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Item C14 C.14' i�` CountCounty ��Monroe. ,y, ? "tr, BOARD OF COUNTY COMMISSIONERS y M T� \�1a� Mayor Michelle Coldiron,District 2 �1 1 nff `_ll Mayor Pro Tem David Rice,District 4 -Ile Florida.Keys Craig Cates,District 1 Eddie Martinez,District 3 w Mike Forster,District 5 County Commission Meeting March 17, 2021 Agenda Item Number: C.14 Agenda Item Summary #7915 BULK ITEM: Yes DEPARTMENT: Building TIME APPROXIMATE: STAFF CONTACT: Karl Bursa(305) 453-8759 NA AGENDA ITEM WORDING: Approval of a resolution of the Monroe County Board of County Commissioners adopting FEMA Technical Bulletin 3 "Requirements for the Design and Certification of Dry Floodproofed Non-Residential and Mixed-Use Buildings" dated January 2021 as required pursuant to Monroe County Code Section 122-2(c). ITEM BACKGROUND: Chapter 122 of the Monroe County Code "Floodplain Management" includes rules for interpreting flood hazard issues. The Building Official shall be guided by the current edition of FEMA's 44 CFR, and FEMA's interpretive letters, policy statements and technical bulletins as adopted from time to time by the Board of County Commissioners. FEMA's Technical Bulletins ("bulletins") provide guidance concerning the building performance standards of the National Flood Insurance Program (NFIP), which are contained in Title 44 of the U.S. Code of Federal Regulations. The bulletins are intended for use primarily by State and local officials responsible for interpreting and enforcing NFIP regulations and by members of the development community, such as design professionals and builders. New bulletins, as well as updates to existing bulletins, are issued periodically as needed. The bulletins do not create regulations; rather they provide specific guidance for complying with the minimum requirements of existing NFIP regulations. Adopting these documents as well as internal County policies would serve to allow the County to not only remain in the NFIP as stated in Section 122-1(b), but also to maintain its standing in FEMA's Community Rating System (CRS). An important change to Technical Bulletin 3 include FEMA's determination that Flood Shields for stem wall foundations with glass curtain walls do not meet the "substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy." Proposed floodproofing of this type, therefore, would not be considered compliant with 44 CFR § 60.3(c)(3). Another important change is that FEMA has updated Technical Bulletin 3 to include prohibition of Floodproofing in Coastal A Zones where a Limits of Moderate Wave Action Line (LiMWA) is present. Similar to VE Flood Zones, floodproofing any structure in a Coastal A Zone is prohibited. When the County adopts the new flood maps, after meals, this means any non-residential structure Packet Pg.474 C.14 that was previously allowed to floodproof will no longer be able to do so, and will have to elevate. The proposed resolution would adopt FEMA Technical Bulletin 3 "Requirements for the Design and Certification of Dry Floodproofed Non-Residential and Mixed-Use Buildings" dated January 2021 as required pursuant to Monroe County Code Section 122-2(c). PREVIOUS RELEVANT BOCC ACTION: January 18, 1994 — BOCC approved Ordinance No. 002-1994 adding the language "as adopted by resolution from time to time by the Board of County Commissioners" to the rules for interpreting flood hazard issues. July 15, 2015 — BOCC rejected proposed ordinance amending Section 122-2(c) and directed staff to continue proposing resolutions for adoption of both new and amended documents to be used by the Building Official for guidance on floodplain management. September 16, 2015 — BOCC approved Ordinance 226-2015 adopting FEMA Technical Bulletin 3 "Requirements for the Design and Certification of Dry Floodproofed Non-Residential and Mixed- Use Buildings" dated 1993 as required pursuant to Monroe County Code Section 122-2(c). CONTRACT/AGREEMENT CHANGES: N/A STAFF RECOMMENDATION: Approval. DOCUMENTATION: Technical Bulletin 3 - 2021 Non-Residential Floodproofing - Requirements and Certification Resolution TB 3 w/Legal Stamp FINANCIAL IMPACT: Effective Date: Expiration Date: Total Dollar Value of Contract: N/A Total Cost to County: N/A Current Year Portion: N/A Budgeted: N/A Source of Funds: N/A CPI: N/A Indirect Costs: N/A Estimated Ongoing Costs Not Included in above dollar amounts: N/A Revenue Producing: N/A If yes, amount: Packet Pg.475 C.14 Grant: N/A County Match: N/A Insurance Required: N/A Additional Details: N/A REVIEWED BY: Rick Griffin Completed 02/23/2021 1:36 PM Assistant County Administrator Christine Hurley Completed 03/02/2021 9:40 AM Purchasing Completed 03/02/2021 9:41 AM Budget and Finance Completed 03/02/2021 10:21 AM Maria Slavik Completed 03/02/2021 10:24 AM Liz Yongue Completed 03/02/2021 11:22 AM Paunece Scull Completed 03/03/2021 3:13 PM Board of County Commissioners Pending 03/17/2021 9:00 AM Packet Pg.476 i � •- � t�� €. r i r tc s s ,i"y;': }�} pit{��,z t4 i�r t 1 ' — ;,. « 75 Requirements for the Design 0 and Certification of Dry Floodproofed Non-Residential '0 F= � E ,.f } a T— CD CN and Mixed-Use Buildings Located in Special Flood in Accordance withNational Flood NFIP Technical i ®e Rl* a � o � FEMA ti Packet Pg.477 C.14.a r9 m Comments on the Technical Bulletins should be directed to: 6 Department of Homeland Security/Federal Emergency Management Agency Federal Insurance and Mitigation Administration (FIMA) Risk Management Directorate Building Science Branch 400 C Street, S.W., Sixth Floor Washington, DC 20472-3020 All images in this report were taken or created by FEMA. NFIP Technical Bulletin 3 (2021) replaces NFIP Technical Bulletin 3 (1993), Non-Residential Floodproofing -Requirements and Certification for Buildings Located in Special Flood Hazard Areas in Accordance with the National Flood Insurance Program. NFIP Technical Bulletin 3 contains information that is proprietary to and copyrighted by the American Society of Civil Engineers and information that is proprietary to and copyrighted by the International Code Council, Inc. All information is used with permission. rr For more information, see the FEMA Building Science Frequently Asked Questions website at his://wwwrfemaraov/ To order publications, contact the FEMA emergenc -managers/risk-management/building-science/faq. Distribution Center: 0. If you have any additional questions on FEMA Building Call: 1-800-480-2520 Science Publications, contact the helpline at FEMA- (Monday-Friday, 8 a.m.-5 p.m., EST) o Buildinasciencehelp@fema.dhs.gov or 866-927-2104. Fax: 719-948-9724 Email: FEMApubs@gpo.gov You may also sign up for the FEMA Building Science email subscription, which is updated with publication releases Additional FEMA documents can be and FEMA Building Science activities. Subscribe at htt s:// found in the FEMA Media Library at service.govdelivery.com/accounts/USDHSFEMA/subscriber/ https://www.fema.gov/media-library/ new?tonic id=USDHSFEMA 193 resources. Visit the Building Science Branch of the Risk Please scan this QR code Management Directorate at FEMA's Federal Insurance to visit the FEMA Building , and Mitigation Administration at his://wwwrfemaraov/ Science web page. emergency-managers/risk-management/building-science. .E Packet Pg.478 Table 0 �� Contents Acronyms..............................................................................................................................................................ii c� 1 Introduction......................................................................................................................................................l l] Definition o[Floodnrowfing..................................................................................................................l w 1.2 Floodproofing Certification..................................................................................................................3 1.3 Limitations on the Use o[Dry Floodnrowfing .....................................................................................4 14 l)ry Floodproofing Measures.................................................................................................................3 2 National Flood Insurance Program Regulations...............................................................................................O 3 Building Codes and Standards.........................................................................................................................7 � � 3] International Residential Code.............................................................................................................8 c 3.2 International Building Code and/\SCK24..........................................................................................8 3.3 ANSI/FM 25l0, American National Standard fir Flood Mitigation Equipment-------------ll 4 NAP Flood fn8UyGOCe Implications.................................................................................................................ll 5 Planning Considerations.................................................................................................................................l2 3] Flood Hazards and Site Conditions....................................................................................................l3 3.2 Flood Warning Time............................................................................................................................l4 3.3 Functional Use Requirements------------------------------------.l3 34 Safety and Access-------------------------------------------.l3 u- 76 3.3 RequiredPlans .....................................................................................................................................lO 6 Dry FlUUdU7UUf Og Design Process.................................................................................................................l9 6] Step l: Determine Flood Design Class -------------------------------..2l 6.2 Step 2: Determine the Flood Protection Level ..................................................................................2l Z 6.3 Step 3: Determine Flood Loads ..........................................................................................................22 nw 64 Step 4: Perform u Condition Assessment (Existing Structures) ------------------.2O ^ 6.3 Step 3: Design or Check Structural Components for Resistance k`Flood Loads...........................27 6.6 Step O: Evaluate Building Utility Systemsand Equipment ---------------------27 75 67 Step 7: Design and Specify Flood Shields...........................................................................................28 CO 6.8 Step H: Design Waterproofing System--------------------------------.30 6'9 Stcn9: Design Interior Drainage........................................................................................................32 w 6]0 Stcnl0: Certify the Design and Satisfy Requirements for Plans......................................................33 7 References.....................................................................................................................................................34 NRPTECHN|CAL BULLETIN 3 ]ANUARY2021 � C.14.a Appendix A: FEMA Form 086-0-34, National Flood Insurance Program Floodproofing Certificate for Non-Residential Structures ................................................................................................36 r9 Appendix B: Example Calculation for EstimatingTotal Seepage................................................................42 m Lisp of Figures 76 Figure 1: Steps in designing a dry floodproofing system..........................................................................20 Figure 2: Example FIRM showing building location and BFE.................................................................22 W Figure3: Hydrostatic loads.........................................................................................................................23 Figure 4: Hydrodynamic forces on a building...........................................................................................25 Figure 5: Mixed-use building with non-residential building utility systems and equipment in a dry floodproofed below-grade equipment room and elevated systems that serve the residentialuses.............................................................................................................................28 Figure 6• Common types of flood shields 29 Figure 7: Typical seepage paths for water entering through joints between wall, footer, and slab .......31 Figure 8• Typical sump pump detail 33 Figure A-1: Typical FIRM title block..............................................................................................................37 m 2 Figure A-2: Typical FIRM map index.............................................................................................................37 rr Figure B-1: Example building plan view.......................................................................................................43 CD 4- List of Tables 2 Table 1: Comparison of Selected 2018 IBC and ASCE 24-14 Requirements with NFIP Requirements....8 c Table B-1: Example Building Information 43 2 p g U_ Acronyms ACI American Concrete Institute ICC9 International Code Councilg e z ANSI American National Standards Institute I-Codesg International Codesg N CD ASCE American Society of Civil Engineers IRC® International Residential Code® , BFE base flood elevation LiMWA Limit of Moderate Wave Action CFR Code of Federal Regulations NFIP National Flood Insurance Program CMU concrete masonry unit ORNL Oak Ridge National Laboratory DFE design flood elevation SEI Structural Engineers Institute 2 FEMA Federal Emergency Management Agency SERRI Southeast Region Research Initiative U FIRM Flood Insurance Rate Map SFHA Special Flood Hazard Area FIS Flood Insurance Study USACE U.S.Army Corps of Engineers IBC9 International Building Codeg ii NFIP TECHNICAL BULLETIN 3 JA Packet Pg.480 C.14.a r9 1 Introduction This Technical Bulletin explains and provides guidance m NFIP TECHNICAL BULLETIN on the National Flood Insurance Program (NFIP) ca floodplain management requirements for the design and NFIP Technical Bulletin 0, User's Guide certification of dry floodproofing. This guidance applies to to Technical Bulletins, should be used as new and substantially improved non-residential buildings a reference with this Technical Bulletin. and mixed-use buildings in Special Flood Hazard Areas Technical Bulletin 0 describes the purpose (SFHAs) identified as Zone A(A,AE,Al-30,AH, and AO) and use of the Technical Bulletins. It includes on Flood Insurance Rate Maps (FIRMs). This Technical common concepts and terms, lists useful W Bulletin includes guidance for certification of dry resources, and includes a crosswalk of the o floodproofed buildings for the purpose of obtaining NFIP sections of the NFIP regulations identifying M the Technical Bulletin that addresses each Q flood insurance coverage with floodproofing credit. section of the regulations and a subject index. The NFIP regulations do not permit the use of dry Readers are cautioned that the definitions floodproofing for residential buildings in Zone A, and dry of some of the terms that are used in the floodproofing is not permitted for any buildings in SFHAs Technical Bulletins are not the same when that are subject to high velocity wave action, called coastal used by the NFIP for the purpose of rating high hazard areas and identified on FIRMs as Zone V(V, flood insurance policies. E VE,V1-30, and VO). rr The design and certification of dry floodproofing measures involve engineering evaluations and calculations. FEMA FERIA P-936, FL OODPR®®FING P-936, Floodproofing Non-Residential Buildings (2013), NON-RESIDENTIAL BUILDINGS contains detailed guidance that supplements this Technical FEMA P-936 provides guidance on 2 Bulletin.ASCE 24, Flood Resistant Design and Construction, regulatory requirements, design is referenced throughout this Technical Bulletin because considerations, design loads, site o it is the standard of practice for the design of dry characteristics, and descriptions of dry floodproofed buildings. ASCE 24 is a referenced standard floodproofing methods and equipment. Key in the International Codes° (I-Codes°). information includes: • Functional, operational, and economic 1.1 Definition of Floodproofing factors to consider The NFIP regulations define floodproofing as "any • Tools such as a vulnerability checklist combination of structural and non-structural additions, to help the designer or building owner CD changes, or adjustments to structures which reduce or determine the best dry floodproofing option for articular building eliminate flood damage to real estate or improved real p p g � property, water and sanitary facilities, structures and . Case studies of applied dry floodproofing their contents" (Title 44 Code of Federal Regulations techniques [CFR] § 59.1). In the NFIP regulations "floodproofing" 6 is understood to refer to dry floodproofing. For the • Equations for determining flood forces 2 purposes of this Technical Bulletin, "dry floodproofing" and loads means a combination of measures that make a building • Summary of results from dry and attendant utilities and equipment watertight and floodproofing research and testing for substantially impermeable to floodwater, with structural new construction E components having the capacity to resist flood loads. NFIP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg.481 C.14.a "Wet floodproofing"is not defined in the NFIP regulations.The term is used in FEMA guidance publications and by floodplain management professionals to mean the use of flood damage-resistant materials and construction techniques that intentionally allow floodwater to enter and flow through a structure without causing damage C that requires more than cosmetic repairs. "Wet floodproofing" is sometimes used to refer to the requirements for enclosures below elevated building in Zone A when the enclosures are used only for parking of vehicles, storage, and building access. Wet floodproofing measures are not covered in this Technical Bulletin.For more information on wet floodproofing, see FEMA P-936; NFIP Technical Bulletin 1, Requirements for Flood Openings in Foundation Walls and