President Barack Obama issued an executive order on Friday directing federal, state and local agencies to incorporate projections for sea level rise in planning and construction along the coasts.
The new Federal Flood Risk Management Standard requires that all federally funded projects located in floodplains, including buildings and roads, be built to withstand flooding. The requirement, the White House said in a release Friday, would “reduce the risk and cost of future flood disasters” and “help ensure federal projects last as long as intended.”
“It is the policy of the United States to improve the resilience of communities and Federal assets against the impacts of flooding,” the order states. “These impacts are anticipated to increase over time due to the effects of climate change and other threats. Losses caused by flooding affect the environment, our economic prosperity, and public health and safety, each of which affects our national security.”
According to the National Oceanic and Atmospheric Administration, the U.S. can expect to see up to two feet of sea level rise by the end of the century, largely due to climate change. Warmer temperatures are causing thermal expansion in the oceans, as well as the melting of sea ice, which is pushing sea levels higher globally. A study from the U.S. Geological Survey found that half of the U.S. coastline is at high or very high risk of impacts due to sea level rise.
This is a significant shift, as agencies have typically used historic information on sea level and flooding for planning, rather than future projections. The order directs agencies to use the “best-available, actionable hydrologic and hydraulic data and methods that integrate current and future changes in flooding based on climate science” when evaluating what is in the flood plain. They also have the option of building 2 feet above current base flood elevations for “non-critical” infrastructure and 3 feet above for “critical” infrastructure, or building to the standard of the 500-year flood (a flood with an estimated 0.2 percent chance of happening in any given year).
The Task Force on Climate Preparedness and Resilience released a set of recommendations last November, and establishing this type of guideline was among them.