Flooding in 2012 cost the UK economy up to £600 million, according to the Environment Agency (EA).
The EA has calculated commercial property and contents damage totalled up to £84 million and indirect impacts, such as lost working days, cost around £33 million.
The EA said 175,000 businesses in England and Wales were at risk of flooding, and every firm hit in 2012 suffered an average loss of £60,000.
In the wake of the floods, nearly two thirds of firms reported disruption to their supply chains as a result of the extreme weather.
As part of its annual flood awareness campaign, the EA is urging businesses to sign up to receive warnings and to make flood plans.
The EA said firms are “increasingly coming forward to contribute to local flood defences that would otherwise not get full government funding”, citing the example of Nestlé, which has contributed £1.65 million to defences on the River Dove near its factory in Staffordshire.
Flood minister Dan Rogerson said: “Flooding can cause lasting damage to property, stock and supply chains. That’s why it’s so important that businesses plan ahead.
“Many businesses are already helping to build a stronger economy in areas previously at risk by contributing £148m in partnership funding.
“On top of this we’re also investing over £2.3 billion in tackling the risk of flooding. Together with contributions from other partners, this is more money than ever before.”
The EA has set up a “Climate Ready” support service to help firms assess and manage the risks to their supply chains from extreme weather.