Provides that a unit does not have the power to adopt a law, rule, ordinance, or regulation that is more stringent than or exceeds in any manner the requirements of the department of environmental management's (IDEM) construction stormwater general permit (CSGP). Provides that if a law, rule, ordinance, or regulation is more stringent than or exceeds the CSGP, then: (1) the law, rule, ordinance, or regulation is void; and (2) the unit must continue to discharge its duties under IDEM's CSGP program. Provides that a unit or IDEM may under certain circumstances: (1) issue a written warning to a person engaging in land disturbing activities; and (2) issue a stop work order for the site. Makes conforming changes.