This reply relates to England only.
The Environment Agency’s long term flood risk assessment for England allows people to look up their postcode to understand the likelihood that their home or property might flood, the possible causes of flooding, and where to find advice on managing flood risk. This is available at the Flood Warning Information Service page of Gov.uk, https://flood-warning-information.service.gov.uk/long-term-flood-risk.
To help people take action and to prepare for the risk of flooding the Environment Agency provides free flood warnings across England for flooding from rivers, the sea and groundwater. Over 1.4 million people are registered to this service which sends a message directly by voice message, text, or email when a flood warning is issued. Anyone can sign up by visiting the Environment Agency’s website, or by calling Floodline on 0345 988 1188. There is also a three-point flood plan which advises people on what to do when they receive a flood warning at https://flood-warning-information.service.gov.uk/what-to-do-in-a-flood.
Further information on flood risk, current flood warnings, and river and sea levels can be found on the Environment Agency’s website.