Updates to Floodplain Development Code took effect July 31

The Portland City Council approved new floodplain development regulations effective July 31, aligning with FEMA's Pre-Implementation Compliance Measures (PICMs) to comply with the Endangered Species Act. New projects in flood hazard areas must now compensate for lost flood storage through excavation or the removal of displacing structures. Additionally, developers are required to follow the City’s Stormwater Management Manual and replace trees removed within flood zones. These changes build on actions from October 2023, which aimed to increase flood storage compensation and strengthen environmental protections. The PICMs specifically apply to areas within the FEMA 100-year flood hazard zone that did not receive code updates.

Regulations mandate that developers plant natural vegetation equal to 5% of the new development area near the water mark. They also require flood storage compensation ratios that can be as high as two times the displaced volume. These efforts aim to prevent the loss of floodplain functions, including fish habitat and water quality.