Army Corps Of Engineers

A Lobbying group in Illinois is weakening regulations from the Army Corps of Engineers that prevents towns from building levees that harm their neighbors.

"If I can one day visit a place and say that I helped make it a more livable and beautiful place, I'll be happy," says Chen, who's on our list of this year's most exciting young thinkers.

And local governments continue to approve real estate development inside floodplains.