Floods due to rising water, and the potential for flash flooding, are usually forecast sufficiently in advance for appropriate preparation to be effective. When floods or flash flood potential (Flash Flood Watch) are forecast:​

• Monitor radio, television or the National Weather Service for forecast and water condition updates.
• If your building is likely to be flooded, move records, equipment, and furniture to upper floors or to higher locations. Electric motors and other sensitive parts of equipment (including furnace and water heater, washer and dryer) may be removed, placed in plastic bags, and elevated even if the appliance itself cannot be moved. Also, store chemicals where floodwaters can’t reach them and cause contamination.
• Move livestock to higher ground, as appropriate.
• Prepare vehicles for the possibility of evacuation (check gas, tires, etc.).
• Have portable radio, flashlights, extra batteries, candles, first aid supplies, water, and nonperishable food available if needed.
• Identify a safe area to which evacuation is feasible, and safe routes to get there.

If a flood occurs, or a flash flood is definitely expected (FLASH FLOOD WARNING):

• If you’re out of the city and in an area threatened and vulnerable to a flash flood (Low Ground), evacuate Immediately! Do not hesitate! A minute’s delay may cost you your life!
• If in an area threatened by Flood, select your valuables and evacuate as instructed by public safety officials.
• Disconnect any electrical appliances that cannot be moved, but not if you are already wet or standing in water.
• Plug all drains, including toilets (bowls may be removed and drains plugged).
• Bring outside items indoors, or tie them down securely.

When Evacuating:

• Leave early enough to avoid being marooned by flooded roads.
• Follow official instructions. Do not take shortcuts.
• Turn off electricity, gas, and water at mains. Lock doors.
• Take medications and important papers with you. If time permits, pack emergency supplies, including clothing, bedding, flashlights, radio, batteries, food, and water.
• Listen to radio, television or the National Weather Service for recommended routes.
• Watch out for washouts, fallen wires, broken sewer, water, or gas mains.
• Drive slowly in water using low gear, abandon vehicle immediately if it stalls in water, if it is safe to do so. Do not attempt to move a stalled vehicle.
• If on foot, don’t cross flooded areas if water is above ankles.

After a flood:

• Do not use fresh foods that have come in contact with flood waters.
• Test all drinking water before drinking.
• Wait until authorities give permission before returning to the disaster area. You may hamper rescue and emergency operations.
• Make sure all electrical equipment has been checked and dried before using it. Never handle live electrical equipment in wet areas.
• Never use open flames to examine buildings as there may be broken gas lines or flammables inside.
• Report all utility line damage to police, fire and utilities as soon as possible.
• Self-help information will be provided to City of Redlands residents via the local Information Broadcast System. Broadcasts may be heard on several AM and FM radio stations as well as through all Spectrum Cable TV channel 3 and Frontier Channel 35. 
• Do an assessment of damage, compare this with your household inventory, and call your agent to report loss.

A flash flood watch means - heavy rains may result in flash flooding in a specified area. Be alert and prepare for the possibility of a flood emergency which will require action.

A flash flood warning means - flash flooding is occurring or is imminent in certain areas. Move to safe ground immediately!

Resource Information:

FEMA: Floods | Ready.gov
San Bernardino County: Flood Control Planning
State of California: Flood Management
Flood Control Master Plan | City of Redlands
Before the Storm: Prepare Yourself | City of Redlands