Yuba County, CA Environmental Rules: Flood Zones (2026)

Yuba County's flood-prone landscape - bordered by the Feather and Yuba Rivers and crossed by Bear River and Dry Creek - has been struck by five major floods since 1950. The County participates in the National Flood Insurance Program (NFIP) under federal regulations at 44 CFR Part 60, and regulates floodplain development through Yuba County Code Chapter 10.30 (Floodplain Management) - part of Title X (Building and Construction). The chapter implements FEMA's minimum standards and adds the County's freeboard requirement: new construction and substantial improvements (improvements equaling or exceeding 50% of the structure's pre-improvement market value) in Special Flood Hazard Areas (SFHAs - Zones A, AE, AH, AO, A99, V, VE on FEMA Flood Insurance Rate Maps) must be (1) anchored against movement by floodwaters, (2) constructed with flood-resistant materials, (3) designed to resist flood forces, and (4) flood-proofed or elevated so the first floor of living space and all mechanical services is at least one foot above the 100-year flood (base flood) elevation. Per the County's 2022-2023 Program for Public Information, current FEMA data identify 124 policies in the SFHA, 620 policies in Shaded X / A99 Zones, and 874 Preferred Risk policies in Zone X within Yuba County, with an estimated 2,300 structures located in the mapped floodplain. The Yuba Water Agency (formerly Yuba County Water Agency), governed by the Three Rivers Levee Improvement Authority (TRLIA) coordination, manages the regional flood-control system - including New Bullards Bar Dam and the Yuba/Feather levee improvements - that protects much of South Yuba County. California Government Code Sections 65302(g)(2) and 65860.1 require local general plans to include flood protection elements and consistency with State Plan of Flood Control (SPFC) updates. Within designated 200-year floodplain areas of the Sacramento-San Joaquin Valley (Senate Bill 5 / 2007), the County must restrict development to areas with adequate 200-year flood protection - a stricter standard than the federal 100-year benchmark. Floodplain development permits are issued by the Yuba County Public Works Department; substantial-damage and substantial-improvement determinations are made by the Building Official.