The Hampton Roads Military Transportation Needs Study is comprised of three phases:
1. Highway Network Analysis (September 2011)
2. Military Commuter Survey (September 2012)
3. Roadways Serving the Military and Sea Level Rise/Storm Surge (July 2013)
The third and final phase of this study was recently approved by the HRTPO Board at the July 18th meeting.
The Hampton Roads region contains one of the largest natural harbors in the world, making the region an attractive location for military facilities. This coastal location also makes many of these military facilities susceptible to projected relative sea level rise and potential storm surge threats, impacting overall defense readiness. The threat of flooding is a concern for the military in the region since military operations require a transportation network that moves cargo and personnel quickly and safely.
The impacts of relative sea level rise and storm surge have been recognized along the southeast coast for many years, particularly for low-lying communities such as Hampton Roads, Virginia. National, state, regional, and local organizations have participated (or are currently participating) in initiatives that address this pressing issue in order to raise awareness and develop potential solutions. This study (phase three) builds on previous studies and related work to estimate the relative sea level rise and potential storm surge threats to the “Roadways Serving the Military” network established in phase one of the Hampton Roads Military Transportation Needs Study. In the first phase, HRTPO staff reviewed the “Roadways Serving the Military” to determine deficient locations, such as congested segments, deficient bridges, and inadequate geometrics. This third phase of the study continues the work in phase one by determining flooding-based deficient locations along the roadway network. It expands upon the work and methodologies developed by the Hampton Roads Planning District Commission (HRPDC) and the Virginia Institute of Marine Science (VIMS), by identifying military roadway segments vulnerable to submergence. Additionally, submergence of other local roadways that provide access to and from the “Roadways Serving the Military” which may be vulnerable to flooding have been identified.
Given the uncertainty in how much relative sea level rise will occur and how fast it will accelerate, current research suggests that 1.5 feet of rise (from 1992) could occur in Hampton Roads sometime between 2032 and 2065. With the forecast year of the next HRTPO Long-Range Transportation Plan being 2040, a 1.5 foot relative sea level rise (1992 to ~2040) scenario was used in this analysis. Based on past storm events, a 3 foot storm surge is a reasonable level to expect for moderate future storms. For example, the surge at Sewell’s Point during Hurricane Irene (2011) was measured at 4.2 feet, while the surge from Hurricane Isabel (2003) at the same location was measured at 4.4 feet. The combination of 1.5 feet of relative sea level rise and 3 feet of storm surge would result in a total relative water rise of 4.5 feet.
This study (phase three) used elevation data from the HRPDC in conjunction with Geographic Information System (GIS) software to identify potential flooding for “Roadways Serving the Military”, specific segments that would be submerged by 4.5 feet of relative water rise (1.5’ relative sea level rise plus 3’ storm surge). Maps of these locations are provided below. Additionally, subarea maps that provide a closer view of various Hampton Roads jurisdictions are provided within the report. The results show that the “Roadways Serving the Military” in the Cities of Chesapeake, Hampton, Norfolk, Portsmouth, and Virginia Beach are vulnerable to potential future relative water rise.
The HRTPO plans to update the Hampton Roads Military Transportation Needs Study as necessary. HRTPO staff may update phases I (Highway Network Analysis), II (Military Commuter Survey), and III (Roadways Serving the Military and Sea Level Rise/Storm Surge) of the study as conditions change and warrant additional analysis. The three-phase study can also serve as a basis for future military-related studies.
Click on the following link to access the final report: