If you are worried about flooding, the five issues listed below need to be seriously considered.
Can water enter via doors, windows and other openings?
The answer is almost always yes. Unless they have been built specifically to prevent water ingress (unlikely), you have to protect your building apertures.
Will water come in through my walls?
The answer may surprise you, but quite often it is also yes. Most bricks and more often the mortar joints are porous, letting in water after a short time. If floodwater is liable to persist for more than 24 hours it may well come in through your walls.
Will water come through downstairs drain outlets, like toilets, and sinks?
Unless you have protected those outlets the answer again is probably yes depending on the depth of floodwater and back pressure. You have to consider protecting your drain inlets.
Will water come up through my floors, or through my airbricks?
This depends on ground material, floor structure and even foundations. If your house is built directly on to an impermeable material such as clay then rising groundwater will probably not come up.
How strong are my walls?
If you stop water coming into your building then its weight bears against the building perimeter walls. They have to be strong enough to take the expected weight of water, or they may suffer damage in flood conditions.
Source: The Environment Agency
If you suspect you are at risk, an All Trades professional can carry out a free comprehensive flood risk assessment, and then suggest the best ways of protecting your property from flooding.
Common Sources Of Flooding
What You Can Do To Prepare