The new version of the Hydrologic Engineering Center’s River Analysis System (HEC-RAS), the most widely used river hydraulics software package in the world, now has the ability to perform two-dimensional hydrodynamic modeling. With its new modeling capabilities, detailed flood mapping, and flood animations, HEC-RAS 5.0 provides a powerful tool for analyzing flood risk.

Introduction

HEC-RAS is used by all U.S. Army Corps of Engineers (USACE) District and Division offices, other Federal agencies, state and local governments, private industry, environmental organizations, universities, and engineers worldwide.  It has been downloaded in more than 200 countries.

Until recently, HEC-RAS was limited to one-dimensional river hydraulics computations. Prompted by recent dam and levee safety analysis needs, and the overall desire to improve the hydrodynamic modeling capabilities for general floodplain modeling studies, the USACE Hydrologic Engineering Center developed and integrated two-dimensional hydrodynamics within the HEC-RAS unsteady flow computational engine.  HEC-RAS now has the ability to perform one-dimensional hydrodynamic modeling; completely separate two-dimensional hydrodynamics; and integrated one- and two-dimensional hydrodynamic modeling.

Two-Dimensional Modeling Capabilities

Two-dimensional flow areas have been added into HEC-RAS, such that users can easily combine one-dimensional and two-dimensional elements.  The software allows for multiple two-dimensional flow areas, with flexible connections to one-dimensional elements, as well as directly connected boundary conditions.  The two-dimensional modeling capabilities within HEC-RAS were built from the ground up to be directly integrated within the HEC-RAS unsteady flow engine.  In addition, several unique capabilities have been developed that will allow modelers to develop accurate and efficient one- and two-dimensional models. 

The ability to perform combined one-dimensional and two-dimensional modeling within the same unsteady flow model will allow modelers to work on larger river systems, using one-dimensional modeling where appropriate and two-dimensional modeling in areas that require a higher level of hydrodynamic fidelity.  A common example of where this new capability is useful is for rivers with levees: the modeler can use the one-dimensional model elements for the main river system and the two-dimensional model elements for the interior areas landward of the levees.  The software can be used to evaluate possible levee overtopping and breaching.

Example of a combined one-dimensional/two-dimensional HEC-RAS model for evaluating levee safety.

Additionally, the new two-dimensional modeling tools allow users to quickly generate hydraulic models.  HEC-RAS 5.0 has been used to assist with emergency flood operations both in South Carolina and Texas during recent major storms and floods.  HEC-RAS hydraulic models were quickly developed for areas that had none.  These models were used to map reasonable estimates of flood inundation to assist emergency operations. 

Example of a small dam breaching analysis for flooding in South Carolina.

Detailed Flood Mapping and Flood Animations.  Mapping of the inundated area, as well as animations of the flooding, can be completed within HEC-RAS using RAS Mapper.  The mapping of the two-dimensional flow areas is based on the detailed underlying terrain.  HEC-RAS Version 5.0 can produce spatial mapping of water surface elevations, water depths, velocities, inundation boundaries, flood arrival times, flood durations, depth x velocity, stream power, and shear stress.  Additionally RAS Mapper has options to turn on particle tracing and velocity vector arrows for improved visualization of the water direction and magnitude.  These new mapping tools are extremely useful for understanding water movement and detailed hydraulic issues.

Example HEC-RAS two-dimensional model of the 17th Street outfall structure in New Orleans showing inundation areas and velocities, with velocity tracers for improved visualization.

USACE held its 2015 Interagency Flood Risk Management Workshop December 2-4, 2015, in Southbridge, Massachusetts. The workshop brought together nearly 200 participants to explore the intersection between flood risk management and resilience. Representatives and subject matter experts from USACE and six other Federal agencies, 37 states, local participants, the private sector, non-governmental organizations, and academia identified ways to increase resilience as they address flood risk.

A series of project development exercises provided participants with the opportunity to develop interagency project ideas, incorporating concepts from a resilience framework and receiving feedback from others. Participants also considered policy changes in support of flood risk management, offered feedback to inform the future direction of the USACE Flood Risk Management Program, and considered efforts to use scientific data and information to promote action and adaptation. The workshop concluded with options for joining either various small group discussions or a field trip to a nearby levee system with consideration of interim risk reduction measures and risk communication opportunities and challenges.

Workshop materials are available online, including both an overall agenda and a daily agenda with links to available presentations and handouts.

The redesigned Silver Jackets website is now available!  The redesigned site features improved organization, enhanced searchability, and new content regarding actions taken by state-led Silver Jackets teams across the nation.  The site also provides a portal for team members to access resources that support internal team development and sharing. Suggestions on the redesigned website are welcome.

The site was revised after considering broad suggestions offered during listening sessions for an earlier revision of the Flood Risk Management Program website, as well as specific comments offered by Silver Jackets team members during various meetings and webinars where the website was featured.  USACE revised existing content and developed new content as part of its ongoing role to support state Silver Jackets teams.

The Silver Jackets Program provides a formal and consistent strategy for an interagency approach to planning and implementing measures to reduce the risks associated with flooding and other natural hazards.  State-led Silver Jackets teams bring together multiple state, federal, and sometimes tribal and local agencies to learn from one another, facilitate collaborative solutions, and reduce flood risk and other natural disasters.  Within USACE, the Silver Jackets Program facilitates implementation of its Flood Risk Management Program at the state level.  USACE established the Flood Risk Management Program to work across the agency to focus its policies, programs, and expertise and to align USACE activities with counterpart activities of other federal, state, regional and local agencies in order to manage and reduce flood risk.

The U.S. Army Corps of Engineers (USACE) issued an Advanced Notice of Proposed Rulemaking (ANRP) to request public comment by 14 April 14 2015, on potential revisions to 33 CFR Part 203, Emergency Employment of Army and Other Resources, Natural Disaster Procedures.

USACE has authority under Public Law 84-99 (PL 84-99) to undertake activities including disaster preparedness and advance measures, emergency operations including flood response and post-flood response, and the rehabilitation of flood risk management projects damaged or destroyed by floods. PL 84-99 authorities also include the protection or repair of federally-authorized Coastal Storm Damage Reduction projects.

USACE is considering updating policies and procedures for activities administered under PL 84-99 to better align them with national preparedness and response frameworks, to encourage broader flood risk management activities by sponsors, to reduce repetitive damage to projects, and to incorporate a life-cycle risk management approach. These changes support the agency’s strategic direction and advance risk-informed decision making, increase risk communication efforts, improve relationships with non-federal sponsors, and enhance long-term sustainability and resilience of projects.

USACE is soliciting stakeholder feedback on the overall policy concepts being considered through an ANPR. The ANPR provides background information on PL 84-99 authority, objectives of the policy changes under consideration, summary of the policy concepts, and targeted questions to help focus public comments. The ANPR has a 60-day comment period (closes 14 April 2015) through which interested parties can provide input prior to the development of the Proposed Rule for 33 CFR Part 203. Comments may be submitted through one of the following options:

• Electronically  through the Federal eRulemaking Portal
• Via email to 33CFR203@usace.army.mil (include docket number, COE-2015-0004, in subject line of message)
• By mail to:
  HQ, US Army Corps of Engineers
  441 G Street NW, ATTN: 33CFR203/CECW-HS/3D64
  Washington DC 20314-1000

Following the ANPR comment review, USACE will update and publish the Proposed Rule for a 60-day comment period, revise the document based on comments received, publish the Final Rule, and then revise USACE internal guidance for 33 CFR Part 203 implementation.

If you are interested in learning more about the PL 84-99 Program and/or your opportunities to provide input to changes this program please contact Jeff Jensen.

A fact sheet provides additional details about consideration of PL 84-99 changes.

On January 30, 2015, the President issued Executive Order (EO) 13690: Establishing of a Federal Flood Risk Management Standard and a Process for Further Soliciting and Considering Stakeholder Input. The EO amends existing EO 11988: Floodplain Management originally issued in 1977, to include the Federal Flood Risk Management Standard (FFRMS). The original EO 11988 governs federal actions in floodplains and includes an eight-step decision making process aimed to encourage wise floodplain management decisions.

