Milwaukie adopts flood-hazard code amendments to comply with federal requirements; ordinance declared emergency

Milwaukie, Ore. — The Milwaukie City Council on Feb. 11, 2025 adopted an ordinance amending Title 18 of the Milwaukie Municipal Code to implement updated flood-hazard regulations that align with new federal requirements. The ordinance (file ZA2024-003, ordinance 2248) was adopted by unanimous vote and declared an emergency to take effect immediately.

Senior planner Bridal Kelvrom presented the staff report and said the amendments respond to recent federal guidance tied to ongoing litigation over the National Flood Insurance Program and its impacts on protected fish species. The new rules add three functional protections to the city’s floodplain code: flood storage, water quality and riparian vegetation. The code identifies proxies and mitigation standards, including: - Riparian Buffer Zone (RBZ): a 70-foot zone measured from top of bank or ordinary high water mark where mitigation requirements are highest if development affects floodplain functions. - Flood-storage proxy: changes to undeveloped space must be mitigated at a 2:1 ratio where feasible. - Water-quality proxy: increases in impervious surface must be offset by maintaining or increasing pervious surface. - Riparian vegetation proxy: removal of trees 6 inches diameter at breast height or larger triggers mitigation, with higher ratios inside the RBZ and a 3:1 standard noted in the staff presentation. - Beneficial-gain standard: projects are expected to provide additional planting equal to 5% of the project area to net positive vegetation gains.

Kelvrom displayed maps showing the Willamette River, Kellogg Creek and Johnson Creek floodplain areas and explained the RBZ and RBZ fringe distinctions. He told the council that roughly 75 private properties fall within the 100-year floodplain and had received required Measure 56 mailed notice.

One resident, Roy Weidman, asked where to obtain floodplain maps and how tree removals and vegetation work on private property would be regulated; staff offered to follow up directly with property owners and said FEMA’s online maps and city GIS are available.

After concluding the public comment portion of the hearing, the council moved for first and second readings by title only and adoption of the ordinance, citing the need to remain eligible for the National Flood Insurance Program and to implement the FEMA model provisions. The roll call vote was recorded as: Councilor Costerbote — aye; Councilor Massey — aye; Council President Anderson — aye; Councilor Stavenjord — aye; Mayor Beatty — aye. The motion passed 5–0. The ordinance number was reported as 2248 and the file number ZA2024-003 was entered into the record.

Staff said they will make maps and follow-up information available to property owners and that the city will continue coordinating with FEMA and other agencies as the federal process progresses.