Glenn

Glenn County (population ~28,000) is a rural agricultural county on the west side of the Sacramento Valley directly north of Colusa County. The county seat is Willows; incorporated cities are Willows and Orland. Major unincorporated communities include Hamilton City, Artois, Butte City, Elk Creek, Glenn, Bayliss, Capay, and Kanawha. The county is dominated by row-crop and orchard agriculture (almonds, walnuts, rice, dairy) and contains the Sacramento National Wildlife Refuge complex (Sacramento NWR is headquartered in Willows). The county Board of Supervisors administers ADU permitting in unincorporated territory under California Government Code Sec. 65852.2 and 65852.22 (state ADU preemption regime). Most unincorporated parcels are agricultural; ADU placement is heavily influenced by Williamson Act contracts, the Sacramento River levee/floodway system, and the Sacramento Valley right-to-farm ordinance.

• Glenn County Code Title 15 - Land Use and Development, ADU/JADU provisions
• Cal. Gov't Code Sec. 65852.2 (Accessory Dwelling Units)
• Cal. Gov't Code Sec. 65852.22 (Junior Accessory Dwelling Units)
• California Williamson Act (Land Conservation Act of 1965, Cal. Gov't Code Sec. 51200 et seq.)
• Glenn County Right-to-Farm Ordinance

State-floor overlay: California state ADU preemption applies in full to unincorporated parcels. AB 1033 condo-conversion election status pending verification. AB 976 prohibits owner-occupancy mandates on detached ADUs. HCD oversight: ordinance amendments submitted within 60 days per Sec. 65852.2(h).

Glenn County overlays of consequence: Williamson Act agricultural-preserve contracts on virtually all rural parcels; FEMA SFHA along the Sacramento River, Stony Creek, and the floodway between the Sacramento River and Butte Sink; Central Valley Flood Protection Board levee/floodway jurisdiction over Sacramento River reclamation districts; Sacramento National Wildlife Refuge complex (Sacramento, Delevan, Colusa, Sutter, and Llano Seco NWRs - Sacramento NWR is headquartered in Willows) federal habitat overlays adjoining unincorporated parcels; Hamilton City levee setback project (USACE/CVFPB completed 2017-2022) which materially expanded the Sacramento River floodway and decommissioned old levees through previously developed Hamilton City; CAL FIRE State Responsibility Area on the western Coast Range / Mendocino National Forest edge (Elk Creek area); and right-to-farm ordinance binds residential occupants of ag-overlay parcels.

• Williamson Act / Land Conservation Act contracts
• FEMA SFHA - Sacramento River / Stony Creek / Hamilton City setback
• Central Valley Flood Protection Board jurisdiction
• Sacramento NWR Complex - headquartered Willows
• CAL FIRE State Responsibility Area - western Coast Range

Glenn County Planning and Public Works Department issues ADU permits for unincorporated parcels. Practical permitting frictions: Williamson Act agricultural-preserve contracts on the vast majority of unincorporated rural parcels (which constrain non-agricultural improvements and require county compatibility analysis), Sacramento River and Stony Creek levee setbacks (Central Valley Flood Protection Board jurisdiction), Hamilton City levee setback project (USACE/CVFPB) which has reshaped flood zones along the Sacramento River, septic/well infrastructure (essentially no public sewer outside the two incorporated cities), CAL FIRE State Responsibility Area on the western Coast Range portion of the county including Mendocino National Forest edge (Elk Creek, Stonyford-adjacent areas), and right-to-farm acknowledgement requirements for residential occupants of ag-overlay parcels.