Preparing a community’s buildings and infrastructure for a hurricane or earthquake can be an incredibly complicated and costly endeavor. A new online tool from the National Institute of Standards and Technology (NIST) could streamline this process and help decision makers invest in cost-effective measures to improve their community’s ability to mitigate, adapt to and recover from hazardous events.
With input from local and state government officials, NIST researchers developed the Economic Decision Guide Software (EDGe$) tool, a platform-independent web app, to provide a standard and easy-to-use method of evaluating and comparing different community projects to improve resilience. For community planners weighing options — whether to build a levee or add green space to reduce flooding in a neighborhood, for example — EDGe$ could reveal key economic insights about which choice would be a better fit. The new tool could be beneficial for state, local and private sector planners.
“We have tried to make EDGe$ as user-friendly and straightforward as possible for economists and non-economists alike,” said Jennifer Helgeson, a NIST research economist and lead developer of the tool.
Because myriad factors affect how communities respond to disaster, decision-makers could spend an eternity mulling over which resilience measures would provide the greatest benefits relative to the costs. But EDGe$ users may have an easier time cutting through the noise.
The online tool requests user input about variables that are most crucial for determining the value of a resilience action, including often overlooked factors, such as benefits that accrue day to day even if disaster does not strike. It can also include the effects of projects on neighboring communities, Helgeson said.
Would improving the earthquake resistance of a bridge also ease traffic for a neighboring town? Could a green space in a flood-prone area double as a public park? EDGe$ supports these types of considerations, Helgeson said.
EDGe$ calculates several important figures that indicate the value of investments, such as benefit-to-cost ratios, internal rates of return and returns on investment (whether a hazardous event occurs or not). The metrics from each potential plan, including one where no action is taken, are then laid out side by side so they can be easily compared.
Helping a Coastal Community Keep Floods at Bay
During the development of EDGe$, Helgeson worked closely with engineers planning for resilience at the Delaware Department of Transportation (DelDOT). The engineers tested out beta versions of the software on a real-world project and provided feedback that helped fine-tune its user interface.
That project focused on identifying flooding vulnerabilities along a 27.4-kilometer (17-mile) stretch of State Route 1 (SR 1), a coastal highway in Delaware. DelDOT, along with local and federal partners, found many vulnerable areas initially, but upon closer inspection, two stood out from the rest.
Both sites lie on a section of road flanked by the Atlantic Ocean on one side and Rehoboth Bay on the other. During storms these areas along SR 1 experience frequent flooding, as strong winds blowing over the only outlet to the ocean can prevent water from leaving the bay.
“What happens is the bay kind of fills like a bathtub,” said LaTonya Gilliam, a DelDOT assistant director of transportation engineering who worked on the project. “That causes flooding from the bay side onto the roadways.”
Gilliam and her team determined that the two sites were the highest priority and identified resilience measures for each. One called for raising the road by 6 inches while the other included building up sand dunes and placing bags of oyster shells at the shoreline to dampen the power of waves.
Gilliam used EDGe$ to check her own calculations and confirmed that the benefits were enough to move forward with the two projects, which have since been completed.
For community planners with less expertise or fewer resources than DelDOT, EDGe$ might be even more valuable.
“Without tools like EDGe$, it would be very difficult for a town or county to determine where to start,” Gilliam said.
Helgeson wants to get the tool into the hands of the communities that need it most, such as flood-prone eastern North Carolina. There, she will soon be training emergency managers and planners on using the software to invest in cost-effective community resilience measures in collaboration with colleagues at East Carolina University.
“We are also realizing there is also potential for EDGe$ to be useful in supporting economic and social functions during situations such as the current pandemic,” Helgeson said. “Although this is an area we’ve yet to focus on, resilience needs apply broadly across human-made and natural events.”
EDGe$ is based on the NIST Community Resilience Planning Guide for Buildings and Infrastructure Systems — used by several communities across the county — and the companion Community Resilience Economic Decision Guide for Buildings and Infrastructure Systems.