The FFRMS builds on work done by the Hurricane Sandy Rebuilding Task Force, which announced in April 2013 that all Sandy-related rebuilding projects funded by the Sandy Supplemental (Public Law 113-2) must meet a consistent flood risk reduction standard. The Hurricane Sandy Rebuilding Strategy recommended that the federal government create a national flood risk standard for Federally-funded projects beyond the Sandy-affected region. In implementing the Standard, federal agencies will be given the flexibility to select one of three approaches for establishing the flood elevation and hazard area they use in siting, design, and construction:

• Utilizing best-available, actionable data and methods that integrate current and future changes in flooding based on science,

• Two or three feet of elevation, depending on the criticality of the building, above the 100-year, or 1%-annual-chance, flood elevation, or

• 500-year, or 0.2%-annual-chance, flood elevation.

All options to determine the floodplain in which these Orders apply also include attention to whether a federal action in a floodplain is a critical action. The new EO and FFRMS are not retroactive and will only apply to new construction that uses federal funding.

The new EO also encourages agencies to consider natural systems, ecosystem processes, and nature-based approaches when development alternatives for consideration. This is consistent with recommendations and findings in the recently released North Atlantic Coast Comprehensive Study (NACCS). Both the NACCS and the FFRMS aim to reduce risk and increase resilience of communities’ abilities to withstand and rapidly recover from storm damages in addition to encouraging the use of natural systems, ecosystem processes, and nature-based approaches.

Agencies will not implement the new EO and FFRMS until public dialogue has taken place. Draft interagency Implementing Guidelines were developed and have been issued for public review and comment. The document will be available through May 6 for public comment. In conjunction with the public comment period on the interagency guidelines to implement the new Order, FEMA will be hosting at least seven stakeholder sessions. Six will be held in different locations and one session will be held virtually. These include meetings to be held in Des Moines, IA (March 3); Biloxi, MS (March 5); Sacramento, CA (March 11); Hampton Roads, VA (March 11); New York City, NY; and the National Capitol Region.

For additional details on stakeholder session location and participation, please contact FEMA, or see the Federal Register notice. Feedback gained during these sessions will inform revisions to the interagency Implementing Guidelines document, as well as inform individual agency guidance updates. In the months ahead, the U.S. Army Corps of Engineers will seek dialogue as the agency develops its implementing procedures for EO 13690 and the FFRMS.

Please contact Katelyn Noland or Stephanie Bray for more information.

The U.S. Army Corps of Engineers recently completed a report detailing the results of a two-year study to address coastal storm and flood risk to vulnerable populations, property, ecosystems, and infrastructure in areas of the North Atlantic region of the United States affected by Hurricane Sandy.

The study, known as the North Atlantic Coast Comprehensive Study, is designed to help local communities better understand changing flood risks associated with climate change and to provide tools to help those communities better prepare for future flood risks. It builds on lessons learned from Hurricane Sandy and attempts to bring to bear the latest scientific information available for state, local, and tribal planners.

The conclusions of the study, as detailed in the final report, include several findings, outcomes, and opportunities, such as the use of a nine-step Coastal Storm Risk Management Framework that can be customized for any coastal watershed.

More information is available at http://www.nad.usace.army.mil/compstudy, including the final report and its appendices; associated technical products and tools advanced by the study to close data gaps; and a short overview video, interactive graphics, and links to the study’s webinars.

The 2014 Interagency Flood Risk Management Project Workshop, held August 19-21 in Southbridge, MA, brought together 125 partners from federal, state, and local governments. Participants shared their collective experience with interagency projects and addressed opportunities for improving future use of interagency projects to develop shared solutions to flood risk management challenges.

Participants heard from a panel of Federal agency representatives about the benefits their agencies experienced through participation with Silver Jackets interagency teams. Panelists focused on demonstrating the value that Silver Jackets teams can offer to other Federal agencies and better communicating these benefits to new potential partners. Later, panelists in a separate federal interagency “resource roundtable” presented programs and resources of Federal agencies that may not be well known among interagency teams. Both interagency panels highlighted opportunities for new partners and new ways to engage that can further increase the range of resources, programs, and authorities available to interagency teams.  An August 2014 special edition of the Silver Jackets Newsletter reinforced the opportunities presented by providing a reference of federal agency programs, resources and training opportunities that interagency teams can leverage to achieve their flood risk management goals.

