IL HB5130

Amends the Rivers, Lakes, and Streams Act to require the Department of Natural Resources to consider flood discharge that would overtop a levee or flood wall when reviewing permits for levee or flood wall construction, maintenance, or repair.

Defines "worst-case scenario analysis" as calculating maximum increases in flood heights, velocities, and damages caused by a project due to conveyance and storage losses, including both the project alone and combined effects of other existing and reasonably anticipated obstructive construction in the locality.

Takes effect immediately upon becoming law.