Walls of Enclosures; NFIP Technical Bulletin 2, Flood Damage-Resistant Materials Requirements; NFIP Technical Bulletin 7, et Wet Floodproofing Requirements; and FEMA P-2140, Floodplain Management Requirements for Agricultural Structures and Accessory Structures (2020a). FEMA P-2140 describes wet floodproofing measures as they apply to specifically defined agricultural structures and small accessory structures. TERMS USED IN THIS TECHNICAL L.L I • Active: Dry floodproofing measures or system components that require human intervention or action before the onset of flooding to be effective(e.g., flood shields that must be installed, valves that must be closed). • Ancillary area: Common area such as a lobby, foyer, office used by building management, exercise space, meeting room, and mail room (FEMA P-2037, Flood Mitigation Measures for Multi-Family Buildings [2019a]). rr • Basement: "Any area of the building having its floor subgrade(below ground level)on all sides" (44 CFR§59.1). The NFIP regulations do not allow basements to extend below the base flood elevation (BFE) except in dry floodproofed non-residential buildings. • Flood protection level: Elevation to which flood protection measures are designed. The flood protection level is the most restrictive of(1)the BFE plus the prescribed amount of freeboard specified in ASCE 24, (2)the design flood elevation (DFE) if a different flood is used for regulatory purposes, and (3)the elevation relative to the BFE specified in local floodplain management regulations. • Flood shield: Removable or permanent, substantially impermeable protective cover or panel for openings in the portions of a dry floodproofed building that are below the flood protection level (e.g., door, window, louver). • Floodproofing: "Any combination of structural and non-structural additions, changes, or adjustments o to structures which reduce or eliminate flood damage to real estate or improved real property, water and sanitary facilities, structures and their contents" (44 CFR§59.1). cv • Mixed-use building: Building that has both residential and commercial or other non-residential uses. The term does not include multi family residential buildings that have ancillary areas but no non-residential uses. • Non-residential building: Building that has a commercial or other non-residential use. • Passive: Dry floodproofing measures or system components that do not require human intervention or action before the onset of flooding to be effective(e.g., specially designed doors that are sealed when closed, designed window systems, flood shields that are designed to close automatically when triggered by rising floodwater). (continued on page 3) 2 NFIP TECHNICAL ULL TIN 3 JA Packet Pg.482 C.14.a TERMS USED IN THIS TECHNICAL L.L TI (continued) r9 • Residential building: Building designated for habitation.Ancillary areas of residential buildings that serve only residents are residential ancillary areas and include laundry facilities, storage rooms, mail rooms, recreational rooms, parking garages, and exercise facilities. • Substantially impermeable:The use of materials and techniques that restrict the passage of water 6 and seepage through pathways(joints, cracks, openings, channels) and points of entry and that limit the accumulation of water during flooding. According to ASCE 24 and the U.S. Army Corps of Engineers (USACE), a structure is considered substantially impermeable if the maximum accumulation of water is not more than 4 inches in a 24-hour period without relying on devices for the removal of the water (USACE, 1995). • Zone A: Flood zones shown on FIRMs as Zone A, AE, Al-30, AH, AO, A99, and AR. • Zone V: Flood zones shown on FIRMs as Zone V, VE, V1-30, and VO. Other terms used in this Technical Bulletin are defined in the glossary in Technical Bulletin 0. When a building owner proposes dry floodproofing measures for a non-residential building that is in an NFIP- E participating community,the owner must provide certification that the structural designs,specifications, and plans for the construction of the dry floodproofing measures were developed and/or reviewed by registered professional W engineers or architects (design professionals). The certification must state that the proposed dry floodproofing design and proposed methods of construction are in accordance with accepted standards of practice for achieving the required performance. Design professionals who sign and seal certifications must be licensed to practice in the 0 state where projects are located. 0 FEMA Form 086-0-34, NFIP Floodproofing Certificate for Non-Residential Structures (FEMA, 2019b),provides o information necessary for insurance underwriters to rate dry floodproofed buildings. The same form should be _ 76 used to satisfy the requirement for design professionals to certify designs and as-built drawings and inspection. The certificate identifies ASCE 24-14 and ASCE 24-05 (or equivalent) as the accepted standard of practice. W The certificate requires the building owner's name ASCE 24 IS THE STANDARD OF PRACTICE and the address or other description of the building FOR DRY FL.00DPROOFING DESIGN z T_ location. It has three sections: N ASCE 24, Flood Resistant Design andCD • Section I: Site information from the FIRM. Construction, is a consensus standard that was developed and is maintained by the • Section IL• Certification of the elevation to which American Society of Civil Engineers(ASCE). the building is floodproofed. The elevation (where ASCE 24 is a referenced standard in the BFEs are provided on FIRMs) or the height above I-Codes, which means it is considered part of the lowest adjacent grade (where BFEs are not the requirements in these codes. provided) to which the building is floodproofed. ASCE 24 represents the standard of practice Section II must be signed and sealed by a land for the design of buildings and structures in I® surveyor, engineer, or architect authorized by law to flood hazard areas, including the design of dry certify elevation information. floodproofed buildings. NFIP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg.483 C.14.a • Section III: Certification by a registered professional engineer or architect that"the structure,based upon development and/or review of the design, specifications, as-built drawings for construction and physical inspection"has been designed and constructed in accordance with "the accepted standards of practice (ASCE 24-05,ASCE 24-14, or their equivalent) and any alterations [of the structure]" meet these standards and specific listed provisions (i.e., are watertight and substantially impermeable and have structural components that are capable of resisting flood forces). 6 2 See Appendix A for further instructions on completing the certificate. 1.3 Limitations on the Use of Dry Floodproofing Dry floodproofing is permitted for new and substantially improved non-residential and non-residential portions of mixed-use buildings in Zone A, but not for residential buildings in Zone A or any building in Zone V. The NFIP regulations and published FEMA guidance use "residential' and "non-residential' but do not define these terms. However, "residential' in general refers to dwelling units and the building systems and ancillary areas j that support the units. Building systems include electrical, heating, ventilation, plumbing, and air conditioning equipment and other service equipment.Ancillary areas include areas that are designated or used by on premises guests. "Non-residential' refers to buildings with commercial or other non-residential uses. ASCE 24 has a more extensive definition of"residential' and defines "non-residential' as buildings that are not classified as residential. ASCE 24 commentary defines "mixed-use" and "residential portions of mixed-use buildings." W m FEMA considers buildings with both non-residential rr and residential uses to be mixed-use buildings. The non- HOTELS AND MOTE residential portions of mixed-use buildings are allowed Hotels and motels are commercial buildings. to be dry floodproofed provided that all residential For floodplain management purposes, guest units, building systems and service equipment that rooms and the building systems and service serve residential units, and ancillary areas used by equipment that serve guest rooms are residents are elevated above the required elevation. See considered residential and are not permitted FEMA P-2037,Flood Mitigation Measures for Multi-Family to be located in areas of the building that Buildings, for more information. are dry floodproofed. The requirements for In keeping with the requirements for enclosures below building systems and service equipment that serve guest rooms and access to guest rooms elevated residential buildings, lobbies that provide are the same as the requirements for the W access to both residential and non-residential portions of residential portions of mixed-use buildings. mixed-use buildings are allowed to be dry floodproofed o provided there are separate accesses to the residential N portions. When an access to the residential portion of N a mixed-use building is below the flood protection elevation and the access is enclosed by walls, the walls must M comply with the requirements for enclosures below elevated buildings (sometimes called wet floodproofing). S m The NFIP regulations for dry floodproofing apply only in SFHAs identified on FIRMS as Zone A(A,AE,Al-30, AH, and AO). Dry floodproofing is not permitted in SFHAs identified as Zone V (V, VE, V1-30, and VO). For 76 Zone A, the regulations do not specify limits on the use of dry floodproofing based on flood depth,flood velocity, .2 or the presence of waves. However, FEMA does not recommend use of dry floodproofing systems in areas where: • The depth of water under base flood conditions is greater than 3 feet. • Base flood velocities exceed 5 feet per second. • Moderate wave heights (1.5 to 3 feet) are present during base flood conditions. 4 NFIP TECHNICAL ULL TIN 3 JA Packet Pg.484 C.14.a 1.4 Dry Floodproofing Measures Dry floodproofing measures include but are not limited to the following: • Portions of a building,including walls and slabs, reinforced to resist water pressure and floating debris impacts 2 ca • Doors and windows that are specially designed to be watertight when closed without flood shields M • Removable or permanently installed, substantially impermeable panels to cover doors,windows, and other r_ openings U • Paints, membranes, gaskets, and other sealants that reduce water seepage LU • Sump pumps or self-priming pumps that control the level of seepage water • Backflow(non-return)valves or shutoffvalves that prevent floodwater from entering through sewer and o drainage pipes and/or sewage ejectors that pump sewage to above the flood protection level before the pipes connect to a vertical sewer line • Seals that prevent the entrance of floodwater through joints and utility penetrations • Electrical equipment and circuits that are protected to the flood protection level N • Backup or emergency power for sump pumps and other seepage control measures that is protected to the flood W protection level E The planning considerations in Section 5 should be r reviewed before determining which dry floodproofing LEVEES AND FLOODWALLS measures or combination of measures are feasible for Levees and floodwalls are not considered specific locations and before undertaking structural designs dry floodproofing measures for buildings to ensure that the measures will provide the appropriate 2 because they are separate structures level of flood protection. Planning considerations include and not part of the buildings. Levees building location, flood characteristics (flood velocities, and floodwalls that are designed and 2 depths, duration of flooding, how quickly floodwater constructed to provide flood protection to rises, and debris impacts), level of protection required, a single building or a group of buildings flood warning time, safety and access, flood emergency are not addressed in this Technical operations plan, and inspection and maintenance plans. Bulletin. Although levees and floodwalls can be used to mitigate flood damage, Questions about dry floodproofing requirements should be o they may not be used to bring a building directed to the appropriate local official, National Flood into compliance with NFIP requirements. N Insurance Program State Coordinating Office, or FEMA CD N Regional Office. m N IP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg.485 C.14.a r9 2 National Flood Insurance m Program Regulations An important NFIP objective is protecting buildings constructed in SFHAs from damage caused by flooding.The .2 SFHA is the land area subject to flooding by the base flood. SFHAs are shown on FIRMS prepared by FEMA as Zones A and V. The base flood is the flood that has a 1 percent chance of being equaled or exceeded in any given year (commonly called the "100-year" flood). The NFIP floodplain management regulations include minimum building design criteria that apply to: LU • New construction • Work determined to be Substantial Improvements, including improvements, alterations, and additions • Repair of buildings determined to have incurred Substantial Damage CJ A defining characteristic of the NFIP regulations applicable in any Zone A is the requirement for the lowest floor (including basement) of residential buildings to be elevated to or above the BFE. Non-residential buildings in Zone A must be elevated or dry floodproofed to or above the BFE. Dry floodproofing is not permitted in Zone V. C E The NFIP regulations for dry floodproofing of non-residential buildings are codified in 44 CFR Part 60, Criteria for Land Management and Use. Specific to this Technical Bulletin, 44 CFR§ 60.3(c)(3) states that a community r. shall: Require that all new construction and substantial improvements of non-residential structures within Zones Al 30, AE and AH zones on the community's firm [sic] (1) have the lowest floor (including 0 basement) elevated to or above the base flood level, or (ii) together with attendant utility and sanitary facilities, be designed so that below the base flood level the structure is watertight with 0 walls substantially impermeable to the passage of water and with structural components having the U_ capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. Section 60.3(c)(8) states that in Zone AO (areas of sheet flow with depths of 1 to 3 feet), a community shall: Require within any AO zone on the community's FIRM that all new construction and substantial improvements of nonresidential structures(i)have the lowest floor(including basement)elevated above the highest adjacent grade at least as high as the depth number specified in feet on the community's z T_ FIRM (at least two feet if no depth number is specified), or (ii) together with attendant utility and N CD sanitary facilities be completely floodproofed to that [base flood] level to meet the floodproofing N standard specified in [44 CFR}§ 60.3(c)(3)(ii). Section 60.3(c)(4) requires that floodproofing designs be certified in the following manner: Provide that where a non-residential structure is intended to be made watertight below the base flood level, (1) a registered professional engineer or architect shall develop and/or review structural design, specifications, and plans for the construction, and shall certify that the design and methods of construction are in accordance with the accepted standards of practice for meeting the applicable provisions of paragraphs (c)(3)(11) or (c)(8)(11) of this section, and (ii) a record of such certificates which includes the specific elevation (in relation to mean sea level) to which such structures are floodproofed E shall be maintained with the official designated by the community under [44 CFR] § 59.22(a)(9)(iii). 6 NFIP TECHNICAL BULLETIN 3 JA Packet Pg.486 C.14.a NFIP REQUIREMENTS AND HIGHER UL T Y STANDARDS r9 State or Local Requirements.State or local floodplain management requirements that are more restrictive or stringent than the minimum requirements of the NFIP take precedence. The Technical Bulletins and other FEMA publications provide guidance on the minimum requirements of the NFIP and describe best practices. Design professionals, builders, and property owners should contact local 76 officials to determine whether more restrictive provisions apply to buildings or sites in question. All other applicable requirements of the state or local building codes must also be met. Substantial Improvement and Substantial Damage.As part of issuing permits, local officials must review not only proposals for new construction but also for work on existing buildings to determine whether the work constitutes Substantial Improvement or repair of Substantial Damage. If the work is determined to constitute Substantial Improvement or repair of Substantial Damage, the buildings must be brought into compliance with the NFIP requirements for new construction. Some communities modify the definitions of Substantial Improvement and/or Substantial Damage to be more restrictive than the NFIP minimum requirements. For more information on Substantial Improvement and Substantial Damage, see FEMA P-758, Substantial Improvement/Substantial Damage Desk Reference(2010a), and FEMA 213, Answers to Questions About Substantially Improved/Substantially Damaged Buildings(2018a). Higher Building Elevation Requirements.Some states and communities require that non-residential buildings be elevated or dry floodproofed (allowed only in Zone A)above the NFIP minimum requirement. The additional elevation is called freeboard. Design professionals, builders, and property owners should check with local officials to determine whether a state or community has freeboard requirements. 