Federal Emergency Management Agency (FEMA)
Floodplain Designation

San Luis Obispo Creek at Buckley Road, January 2006
Flood at Buckley Road

The 1981 FEMA Flood Insurance Rate Map (FIRM) depicts a generally 300-400 meter (1000-1300 foot) band of flooding (100-year average recurrence interval) extending along SLO Creek, with narrower widths along Stenner and Prefumo Creeks. The extent of flood prone areas was verified by hydrologic/hydraulic studies completed as part of this WMP. However, the WMP Hydraulic/Hydrology studies (Appendix C) found the depth and frequency of flooding to be greater than in the FEMA studies.

The 1995 flood caused significant damage to private property within the City and SLO Creek, especially the Mid-Higuera area, but provided some clearing and enlargement of the waterway. If this same flood occurred today, (2002) it would probably not produce the depth of flooding experienced in 1995. Conveyance capacity increased at many locations by down cutting and widening the channel through erosion and removal of flow inhibiting vegetation. However, in many areas the channel vegetation has recovered. At other locations the capacity has been reduced by sediment deposition (Marsh Street and Los Osos Valley Road Bridges), and at point bars on the inside of channel meanders. The most noticeable area of willow-hardened bars occurs in Reach 8 near and downstream of the City’s Wastewater Treatment Plant below Prado Road.