Additional presentations during the workshop focused on interagency projects.  Representatives from various state Silver Jackets teams overviewed example interagency projects and highlighted key lessons learned from each. Another panel focused on trends, drivers, and developments in flood risk management that may influence future interagency projects.  Workshop participants considered successful project starts, communicating interagency project success, and overcoming common challenges and obstacles in interagency project implementation.

The workshop included significant opportunity for small group discussion. Participants self-selected from among several topics for more detailed focus groups or for discussing how to tackle issues from a regional geographic perspective.

Critical challenges identified by participants included identifying interagency partner resources within various funding cycles and funding constraints, preventing future at-risk development, developing nonstructural measures in a structural culture, and identifying shared goals among all partners that will be acted on at the conclusion of a project.

All workshop materials are available online.  Available materials include the workshop agenda with links to presentations given during the workshop, workshop handouts and resources (including the August 2014 special edition of the Silver Jackets newsletter and posters providing key information on scores of interagency projects nationwide), and photos taken during the workshop.

On March 21, 2014, USACE issued interim policy on eligibility for rehabilitation assistance for levee systems.  The interim policy was developed in response to numerous changes over the last few years in the agency’s strategic direction, and is intended to keep the Rehabilitation Program operational during a longer-term policy revision effort.  USACE revised its policy on eligibility for rehabilitation assistance under Public Law 84-99 (PL 84-99) to better synchronize the Rehabilitation Program with the agency’s strategic direction for flood risk management and levee safety.  The eligibility criteria for rehabilitation assistance promote broader flood risk management activities, including emergency preparedness planning, risk communication, and risk-informed prioritization of maintenance activities.  Development of new policy for rehabilitation assistance will be a long-term effort as it will require changes to 33 Code of Federal Regulations Part 203 through a rule-making process.

The interim policy allows eligibility determinations to continue while the final policy is developed.  The interim policy applies only to levee systems; determinations for other types of flood risk management projects will be on hold until the final policy is developed.  The interim policy’s eligibility criteria for levee systems are a subset of the inspection items included on the current Levee Inspection Checklist.  The subset includes the items that, based on the current inspection rating description, were most directly related to performance of the levee system.  These items were also selected to ensure that no incentive would be created for public sponsors to take actions that might negatively impact natural resources or tribal rights.  To that end, vegetation on levees is no longer a criterion to be considered in eligibility determinations for rehabilitation assistance.    

The interim policy is effective immediately and will be used in all future Initial Eligibility Inspections and Continuing Eligibility Inspections for the PL 84-99 Rehabilitation Program.  For levee systems that do not meet the interim eligibility criteria, the System-Wide Improvement Framework  (SWIF) remains an option for levees to maintain eligibility while making progress on addressing system deficiencies.  For levee systems currently with an approved Letter of Intent (LOI) or accepted SWIF plan, the public sponsor will have the choice to a) address all system-wide issues in the current plan, b) reprioritize to focus on the interim eligibility criteria, or c) cancel the LOI or SWIF and follow the interim policy if the interim eligibility criteria can be met.  The SWIF policy represents the broader flood risk management approach that is anticipated to be the direction of the final Rehabilitation Program policy.

A presentation, talking points, fact sheet, and questions and answers regarding the interim policy are also available.

The congressional response to 2012’s Hurricane Sandy included legislation for a comprehensive study to identify regional, systemic vulnerability of populations at risk along the north Atlantic coast. The study, which the U.S. Army Corps of Engineers North Atlantic Division spearheads, brings together experts from government, non-government organizations, academia and industry to develop a framework that provides risk reduction strategies and promotes coastal resilient communities.

In Phase 1, experts began coordinating to assemble existing and future conditions. The assessments and products of this initial phase included: storm suite modeling, state-specific coastal risk frameworks, storm economic impact estimation tool, sea level rise and vulnerability assessments and maps, and identification of risk and preliminary approaches for system resilience.

Phase 2, beginning in the first quarter of 2014, will seek to validate the process and enhance collaboration. Activities in the second  phase will include alignment with other regional plans, solicitation and incorporation of interagency, partner and international comments, and additional analyses as warranted.

Phase 3 will start in the fall of 2014 and will include preparing a report for submission to Congress in January 2015.