0 rr References to building elevations in the Technical Bulletin, including the required flood protection level, should be construed as references to the community's elevation requirement where freeboard is required. ' 0 0 3 Building Codes and Standards 0 U_ In addition to complying with NFIP requirements, all new construction, Substantial Improvements, and repair of Substantial Damage must comply with the applicable building codes and standards adopted by states and communities. The I-Codes, published by the International Code Council® 0 (ICC°), are a family of codes that includes the International INTERNATIONAL BUILDING CODE N AND ASCE 24 COMMENTARIES C° Residential Code® (IRC®), International Building Code® N (IBC°), International Existing Building Code® (IEBC°), and The ICC publishes companion c� codes that govern the installation of mechanical, plumbing, fuel commentary for the IBC, and ASCE gas service, and other aspects of building construction. FEMA publishes a companion commentary regulatory, not h re 0 has deemed that the latest published editions of the I-Codes for ASCE 24.Although g Y� generally meet or exceed NFIP requirements for buildings the commentaries provide information and structures in flood hazard areas. Excerpts of' the flood and guidance that is useful for provisions of the I-Codes are available on FEMA's Building complying with, interpreting, and enforcing requirements. Science — Flood Publications webpage (htths: '�-+`��`��`.f<:mf�.s�,ca��/ f',V1ll(`Q f',V➢w`y Q1ll 1n° f Qs -isle Q➢➢1V1�1 `f'u➢➢f`,Q1V I111pIw�pV1 sw pf Q1;f,il1(1(1;). E U NFIP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg.487 C.14.a International3.1 i i The International Residential Code (IRC) applies to one- and two-family dwellings and townhomes not more than three stories above grade plane. The IRC does not allow dry floodproofing of buildings within its scope. 3.2 International Building The International Building Code (IBC) applies to all applicable buildings and structures. While used ASCE 24 AND NFIP DRY W primarily for buildings and structures other than FLO®DPR®®FING REQUIREMENTS dwellings within the scope of the IRC, the IBC may also FEMA interprets the NFIP regulations to be used to design dwellings. be more restrictive than ASCE 24 in two respects: The flood provisions of the latest published editions of . Temporary flood protection systems that the IBC generally meet or exceed NFIP requirements for cover exterior walls cannot be used in lieu *� buildings through reference to the standard ASCE 24, of a substantially impermeable wall (see Flood Resistant Design and Construction. "ASCE Interpretation of ASCE 24-14 Flood ASCE 24 applies to structures that are subject to Shield Requirements and FEMA Position on Whether a Flood Shield Configuration N building code requirements. ASCE 24 requirements for Meets NFIP Dry Floodproofing dry floodproofing, summarized in Table 1, are similar Requirements" at the end of Section 3.2 of E to the NFIP requirements. Table 1 refers to selected dry this Technical Bulletin). floodproofing requirements of the 2018 IBC and ASCE Cr • Flood damage-resistant materials are 24-14 and notes changes from 2015 and 2012 IBC and required where seepage would collect ASCE 24-05 along with a comparison to the NFIP inside dry floodproofed areas up to at least requirements. Subsequent editions of the IBC and ASCE 4 inches above the floor. 24 should include comparable requirements. 0 Table 1:Comparison of Selected 2018 IBC and ASCE 24-14 Requirements with NFIP Requirements 0 a Definition 2018 IBC Section 202 Definitions. The definition of"dry in of dryflood roofin IBC and °� Defines dry floodproofing as a combination of design floodproofing" � floodproofing modifications resulting in a building, including the attendant ASCE 24) is equivalent to the utilities and equipment and sanitary facilities, being watertight NFIP definition of"floodproofing" 0 with walls that are substantially impermeable and able to resist in NFIP 44 CFR§59.1. T. the loads required by ASCE 7, Minimum Design Loads and N Associated Criteria for Buildings and Other Structures. , Change from 2015 to 2018 IBC: No change. "9 Change from 2012 to 2015 IBC: Added "and equipment." ASCE 24-14 Section 1.2 Definitions. Defines dry floodproofing as a combination of measures that results in making a structure and its utilities and equipment watertight with all elements substantially impermeable and with structural components having the capacity to resist flood loads. Change from ASCE 24-05: Expands the definition to require building and utilities and equipment serving the building to be watertight with walls substantially impermeable and able m to resist flood loads rather than only requiring the building envelope to be substantially impermeable. 8 NFIP TECHNICAL BULLETIN 3 JA Packet Pg.488 C.14.a Table 1:Comparison of Selected 2018 IBC and ASCE 24-14 Requirements with NFIP Requirements (cont.) �j •� 1 ~� `�� I,��'�{III� I,('l� I�� r�i1'�4 �� r9 ,a General flood 2018 IBC Section 1612.2 Design and construction. Exceeds NFIP 44 CFR m hazard area 60.3(a)(3)with morespecificity. 0 Requires buildings and structures located in flood hazard areas § requirements to be designed and constructed in accordance with Chapter 5 of ASCE 7 and ASCE 24. 2 Change from 2015 to 2018 IBC: Section renumbered from 1612.4 to 1612.2. W Change from 2012 to 2015 IBC: Applies coastal high hazard area requirements in Coastal A Zones, if delineated. Flood hazard 2018 IBC Section 1612.4(1.3) Flood hazard documentation. Equivalent to NFIP 44 CFR documentation 60.3 c 4. Requires submission of a certification statement prepared § ( )( ) and sealed by a registered design professional that dry floodproofing is designed in accordance with ASCE 24. Change from 2015 to 2018 IBC: Section renumbered from W 1612.5 to 1612.4. Change from 2012 to 2015 IBC: Applies coastal high hazard area requirements in Coastal A Zones, if delineated. N Elevation ASCE 24-14 Section 1.5.2 Elevation Requirements. Exceeds NFIP 44 CFR Allows for dry floodproofing of non-residential and the non- §60.3(c)(3)and (8) by requiring m residential portions of mixed-use buildings below the BFE plus freeboard specified freeboard or the DFE, whichever is higher, provided rr the dry floodproofing measures meet the requirements in Chapter 6. ASCE 24-14,Section 2.3, Elevation Requirements. — 0 Allows for dry floodproofing of non-residential and the non- residential portions of mixed-use buildings below the BFE plus specified freeboard or DFE, whichever is higher, provided the dry floodproofing measures meet the requirements in Chapter 6. 0 Change from ASCE 24-05: Requires Flood Design Class 4 buildings to be elevated or to be protected to BFE plus 2 feet, or DFE, or 500-year flood elevation, whichever is highest. m Dry ASCE 24-14 Section 6.2 Dry Floodproofing. Exceeds NFIP 44 CFR 0 floodproofing Permits dry floodproofing of non-residential buildings and §60.3(c)(3)with more specificity, non-residential portions of mixed-use buildings when the except(1)the NFIP requires the 0 buildings are located outside High Risk Flood Hazard Areas, use of flood damage-resistant Z Coastal High Hazard Areas, and Coastal A Zones materials in areas where seepage CD • Requires techniques that make structures substantially can accumulate and (2) FEMA N impermeable and requires the use of flood damage-resistant deems that temporarily installed materials, except on the interior of structures means of flood protection that 0 cover walls are inconsistent with • Requires sump pumps to remove water that accumulates from the requirement that walls be the passage of vapor and seepage during flooding substantially impermeable(see 0 • Limits dry floodproofing to flood hazard areas with flood text box"ASCE Interpretation velocities that are less than or equal to 5 feet per second of ASCE 24-14 Flood Shield 2 during the design flood Requirements and FEMA Position 0 • Requires walls below the minimum elevations of dry on Whether a Flood Shield 0 floodproofing specified in Table 6-1 to be substantially Configuration Meets NFIP Dry impermeable to passage of water Floodproofing Requirements" on page 10). m 0 NFIP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg.489 C.14.a Table 1:Comparison of Selected 2018 IBC and ASCE 24-14 Requirements with NFIP Requirements(cont.) Dry • Requires walls, floors, and flood shields to resist hydrostatic, floodproofing hydrodynamic, and other flood loads, including the effects of (cont.) buoyancy • Specifies that soil or fill adjacent to a structure must be 2 compacted and protected from erosion and scour • Requires that at least one door, window, or other opening W for emergency escape and rescue be above the elevation specified in Table 6-1 • Specifies several limitations when human intervention is necessary to activate or implement dry floodproofing measures Change from ASCE 24-05: Does not require flood damage- resistant materials on the interior of dry floodproofed portions of buildings. W CJ ASCE N INTERPRETATION OF ASCE 24-14 FLOOD SHIELDREQUIREMENTS m AND FIRMA POSITION Fi THER A FLOOD SHIELDI U ATI MEETSIP DRY FLOODPROOFING REQUIREMENTS In November 2016, ASCE issued a formal interpretation of whether a specific configuration of flood shields meets the dry floodproofing requirements of ASCE 24-14.1 The configuration is described as a building that is supported by an impermeable reinforced concrete stem wall (foundation) with permeable exterior walls such as glass curtain walls. The question was whether the use of removable flood shields as c 0. a component of the exterior building facade would render the exterior walls impermeable along the entire ` length of the fagade. Diagrams included in the request for the interpretation show flood shields attached at the base to the impermeable foundation stem wall and attached to vertical, structural columns between spans of the glass curtain wall system. m The ASCE interpretation determined that the flood shield configuration described and shown in the request meets the dry floodproofing requirements of ASCE 24-14 provided the building and shields meet all other dry floodproofing requirements, provided the flood shields are "close to and attached to the building facade," and provided the shield attachment is "via guides, fasteners or supports that are c permanent parts of the building facade."2 CD The FEMA position is that the ASCE interpretation is contrary to the NFIP requirements because exterior wall sections that are neither substantially impermeable nor able to resist flood loads will not meet the intent of 44 CFR§60.3(c)(3)that walls must be"substantially impermeable to the passage of water and - m with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy." Therefore, any temporarily installed means of flood protection that cover such walls would not be considered compliant. . 1 Jonathan C.Esslinger,Director,Technical Advancement and Codes&Standards,ASCE,written communication,November 29,2016. 2 Ibid,Page 5. U 10 NFIP TECHNICAL BULLETIN 3 JA Packet Pg.490 C.14.a for Flood Mitigation Equipment ANSI/FM 25 10,American National Standardfor Flood Mitigation Equipment (ANSI/FM, 2020), describes performance and ANSUFM 25109 AMERICAN NATIONAL testing requirements that must be met for flood mitigation STANDARD AND APPROVED equipment and products, as defined in the standard, to be 111P 1' P 11 1' approved. Performance testing criteria are established for ANSI/FM 2510: www.fmapprovals.com each type of equipment and products. The following types of FM Approved equipment and products: equipment and products are addressed in the standard: https://nationalflood barrio reorq 2 • Opening barriers (called flood shields in this Technical Bulletin) o • Flood glazing(permanent,passive barrier of reinforced glass material that is set and sealed within a �— structural frame) CJ • Flood mitigation valves (called backflow, non-return, or shutoffvalves in this Technical Bulletin) • Flood mitigation pumps (sump pumps, self-priming pumps, and other types of pumps used for seepage control) W • Penetration sealing devices rr • Perimeter barriers (not applicable to this Technical Bulletin) 0 4 ications 0 0. NFIP Flood Insurance Impl 'a 0 Careful attention to compliance with the NFIP requirements, local building codes and standards, and floodplain management NFIP FLOOD INSURANCE FOR regulations is important during design,plan review,construction DRY FLOODPROOFEDUIL I 0 and inspection. Compliance influences both vulnerability to P P Y While current owners and developers flood damage and the cost of NFIP flood insurance. who are considering constructing An insurance agent with NFIP experience should be consulted dry floodproofed non-residential buildings may not intend to purchaseCD during the design phase of buildings with dry floodproofing to NFIP flood insurance coverage, the estimate the cost of NFIP flood insurance. The consultation is cost of the coverage may be a factor particularly important when considering whether to include for future owners. dry floodproofing of non-residential portions of mixed-use buildings or dry floodproofing of' below-grade parking areas under non-residential and mixed-use buildings (see NFIP Technical Bulletin 6, Requirements for Dry Floodproofed Below-Grade Parking Areas Under Non-Residential and E Mixed-Use Buildings). Designers should pay particular attention to the flood protection level (level to which buildings will be dry floodproofed). The NFIP regulations applicable to non-residential structures in Zone A require the lowest floor (including basement) to be elevated to or above the BFE or the structures may be dry floodproofed below the NFIP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg.491 C.14.a BEE. However, the NEIP flood insurance rating procedures provide credit for dry floodproofing only if the dry floodproofing measures are certified to be at least 1 foot above the BEE, even if that level of protection is not required by local floodplain management regulations.The NEIP also requires applications for insurance coverage C for dry floodproofed buildings to include the NEIP Eloodproofing Certificate (see Section 1.2 and Appendix A of this Technical Bulletin). The methodology used by the NEIP to determine the NEIP flood insurance rate for dry floodproofed 6 non-residential buildings and non-residential portions of mixed-use buildings is based on the "non-subsidized" rate with a credit (percentage discount) applied to that rate. The amount of credit is based on the information about the dry floodproofing components that must be included with NEIP flood insurance applications. Building owners and designers should consult with flood insurance providers before starting design work to understand LU how design decisions can impact NEIP flood insurance premiums. U 5 Planning Considerations CJ Many factors and planning considerations influence the decision-making process when determining the feasibility of dry floodproofing options for specific buildings. Whether buildings are new construction designed to be dry W floodproofed or existing buildings being considered for retrofitting with dry floodproofing measures, the dry E floodproofing options that are examined and selected should: rr 0) • Comply with the applicable floodplain management and design requirements CD • Reduce flood damage below the flood protection level S 0 • Provide for the safety of personnel responsible for the deployment of components that require human 2 intervention 0 • Be feasible to implement, maintain, and operate 76 • Be usable following recommended cleaning after flood events m • Result in a level of residual risk that is acceptable to the owner W Design professionals should assess the site during the planning phase to determine site-specific flood hazards that will influence the design of dry floodproofing measures, building vulnerability, and how well the building may z perform during flood events (see Section 5.1). The assessment should include a flood vulnerability assessment CD to examine site conditions and, for existing buildings, the vulnerability of architectural and structural systems, N building envelope, and utility systems (mechanical,plumbing, gas, electrical). Other important planning considerations include determining the available warning time prior to the onset of flooding (see Section 5.2), functional use requirements (see Section 5.3), safety and access before and during flooding (see Section 5.4), and early consideration of required plans (Section 5.5), including flood emergency 6 operations plans and maintenance and inspection plans. .2 The design professional should review the assessment findings with the building owner to determine whether dry W floodproofing is appropriate and whether the results indicate any constraints on the design. Determining the flood F warning time, described in Section 5.2 of this Technical Bulletin, is critical before deciding whether active dry 0) floodproofing measures are feasible or appropriate,or whether passive measures or elevation should be considered. 