There are 1210 properties currently at risk in Witney
A new flood map brings the hotspot areas of Oxfordshire into sharper focus.
Witney has seen the largest increase in at-risk properties, with 360 added to the flood map and 270 removed altogether.
A total of 1210 properties are at risk in the town, which has seen an 8% increase on last year's figures.
Better mapping and modelling technology, data gathered from the 2007 floods and more accurate representations of ground height levels has enabled the Environment Agency to release its most detailed figures yet.
A spokeswoman said: "If your home or business is on land which is in the flood map you are at risk of flooding, even if you have not been flooded before.
"It does not mean you will definitely be flooded, but the Environment Agency advises all home and business owners living within the flood map to be aware of the risks, and to plan and prepare accordingly should the worst happen."
The flood map goes online on February 18.
It indicates changes to the rest of Oxfordshire are relatively small, with Standlake having the most new properties added at 11.
However, 32 of its homes were removed from the danger list.
Crawley, Ducklington, Northmoor and Eynsham have also had the number of at-risk properties reduced.
Find out how to be prepared for fluvial flooding by visiting
or calling the free 24 hour Floodline service on 0845 988 1188.