 Public Informaon Comments 4.4.2 Acon Plan ............................................................................ 157 A-5 References A-6 Local Plans of Conservaon and Development 4.4.3 2016 Migaon Strategies by Municipality .......................... 158 Appendix B 4.3.3.1 Darien 2016 Migaon Strategies ...................................160 B-1 Municipal Flood Maps 4.3.3.1 Greenwich 2016 Migaon Strategies .............................165 4.3.3.1 New Canaan 2016 Migaon Strategies ..........................173 B-2 Climate Change Analysis 4.3.3.1 Norwalk Migaon Strategies ..........................................177 B-3 Hazus-MH Methods and Reports 4.3.3.1 Stamford 2016 Migaon Strategies ...............................181 B-4 Repeve Loss Properes 4.3.3.1 Weston 2016 Migaon Strategies ..................................188 4.3.3.1 Westport 2016 Migaon Strategies ...............................193 4.3.3.1 Wilton 2016 Migaon Strategies ...................................212 HMP 2016 Update - Pg ii Tables Chapter Table Title Source Pg # 1 1.1-1 Eligible Project Acvies by Program FEMA 2 1 1.3-1 Populaon Density by Municipality, Region and State, 2012 U.S. Census Bureau, 2008-2012 Ameri- 6 can Community Survey 1 1.3-2 South Western Region Housing Units - 1990 to 2010 U.S. 1990, 2000, 2010 Census Bureau 6 1 1.3-3 South Western Region Housing Characteriscs US Census 2008-2012 American Com- 7 munity Survey 1 1.3-4 Grand List by Municipality CT OPM 10 2 2.1.2-1 2016 Hazard migaon Plan (HMP) Advisory Commiee Appointees WCCOG 14 2 2.1.2-2 2016 HMP Municipal Parcipants WCCOG 15 2 2.1.3-1 HMP Meengs WCCOG 16 2 2.2.2-1 Survey Results, Queson #1 WCCOG 25 2 2.2.2-2 Survey Results, Queson #2 WCCOG 25 2 2.2.2-3 Survey Results, Queson #3 WCCOG 25 2 2.2.2-4 Survey Results, Queson #4 WCCOG 25 2 2.2.2-5 Survey Results, Queson #5 WCCOG 26 2 2.2.2-6 Survey Results, Queson #6: WCCOG 27 3 3.0-1 Hazards Idenfied by Municipality WCCOG, SWR Municipalies 30 3 3.0-2 Assets impacted by municipal hazard type 30 3 3.0-3 Regional Hazard Summary WCCOG 31 3 3.2.1-1 Dam Failure Hazard Summary by Municipality WCCOG, SWR Municipalies 32 3 3.2.1-2 CTDEEP Dam Safety Classificaons CT DEEP 32 3 3.2.1-3 Parameters for Locaon, Maximum Probable Extent (Magnitude/Strength), and 33 Probability of Future Events 3 3.2.1-4 Class C Dams in the South Western Region CT DEEP 34 3 3.3.1-1 Drought Hazard Summary by Muncipality WCCOG, SWR Municipalies 36 3 3.3.1-2 PDSI classificaon key NOAA NCDC 37 3 3.3.2-1 Top 15 Annual Droughts in South Western Region from 1901-2013 NOAA NCDC 38 3 3.4.1-1 Earthquake Hazard Summary by Municipality WCCOG, SWR Municipalies 39 3 3.5.1-1 Erosion Hazard Summary by Municipality WCCOG, SWR Municipalies 43 3 3.7.1-1 Extreme Cold Hazard Summary by Municipality WCCOG, SWR Municipalies 44 3 3.8.1-1 Extreme Heat Hazard Summary by Municipality WCCOG, SWR Municipalies 46 3 3.9.1-1 Flood Hazard Summary by Municipality WCCOG, SWR Municipalies 49 3 3.9.3-1 Flood Frequency Definions State of CT 2014 HMP 51 Pg iii - HMP 2016 Update Chapter Table Title Source Pg # 3 3.9.3-2 Count of Flood Events by Municipality NOAA, NCDC 51 3 3.9.4-1 Municipal assets within HAZUS defined Coastal and Riverine 1% annual flood zones WCCOG, DEMHS, DEEP, FEMA 53 3 3.9.4-2 Municipal assets within HAZUS defined Coastal and Riverine 0.2% annual flood zones WCCOG, DEMHS, DEEP, FEMA 53 3 3.9.4-3 Flood Stascs by Municipality WCCOG, FEMA HAZUS 53 3 3.9.5-1 NFIP RLP Claim Stascs by Municipality FEMA NFIP 54 3 3.9.5-2 NFIP SRL Claim Stascs by Municipality FEMA NFIP 54 3 3.10.1-1 Hail Hazard Summary by Municipality WCCOG, SWR Municipalies 55 3 3.11.1-1 Hurricane Hazard Summary by Municipality WCCOG, SWR Municipalies 56 3 3.11.1-2 Safir Simpson Scale NOAA 57 3 3.11.4-1 HAZUS Esmated Hurricane Sandy Wind Damage in $1000s WCCOG, HAZUS 60 3 3.13.1-1 Severe Storm Hazard Summary by Municipality WCCOG, SWR Municipalies 61 3 3.13.1-2 Lightning Hazard Summary by Municipality WCCOG, SWR Municipalies 61 3 3.13.1-3 Severe Wind Hazard Summary by Municipality WCCOG, SWR Municipalies 62 3 3.14.1-1 Severe Winter Weather Hazard Summary by Municipality WCCOG, SWR Municipalies 64 3 3.14.1-2 Northeast Snowfall Impact Scale (NESIS) Wikipedia 65 3 3.14.4-1 Municipal Assets Within Historical Max Snow Depth between 24"-30" by Municipali- WCCOG, DEMHS, FEMA 67 ty 3 3.15.1-1