12 NFIP TECHNICAL BULLETIN 3 JA Packet Pg.492 C.14.a Active dry floodproofing measures require human intervention or action before the onset of flooding PLANNING, DESIGN,AND OPERATIONAL and passive dry floodproofing measures do not CONSIDERATIONS require human intervention. For guidance on conducting a flood vulnerability Building owners should also consider residual risk assessment and designing dry floodproofing as part of determining whether dry floodproofing measures to reduce flood damage and interruption ru is an appropriate solution. Residual risk is the of building operations, see: E remaining exposure to loss after the designed • FEMA P-936, Appendix C, "Checklist for floodproofing measures have been implemented. Vulnerability of Flood-Prone Sites and Buildings" For example, losses could be higher than expected. FEMA P-2022, Mitigation Assessment Dry floodproofing systems are designed for a Team Report.Hurricane Harvey in Texas, selected flood protection level, but during extreme Appendix C, "Dry FIOOdproofing: Planning and o events,floodwater may rise higher than the selected Design Considerations(Recovery Advisory 1)" flood protection level and high water may affect (FEMA, 2018c) some sites for longer than the anticipated periods u of inundation. In addition dry floodproofing For guidance on how to effectively implement dry U floodproofing measures, see: systems can fail. Common causes of failure are unidentified points of entry for floodwater, poorly • FEMA P-2023, Mitigation Assessment Team Report. Hurricane Irma in Florida, A m maintained components of a system, components h Appendix C, with insufficient resistance to flood loads, and "Dry Floodproofing: Operational Considerations failure to implement active measures that require (Recovery Advisory 1)" (FEMA, 2018b) rr W human intervention (especially for complex systems). Designers and owners should evaluate the residual risks associated with dry floodproofing measures, and owners 0 should consider the financial impacts if the dry floodproofing system fails. Added costs include down time, clean 0. up, and repairs. Some financial risk can be offset by purchasing flood insurance. c 0 5.1 Flood Hazards and Site Conditions Selecting eflective dry floodproofing measures requires evaluating the flood hazard conditions at the site for the RESTRICTIONS BASED ON FLOOD flood used for design purposes, typically at least the base ZONE AND CONDITIONS flood 1- ercent-annual-chance flood). The assessment should z ( P ) The NFIP regulations do not allow determine flood velocity, depth of flooding, rate of floodwater dry floodproofing in Zone V. ASCE 24 CD N cv rise and fall, frequency of flooding, duration of flooding, and restricts the use of dry floodproofing in possible debris impacts. Zone V and in Coastal A Zones if a Limit of Moderate Wave Action (LiMWA) is Design professionals and building owners should review delineated On flood maps. Communities Chapter 2 in FEMA P-936 for guidance on determining may have additional requirements, such ca design loads and the site characteristics that need to be as not allowing dry floodproofing to be ru identified in order to determine whether dry floodproofing used in flOOdways. is feasible and to successfully design and construct a dry floodproofed building. A factor that may influence the decision to use dry floodproofing is flood velocity. The USAGE recommends in its E Flood Proofing Regulations (1999) that dry floodproofing not be used where expected flood velocities exceed 5 feet U N IP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg.493 C.14.a per second.ASCE 24 limits the use of dry floodproofing to where expected flood velocities adjacent to a structure are less than or equal to 5 feet per second, although ASCE 24 commentary suggests that local officials may accept certified designs that demonstrate resistance to higher velocities. In this Technical Bulletin, see Section 6, Step 3B, for possible sources of data for determining expected flood velocities. Warning5.2 Flood i Flood warning time is an important factor when considering active dry floodproofing measures. Flood warning time is the length of time between the recognition that flooding may occur and when floodwater begins to affect a site. Designers should determine whether warnings issued by credible sources would provide enough time to implement any active dry floodproofing measures. Lu The first step is to determine the flood warning time, which is 0 site specific. The next step is to determine whether the flood SOURCES FOR ESTIMATES warning time would be sufficient to implement the measures OF FLOOD WARNING TIME j the designer is considering (see Section 5.5.1 of this Technical Possible sources of information about CJ Bulletin) and to provide time to safely evacuate the site. flood warning time are state or local emergency management agencies, Flood warning time varies depending on the source of flooding g Y g g N and the capabilities of the entities that are responsible for local floodplain managers, river basin monitoring flood conditions or issuing flood warnings. Flood authorities and drainage districts, state E warning times can vary widely: water resources agencies, National Weather Service, U.S. Geological rr • Small watersheds especially those in mountain and hill p y y Survey, and USACE District Offices. regions, may be subject to flash flooding with very little or no warning before the onset of flooding. 2 • Larger rivers and waterways may take hours, days, or weeks for floodwater to crest. • Flooding in coastal areas usually has several days of warning, although storm paths can change abruptly, which can shorten or lengthen warning times. Dry floodproofing measures are active or passive. Active measures require human intervention to install, deploy, or otherwise activate. When feasible, building owners and DESIGN LIMIT � designers should consider passive measures because effectiveness ON HUMAN INTERVENTION does not depend on human intervention. Examples of passive Active dry floodproofing measures z measures are specially designed doors that are always sealed should be designed to meet the limit CD N cv when closed, designed window systems, and flood shields that for human intervention specified in , are designed to automatically close when triggered by rising ASCE 24—a minimum of 12 hours floodwater on the site. of flood warning time unless the community operates a flood warning A key consideration for determining flood warning time is not system, in which case the designer the time it takes for floodwater to reach the flood protection should determine how much time may level but the time it takes for flooding to begin to affect the be available. site and reach the point where water enters the building if dry floodproofing measures have not been deployed. For example, if floodwater reaches the lowest point of entry E 14 NFIP TECHNICAL BULLETIN 3 JA Packet Pg.494 C.14.a during a 10-p ercent-annual-chance event, the flood warning time must be sufficient to allow the implementation of active measures prior to floodwater reaching the 10-percent-annual-chance elevation. The amount of time needed to implement active dry floodproofing measures varies depending on factors such S as the number and complexity of the measures that require timely action to function as designed. Determining whether the flood warning time would be adequate requires estimating the total time needed to: CO 76 • Recognize the threat, including whether anticipated storm conditions will have high winds that could hamper g installation • Notify persons or contractors responsible for installation or deployment • Travel to building locations • Locate, activate, deploy, and install the measures,which may require heavy equipment not typically on site, such as forklifts • Evacuate people implementing the measures using predetermined evacuation routes, taking into account ; whether roads or bridges may be closed by state or local officials(e.g.,when high winds or overtopping by floodwater are anticipated) For more information on flood warning time, see FLMA P-936, Chapter 2. N Functional5.3 i E The functional use of buildings and the spaces within them must be evaluated when considering dry floodproofing r measures. If extended interruption of function would be detrimental, building owners should consider whether �= dry floodproofing is a viable option compared to elevating buildings. The location,purpose, and frequency of use of entrances may dictate the type of dry floodproofing measure that is selected. For example, doorways that are used often may not be suitable for special doors that are designed to seal when closed because the gaskets may 0. wear more quickly. Another example is vehicle openings and delivery doors where accidental vehicle impact may a damage permanently mounted brackets for flood shields. c U_ Mixed-use buildings have additional functional use considerations because separate access must be provided to the elevated residential portions of these buildings when shared accesses(lobbies to residential and non-residential portions) are dry floodproofed. When the separate access to the residential portions of a mixed-use building is enclosed by walls,the walls must comply with the requirements for enclosures below elevated buildings(sometimes called wet floodproofing). z T_ CD 5.4 Safety and Access N For safety, dry floodproofed buildings should not be occupied during flood conditions. Safety and access considerations are especially important when evaluating mixed-use buildings and whether it is appropriate to design dry floodproofing measures for the non-residential portions of these buildings. Flooding may rise higher than the flood protection level or dry floodproofing system components may fail, endangering the occupants. 6 2 Flooding may limit access and timely response by emergency personnel. ASCL 24 requires an exit door, exterior door, or window at or above the flood protection level that can be used as an emergency escape and rescue opening. The opening must be capable of providing human ingress and egress during flooding. N IP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg.495 C.14.a Required5.5 FACTORS THAT CONTRIBUTE TO THE Buildings that will be dry floodproofed should FAILURE F DRY FLOODPROOFING SYSTEMS have both flood emergency operations plans and The Mitigation Assessment Teams that FEMA inspection and maintenance plans. When active deploys after some major disasters issue dry floodproofing measures are specified (human reports that include observations of damage and intervention is required to implement), ASCE 24, factors that contributed to flood damage. The Chapter 6, requires flood emergency plans that are reports issued after Hurricane Harvey in Texas approved by local officials. See Section 5.5.1 of this (FEMA, 2018c) and Hurricane Irma in Florida Technical Bulletin. (FEMA, 2018b) identify the following factors that may have contributed to the failure of dry Lu Communities are encouraged to require submission floodproofing systems: of these plans along with the construction documents and design certifications required as part of an • Lack of plans that detail installation application for a building permit. The required requirements for active dry floodproofing submission of a flood emergency operations plan and measures or operations and inspection and inspection and maintenance plan may be specified in maintenance plans with insufficient detail local floodplain management regulations or building • Occupants and building managers who were codes. not aware of the dry floodproofing systems Emergency operations plans and inspection and • Missing, damaged, degraded, and leaking maintenance plans are required to be submitted gaskets around flood shields with applications for NFIP flood insurance coverage . Modification of dry floodproofing components to receive credit for dry floodproofing measures (see by uninformed maintenance contractors ' Section 4 of this Technical Bulletin). 0 5.5.1 FloodOperations Flood emergency operations plans address the implementation of active dry floodproofing PERIODIC PLAN REVIEWS, 76 measures when flood events are anticipated. Design DRILLS, INSPECTIONS professionals engaged in designing dry floodproofed An annual review of flood emergency operations buildings should evaluate flood warning time and plans, with exercises for personnel to practice the estimated time and level of effort necessary to installing and deploying measures that require install and deploy various measures that require human intervention, is critical for success when z human intervention well in advance of the onset flooding occurs. CD of flooding or high winds (see Section 5.2 of this c44 Some communities conduct periodic inspections , Technical Bulletin). When there may be insufficient of dry floodproofed buildings, and some require time to implement specific measures and evacuate, p p the submission of reports documenting third- :N designers should re-examine the measures and party inspections. specify those that can be installed safely within the ca available warning and evacuation time. If the entire dry floodproofing system cannot be implemented and personnel safely evacuated in the available time, designers should specify alternative dry floodproofing system components or advise owners to consider elevation when compliance is required. m 0 16 NFIP TECHNICAL ULL TIN 3 JA Packet Pg.496 C.14.a Building owners, operators, and responsible personnel must be able to implement the plan and make sure that occupants REQUIRED POSTING F FLOOD � are aware of what is required when plans are activated. Flood EMERGENCY OPERATIONS PLANS � emergency operations plans must be tailored for each dry I i!I I L LOCATIONS floodproofed building. At a minimum, plans should specify the ASCE 24, Chapter 6, requires following: flood emergency operations plans • The personnel, equipment, tools, and supplies needed to be permanently posted in dry 2 to deploy all dry floodproofing system components with floodproofed buildings in at least two sufficient time prior to the onset of flooding or conditions clearly visible locations. h® such as high winds that could interfere with efficient LU deployment of measures �- • Clearly defined chain of command and assigned responsibilities for personnel involved in the installation of o dry floodproofing measures • Procedure for notifying personnel responsible for installing dry floodproofing measures, along with a list of duty requirements • Decision tree that identifies the sequence, timeline, and responsible parties for installing the dry floodproofing components, including the triggers or benchmarks that will initiate procedures do • Written description and map of the storage locations and types of dry floodproofing measures to be installed a) or deployed, along with any equipment, tools, and materials required for installation • Conditions that require the deployment of active dry floodproofing measures (e.g.,installation of flood shields, r closing of flood doors, closing of manual valves, staging of pumps) • Instructions for installing or deploying each dry floodproofing measure and the order of installation if important for effectiveness 0 2 • Repair procedures and component maintenance procedures that may be necessary during a flooding event .� • Instructions for connecting standby(emergency)power source (e.g., generator)for critical equipment such as 2 sump pumps and egress lighting • Contact information for the manufacturer and designer to expedite obtaining replacement parts and support as needed • Evacuation plans for all personnel(see Section 5.2) • Requirements for installation and deployment drills and training program (at least once a year) c • Requirement for regular review and update of the plan procedures N cv 5.5.2 InspectionI I A comprehensive inspection and maintenance plan for the entire dry floodproofing system is needed to ensure that the system components, measures, materials, and equipment required for the system to function as intended are inspected and maintained periodically. The design professionals who design and certify dry floodproofing 6 systems should prepare the inspection and maintenance plans. It is good practice for building owners or operators .2 to engage design professionals to coordinate regular inspections and address significant deficiencies identified during inspections. F® N IP TECHNICAL BULLETIN 3 JANUARY 2021 17 Packet Pg.497 C.14.a Observations by FEMA Mitigation Assessment Teams after significant flood events indicate that some dry floodproofing systems did not provide the intended level of protection in part because components of the systems were not regularly tested or properly maintained. For additional information, see Appendix C in FEMA P-2022 and Appendix C in FEMA P-2023. Inspection and maintenance plans should include a schedule for regular inspection and maintenance of the components, materials, and equipment that are needed to activate dry floodproofing measures. Manufacturer manuals typically provide recommendations for the aspects that need to be checked during inspections and maintenance, the frequency of inspections, and ordering information for replacement parts. FEMA Form 086-0-34, NFIP Floodproofing Certificate for Non-Residential Structures, lists the minimum information that maintenance plans must have in order to obtain NFIP flood insurance coverage (see Section 4 Lu and Appendix A of this Technical Bulletin). The content of a comprehensive inspection and maintenance plan depends on the elements of the specific dry floodproofing system. At a minimum, the following should be addressed: cis • Exterior envelope of the structure, such as wall and foundation systems, to identify possible structural and waterproofing deficiencies such as cracks,water staining, and penetrations • Slabs and wall/slab joints,including structural and drainage deficiencies N • Flood shields, gates,panels, doors, glazing, and other components designed to provide dry floodproofing protection, including seals, gaskets, fasteners, and mounting hardware and tools E • Sump pumps(or self-priming pumps) and interior drain system rr • Testing o emergency enc generators, sum um and other drainage g Yg � PP pumps, e measures g • Backflow(non-return)valves or shutoffvalves CD • Location of all flood shields, gates,panels, and other components including all hardware along with any 0 materials or tools needed to seal the dry floodproofed area • Contact information for the manufacturer of the shields and other components to determine the availability of 0 replacement gaskets, seals, and other parts and to ask questions a- 76 • Cadence of inspection and maintenance plan m Inspections should be performed regularly, usually once a year. Inspections can be coordinated with regular drills during which ANNUAL INSPECTION W responsible personnel practice deploying measures that require AND MAINTENANCE human intervention and other actions specified in flood emergency Performing annual inspections operations plans. The inspection should identify items that are also helps increase personnel cv deficient, items in need of repair or replacement, and the materials and occupant awareness of the , and equipment needed to implement repairs. Building owners and presence and importance of the operators should examine the inspection reports and promptly make dry floodproofing systems. repairs and address deficiencies. ca 18 NFIP TECHNICAL ULL TIN 3 JA Packet Pg.498 C.14.a r9 6 Dry Floodproofing Design Process Section 1.2 of this Technical Bulletin explains that communities must require dry floodproofing designs USE OF ANSUFM 2510 APPROVED to be certified and that the NFIP Floodproofing EQUIPMENT AND PRODUCTS Certificate for Non-Residential Structures (FEMA The use of equipment and products that are Form 086-0-34) should be used for this purpose tested and approved in accordance with (see Appendix A of this Technical Bulletin). The ANSI/FM 2510,American National Standard for certificate requires registered design professionals Flood Mitigation Equipment, is not required for to certifythat dry floodproofing measures have Y P g compliance with the NFIP or ASCE 24. However, been designed and constructed in accordance specifying approved equipment and products with ASCE 24 or its equivalent. The certificate may provide designers with more assurance requires certification of designs and "as-built when developing designs for dry floodproofing :L- drawings for construction and physical inspection." systems. Certification of as-built dry floodproofed systems ANSI/FM 2510, described in Section 3.3 of this provides increased assurance to building owners and Technical Bulletin, specifies the flood conditions N operators. for the testing of each type of equipment and The accepted standard of practice for the design product. Designers should verify applicability E of' dry floodproofing measures is ASCE 24. of approved equipment and products for rr This section provides a step-by-step guide for site-specific flood Conditions. developing dry floodproofing designs that comply with ASCE 24. Designers should first evaluate the planning considerations described in Section 5 of this Technical Bulletin and review additional guidance in FEMA P-936. The process is applicable to the design of new construction with dry floodproofing systems and 0. retrofitting of existing buildings with dry floodproofing measures. 