SESSION 5C FLOODPLAIN ISSUES 1

Transcription

1 SESSION 5C FLOODPLAIN ISSUES 1 159

2 NFIP LEGISLATION IMPLEMENTATION UPDATE Richard J. Sobota, 1 CFM, CPCU, FEMA/DHS Both the Biggert-Waters Flood Insurance Reform Act of 2012 and the Homeowner Flood Insurance Affordability Act of 2014 contain numerous provisions affecting the National Flood Insurance Program, and these will require implementation over an extended period of time. This presentation is intended to provide an overview of both pieces of legislation, and to share our progress-to-date, explain some of the processes involved, and outline our strategies and timelines for future implementation. 1 Insurance Specialist; FEMA Region III, 615 Chestnut Street, Philadelphia, PA 19106; ; richard.sobota@dhs.gov 160

3 AFTER THE WAVE OF NEW FEMA REGION III COASTAL HAZARD STUDIES, WHAT S NEXT? RESILIENT COASTAL COMMUNITIES! Mari Radford, 1 CFM, FEMA Region 3; Alison Kearns, 2 CFM, FEMA Region The Federal Emergency Management Agency (FEMA) Region III includes many coastal counties and cities in Virginia. As part of FEMA s RiskMAP Program, an identification and assessment of the coastal flooding risks has been performed and updated Flood Insurance Rate Maps (FIRMs) and Flood Insurance Studies (FISs) have been produced and released for more than 30 Virginia coastal counties and cities. Many coastal communities have also received innovative nonregulatory RiskMAP Flood Risk Products in addition to their maps, to help better identify risk, take action to reduce it and increase their resiliency. To that end, Region III is organizing Resilience Meetings for all coastal counties and cities to continue the dialogue of resilience by presenting these non-regulatory products as well as other tools in the risk reduction toolkit (CRS, grants, etc.). Because no two communities are alike; FEMA is tailoring each Resilience Meeting to meet the needs of the jurisdiction and to leverage actions already taken. Strategies to promote flood risk and increase resilience will involve not just the regulatory and non-regulatory products, but opportunities for training and bringing new and old partners to the table for this important discussion. We will explore existing barriers and incentives for communities to take action to reduce risk including FEMA Federal grants related to reducing future losses. Other Federal agencies as well as our state partners - share tools and information that they have available for communities to use in assessing and implementing mitigation strategies. The information exchanged among FEMA, our partners and the communities is helping to improve the understanding of local needs for future flood hazard mapping, flood risk, mitigation planning, and communication. In this presentation we will discuss the experience of developing a Coastal Resilience Strategy and participating in Resilience Meetings. We will also share success stories and describe what mitigation strategies have been employed within the coastal areas of the Region to date. 1 Mitigation Planning Specialist; 615 Chestnut Street, Philadelphia, PA 19034; ; mari.radford@fema.dhs.gov 2 Community Planning Specialist; 615 Chestnut Street, Philadelphia, PA 19034; ; alison.kearns@fema.dhs.gov 161

4 UNDERSTANDING FOUNDATION FLOOD VENTS AND FEMA S TECHNICAL BULLETIN 1 Summary: Donald Jernigan, 1 CFM, CDT, Smart Vent Products, Inc. This course provides insight into the importance of proper foundation flood vents and compliance with Building Codes and FEMA standards and how they can effectively prevent major damage to buildings due to flooding. The course will review applicable codes pertaining to foundation flood venting, including a complete review of FEMA s new Technical Bulletin TB-1. After the course, participants will have a thorough understanding of the difference between non-engineered openings and engineered openings and the important role they play in designing a sustainable structure. Learning Objectives: Understand applicable codes pertaining to Foundation Flood Venting. (5 min) Cover the new ICC regulations, ASCE and the National Flood Insurance Program (FEMA) Regulations, including a complete review of TB (30 min) Have a thorough knowledge of the new NFIP floodplain Elevation Certificate, including the surveyor s responsibility. Calculate the sq. ft. of enclosed area correctly. (10 min) Review the requirements of Engineered Opening and Non-Engineered Openings. (10 min) Understand and appreciate the process of independent evaluation of construction products and their value to architects and code officials. (5 min) Review changes found in ASCE Method of Delivery: An upbeat PowerPoint presentation 1 Technical Sales Representative; 430 Andro Drive, Unit 1 Pitman, NJ 08071; ; djernigan@smartvent.com 162

5 WHAT CAN WE DO ABOUT NUISANCE FLOODING IN THE COASTAL PLAINS? Seshadri Iyer, 1 Ph.D., PE, CFM, AECOM; Tim Clarke, 2 CPM, AECOM; Jeff Waller, 3 PE, City of Virginia Beach Nuisance flooding in coastal plains may be attributed to the presence of low lying areas; low relief; high groundwater; tidal flooding; large runoff volumes and high peak flows generated from impervious areas; and/or hydraulically inadequate drainage system(s). Any combination of these attributes presents a mind boggling task of finding a techno-economically feasible drainage solution. A myriad of other factors compound this quandary. Firstly, coastal plains tend to be highly developed and have: a large number of other underground utilities present in the area; highly travelled lanes and extensive traffic controls; land subsidence impacting existing drainage infrastructure (pipes under adverse slopes); and seasonal beach tourism demands. On top of this, aged infrastructure may no longer be accurately represented by record data such as GIS information, as-builts, etc. and pertinent attributes such as size, material, alignment, datum and/or invert elevations for various utilities may be missing or no longer valid. Further, aging stormwater infrastructure may not meet current design standards which creates a problem in establishing any new connections. Also, the existing infrastructure may have been constructed prior to the onset of the new stormwater management regulations for water quality and quantity and any modifications or improvements to the existing drainage system will entail meeting the new regulations. In the Central Beach District of the City of Virginia Beach, one of the intersections on a major arterial roadway experiences nuisance flooding. All of the aforementioned attributes that contribute to nuisance flooding are observed at this intersection. Significant tailwater impacts from receiving waters result in decreased capacity of the existing stormwater conveyance system. A SWMM model of the existing drainage system affirms these issues by indicating nodal flooding at the intersection. As if this were not enough, upstream structure flooding will sheet flow down gradient into this intersection like rubbing salt against the wound! The City contracted AECOM (formerly URS) in finding an amicable, long-term solution that is cost effective. Three alternatives were conceptualized a short-term gravity solution; a longterm suction wet well and pumping solution; and the utilization of the existing 16th Street pump station. This paper discusses each alternative in depth, their cost opinions, a prioritization plan and recommendations. 1 Senior Water Resources Engineer; 277 Bendix Rd., #500, Virginia Beach, VA 23452; ; seshadri.iyer@aecom.com 2 Project Engineer; 277 Bendix Rd., #500, Virginia Beach, VA 23452; ; tim.clarke@aecom.com 3 Project Manager; 2405 Courthouse Dr., Virginia Beach, VA 23456; ; jwaller@vbgov.com 163