Slow Rise Flooding
While most of Sutter County would be threatened by inundation as a result of dam failure
at several Northern California reservoirs (e.g., Oroville and Shasta Dams), the highest
risk disaster threat to Sutter County is flooding from heavy winter storms. This type of
incident follows an extended period of heavy rainfall and steadily rising river levels
over a period of days; hence the name "slow rise flood." Flooding could result from levee
failure or overtopping. This type of event is always accompanied by the back-up of surface
drainage flows in low-lying areas.
Sutter County has a plan to alert its citizens to the hazards from flooding; however,
everyone must take responsibility for their own individual and family planning and
preparation. Further, it is a good idea to be at least minimally prepared at all times
for a sudden emergency. The
American
Red Cross website
carries a guide to personal emergency preparation. You may wish to
consult the site and use it to decide the appropriate level of preparation for you and
your family as an on-going precaution for all types of emergencies.
- For more information on preparing for a flood emergency visit our Emergency Management Flood Preparedness website
Flooding Warning System
Sutter County utilizes three emergency activation phases in its flood warning system. Planning and Preparation Phase:In this phase, the river has flowed over the banks of the main channel, and government assumes a readiness condition. Ready for Action Phase:
All those in the affected area should be ready for an Advisory Evacuation Notice or Mandatory Evacuation Order to be given at any time. Any last-minute preparations should be made. (An Advisory Evacuation Notice is issued when conditions exist which indicate a Mandatory Evaluation order may be given in the near future. The threat to lives is not yet imminent but there is potential for rapidly changing conditions to develop into a serious threat. Residents are advised to leave the area. A Mandatory Evacuation is ordered when conditions exist that seriously endanger lives. The danger is imminent. All non-essential persons are ordered to immediately leave the area via the described evacuation routes.) Emergency Phase:
At this point, the likelihood of a mandatory evacuation of the affected area becomes much greater. It will probably be called in the near future, and there will be little or no time for individuals or business owners to take further protective actions. It is crucial for persons to pay close attention to emergency information provided by the County and the Cities. To determine which phase is in effect, please listen to a local radio or television station (see following paragraph) for the reported river levels and then review the table below which portrays the river levels, in feet, for the three emergency activation phases for the various areas of the county.
Emergency Activation Phases
| Sutter County Slow Rise River Flood Threat Outline of Emergency Activation Phases | ||||
| Basin | Monitoring Station | Planning & Preparation Phase | Ready for Action Phase | Emergency Phase |
| Meridian | Sutter By-Pass @ Longbridge | <50.5 | >=50.5 | >56.6 |
| Meridian | Sacramento River @ Colusa Bridge | <66.5 | >=66.5 | >70.0 |
| Robbins | Sacramento River @ Tisdale | <51.0 | >=51.0 | 54.0 |
| Robbins | Sacramento River @ Knights Landing | <40.0 | >=40.0 | >43.5 |
| Southeast County Basins | Feather River @ Nicolaus | <42.6 | >=42.6 | >46.4 |
| Yuba City & Live Oak Basins | Feather River @ 5th St. Bridge | <70.0 | >=70.0 | >77.0 |