0 An overview of the design steps is shown in Figure 1. m 0 T_ cv CD cv r9 m 76 .E NFIP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg.499 C.14.a ................................................................................................................................................................................................................................................................................................................... Step 1 Determine Flood Design Class (ASCE 24, Table 1-1). M Step 2 Determine flood protection level based on most restrictive of BFE, ASCE 24, and local regulations. Step 3 Determine flood loads (ASCE 7). .M........................................................ ........................................................M M.M.M.M.M.M.M.M.M.M.M.M.M.M.M.M.M.M.M.M.M.M.M.M.M.M. W Existing New W Is the structure ........... existing or new? ,w 0 Step 4(Existing Structures) Perform condition assessment of portions of structure that will be relied on to resist flood loads. U ...M...M...M...M...M...M...M...M...M...M...M...M...M...M...M...M...M...M...M...M...M...M.., ........................................................................................................................................................................................................................................................... Step 5(Existing Structures) Step 5 N Check whether existing structural elements Design structural elements have adequate strength and stiffness to to have adequate strength resist flood loads. Check that the structure and stiffness to resist flood has adequate resistance to buoyancy. loads. Design foundation to ............................................. have have adequate resistance � Is structural a to buoyancy. g g „�'°"stre n the n i n or mod i ficati o n Yes ---------------------------------------------- needed? No 01, n 0 Step 6 Evaluate building utility systems and equipment. ............................................................................ Step 7 Design/specify flood shields at openings y (e.g., doors, windows) below the flood protection , level to resist flood loads. Step 9CD Step 8 Design interior drainage N Design waterproofing system. Address I system for amount of ' penetrations and joints in walls and slabs. M a Perform seepage calculations to demonstrate �n expected seepage calculated S in Step 8. Locate and size Select fewer/alternate that expected amount of seepage through wall sump pumps to expel the flood shields and/or systems,joints, and around flood shields is less expected seepage volume. waterproofing than 4 inches of water depth during a 24-hour ................................. membrane to reduce period if no devices are provided for removal. M seepage. Step 10 Certify the design. Satisfy No m Is expected """.......... Yes requirements for flood ... seepage less than 4 inches "' r«r«r«r«r«r«r emergency operations plans in 24 hours? ww and inspection and Figure 1:Steps in designing a dry maintenance plans. floodproofing system *, 20 N IP TECHNICAL BULLETIN 3 JA Packet Pg. 500 C.14.a a Determinei When designing in accordance with ASCE 24, the design professional begins the design process by determining M the Flood Design Class (called "classification" in the 2005 edition). Flood Design Class is based on the use or occupancy of a building or structure, and the risk to the public should the building be damaged or the occupancy 5 function be impaired by flooding.ASCE 24,Table 1-1, defines four Flood Design Classes. .E Determinei The flood protection level is the elevation to which flood protection measures will be designed. The NFIP regulations specify that when non-residential buildings are dry floodproofed, the structures must be watertight LU and substantially impermeable below the base flood level or BFE. 0 ASCE 24 requires the minimum flood protection level to be the elevations listed in ASCE 24,Table 6-1,but state or local floodplain management regulations may require higher levels. ASCE 24 specifies flood protection levels .2 based on the assignment of one of four Flood Design Classes (similar to risk categories). CJ The minimum flood protection level for Flood Design Class 2 and Class 3 buildings is the BFE plus 1 foot or "DESIGN FLOOD ELEVATION" IN ASCE 24 N the design flood elevation (DFE), whichever is higher. C ASCE 24 defines and uses the terms design m The minimum flood protection level for Flood Design flood" and "design flood elevation" (DFE) E Class 4, considered critical and essential facilities, is to account for communities that elect to the hirr ghest of the BFE plus 2 feet, the DFE, or the 500 adopt flood hazard maps based on floods year flood elevation. Flood Design Class 1 includes that are higher than the base flood (the temporary structures, accessory storage structures, small 1-percent-annual-chance flood) or to include parking structures, and certain agricultural structures additional areas not shown on FIRMS. and also requires protection to BFE plus 1 foot or the 0 Adding freeboard above the BFE as an DFE,whichever is higher. Local floodplain management additional factor of safety is also a common officials should be consulted to determine whether local practice for establishing a minimum elevation 0 regulations require the flood protection level to be higher requirement. than the minimum elevations in ASCE 24. When communities simply adopt FEMA FISs The BFE is the computed water surface elevation for and FIRMs and use the base flood and BFE the 1-percent-annual-chance flood. When shown on for regulatory purposes, the DFE is the same FIRMs, the BFE is often rounded to the nearest whole as the BFE, 0 z number. Designers should also check elevations shown N CD in Floodway Data Tables and Flood Profiles included in N Flood Insurance Studies (FISs)when FEMA has developed engineering analyses. Figure 2 shows a sample FIRM ' ry marked to show a building location and applicable BFE. m Some FISs and FIRMs do not provide detailed information and/or BFEs for all sources of flooding, particularly smaller streams and tributaries. When a FIRM panel does not show a BFE or when detailed flood elevation 76 information is not available, designers will need to take additional steps to determine the BFE. Local officials may 2 have information from other sources or may direct designers to other sources, including USAGE District Offices and FEMA Regional Offices. Additional steps may be necessary when 500-year flood elevations are not included in the FIS but are needed for the design of critical facilities. Statistical methods or engineering analyses may be required to identify critical flood characteristics. E N IP TECHNICAL BULLETIN 3 JANUARY 2021 91 Packet Pg. 501 C.14.a tiv 4$, y■y�] 1 � 4it�{V 9 S.r tb �Y x ( a't1 II C9 � { {, 1E ! R 10 r, CD 71 tt y Figure 2: Example FIRM showing building location and BFE An important consideration is that the flood protection level specified in ASCE 24 or local regulations is the minimum level to which buildings must be dry floodproofed.There is no restriction on designing dry floodproofing to provide protection for a higher flood elevation than what is required. Incorporating additional freeboard could help accommodate increases in future flood elevations, which may be caused by changes in storm intensity, increased development of surrounding areas, or ground subsidence. Owners and designers should discuss the 0 acceptable level of protection given the value of the buildings, contents, occupancies, availability of replacement equipment, costs associated with business interruption and function, and cost-effectiveness of dry floodproofing. N Owners may decide that a higher level of protection is appropriate. Determine After the flood protection level has been determined, the next step is to determine the flood loads that would act on a building at the selected location. For design purposes, flood loads are the result of floodwater rising to the .2 flood protection level and moving past an object such as a building or component of a building foundation. Flood loads are discussed in ASCE 7, which should be the primary source for calculating flood loads. Resources such as FEMA P-936 and FEMA P-55, Coastal Construction Manual(2010b), provide helpful information on determining site-specific loads. The four types of flood loads are: E U 22 NFIP TECHNICAL BULLETIN 3 JA Packet Pg. 502 C.14.a • Hydrostatic loads, including buoyancy,which is the vertical hydrostatic force resulting from the displacement of a given volume of floodwater(Step 3A) • Hydrodynamic loads (Step 313) m • Wave loads (Step 3C) :5 • Impact loads (Step 3D) 6 .E Step 3E is load combinations,which are combinations of all types of loads,including flood loads. DETERMINING DEPTH OF FLOODING flooding of depth All applicable flood loads must be considered over The de p g is critical in calculating � the entire dry floodproofing system below the flood flood loads. Designers of dry floodproofing W protection level, including the portion above the BFE. systems should use the flood protection level Flood loads act on above-grade portions of buildings elevation rather than the BFE or DFE when determining the depth of flooding for the Q when floodwater is present and on below-grade 4- calculation walls and slabs when saturated soil conditions calculation of flood loads. 0) may be resent or may occur during flooding. Y P Y g g• An overview of the types of flood loads is provided in N Step 3A through Step 3E. m . . Hydrostatic rr Hydrostatic loads are imposed by standing water on an object or building. Hydrostatic loads on specific buildings W are determined using the flood protection level and must be applied to all building surfaces, both above and below the ground surface. Hydrostatic loads, also called pressures, are oriented horizontally on wall elements and increase linearly with depth of water(see Figure 3). For buildings with below-grade areas (basements), hydrostatic 0 loads extend to the bottom of below-grade walls and are calculated using a saturated soil condition (see ASCE 7 a Chapters 3 and 5). c U_ m Flood protection level Water surface level Hydrostatic load CD ,a< Ground c� Buoyancy force 1 :. m Additional pressure 2 from saturated soil Buoyancy force Figure 3: Hydrostatic loads N ICE TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg. 503 C.14.a Vertical hydrostatic force (buoyancy) can be determined by multiplying the specific weight of water and the volume of floodwater displaced by a submerged object. Buoyant forces act upward on the bottom of foundation walls and base slabs and are resisted by the weight of the building and the structural capacity of the slab to resist uplift loads. See FEMA P-936, Chapter 2, for information on determining hydrostatic loads and analyzing buoyancy forces. When flood shields are included in dry floodproofing systems to prevent floodwater from entering openings in the g building envelope (such as windows and doors), the shields must extend up to at least the flood protection level. A common practice is to extend flood shields an additional foot or more since even small amounts of splash or overtopping of a shield could result in a significant volume of floodwater entering the building. Flood shields must be designed to resist the hydrostatic load applied over the entire shield, and there must be a continuous load path uJ through mounting systems to the walls and ultimately to foundations. See Step 7 for additional information on designing flood shields. o 6.3.2 Step 3B.- Hydrodynamic Loads Hydrodynamic loads are imposed by water flowing around fixed objects such as buildings. These loads are a function of flow velocity and the geometry of the object or building. Upstream surfaces receive positive (frontal) pressures, side surfaces experience the effects of drag, and downstream surfaces have negative (suction) pressures do (see Figure 4). 0) Hydrodynamic loads are determined by basic fluid mechanics. They increase as the size of the object around ' which the flow passes increases and with the square root of the flow velocity. Hydrodynamic loads vary with the r shape of the object and associated drag coefficients. CD ASCE 24, Chapter 6, limits the use of' dry floodproofing S 4- to areas where flood velocities are less than or equal to 5 DETERMINING FLOODVELOCITY 0 2 feet per second. ASCE 24 commentary acknowledges that .0 Possible sources of data for determining o eflective designs may account for higher velocities and notes expected flood velocity include studies o that it is the community's decision as to whether to accept U- by government agencies, hydraulic dry floodproofing proposals in areas with velocities higher calculations, historical measurements, �- than 5 feet per second. and Floodway Data Tables in FEMA FISs, Determining the flood velocity can be a challenging part among others.The Floodway Data Tables of estimating hydrodynamic loads on structures. Local, represent conditions during a 1-percent- annual-chance event. Where the flood o state, and federal government agencies and the Floodway z Data Tables in FEMA FISs developed for waterways where protection level is higher, designers should N consider that flood velocities for an event FEMA performed detailed analyses are potential resources equaling the flood protection level may of velocity information. be higher. When data are not available for ASCE 7 provides guidance on how to determine estimating flow velocities for a specific m hydrodynamic loads and makes allowances for conditions site, designers should contact experienced when it is possible to calculate hydrodynamic loads as an hydrologists or hydraulic or civil engineers equivalent hydrostatic load. FEMA P-936, Chapter 2 to develop estimates. also describes hydrodynamic forces and how to determine a drag coefficient based on the shape of buildings and produce the total hydrodynamic force against a building or a given surface area. E 24 NFIP TECHNICAL ULL TIN 3 JA Packet Pg. 504 C.14.a Negative pressure/suction M on downstream side 4 2 i ! l�f� 1f1�11)S�1 f ! s� tr s t }t) 'J W O Frpntal impactlog`o ^ upstr�arps�de � tJ Figure 4: Hydrodynamic forces on a building N E 2 The NFIP regulations do not permit the use of dry floodproofing in SFHAs that are subject to high velocity wave :5 action, called coastal high hazard areas and identified on FIRMS as Zone V(V,VE,V1-30, and VO). FEMA does W not identify other areas that may experience waves,including expansive riverine floodplains. ASCE 24 does not permit dry floodproofing in Zone V or in Coastal A Zones when a Limit of Moderate Wave Action(LiMWA) is delineated on a FIRM. In addition,ASCE 24, Section 3.7.2, requires structures in noncoastal 2 flood hazard areas subject to wind-driven waves that are equal to or greater than 3 feet high to be designed in a accordance with the requirements for coastal high hazard areas. While wave loads are typically not considered in c U_ dry floodproofing designs,ASCE 24 commentary cautions that waves less than 3 feet in height can cause damage 6 and should be considered in calculating flood loads. These waves may occur inland of the Zone V boundary where a LiMWA has not been delineated and in other floodplains where wind-driven waves may develop. Critical facilities could be located landward of Zone V and Coastal A Zones but under a design condition where the flood depth could support higher wave heights,which should be addressed in the design. 