In 2015, President Obama proposed a new Federal Flood Risk Standard for federal infrastructure investments and other major federal actions. The proposal was to add an additional margin of safety to these federal actions - from the current protection against a flood event with a 1% chance of happening (100-year flood), to protections against stronger storms floods that have only a .2% chance of happening (500-year flood event).
The proposal also allowed agencies to use a climate-based standard, so if local or regional projections were for greater flooding/storm intensity/sea level rise, you could add additional protections. But at a minimum, the 500-year event was the safety level used.
The standard is now under review by the new administration and many of us who support the higher standard are pushing to keep it in place. With plans for a major federal infrastructure push early in this Administration, it is more important than ever that this proposal be kept.
(Postscript: President Trump rescinded this executive order with one of his own on August 15, 2018, just ten days before Hurricane Harvey devastated Houston, flooding many areas outside of today's flood plain that would have been covered by the Obama executive order.)