Reservoirs in the Southern Water area are now full or nearly full.
Officials have made the announcement following months of rain.
Southern Water said that, in fact, water levels are now at about double what they were this time last year.
A spokesperson said: “Levels of the company’s four above-ground reservoirs are well above average - as are the underground sources which supply 70 per cent of the company’s water supply.”
And Southern’s water quality and strategy manager Meyrick Gough said: “The weather over the past 12 months has been very unpredictable, making life difficult for everyone.
“People will remember that this time last year we were feeling the effects of two very dry winters and reservoir and aquifer levels were worryingly low.
“Now, we’re in the opposite position with some customers experiencing very difficult conditions as a result of the amount of rainfall we have received.”
Autumn and winter are important seasons for water companies as this is when reservoirs and underground sources are refilled in time for the spring and summer, when demand is much higher.
In January, the Environment Agency said many key groundwater sites in the South East were at “notably high levels or higher” for the time of year.
Meyrick added: “In England, we’ve had two dry winters followed by the wettest year on record.
“Now that we’ve entered spring, from a water resources point of view we are in a very strong position.”
Southern Water is currently updating its 25-year plan for securing water supplies in the South East and is including plans to make the water supply for customers more resilient to changing weather patterns in the future.
The Water Resources Management Plan is updated every five years and will be published for public consultation between May and July this year.