0 Design professionals should investigate historical flood damage near the site to determine whether wave forces could be present and could be significant enough to address in determining flood loads. Investigating historical N flood damage is also appropriate for sites that are landward of Zone V boundaries if a LiMWA has not been , delineated. Guidance on evaluating and determining appropriate wave loads and how to calculate the forces on various structural elements is included in ASCE 7, and additional information is provided in FEMA P-55. . Impact 2 Impact loads result from debris that is transported by floodwater and strikes buildings. Such debris includes trees, boulders, ice floes, unsecured tanks and containers, vehicles, and material from damaged buildings. The magnitude of impact loads is difficult to predict due to the uncertainty of the size and weight of the objects. �. Determining the magnitude of debris impact loads should be based on a rational approach. The loads should be W applied as a horizontal, concentrated load acting at the most critical location at or below the flood protection level. U N IP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg. 505 C.14.a ASCE 7 should be used as the source of how to calculate debris impact loads with FEMA P-936 as the source of helpful information and guidance on evaluating debris impact loads. r9 6.3.5 Step 3E. Load Combinationsm Buildings need to be designed to resist all loads and load combinations. The applicable flood loads that are described above must be combined with other loads in accordance with ASCE 7. The design professional is 6 permitted to combine loads by using Allowable Stress Design (ASD) or Strength Design (also known as Load Resistance Factor Design [LRFD]). e( Condition (Existing When considering retrofitting an existing structure for dry floodproofing measures, design professionals must perform a CONDITION ASSESSMENTS condition assessment of the portions of the structures that will OF EXISTING STRUCTURES be relied on to resist the flood loads determined in Step 3. The See ASCE 11-99, Guide for Structural assessment should be performed in two steps. The first step is a Condition Assessment of Existing preliminary assessment consisting of a visual examination of the Buildings, and Appendix C of FEMA buildingand a review of available structural and architectural P-936 for useful information on � drawings. performing condition assessments of E If' the preliminary assessment suggests that dry floodproofing existing structures. rr may be possible, the second step is a more thorough assessment w involving a review of as-built drawings (if available) and any plans or other documents related to any modifications of the structural elements after initial construction. Where C adequate plans are not available,invasive testing to determine the structural aspects and condition of the building 0 may be necessary. Cracks and penetrations through walls and slabs must be identified and examined to determine a. whether they would become pathways for seepage. The assessment results should be documented in written 0 reports. U_ 76 Design professionals use condition assessments to design modifications to existing structures that will satisfy dry floodproofing performance requirements. Modifications and key areas to identify include: • Strengthening structural walls or floor systems a • Sealing wall penetrations o T_ • Installing waterproofing membranes CD N N • Locating where flood shields are needed • Locating where seepage will accumulate and sump pumps are needed If soil boring information for the site is not available, a geotechnical investigation may be necessary to determine lateral earth pressures and allowable soil-bearing capacities. Other geotechnical issues that may need to be 76 considered include the presence of expansive or collapsible soils, potential for scour, permeability of soils, and compaction behavior of soils. See the discussion of site factors in FEMA P-936, Section 2.4, for additional information. 26 NFIP TECHNICAL ULL TIN 3 JA Packet Pg. 506 C.14.a a Designl Components Resistancefor l After flood loads have been determined in Step 3 and for existing buildings, the condition has assessed in Step 4, design professionals should next demonstrate that the structural elements (walls, foundations, and slabs) within areas to be dry floodproofed will have adequate strength to resist flood loads. To comply with ASCE 24, the 76 structural components of new construction must be designed in accordance ASCE 7 to resist combined flood and E other loads(e.g., dead load, live load,wind loads, seismic loads). U For existing buildings, the structural components that will resist flood loads need to be checked to determine whether they have adequate strength and stiffness. Structural components such as exterior walls, foundation LU elements, and diaphragms will likely experience substantial increases in loads after dry floodproofing measures W are applied. Exterior walls commonly require strengthening with supplemental vertical or horizontal structural o members to resist flood loads. Existing cracks and penetrations below the flood protection level must be sealed to limit seepage during flooding. Another aspect of resistance to flood loads is whether building elements, such as slabs, have adequate resistance to uplift caused by buoyancy.ACI 350.4R-04, Design Considerations for Environmental Engineering Concrete Structures (ACI, 2004), is a helpful resource in determining the appropriate factor of safety to use to check uplift due to buoyancy. Some building elements may require strengthening or other modification to accommodate uplift W pressures caused by buoyancy. Evaluaterr it ing Utility Systems and Equipment Designers must determine the needs of building utility systems and equipment in dry floodproofed buildings and S 4- identify the appropriate ways to satisfy floodplain management and building code requirements.The requirements 0 L. apply to building utility systems(mechanical, electrical, and plumbing) and equipment(including fire controls and emergency power or generators). The preferred solution is to locate building utility systems and equipment above the flood protection level. Building utility systems and equipment that serve non-residential buildings and non-residential portions of m mixed-use buildings are allowed in dry floodproofed areas. If dry floodproofing systems fail or are overtopped by :2 floodwater rising above the flood protection level, building utility systems and equipment may be damaged and not repairable, which could contribute to loss of building functionality. Backflow (non-return) valves or shutoff r_ valves should be installed to prevent floodwater from entering through sewer and drainage pipes, and sewage z ejectors should be installed to pump sewage to above the flood protection level before connecting to a vertical CD sewer line. N The NFIP regulations and ASCE 24 permit equipment and service facilities to be below the flood protection level when "designed ... to prevent water from entering or accumulating within the components during conditions of a� flooding" (44 CFR§ 60.3(a)(3)(iv)). The expectation is that after being submerged, equipment and facilities below the flood protection level will be able to be restored to functioning with minimal cleaning and repair. Unless 6 equipment and service facilities are specifically designed to be submerged,they should be elevated on platforms or located on the roof,inside a freestanding engineered dry floodproofed walled area, or inside the dry floodproofed U building. A good practice is to install connections for temporary equipment above the flood protection level or design interior core areas, as discussed in Section 3.3 of FEMA P-936.Additional guidance is available in FEMA P-348,Protecting Building Utility Systems from Flood Damage(2017). N IP TECHNICAL BULLETIN 3 JANUARY 2021 97 Packet Pg. 507 C.14.a When non-residential portions of mixed-use buildings are designed with dry floodproofing systems, the building utility systems and equipment that serve the residential uses are required to be elevated above the flood protection level and not located in areas that are protected with dry floodproofing(see Figure 5). m iltilltlt�"'��iiit. Resldentlal building utility Rooftop HVAC unit i�r l�l�� llp sir system in penthouse ti ( Wet s �1�f �)�� ' floodp roofed residential t �s7�tj�1 {t��n access Flood protection a level I ) Flood shield rr I Below grade FIRST FLOOR: Non-residential non-residential I ' building utility system SECOND FLOOR: Residential and equipment room 0 Figure 5: Mixed-use building with non-residential building utility systems and equipment in a dry floodproofed below-grade equipment room and elevated systems that serve the residential uses o DesignIShields When dry floodproofing systems are designed with doors,windows, or other openings below the flood protection level, design professionals must design or specify flood shields so the entire system performs as intended. Before finalizing designs, designers must determine the available warning time and the likely ability of personnel who would be responsible for deploying active dry floodproofing measures. Designers must also understand the z requirements for installing different types of shields (see Section 5.2 of this Technical Bulletin). CD Flood shields must be strong enough to resist all imposed flood loads. It is also critical to determine SPECIAL GLAZING SYSTEMS whether the shields will be mounted on structural elements of buildings or on door and window Some manufacturers produce glazing (window) frames. When mounted on door and window systems with laminated glass, seals, and frames frames, the frames must be capable of carrying designed to resist flood loads while meeting the loads exerted on the shields. Designers should occupant needs for natural light.These window consider specifying flood shields that are tested systems(sometimes called submarine or aquarium and certified to the requirements of' ANSI/FM glass)are passive dry floodproofing measures because installing flood shields is not required 2510 (see Section 3.3 of this Technical Bulletin). when flooding is anticipated. 28 NFIP TECHNICAL BULLETIN 3 JA Packet Pg. 508 C.14.a To limit seepage, flood shields typically have flexible gaskets around their perimeter. Various manufactured products are available. Figure 6 illustrates common types of shields, although other types may be available. Some permanent doors can be designed to function as flood shields when closed, although this may not be a viable option when doors are used frequently because of wear on gaskets and seals. Some flood shields are mounted next to openings to facilitate rapid deployment. Many flood shields are modular, can be stored nearby, and installed when needed. ca 76 LU Drop In Drop In E rr tS `fir �j3z,'�, li�lll CD 0 2 m UL a l law,Im �t Bolt On Sliding 0 cv r9 m Hinged Automatic/ Passive m E Figure 6:Common types of flood shields N IP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg. 509 C.14.a Building owners and designers are cautioned that FEMA does not consider temporarily installed flood protection that covers walls, including glass curtain walls, to meet the NFIP minimum requirement that walls must be "substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and eflects of buoyancy" (44 CFR§ 60.3(c)(3)). 6.8 Step 8: Design Waterproofing System 76 In addition to ensuring that structures are capable of withstanding flood loads, design professionals need to ensure that areas below the flood protection level are watertight and substantially impermeable. To be considered substantially impermeable, the waterproofing system below the flood protection level must limit seepage through walls, floors, utility penetrations,joints, cracks, and around flood shields. The system must not allow more than W 4 inches of water depth from seepage to accumulate during a 24-hour period without relying on devices to W remove the water(e.g., sump pumps). Estimating seepage from each component of the waterproofing system is an o important step because designers may need to alter designs to be able to certify that the designs stay within the accumulation limit. . .1 Step 8A.- Estimate Seepage through Wall Systems Estimating the total seepage accumulation through a given wall system is challenging due to the many types do of systems and the lack of available testing information for each type. However, in 2011, Oak Ridge National Laboratory (ORNL) tested 11 common wall assemblies under a simulated hydrostatic load for a 3-foot water E depth to measure seepage when exposed to flooding over a 24-hour period. SERRI [Southeast Region Research .5 rr Initiative] Report 80024-01,Floodproo f Construction: Working for Coastal Communities,describes the test methodology and measured seepage accumulation for the 11 wall assemblies (ORNL, 2011). The wall systems considered in the SERRI study included concrete masonry unit blocks with sprayed- and sheet- applied water-resistive membranes,insulated concrete formwork, and metal structural insulated panels. Designers 0. should review the SERRI report to determine whether one of the tested wall systems could be considered similar a enough to the wall system under consideration. If the wall systems are similar enough, the measured seepage accumulation results documented in the SERRI report could be used to derive approximate seepage values over a 6 24 hour period. Appendix B of this Technical Bulletin provides an example that illustrates the use of the SERRI results to estimate the seepage rate through a wall system to determine whether the dry floodproofed space is :2 substantially impermeable. The total seepage through a given wall system can be estimated by applying seepage rates to the area of wall z exposed to floodwater. When using the SERRI report, the designer should recognize that the amount of seepage N accumulation recorded in the study may not be fully representative of actual seepage volumes when there are N differences in construction materials and methods from those described in the study and when flood conditions differ, such as flood depths other than 3 feet. When greater precision of wall seepage rates is desired, it may be necessary to construct a mockup for a particular wall assembly to test under hydrostatic load to measure seepage a) rates. For an example calculation of seepage through walls, see Steps la and lb in Appendix B. ru . 30 NFIP TECHNICAL BULLETIN 3 JA Packet Pg. 510 C.14.a 6.8.2 Step : Estimate Seepage through Joints and Penetrations Various joints and gaps around utility penetrations are typically present in below-grade foundation systems M and, in particular, the joints between foundations and lowest slabs. Because of the difficulty of sealing the joint m between the exterior wall and slab, this joint is the most prone to allowing seepage into dry floodproofed areas :5 (see Figure 7). In new construction, designers should specify and detail waterstops or joint seals that can resist the CO anticipated hydrostatic pressures. cis C Flood protection level Utility penetration Wall Seepage �,YNIn a «�ti4,1111�� r t rr Figure 7:Typical seepage paths for water entering through joints between wall,footer,and slab A common approach for existing buildings is to inject chemical grout into joints, wall penetrations, and cracks. 0 The grout reacts with water and expands to form watertight, flexible seals. When determining whether this M method is appropriate for expansion joints, the designer should evaluate whether the chemical grout would allow the joints to perform as intended. Alternative sealing products use a flexible material that fills the space between the utility penetration and the wall when fasteners are tightened. If known cracks or joints are not sealed, the designer will need to take these seepage sources into account when determining total seepage in a 24-hour period. 0 During the design of floodproofing systems for new buildings and when assessing the condition of existing T_ buildings, designers should identify all joints and penetrations in the walls and slabs. Seepage through joints and N CD penetrations must be estimated. An example of the calculation of seepage through expansion joints is shown in N Appendix B. Manufacturers of some of the materials that are used to seal expansion joints and other penetrations may provide information that can be used to estimate seepage rates.When seepage rates under flood conditions are not provided or deemed inadequate for the purpose of dry floodproofing, designers may decide that it is necessary to perform mock-up testing of joints or penetration assemblies using the anticipated hydrostatic pressures. CO 76 For an example calculation of seepage through expansion joints, see Step 2 in Appendix B. N ICE TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg. 511 C.14.a t Estimate around IShields When flood shields are included in dry floodproofing systems, designers need to estimate the expected seepage around the GASKET AND SEAT_ MAINTENANCE: � m wetted perimeter of each shield, which typically has a gasket CRITICAL C that seals the shield to the building walls, frames around ca openings, or foundations. The amount of seepage depends on Post-disaster assessments have cis indicated that poorly maintained shield .E several factors,including the duration of flooding and integrity gaskets and seals are a common of the seal which, in turn, depends on maintenance and source of excessive water leakage. installation. Designers may need to adjust the initial designs, This situation can occur when gaskets reduce the number of flood shields, or specify a different types and seals deteriorate due to weather of flood shield if the calculations indicate that the seepage will or dry rot or are torn during handling or exceed the total allowed accumulation of seepage (4 inches storage and are not replaced. o over a 24-hour period). Manufacturers of various types of flood shields with gaskets and seals have tested some products under hydrostatic load to measure seepage rates (see Section 3.3 of this Technical Bulletin). Testing information should be obtained from manufacturers to estimate the volume of seepage,which may be provided as gallons per hour per linear foot of wetted perimeter. W For an example calculation of seepage around flood shields, see Step 3 in Appendix B. m 6.8.4 Step : Estimate Total Seepage through Waterproofing After estimates of seepage through wall systems, through joints and penetrations, and around flood shields ' are calculated, the total seepage can be estimated. For buildings to be certified as meeting the substantially ;S impermeable requirement, the maximum accumulation in the dry floodproofed portion of the buildings must 0 not exceed 4 inches of water depth over a 24-hour period without relying on devices for removal of water. If the total seepage estimate exceeds the 24-hour limit, the designer must adjust the design and selected components as 0 necessary to satisfy the accumulation limit. Although sump pumps are required to handle seepage (see Step 9), u' 76 sump pumps cannot be relied on to meet the maximum accumulation limit of 4 inches over a 24-hour period. m For an example calculation estimating total seepage, see Step 4 in Appendix B. 6.9 Step 9: Design Interior Drainage 0 Most spaces below the flood protection level of dry floodproofed buildings will not stay completely dry during CD flood events. Therefore, interior drainage systems should be designed to limit the accumulation of seepage. N Designs must specify the paths along which seepage will flow and collect and where drains and sumps will be M installed. ASCE 24 requires the use of sump pumps to remove water accumulation due to any passage of vapor S m and seepage of water during flooding events, described in Step 8. If a building loses power,backup power fails to work properly, or sump pumps fail to operate, significant amounts of seepage could accumulate. For this reason, sump pumps cannot be relied on as the sole or primary means of .2 meeting the dry floodproofing requirements. Sump pumps should only be relied on to address minor seepage and U leaks that were not properly identified during condition assessments of existing buildings. Sump pumps should be located at the point of lowest slab elevation, with the bottom of sump pits positioned well 0) below the bottom of base slabs.A typical sump pump detail is shown in Figure 8. In large below-grade areas, it is common practice to install piping in gravel-filled trenches below the base slab at the perimeter of the foundation e( 32 NFIP TECHNICAL BULLETIN 3 JA Packet Pg. 512 C.14.a Check Discharge valve pipe Cord and To battery or M plug backup power unit Sump Sump cover Drain line 100 t8 k ' F_E d o We o ..o ...o. a a a a Drain line g F® Varies(typically 18 to Submersible 24 inches) sump pit _ uJ Varies I C (typically 18 to 36 inches) Figure 8:Typical sump pump detail walls to provide a path for groundwater to access one or more sump pumps. A quickly rising water table or saturation from surface water,which occurs in many flood conditions, can produce enough seepage to overwhelm sump pumps if seepage rates into dry floodproofed spaces are high. Backup or emergency power for sump pumps is necessary due to the potential for power outages during flood events. 