Mitigation Assessment Team Report Hurricanes Irma and Maria in Puerto Rico Building Performance, Observations, Recommendations, and Technical Guidance FEMA P-2020 / October 2018 Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of FEMA. Additionally, neither FEMA nor any of its employees makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, product, or process included in this publication. Users or information from this publication assume all liability arising from such use. All photographs and figures used in this report were taken by the Mitigation Assessment Team (MAT) or developed for this report unless stated otherwise. Map imagery sources (unless otherwise noted in the report): CariCOOS https://www.caricoos.org/ USGS https://www.usgs.gov/ Weather Flow http://weatherflow.com NSF RAPID https://nsf.gov NOAA https://storms.ngs.noaa.gov/ MITIGATION ASSESSMENT TEAM REPORT Hurricanes Irma and Maria in Puerto Rico Building Performance Observations, Recommendations, and Technical Guidance FEMA P-2020 / October 2018 Members of the Mitigation Assessment Team Team Leaders Team Managers Daniel Bass, RA, CFM, FEMA HQ Stuart Adams, EI, CFM, Stantec Edward Laatsch, PE, FEMA HQ Scott Tezak, PE, BSCP, Atkins Team Members Luis Aponte Bermúdez, PhD, PE Ancuta Lungu, FEMA HQ Roberto Alsina, Diversity Professional Services, LLC Andrew Martin, CFM, FEMA Region II Erin Ashley, PhD, LEED AP, Atkins Desidero Maldonado, PE, Atkins Dana Bres, PE, Department of Housing and Urban Jeanine Neipert, FEMA HQ Development Juan Nieves, EI, CFM, Dewberry David Conrad, PE, Atkins John “Bud” Plisich, FEMA Region IV Astrid Diaz, RA, ADV Architects Rebecca Quinn, CFM, RCQuinn Consulting, Inc. Jason Fennell, PE, Forte & Tablada Shudipto Rahman, FEMA Region II Jeff Gangai, CFM, Dewberry Audrey Rierson, JD, Federal Allliance for Safe Homes, Inc. Julie Grauer, CFM, FEMA HQ Michael Rimoldi, CBO, CFM, Federal Alliance for Safe Homes, Matthew Holland, PE, CFM, Stantec Inc. John Ingargiola, EI, CFM, CBO, FEMA HQ John Squerciati, PE, CFM, Dewberry Marc Levitan, PhD, National Institute of Standards and Jonathan Westcott, PE, FEMA HQ Technology Ryan Littlewood, Stantec Internal Support (STARR II) Drone Support GIS Specialist Technical Editor Hayden Gower, Stantec Tim Ward, GISP, Stantec Ryan Littlewood, Stantec Formatting/Graphic Artists Corina Coulas, Stantec Quality Control Alesia ZaGara, Stantec Steve Kalaf, CFM, PMP, Dewberry Marc Pearson, Stantec MITIGATION ASSESSMENT TEAM REPORT In response to Hurricanes Irma and Maria, the Federal DEDICATION Emergency Management Agency (FEMA) deployed a Mitigation Assessment Team (MAT) to evaluate The Puerto Rico Mitigation damage, document observations, and, based on Assessment Team dedicates these, offer conclusions and recommendations on the performance of buildings and other structures affected this report to the memory of by wind forces, flooding, and other hazards due to the the victims of Hurricanes hurricanes. The MAT included FEMA Headquarters Irma and Maria, and and Regional Office engineers, representatives from the families, friends, and other Federal agencies, government officials from communities suffering from the Commonwealth of Puerto Rico, and experts from academia and the design and construction industries. their loss. The Mitigation The conclusions and recommendations in this report Assessment Team hopes this are intended to provide decision makers, designers, report will help others avoid contractors, planners, code officials, industry groups, similar losses in the future. government officials, academia, homeowners, and business owners and operators with information and technical guidance that can be used to reduce future hurricane damage. MITIGATION ASSESSMENT TEAM REPORT HURRICANES IRMA AND MARIA IN PUERTO RICO Executive Summary In September 2017, Hurricanes Irma and Maria significantly impacted Puerto Rico. Irma was a Category 5 hurricane when its eye passed within 30 miles (48 kilometers) of the Puerto Rican island of Culebra on September 6, 2017. Peak wind gust speeds in the Commonwealth of Puerto Rico were over 120 miles per hour (mph) (193 kilometers per hour [kph]) and over 10 inches (25 centimeters) of rainfall was recorded. Thousands of buildings were damaged and over a million residents lost power. Just two weeks later, on September 20, while much of Puerto Rico was still recovering, Maria made landfall as a Category 4 hurricane. Preliminary peak wind gusts in Puerto Rico were over 140 mph (225 kph), over 35 inches (89 centimeters) of rainfall was recorded, and storm surge of over 6 feet (2 meters) was estimated. The hurricanes caused numerous deaths. Hundreds of thousands of buildings were damaged