For more information on the study, visit http://www.nad.usace.army.mil/CompStudy.aspx

The U.S. Army Corps of Engineers (USACE) and the National Oceanic and Atmospheric Administration (NOAA) have developed Infrastructure Systems Rebuilding Principles for the North Atlantic Coast following widespread damages to the coast during Hurricane Sandy in October 2012. The principles aim to inform efforts to rebuild more resilient and sustainable coastal communities capable of adapting to and mitigating for coastal hazards.  The joint USACE-NOAA document details principles that are designed to improve long-term performance of coastal rebuilding and restoration actions taken though the Infrastructure Systems Recovery Support Function under the National Disaster Recovery Framework.

The rebuilding principles are developed on a regional scale to anticipate changes to the environment, integrate economic, social and environmental resiliency and sustainability, and promote long-term community protection.  The principles also recognize that natural systems and processes are linked with and contribute to the resiliency of physical infrastructure, coastal economies and community well-being. Through the principles, USACE and NOAA agree to work together across multiple scales of government and with relevant external entities and stakeholders to develop long-term strategies that protect and restore natural resources and functions of the coast, while enhancing coastal resilience. This effort includes involving stakeholders; aligning agency actions; leveraging partnerships; aligning and delivering data, tools and information; and conducting assessments to determine what is and is not working.
 
The principles are designed to improve coastal resilience through a systems approach that incorporates natural, social and built systems as a whole, and to identify and align priority actions and investments to support and empower coastal communities. USACE and NOAA also aim to promote increased recognition and awareness of risks and consequences among stakeholders and the public. An increased understanding of risk is also needed for decision makers so they are more able to make informed decisions based on the best available information amidst changing climate, environment, land use and coastal development. The agencies also look to encourage coordination of and common approaches to characterization of risks. The document will be used to inform the North Atlantic Coast Comprehensive Study.

The U.S. Army Corps of Engineers (USACE) Flood Risk Management and Silver Jackets Programs held a series of webinars August 20-22, 2013, to share information and experiences among those actively managing flood risk. An additional day of training was offered on August 23. Audio recordings and presentation materials are available for download at http://www.nfrmp.us/frmpw/2013webinarweek/agenda.cfm. A total of 414 participants registered, and on average approximately 150 people participated across all concurrent sessions at any given time.

The webinars focused on integrating and leveraging efforts to reduce flood risk. Our nation is confronted with numerous challenges in managing flood risks to public safety and economic enterprise. While the USACE has a key role in managing flood risks, no single federal or non-federal entity is solely responsible. Rather, multiple federal, state, local and tribal agencies, as well as private citizens, play a role in flood risk management. The series of webinars provided an opportunity for flood risk management professionals to share their knowledge and experiences, with a goal of promoting mutual efforts that are efficient, effective, and connected. The 2013 “Webinar Week” helped maintain information exchange, relationships, and momentum between face-to-face biennial Flood Risk Management and Silver Jackets Workshops, the next of which is expected to occur in 2014.
 

Ms. Karen Durham-Aguilera, USACE Director of Contingency Operations and Homeland Security, has approved the Program Management Plan (pdf, 1.75 MB) developed for the USACE Flood Risk Management Program, providing further guidance and information on the implementation of the program to supplement the initial guidance first issued to the MSCs and Districts in October of 2009. Under the original guidance, each Major Subordinate Command (MSC, commonly referred to as the Divisions) and District was directed to establish a Flood Risk Management Program and identify an FRM program manager and a Silver Jackets program manager (MSC offices) or coordinator (District offices).

The Program Management Plan provides structure and framework for the Flood Risk Management and Silver Jackets Programs. Due to the changing nature of these challenges, initiatives and actions with time, this Program Management Plan is anticipated to be a working document that will be periodically updated to reflect current conditions in flood risk management.

The Program Management Plan also provides important information on the organizational structure of the program and provides an understanding of what would be considered success. This information will help ensure consistency in implementation of the program across the Corps, while allowing for the accommodation of unique circumstances and needs between MSCs and Districts. One appendix to the Program Management Plan is a detailed Communications Strategy that will assist in both internal and external coordination on flood risk management issues.