0) To select a sump pump as part of a dry floodproofing system, the designer should consider the advantages of each pump type and make the selection based on the estimate of total seepage rate (Step 8),pump capacity(gallons per r minute),pump head, and electrical power required to operate the pump. �= 6.10 Step 10: Certify the Design and Satisfy Requirements for Plans c The final step in the dry floodproofing design process is for registered professional engineers or architects to certify REQUIRED DOCUMENTS FOR NFIP c designs. FEMA Form 086-0-34, NFIP Floodproofing FLOOD INSURANCE POL.ICI Certificate for Non-Residential Structures, is used by DRY FLOODPROOFED BUILDINGS m most communities to meet the NFIP requirement that When building owners apply for NFIP flood communities obtain certifications for dry floodproofing insurance policies for a dry floodproofed designs. See Section 1.2 of this Technical Bulletin for building, the NFIP requires a signed and additional information on the certificate and Appendix A sealed NFIP Floodproofing Certificate, for instructions on completing the certificate. flood emergency operations plan, and N When human intervention is required to implement any inspection and maintenance plan. component of dry floodproofing systems,ASCE 24 requires designers to meet specific requirements related to flood warning time (see Section 5.2 of this Technical Bulletin), a� flood shield design (Step 7, above), and flood emergency operations plans (see Section 5.5 of this Technical Bulletin). These requirements are also discussed in FEMA P-936. When dry floodproofing system designs are complete, designers should verify that flood emergency operations plans address all required elements and should review the plans with building owners. Inspection and maintenance plans, described in Section 5.5 of this Technical Bulletin, are necessary for the long- r_ term functioning of dry floodproofing systems. When dry floodproofing system designs are complete, designers a) should verify that inspection and maintenance plans address all required elements and should review the plans with building owners. NFIP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg. 513 C.14.a r9 7 References This section lists references cited in the Technical Bulletin.Additional resources related to NFIP requirements are 5 provided in Technical Bulletin 0. 76 ACI(American Concrete Association). 2004.AGI 350AR-04,Design Considerations for Environmental Engineering .2 Concrete Structures.Available at httl)s://www.concrete.on-(,/store/l)roductdetal.l.asl)x`?ItemlD=:350404&Form at== � DOWN .,C)D&L..an4. ua(. € English [jnj.ts= [jS AND METRIC.'. � ANSI/FM (American National Standards Institute/FM Approvals). 2020.ANSI/FM 2510,American National Standard for Flood Mitigation Equipment.Available at httl)s://www.fniappro al.s.com/appro al-standards. � O ASCE/SEI(American Society of Civil Engineers/Structural Engineers Institute). 1999.ASCE 11-99, Guide for Structural Condition Assessment of Existing Buildings.Available at httl)s://www.asce.or(,/. ASCE/SEI. 2005.ASCE 24-05, Flood Resistant Design and Construction. Available at httl)s://www.asce.or(,/. ASCE/SEI. 2014.ASCE 24-14, Flood Resistant Design and Construction. Available at httl)s://www.asce.or(,/. d_n ASCE/SEI. 2016.ASCE 7-16,Minimum Design Loads and Associated Criteria for Buildings and Other Structures. E Available at httl)s://www.asce.or(,/. rr w FEMA(Federal Emergency Management Agency). Various. NFIP Technical Bulletins. Current editions available at htths: ��v�• .f<m�. ov em<rs<t7cv rnf�rr�<�y<r� risl4 rn�ni7f�s<rnr:nt {auilclirrs sci<rrc< nationfdl llood-insurance,-uechnicaI lsulleuins: 0 2 • Technical Bulletin 0, User's Guide to Technical Bulletins 0 • Technical Bulletin 1,Requirements for Flood Openings in Foundation Walls and Walls o f Enclosures e U- • Technical Bulletin 2,Flood Damage-Resistant Materials Requirements • Technical Bulletin 6,Requirements for Dry Floodproo fed Below-Grade Parking Areas Under Non-Residential and � Mixed-Use Buildings • Technical Bulletin 7, Wet Floodproofing Requirements c FEMA. 2010a. FEMA P-758,Substantial ImprovementlSubstantial Damage Desk Reference. N Available at https://www.fema.gov/emenl;ency--mana(,e s/ri.sl--mana(,ement/bul.ldi.n(-science/ e,i multi--hazardkt:---:text::=:-Document I EMA%20P--753. FEMA. 2010b. FEMA P-55, Coastal Construction Manual.Available at httl)s://www.fema.(,ov/media--libn-an-y-- a� data/20130726--1510--20490--2399/fennna55 voli.combined.pdf. FEMA. 2013. FEMA P-936,Floodproofing Non-Residential Buildings.Available at httl)s://www.fema.guv/ 2 emeus,I,ncN-ma.nao,crs/risk-ma:na;cmc�it/btjilding-science/O odb`:..--:text 1^lluM 11-936. � FEMA. 2017. FEMA P-348,Protecting Building Utility Systems From Flood Damage.Available at httl)s://www.fema. F gox/cmcu-5Z,cnncN-ma.nao,crs/risle-ma.na;cnnc�nt/btjilding-science/Ooodb`: -:text 1F^IuM 11-3=1 . E 34 NFIP TECHNICAL BULLETIN 3 JA Packet Pg. 514 C.14.a FEMA. 2018a. FEMA 213,Answers to Questions About Substantially ImprovedISubstantially Damaged Buildings. � Available at httl)s://www.fema.(,uv/emer(,ency--mana(,e s/ri.sk--mana(,ement/bui.ldi.ng science/multj..-- � hazard4: :text= E;MA 213. � m FEMA. 2018b. FEMA P-2023,Mitigation Assessment Team Report:Hurricane Irma in Florida. Available at httl)s://NN,,ww fema_(,oc ,,/emer( encWy--mana(, rs/ri.sk--mana4.,ement/building--sc i.encWe/mi.ti4.�ation assessment-- � team .,:text FEMA 11-2023. .2 C FEMA. 2018e. FEMA P-2022, Mitigation Assessment Team Report:Hurricane Harney in Texas.Available at httl)s://NN,,ww fema_4.,ov/emer( encWy--mana(, rs/ri.sk--mana4.,ement/buiIdi.ng--sc i.encWe/mi.ti(,ation assessment-- � team4 ..:text FEMA 11-2022. FEMA. 2019a. FEMA P-2037, Flood Mitigation Measures for Multi-Family Buildings.Available at httl)s://(Wuntent. s utideluticri,.co�ii/attaeliments/1TSDUISlE^EMA/2020/06/2=1/fine attaeliments/1481529/16-I-021 Multi- � Oami.lyGuidance 06222020.1)df. FEMA. 2019b. FEMA Form 086-0-34, NFIP Floodproofing Certificate for Non-Residential Structures. U Available at latJ:p :/A �N w.fema..g Xr/food-insti a.nce/feed-form/tinderNN ritinghg . --:text::== odproof n . N FEMA. 2020a. FEMA P-2140,Floodplain Management Requirements for Agricultural Structures and Accessory Structures.Available at fattps://w �N.fema.goXr/Media.-collectio�l/floodpiain-ma,nao c�nc�it-requireme�its- agrieuittira:i-a.nd-aceessori-stu-ueturesh`: :tcxt=:-FEM 11-2WO. rr FEMA. 2020b. National Flood Insurance Program Flood Insurance Manual. Available at https://www.fcma.gov/ flood-msurat ccANork-AN ith-nfup/manuals. ICC (International Code Council). International Codes.Available at httl)s://cWodes.i.cWcsafe.or(,/cWategory/1--Codes. 0 2 • 2012 International Building Code c • 2015 International Building Code • 2018 International Building Code m ORNL(Oak Ridge National Laboratory). 2011. SERRI Report 80024-01,Floodproof Construction: Working for M Coastal Communities.Available at lattps://staticl.sgtja.respaee.coon/static/5=l5OOd6 c4bOfe2b 6c 3I26=1/t/5=1 , 9343ale4bOd5186e34fOe6/1418937249160/SERR I+Report 1-80024-01 ploodproof+-C;onstrucWtion+_%28Se 0 pt+-2011%29.1)df. _. N USACE. 1995. Flood Proofing Regulations.Available at httl)s://www.l)ubli.cati.ons.usace.army.m1.1/Portals/16/ N 1.publications/E;ngineerPaml)hlets/E P- 11652314 pdf. m N IP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg. 515 C.14.a Appendix A: FEMA Form 086-0-34, National Flood m Insurance Program Floodproofing Certificate for Non-Residential Structures Appendix A of the National Flood Insurance Program's Technical Bulletin 3, Requirements for the Design and Certification of Dry Floodproofed Non-Residential and Mixed-Use Buildings, includes guidance on completing FF,llIA Form 086-0-34, National Flood Insurance Program Floodproofing Certificate for Non Residential LU Structures. Communities that participate in the National Flood Insurance Program (NFIP) must require that designs for dry floodproofing be certified by a registered professional engineer or architect. The registered 2 design professional must develop or review the structural designs, specifications, and plans for the construction .2 of dry floodproofed buildings and must certify that the designs and methods of construction are in accordance with accepted standards of practice for achieving the required performance. Communities must maintain the certifications in their permanent records. These requirements are established in the Floodplain Management Criteria section of Title 44 Code of Federal Regulations (CFR) §§ 60.3(c)(3) and(4). d_n, The following instructions are based on the NFIP Floodproofing Certificate that was issued in Dec. 2019, and E that is scheduled to expire on Nov. 30, 2022. Design professionals must use the current NFIP Floodproofing Certificate or an equivalent statement to comply with the requirement. r TOP OF THE FORM S 4- 0 FLOODPROOFING CERTIFICATE FOR NON-RESIDENTIAL STRUCTURES The floodproofing of non-residerrtial buildings may be permitted as an alternative to elevating to or above the Base Flood Elevation; however,a floodproofing design certification is required.This form is to be used for that certification.Floodproofing of a residential building does not alter a community's floodplain management elevation requirements or affect the insurance rating unless the community has been issued an exception by FEMA to allow floodproofed residential basements.The permitting of a floodproofed residential basement requires a separate certification specifying that the design complies with the local floodplain management ordinance. BUILDING OWNERS NAME m FOR INSURANCE COMPANY USE � y POLICY NUMBER , STREET ADDRESS(including Apt.,Unit,Suite,and/or Bldg.Number)OR P.O.ROUTE AND BOX NUMBER r N CD COMPANY NAIL NUMBER OTHER DESCRIPTION(Lot and Block Numbers,etc.) cy N CITY STATE Zip Code Instructions: A Enter the building owner's name and the address of the building. m 36 NFIP TECHNICAL BULLETIN 3 JA Packet Pg. 516 C.14.a SECTION I SECTION I—FLOOD INSURANCE RATE MAP(FIRM)INFORMATION Provide the following from the proper FIRM: COMMUNITY NUMBER PANEL NUMBER SUFFIX DATE OF FIRM INDEX FIRM ZONE BASE FLOOD ELEVATION 75 [in AO Zones,Use Depth} 100 B C 2 D Indicate elevations datum used for Base Flood Elevation shown above; NGVD 1929 NAVD 1988 E]Other/Source; Instructions: LU B Enter the following information from the Flood Insurance Rate Map(FIRM)and Map Index: • Community Number—Six-digit identification number assigned to the community(also referred to as the community identification number or C;ID). Shown in the title block of the FIRM(see Figure A-1). • Panel Number and Suffix—Identification of the FIRM panel that includes the subject property, shown in the title U block of the FIRM(see Figure A-1). .� • Date of FIRM Index—Most recent revision date for the community's FIRMS is the date on the FIRM Map Index, M which may or may not be the date on the FIRM panel for the property(see Figure A-2). W • FIRM zone—The flood zone in which the building is located, obtained from the FIRM. C Enter the base flood elevation(BFE) at the location of the building. Special Flood Hazard Areas(SFHAs)identified as Zone AO do not have BFEs;instead,a depth number may be shown(use depth of 2 feet if no depth number is shown). r D Select the elevation datum used for the BFE. The vertical datum is shown on the FIRM map legend or in "Notes to Users"on the FIRM. C 2 ( NATIONAL FLOOD INSURANCE PROGRAM I q NATIONAL FLOOR INSURANCE PROGRAM C FIRM FLOOD INSURANCE RATE MAP FLOOD INSURANCE RATE MAP I✓ FLOOD COUNTY, 1 LLDi3I) [L3UNT1', � USA ( 11,ICI USA (� ( AN1) INCORP©RAIED AREAS � ii ';NAND IN ORtkk.V`I'Sr AREAS � SEE a L7.G N I✓ PANEL Of 40 ( Z H111.111111l 777 (PANELS PRIMTEO. n N c44 NUMBER PANEL SUFFIX 990099 0025 D � MAP NUMBER � � I% MAP NUMBER � 99009COO25 D 99009COU00 � EFCTIOE IfATE= ' AUGUST 19,1998 � UG ST 1911998 i � I aaknxl baasreKvD r,'r'ianegen t 9),—Y i i•drai b` g u S—MWaaain ri rtn N8e-Y a7 u�. . E Figure A-1:Typical FIRM title block Figure A-2:Typical FIRM map index N IP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg. 517 C.14.a SECTION 11 Section II is used to certify the elevation (where BFEs are provided on FIRMS) or the height above the lowest adjacent grade (where BFEs are not provided) to which the building is floodproofed. Section II is to be signed and sealed by a land surveyor, engineer, or architect authorized by law to certify elevation information. Persons :5 who sign and seal elevation information must be licensed or authorized to practice surveying in the state where projects are located. �? SECTION II-FLOODPROOFED ELEVATION CERTIFICATION(By a registered Professional Land Surveyor,Engineer,or Architect) All elevations must be based on finished construction. Floodproofing Elevation Information: _ Building is flocdproofed to an elevation of E feet(In Puerto Rico only: meters). F NGVD 1929 NAVD 1988 []Other/Source: (Elevation datum used must be the same as that used for the Base Flood Elevation.) Height of floodproofing on the budding above the lowest adjacent grade is G feet(In Puerto Rico only: meters)- For Unnumbered A Zones Only: ns Highest adjacent(finished)grade next to the building(HAG) H feet(In Puerto Rico only: meters). C1 NGVD 1929 [-]NAVD 1988 Other/Source: (NOTE:For insurance rating purposes,the building's floodproofed design elevation must be at least 1 foot above the Base Flood Elevation to receive rating credit.If the building is floodproofed only to the Base Flood Elevation,then the building's insurance rating will result in a higher Cr premium.See the Instructions section for information on documentation that must accompany this certificate if being submitted for flood W insurance rating purposes.) Instructions: E Enter the floodproofing elevation in whole and decimal units.The floodproofing elevation is the top of the floodproofing 0 measures("height of floodproofing"). The floodproofing elevation must be referenced to the same vertical datum as the BFE identified in Section 1. F Enter the vertical datum the floodproofing elevation is referenced to (NGVD 1929, NAVD 1988, or a locally adopted vertical datum). For a locally used vertical datum, check "Other/Source" and describe the datum and provide the me source. G Enter the height of the floodproofing measures above the lowest adjacent grade.The lowest adjacent grade is the lowest Z ground next to the building. N CD H For unnumbered A Zones,enter the elevation of the highest finished grade adjacent(HAG)next to the building. Enter the vertical datum the HAG is referenced to (NGVD 1929, NAVD 1988, or a locally adopted vertical datum). For a local vertical datum, check"Other/Source" and describe the datum and provide the source. ns 38 NIP TECHNICAL BULLETIN 3 JA Packet Pg. 518 SECTION 11 (cont.) FLOODPROOFING CERTIFICATE FOR NON-RESIDENTIAL STRUCTURES Non-Residential Floodproofed Elevation Information Certification: 5ec#aon[I aertificat�an�s to be signed and sealed by a land surveyor engineer ar arah�tect authari�ed by la'w fa aerf�fy elevation infarrnatian I certify that the information in Section It an this Certificate represents a true and accurate interpretation and determination by .2 the undersigned using the available information and data. I understand that any false statement may be punishable by fine or impilsonment under 18 U.S. Code, Section 1001. CFfjTj IER'S NAME LICENSE NUMBER(or Affix Seat)j TITLE COMPANY NAIVE TODFRESS CITY STATE ZIP CODE SIGNATURE DATE PHONE CJ Instructions: Enter the name, license number, title, company name, and address and phone number of the individual completing E Section 11. Section 11 is to be completed(signed,dated,and sealed)by a land surveyor,engineer,or architect authorized by law to certify floodproofed elevation information. r:5 r SECTION III 0 Section III is used by a registered professional engineer or architect to certify that "the structure, based upon 0 development and/or review of the design, specifications, as-build drawings for construction and physical 'a0. 0 inspection" has been designed and constructed in accordance with "the accepted standards of practice .2 (ASCE 24-05, ASCE 24-14, or their equivalent) and any alterations [of the structure]" meet those standards, are U_ 76 watertight and substantially impermeable and will perform in accordance with 44 CFR§ 60.3(c)(3). The designer r_ also certifies the structure has structural components that are "capable of resisting hydrostatic and hydrodynamic flood forces, including the effects of'buoyancy, and anticipated debris impact forces." W 0 Z T_ C44 CD C44 .2 E NFIP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg. 519 C.14.a SECTION III—FLOODPROOFED CERTIFICATION(By a Registered Professional Engineer or Architect) Non-Residential Flood roofed Construction Certification: 1 certify the structure,based upon development andlor review of the design,specifications, as-built drawings for construction and physical inspection, has been designed and constructed in accordance with the accepted standards of practice(ASCE 24-05.ASCE 24-14 or their equivalent)and any alterations also meet those standards and the following provisions. The structure,together with attendant utilities and sanitary facilities is watertight to the flood proofed design elevation indicated above. is substantially impermeable to the passage of water,and shall perform in accordance with the 44 Code of Federal Regulations K (44 CFR 60.3(c)(3). All structural components are capable of resisting hydrostatic and hydrodynamic flood forces,including the effects of buoyancy,and anticipated debris impact forces. 