and the power grid failed, causing long-lasting interruptions to essential services. Most of the 3.7 million residents were left without power for months, and 95 percent of cellular sites were out of service, leading to complicated and protracted recovery efforts. Puerto Rico experienced high wind speeds throughout the Commonwealth during both storms, particularly on the islands of Culebra and Vieques and along the northeastern coast of the island of Puerto Rico. In some areas of the Commonwealth, wind speeds approached or exceeded the prescribed design wind speed requirements of 145 mph (233 kph) of the American Society of Civil Engineers (ASCE) standard, Minimum Design Loads and for Buildings and Other Structures (ASCE 7-05). This standard is referenced by the 2009 International Building Code (IBC©) and the 2009 International Residential Code (IRC©), which are the model codes legally adopted in the effective building code at the time of both storms, the 2011 Puerto Rico Building Code (PRBC). HURRICANES IRMA AND MARIA IN PUERTO RICO MITIGATION ASSESSMENT TEAM REPORT i EXECUTIVE SUMMARY Damage from storm surge and flooding was severe in some areas, while wind damage was widespread throughout the Commonwealth. Damage from wind-driven rain and other sources of water intrusion was significant across many building types, including critical facilities. High winds caused severe damage, particularly to informally constructed buildings (broadly defined as those not permitted or not built to current building standards) and improperly anchored rooftop equipment. Past Disasters and Mitigation Puerto Rico has a history of reacting to the impact of severe previous hurricanes by Radar image of Hurricane Maria at 0950 UTC, September 20, 2017, just adopting hazard mitigation techniques to before landfall in Puerto Rico. Source: Pasch, Penny, and Berg (2018). minimize future damage. Previous mitigation actions have included establishing or improving building codes and building code enforcement. This was a key recommendation of the Federal Emergency Management Agency (FEMA) Hurricane Georges Building Performance and Assessment Team (BPAT) Report and is recommended again in this report. On September 18, 1989, Hurricane Hugo made landfall in Puerto Rico as a Category 2 hurricane. Hugo caused severe damage to the infrastructure of Puerto Rico, with over thirty thousand people losing their homes. Eighty percent of wooden structures on Culebra and Vieques were destroyed. Property damage is estimated to have exceeded $1 billion in 1989 dollars1. Evidence of mitigation carried out in response to Hurricane Hugo, including the installation of frame connection hardware (hurricane clips) and other wind retrofits was later cited in the Hurricane Georges FEMA report. On September 21, 1998, the Category 2 Hurricane Georges made landfall in Puerto Rico. Georges had devastating effects on an array of building types and infrastructure. In the aftermath of Georges, FEMA made observations and recommendations. Observations included a prevalence of informally constructed buildings. Poor implementation and enforcement of existing codes were cited as a major contributor to the heavy losses. Because Hurricane Georges’s winds were below design speeds for modern building codes, code-compliant construction would likely have proved much more hurricane-resistant than what was observed. Noting deficiencies in the building code, Puerto Rico adopted the 1997 Uniform Building Code (UBC) with local amendments following Georges. The 1997 UBC served as Puerto Rico’s Building Code until the 2009 IBC© was adopted in 2011. Additional mitigation efforts beyond the building code included a major reconstruction and hazard mitigation program after Hurricane Georges called the New Secure Housing Project (NSHP). This project, established in October 1998 by order of then-Governor Pedro Rosselló, had an “on-site component” that replaced vulnerable buildings at existing sites. Its “off-site component” involved 1This is roughly $2 billion in inflation-adjusted September 2017 dollars. ii MITIGATION ASSESSMENT TEAM REPORT HURRICANES IRMA AND MARIA IN PUERTO RICO EXECUTIVE SUMMARY acquiring and removing damaged or destroyed homes in highly flood-, seismic-, and landslide- HURRICANE METRICS prone sites, and replacing them at new sites. Hurricane Irma The NSHP built 1,647 housing units that were designed to the 1997 UBC, and these performed • Several deaths well during the recent hurricanes. • Skirted Puerto Rico as a Category 5 hurricane, approaching within 30 miles (48 kilometers) • Sustained winds in Puerto Rico 58 mph (93 kph) Mitigation Assessment Team • Maximum rainfall 10–15 inches (25–38