SEA LEVEL RISE AND STORM SURGE IMPACTS TO ROADWAYS

Transcription

1 SEA LEVEL RISE AND STORM SURGE IMPACTS TO ROADWAYS IN HAMPTON ROADS P RESENTED BY: S AM B ELFIELD, S ENIOR T RANSPORTATION E NGINEER H AMPTON R OADS T RANSPORTATION P LANNING O RGANIZATION B OARD M EETING A GENDA I TEM #12 M AY 19, 2016

2 Sea Level Rise in Hampton Roads Hampton Roads is 2 nd most vulnerable region to Sea Level Rise in U.S. (behind New Orleans) VULNERABILITY TO SEA LEVEL RISE (SLR) Sea Level Rise is expected to accelerate Sea Level Rise will result in significant impacts: Permanent inundation of some areas. More frequent flooding of other areas. Some areas that have not seen flooding will start to experience it. Source: National Climate Assessment via EPA, data from Hammar-Klose and Thieler / 11

3 Sea Level Rise and Storm Surge Impacts on Transportation Infrastructure SLR increases the risk of flooding on critical transportation infrastructure. Photo by Stephen M. Katz - Virginian-Pilot Repetitive flooding at critical transportation facilities can severely impact travel and hurt regional/ local economies. These impacts will increase the total costs to transportation systems and their users, but they can be reduced through rerouting, mode change, roadway improvements, and a wide range of adaptive actions. Photo by WAVY TV Photo by HamptonRoads.com 3/ 11

4 Regional Involvement in Planning for Sea Level Rise HRPDC and HRTPO Partnership Environmental Sustainability Best Practices for Transportation symposium Partnerships with other stakeholders HRPDC Coastal Resiliency Committee University Efforts (ODU, UVA, W&M, VT) Virginia Institute of Marine Science (VIMS) Hampton Roads SLR Intergovernmental Planning Pilot Project Infrastructure Working Group Hampton Roads Adaptation Forum Hampton Roads Dutch Dialogues (June 19-23, 2015) Develop strategies to promote integrated water management and resiliency 4/ 11

5 Low/Historic (1.6 ) Intermediate Low (2.6 ) Intermediate High (4.9 ) High (7.5 ) VULNERABILITY TO SEA LEVEL RISE BY 2100 (INUNDATION MAP) 5/ 11

6 HRTPO Study Partnering with HRPDC, conducted GIS-based vulnerability analysis for potential sea level rise/storm surge impacts to regional roadways by 2045 (next Long-Range Transportation Plan horizon year). Three scenarios: 1) Sea Level Rise (2 ) 2) Sea Level Rise (2 ) + 25-year storm 3) Sea Level Rise (2 ) + 50-year storm 2045 Analysis Network Existing Local Roadway 6/ 11

7 Flooding Vulnerability for Roadways Purpose: Adaptation Identify roadway segments vulnerable to flooding in order to develop adaptation strategies for those roadways. Road Projects Raise awareness of potential flood locations to consider during design. HRTPO Scoring of Candidate Transportation Projects Consider using the study results to add a flooding vulnerability component within the Project Prioritization Tool. Area Submerged (Scenario 1) Area Submerged (Scenario 2) Area Submerged (Scenario 3) 7/ 11

8 Potential Submergence of Roadways by 2045 Portsmouth LEGEND* Roadway Submerged by 2.0 foot Relative Sea Level Rise Roadway Submerged by 2.0 feet Relative Sea Level Rise + 25-year Storm Surge Roadway Submerged by 2.0 feet Relative Sea Level Rise + 50-year Storm Surge Subarea Map Example Roadway Not impacted 2045 Analysis Network Existing Local Roadway Area Submerged by 2.0 feet Relative Sea Level Rise Area Submerged by 2.0 feet Relative Sea Level Rise + 25-year Storm Surge Area Submerged by 2.0 feet Relative Sea Level Rise + 50-year Storm Surge TEMPORARY INUNDATION 25-year Storm 50-year Storm 4% chance per year 2% chance per year 8/ 11 Prepared by: HRTPO Staff, October 2015 Data source for projected flooded areas: HRPDC Staff, October 2015 *Within the GIS analysis, some roadways with elevated structures (e.g., bridges and overpasses) were identified to be submerged. At these locations, the land below the roadway structure was expected to flood, not the actual roadway. For the 2045 Roadway Network, HRTPO staff used aerial photography to remove those submerged locations. Local roadways, however, were not checked for elevated structures given the large size of that network.

9 Integrating Adaptation Strategies Adaptation strategies reduce potential impacts to ensure transportation system reliability and resiliency. Local Examples: Wythe Creek Road widening project Coordination between Poquoson, Hampton, and NASA Used inundation mapping tool and modeling to make design modifications I-64 Southside High Rise Bridge project As a result of recent sea level rise planning efforts, VDOT increased bridge design height by 5 feet to account for future sea level rise 9/ 11

10 Next Steps Localities/VDOT Use the latest SLR/SS projections when a roadway project is designed. Include adaptation strategies when planning, designing, constructing, or retrofitting transportation infrastructure. HRTPO Staff Provide study results/data to localities for future planning efforts. Review project prioritization tool scoring to incorporate flooding vulnerability component. 10 / 11

11 Final Report All public and stakeholder comments have been addressed and incorporated in the final report. Recommended Action: Accept this technical report as consistent with FY 2016 UPWP Task 7.0 Safety and Security Planning. 11 / 11