Severe flood warnings, meaning lives are at risk, have been issued on Boxing Day for the Bedford area and three other places.
The Environment Agency said there had been heavy rain across the Great Ouse catchment and more was expected, bringing "significant disruption to the community" and also possibly affecting electricity services.
Also covered by severe flood warnings are the Cogenhoe Mill Caravan Site, and the River Nene at Billing Aquadrome with nearby business parks.
Christmas Day saw flooding which forced hundreds of residents in parts of Bedfordshire to flee their homes after the river burst its banks and water flooded on to bridges and roads.
Also, more than a thousand people were forced to flee the Billing Aquadrome holiday park in the county of Northamptonshire on Christmas Eve when severe flood warnings were put in place for the River Nene.
Northamptonshire Police said water had reached 5ft high in some places, with emergency services using boats to take residents in the worst-hit areas to safety.
Detective Superintendent Jamie Piscopo said: "Emergency services are working hard to ensure residents can return to the site as soon as possible, however it is not currently safe to do so.
"We'd urge them to stay away until such time it is safe to do."
Storm Bella is expected to bring heavy rain and severe winds of up to 70mph to some other parts of the UK on Boxing Day, the Met Office said.
An amber wind warning has been issued for parts of southern Wales and southern England and a yellow warning for wind in England, Wales and the south of Scotland will be in force from 3pm on Boxing Day.
A yellow warning for rain has also been issued for parts of Scotland, Wales and much of northern and southwest England.
As of 3.30am on Saturday, there were 78 flood warning, meaning that flooding is expected and immediate action is required; and 101 flood alerts, meaning flooding is possible and people should be prepared.
Natural Resources Wales said there were two flood warnings - for the Lower Dee Valley from Llangollen to Trevalyn Meadows and the River Ritec at Tenby - and five flood alerts. There were no severe flood warnings.