Fain Environmental performed a hydrologic, hydraulic, and geomorphic assessment of four existing undersized culverts on residential properties in Whatcom County. We developed a hydrologic and hydraulic 1-D Hydrologic Engineering Center-River Analysis System (HEC-RAS) for existing culverts and proposed bridges. Fain Environmental designed four full-span bridges to allow for fish passage. Additionally, we analyzed potential scour and clearance between the 100-year water level and the proposed bridge. Annika Fain, PE, is the design engineer of record.