1 certify that the information in Section Ili on this certificate represents a true and accurate determination by the undersigned using the available information and data l understand that any false statement may be punishable by fine or imprisonment under 18 C1.S. Code, Section 1001. CERTIFIER'S NAME LICENSE NUMBER(or Affix Seal) L TITLE COMPANY NAME U ADDRESS CITY STATE ZIP CODE N SIGNATURE (DATE PHONE Instructions: W K The signer of Section III certifies that floodproofing has been designed and constructed to meet accepted standards of practice.Accepted standards of practice must ensure that the criteria of the 2005 or 2014 editions of ASCE 24, Flood 0 Resistant Design and Construction(or the equivalent), are met and that the two specific design statements are valid. o ASCE 24 contains several criteria for dry floodproofing.Design professionals who prepare designs for dry floodproofed 0 buildings and certify NFIP Floodproofing Certificates should review all ASCE 24 criteria before completing and a: signing the certificate.Also see Technical Bulletin 3 and FEMA P-936,Floodproofing Non-Residential Buildings. Enter the name, license number, title, company name, and address and phone number of the individual completing Section 111. Section III is to be completed(signed, dated, and sealed)by a registered professional engineer or architect authorized by law to certify structural designs. D; C T_ cv CD cv r9 m 5 ca r2 r� r� 40 N IP TECHNICAL BULLETIN 3 JA Packet Pg. 520 C.14.a END OF THE FORM The end of the NFIP Floodproofing Certificate lists information that must be attached. The information is needed by the program's underwriters to provide credit for floodproofing. The information also helps to ensure compliance and provide reasonable assurance that due diligence has been applied in designing and constructing :5 floodproofing measures. When the Floodproofing Certificate is used to obtain flood insurance coverage from the NFIP, building owners should consult with flood insurance providers to determine additional required g documentation described in the National Flood Insurance Program Flood Insurance Manual(FEMA, 2020b). FLOODPROOFING CERTIFICATE FOR NON-RESIDENTIAL STRUCTURES Instructions for Completing the Floodproofing Certificate for Non-Residential Structures o o receive credit for floodproofing,a completed Floodproofing Certificate for Non-Residential Structures is required for non-residential and business buildings in the Regular Program communities,located in zones Al'—A30,AE,AR,AR[dual,AO,AH,and A with BF'E. � CJ M In order to ensure compliance and provide reasonable assurance that due diligence had been applied in designing and constructing n floodproofing measures,the fallowing information must be provided with the completed Floodproofing Certificate: N •Photographs of shields,gates,barriers,or components designed to provide floodproofing protection to the structure. •Written certification that all portions of the structure below the 6FE that will render it watertight or substantially impermeable to the passage of water and must perform in accordance with Title 44 Code of Federal Regulations(44 CFR 60.3(c)(3)). •A comprehensive Maintenance Plan for the entire structure to include but not Iimited to: IX • Exterior envelope of the structure • All penetrations to the exterior of the structure 0 • All shields,gates,barriers,or components designed to provide floodproofing protection to the structure • All seals or gaskets for shields,gates,barriers,or components 0 • Location of all shields,gates,barriers,and components as well as all associated hardware,and any materials or specialized toots necessary to seal the structure. Instructions: M The additional information listed in the"Instructions for Completing the Floodproofing Certificate for Non-Residential Structures"at the end of the Floodproofing Certificate must be included. Z T_ cv CD cv r9 m 5 100 .E NFIP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg. 521 C.14.a r9 m Total Seepage Appendix 13: Example Calculation for Estimating Appendix B of the National Flood Insurance Program's Technical Bulletin 3, Requirements for the Design and ca 76 Certification of Dry Floodproofed Non-Residential and Mixed-Use Buildings, contains an example calculation for 2 estimating the total expected seepage into a dry floodproofed area. Total seepage is the combination of seepage through the wall system, seepage around flood shields (barriers), and seepage through joints and penetrations. 0) A description of the calculation of seepage that is illustrated in this appendix is provided in the Technical Bulletin, Section 6.8, Step 8: Design Waterproofing System. To be able to design and certify that a building is substantially impermeable, the design professional needs r_ to estimate the total expected seepage into dry floodproofed areas. A dry floodproofed building that is made substantially impermeable through the use of materials and techniques allows limited accumulation of water to .2 pass or seep through pathways (e.g., cracks, openings, channels) and points of entry during flooding. Water is allowed to accumulate to a depth of not more than 4 inches in a 24-hour period without relying on devices for removal of water. N The estimate of expected total seepage is used to determine whether the proposed dry floodproofing measures r_ will meet the requirement(expected depth of accumulated water is not more than 4 inches). If the expected total E m seepage accumulation exceeds the maximum allowance, the designer must select one or more alternatives to meet the requirements, such as a different wall system, fewer openings that require flood shields, different types of r shields, or relocating utility penetrations. The example calculation in this appendix illustrates how ;S to calculate seepage for an example building. To estimate SERRI REPORT 0 the seepage through the wall system, the example applies RASE® ON 3-FOOT FLOOD DEPTH the results of a seepage study by Oak Ridge National It is important to note that the seepage Laboratory, which were published in SERRI Report accumulation in the SERRI report is based 80024-01, Floodproof Construction: Working for Coastal on a 3-foot flood depth (ORNL, 2011). Communities (ORNL, 2011). The study tested a series of Designers should use caution when "pods" constructed of different materials using different estimating total seepage rates for greater methods by exposing them to 3 feet of water over more flood depths because the seepage rate than 24 hours. may be higher because hydrostatic loads o The wall system selected for the example calculation is would be greater. identified in the SERRI report as "Test Pod H." Test Pod N 0 H was constructed of 8-inch concrete masonry unit(CMU) blocks with elastomeric weatherproofing membrane sprayed onto the exterior of the CMU block face. Excerpts from the SERRI report are included in this appendix, including a diagram of Test Pod H and observations from the flood simulation tests. 76 .E 42 NFIP TECHNICAL ULL TIN 3 JA Packet Pg. 522 C.14.a Calculationin an Example Building Table B-1 and Calculation Steps 1 through 4 illustrate the calculation of the expected seepage for an example building with a wall system that is similar to the one used for Test Pod H in the SERRI report(CMU block with liquid membrane sprayed onto the exterior of the CMU face). Figure B-1 is the plan view of the example building. Table B-1: Example Building Information 6 � i}t 1 ..... S y °� e, 9i�,�uuuuuumiViiViiVuuuuuuuuuuuuuuuuuuuuuuuuuuuumiViiViiViiViiV 1` II° °4 IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII �g �� ° ` Flood depth h=3 feet Building length L=30 feet Building width W=40 feet Exterior doors Number n =3 aoo� Width Waoor= 6 feet Each door is 6 feet wide. 2 Length of joints in exterior LEj=48 feet The assumption of 48 feet for the example building is wall through which seepage is based on the likely placement of expansion joints. expected rn Door 1� 6 feet 0 0 0 4' 0 0 6 feet Door 6 feetfeet>� 0 I I _ 0 ) Door CD if 40 feet cV Figure B-1: Example building plan view "9 m 76 0 0 0 m 0 N IP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg. 523 C.14.a Calculation t la. Estimatethe seepage ratethrough the wall system. This example uses the seepage rate through the wall system of Test Pod H from SERRI Report 80024-01. The M seepage rate through the walls of Test Pod H is calculated using the volume of seepage that accumulated during a m 24-hour period, divided by the area of the pod. CO Area of test pod Apod = 6 ft X 6 ft= 36 ft2 ru Test pod wetted perimeter ppod, = 6 ft+ 6 ft+ 6 ft+ 6 ft= 24 ft Test pod wetted area(flood depth is 3 feet) Apod_,,, = 3 ft X ppod, = 72 ft2 Depth of water(inches) in test pod in d,, = 15.5 in = 1.3 ft 24 hours Note:Depth of water selected from the SERRI report, page A-5,Table A.2 (shown below) Volume of seepage in test pod in 24 hours Vpod_s = d, x Apod = 46.8 ft' CJ Seepage rate through walls of test pod Rwa11 = Vpod_s -Apod_w = 0.65 ft3/ft2 per 24 hours N Calculation t 1b. Applythe estimatedt to the examplebuilding to determineE the volumef seepage through the walls of the examplebuilding i 24 hours rr This example uses the seepage rate determined in Calculation Step 1 for the wall system of Test Pod H from the SERRI Report 80024-01. 2 Example building area Ab1dg = L X W = 1,200 ft2 c Total width of doors L door = door X w = 18 c n door ft .2 Building wall wetted perimeter pw = (2 X L) + (2 X W) — Ldoor = 122 ft m Building wall wetted area Awa11 = pw X h = 366 ft2 Seepage through wall system Swall = Awall X Rwall = 238 ft3 per 24 hours 0 T- cv CD cv r9 m 76 44 NFIP TECHNICAL BULLETIN 3 JA Packet Pg. 524 C.14.a Calculation Step 2. Determine the volume of seepage around flood barriers ) installed of the Ibuilding in 24 hours Some manufacturers test flood shields and gaskets under varying conditions to determine seepage rates (see Section 3.3 in the Technical Bulletin). Seepage rates are often reported in the volume of seepage per length of :5 gasket in a given period of time (ft3/ft-hr or gal/ft-hr). Door wetted length Ldoor_w = ndoor X (h +h +Wdoor) = 36 ft Flood barrier(shield) seepage rate RFB = 0.08 gal/ft-hr = 0.011 ft 3/ft-hr Note: 0.08 gal/ft-hr is based on a manufacturer's technical specification. Designers must determine the actual rate based on specified flood shield(s). Seepage through flood barriers (shields) SFB = Ldoor_w X RFB X 24 hr = 10 ft3 per 24 hours Calculation t t i volume through expansionjoints in the example building Determination of the seepage rate through expansion joints may be difficult and may require more research than wall seepage estimates or flood shield gasket seepage rates. Some manufacturers may provide sufficient product information to allow the designer to estimate the amount of seepage through joint sealants under flood conditions. When seepage rates under flood conditions are not provided or are deemed inadequate for this purpose, designers :5. may decide that it is necessary to perform mock-up testing of joints or penetration assemblies using the anticipated hydrostatic pressures (see Section 6, Step 8B, in the Technical Bulletin). This example considers only seepage through expansion joints. Additional estimates must be made if there are penetrations and cracks below the flood protection level. c Seepage rate at expansion joints REJ = 0.80 gal/ft-hr = 0.107 ft3/ft-hr Note: 0.80 gal/ft-hr is based on testing of similar joint sealants. Dcsigncrs must dctcrmme an appropriate seepage rate based on specified sealants. Seepage through all expansion joints SEI = LEI x REI x 24 hr = 123 ft3 per 24 hours 0 Calculation t l I t the total sti t for the examplebuilding r- cv CD Seepage through walls, plus flood barriers STota1 = Swa11 X SFB + SE1 = 371 ft3 per 24 hours (shields),plus expansion joints Depth of seepage er 24 hours d — S A = 0.31 feet or 3.72 inches per 24 hours pp Seep — Total — bldg Conclusion76 2 For the example building, the total estimated seepage is less than 4 inches in 24 hours, which means the example U building meets the requirement to be considered substantially impermeable. The designer must also satisfy other requirements including determining where the seepage will accumulate and the paths along which seepage water will flow to get to the accumulation area. The interior drainage collection system must be designed to limit the accumulation of seepage (see Section 6, Step 9, of the Technical Bulletin). N IP TECHNICAL BULLETIN 3 JANUARY 2021 Packet Pg. 525 C.14.a SERRI Report Excerpts r9 Southeast Region Research Initiative F' 4.2.8 Test Pod H:Weatherproofed Block 76 2 Test pod H:weatherproofed block(Fig.4.15)was a CMU block structure with a liquid membrane sprayed onto the exterior of the CMU face. • First course(8"in height)of CMU cells filled with mortar. • Fully grouted CMU cells located at corners and at the middle of each wall. • The flood resistive layer was an elastomeric waterproofing coating for LLJ masonry and concrete,applied in four thick coats. • Design was developed as an inexpensive alternative to test pod A:sealed 2 :N block which performed well with a high-end spray-applied water resistive layer. • Elastomeric coating was applied with a residential sprayer. CJ N GROUT FILL.VA"I H WINTER RESISTANT ADD TIVE •; I 8X8XYCiCMll VES'fICAL REINFORCING EAFiS (EVERY' MOP TAR CEMENT WATER RESISTANT ADDITIVEEL si TRUSS MESH IaEINFOFiC:EMENT. S'rAPNLESS STEEL FRUSS MESH ELASTOMEIRIC WEA]HEAPROOFING ", ✓ (U CD SLAB 't ,1 i Fig.4.15.DIAGRAM:test pod H:weatherproofed block. 56 SERRI Report 80024-01 E U 46 NFIP TECHNICAL BULLETIN 3 JA Packet Pg. 526 C.14.a r9 Southeast Re,ion Research Initiative F' A.2 Observations From Flood Simulation 2 Table A.2 is a log of the visual observations taken during flood simulation 1,which took place between June 281h,2011 and June 291h,2011.At specific time intervals,which are noted in the second column of this table,interior water depths were recorded for each test pod. Also,key observations regarding assembly changes are noted where applicable. U- Table A.2.Observations from flood simulation 2. Test Pod G Test Pod H Test Pod A Test Pod 32 Test Pod D2 Test Pod F2 Flooding Interior Interior Interior Interior Interior Interior U Simulated Water Depth Water Depth Water Depth Water Depth Water Depth Water Depth Date Time Depth(in) (in) (in) (in) (in) (in) (in) 28-Jun 7:45AM 0 0 0 0 0 0 0 8:36AM 10 seepage 0 0 0 seepage two seepage two south wall corners corners more 8:SOAM 14 seepage, seepage 0 0 more more 0) capillary started seepeage seepage action seepage, Cr early cells are 0) 9:45AM 24 0 seepage 0 seepage 0.13 seepaging more 10:45 A M 36 0.25 1.5 0 0.5 0.5 0.25 0 11:45AM 36 0.5 3.75 corner 1.5 0.5 0.25 seepage 12:45 PM 36 0.75 6 0 2.25 0.5 0.25 1:45 PM 36 1 6.5 0 3 1 0.25 2:45 PM 36 1 8 0 4 1.25 0.25 _ 3:45 PM 36 1.25 9 0 5 1.25 0.25 5:45 PM 36 1.5 10 0 7 3 0.5 7:45 PM 36 1.5 12 0.25 8 3 0.5 0) 9:45 PM 36 2.5 12.5 0.25 9 2.5 0.5 ug 11:45 PM 36 2.5 14 0.25 10 2.5 0.5 0) 29-Jun 1:45AM 36 3 13.5 0.25 10 3 0.5 3:45AM 36 3 15 0.25 13.5 3 0.5 5:45AM 36 3 15.5 0.25 13.5 3 0.5 7:45AM 36 3.5 15.5 0.25 13.5 3 0.5 9:45AM 36 3.5 16 0.25 14 3.5 0.5 Q 10:45AM 36 3.75 16.5 0.25 14.5 3.75 0.5 11:45AM 31 3.75 16.75 0.25 14.5 3.75 0.5 cy 1:45 PM 12 3.75 17 0.25 15.5 3.75 0.5 5:00 PMj 0 3.75 17 0.25 15.5 3.75 0.5 U U SERRI Report 80024-01 A-5 E U N IP TECHNICAL BULLETIN 3 JANUARY 2021 47 Packet Pg. 527 C.14.b 1 2 3 4 5 ; 6 7 8 9 MONROE COUNTY, FLORIDA 10 MONROE COUNTY BOARD OF COUNTY COMMISSIONERS 11 RESOLUTION NO. -2021 12 13 A RESOLUTION OF THE MONROE COUNTY BOARD OF 14 COUNTY COMMISSIONERS ADOPTING FEMA TECHNICAL 15 BULLETIN 3 "REQUIREMENTS FOR THE DESIGN AND 16 CERTIFICATION OF DRY FLOODPROOFED NON- 17 RESIDENTIAL AND MIXED-USE BUILDINGS" DATED 18 JANUARY 2021 AS REQUIRED PURSUANT TO MONROE 19 COUNTY CODE SECTION 122-2(C) 20 21 22 WHEREAS, Monroe County is currently a participating community in the National 23 Flood Insurance Program (NFIP) and is working on internal County policies to improve upon its 24 interpretation of NFIP regulations; and 25 26 WHEREAS, Monroe County desires to maintain eligibility and improve its standing in 27 FEMA's Community Rating System(CRS); and 28 29 WHEREAS, Monroe County Code Section 122-2(c), in part, requires that in interpreting 30 other provisions of this chapter, the Building Official shall be guided by the current edition of 31 FEMA's 44 CFR, and FEMA's interpretive letters, policy statements and technical bulletins as 32 adopted by resolution from time to time by the Board of County Commissioners; y 33 34 NOW, THEREFORE, BE IT RESOLVED BY THE BOARD OF COUNTY 35 COMMISSIONERS OF MONROE COUNTY, FLORIDA: 36 37 Section 1. Pursuant to Monroe County Code Section 122-2(c), the Board hereby adopts 38 FEMA Technical Bulletin 3 "Requirements For the Design and Certification of Dry 39 Floodproofed Non-Residential and Mixed-Use Buildings" dated January 2021, a copy of which 40 is attached hereto. 41 42 Section 2. The Clerk of the Board is hereby directed to forward one (1) certified copy of 43 this Resolution to the Building Department. 44 45 46 Packet;Pg. 528 C.14.b 1 2 3 PASSED AND ADOPTED by the Board of County Commissioners of Monroe County, 4 Florida, at a regular meeting held on the 171h of March, 2021. 5 6 7 S Mayor Michelle Coldiron 9 Mayor pro tem David Rice 10 Commissioner Craig Cates 11 Commissioner Mike Forster 12 Commissioner Eddie Martinez 13 14 15 16 BOARD OF COUNTY COMMISSIONERS 17 OF MONROE COUNTY, FLORIDA 18 19 BY: 20 Mayor Michelle Coldiron 21 22 (SEAL) 23 ATTEST: KEVIN MADOK, CLERK 24 25 26 As Deputy Clerk 0 #� FEE COUNTY ATTORNEY'S OFFICE PPRO D AS T M PAUNECE SCULL ASSISTANT CO INW ATTQRNEY DATE: '� _ - Packet;Pg. 529