Using information provided in the approved national Program Management Plan as a starting point, the MSC and District Flood Risk Managers are charged with developing implementation plans for their Flood Risk Management Programs. These plans will guide the integration of the National Flood Risk Management Program into the existing MSC and District structure.

The U.S. Army Corps of Engineers successfully hosted 248 flood risk management professionals at its 3rd Flood Risk Management and Silver Jackets Workshop in Harrisburg, Pennsylvania, on August 20-24. Participants focused on inter-agency activities at various levels of government in managing flood risk, discussed program policy and strategies, and shared successes and challenges. The workshop provided an opportunity to network, enhance collaborative problem-solving, and facilitate sharing among Federal and state partners. Workshop objectives included demonstrating results and benefits of collaborative approaches, unifying approaches to communicating flood risk in order to effect action, and refining approaches to delivering Federal government services.

Participants praised the relevance of the workshop to their work and highly rated the workshop overall. Key sessions covered topics such as raising the level of public dialogue to manage flood risk, benefits of mitigation, and achievements of Silver Jackets pilot projects and perspectives on evaluating risk reduction. Informational sessions focused on subjects ranging from flood forecasting to ensuring robust analysis of alternatives for flood mitigation options. Field trips offered a chance to view first-hand either flood risk management experiences in the Harrisburg area or Pennsylvania's Emergency Operations Center and Joint Field Office. Nearly half the participants took advantage of preceding training sessions that offered options for more in-depth learning.

The USACE Flood Risk Management Program works across the agency to focus its policies, programs and expertise toward reducing overall flood risk, and aligns USACE efforts with counterpart activities of other Federal agencies, state organizations, and regional and local agencies. The Silver Jackets program provides an opportunity to consistently bring together state, Federal, and sometimes tribal and local agencies to learn from one another and apply their knowledge to reduce risk.

As part of the Learning from Megadisasters project sponsored by the Government of Japan and the World Bank, “knowledge notes” are available online regarding the 2011 Great East Japan earthquake and tsunami. The knowledge notes analyze and synthesize what worked, what did not, and why, and offer recommendations for developing countries that face similar risks and vulnerabilities. The knowledge notes constitute the first phase of the project and are grouped into the following six themes:

• Structural measures
• Nonstructural measures
• Emergency response
• Reconstruction planning
• Hazard and risk information and decision making
• Economics of disaster risk, risk management, and risk financing

An executive summary and brochure also available. The knowledge notes provide a basis for knowledge sharing and exchanges with developing countries, experts, and practitioners. They were prepared by more than 40 Japanese and international experts, assisted by 50 advisers and reviewers including the Director of Civil Works, U.S. Army Corps of Engineers, who was a member of an independent external review team coordinated by the Earthquake Engineering Research Institute.

On Friday, July 6, 2012, President Obama signed a $105 billion bill that combines two years of surface transportation projects, one year of lower interest rates for student loans and a five-year reauthorization and reform of the National Flood Insurance Program (NFIP).

The compromise provisions applying to the NFIP are based largely on the Senate reform bill that was passed out of Committee (S. 1940) and includes the following key provisions:

• Ending flood insurance subsidies for several classes of structures (severe repetitive loss, properties for which sum of insured losses exceed market value of the property, business properties, substantially damaged/improved properties and properties with new or lapsed insurance policies). This provision was largely contained in both the House and Senate bills and is already being implemented for any residential home that is not a person's primary residence, which was approved by Congress during the last temporary extension of the NFIP (HR 5070).
• Authorizes a National Flood Mapping Program – Prior to this bill, while flood mapping was necessary to implement the program, it had never been authorized. An authorized program, especially in tight budget times, is far preferable to trying to convince Congress to fund something that is not authorized by them. For example, Map Modernization was considered a “Presidential Initiative.” The program is authorized for up to $400 million/year (this is not what it will actually receive which is determined during the budgeting and appropriations process).
• Establishes a Technical Mapping Advisory Council (TMAC). A Technical Mapping Advisory Council is being established to, among other things, recommend to FEMA how to improve the accuracy, quality, use, distribution and dissemination of flood maps and flood risk data; recommend any new/updated mapping standards and guidelines; recommend procedures for delegating mapping activities; recommend methods for improving interagency coordination; and develop recommendations on how to ensure that FIRMs incorporate the best available climate science to assess flood risks.