NC H511

Prohibits stormwater rules and programs from requiring small scale residential development (single-family homes, townhomes, and multiunit residential with four or fewer units) to install new or increased stormwater controls for preexisting development or redevelopment activities that do not remove or decrease existing controls

Allows stormwater rules and programs to require non-residential property owners to install new or increased stormwater controls during redevelopment only if the redevelopment causes land disturbance exceeding 50% of the tract or increases impervious surface by more than 50%

Limits required stormwater controls for redevelopment to only the amount of new impervious surface being created that exceeds the amount of impervious surface that existed before the redevelopment

Permits property owners to voluntarily treat all stormwater from preexisting or redevelopment activities to exceed allowable density under water supply watershed rules

Requires all local governments to include these stormwater control limitations in their stormwater ordinances, effective upon enactment for stormwater rules and program amendments adopted on or after that date