When you know a flood is on the way, you need to take steps to ensure the safety of chemicals and valuables. Move your valuables to as a high a ground as possible; this will include such irreplaceable items such as family photo albums and high school year books. Make sure that chemicals are put at high elevations. Then go through and close all storm shutters and sandbag doorways.
Check your sump pump prior to and after a flood. Clean both the sump and the pump and then test it out by pouring water into the pit. You want the discharge hose at lest several feet away from your home. Be careful not to run sump pump water into the sanitary system.
Before the flood hits, locate all hazardous materials and transfer them to higher ground. This should include paint, oil, and cleaning supplies. Move snow away from he foundation of your house.
Plan an escape route, especially if streets are prone to flooding easily. Don't forget your pets - they are not allowed in shelters due to health regulations. If left behind, animals under stress can cause a lot of damage to your home. Prior to the flood hitting, turn off breakers or unscrew fuses.