Veolia Water Central has announced it is lifting its hosepipe ban with immediate effect.
The company - which covers parts of Hertfordshire, Bedfordshire, Buckinghamshire and Essex - has joined South East Water, Sutton and East Surrey Water in ending the bans.
Seven water companies across southern and eastern England had brought in the hosepipe bans after two unusually dry winters left some groundwater supplies and rivers as low as in the drought year of 1976.
But Thames Water, Anglian Water and Southern Water all removed the restrictions last month - now known to be the wettest June since records began.
A joint statement from the four companies said they were heavily dependent on ground water supplies but these have now recovered sufficiently to enable them to lift the bans.
Mike Pocock, water resources manager at Veolia Water Central, said: "We would ask customers to please continue to use water wisely. While most welcome, this recovery in the aquifers does not remove the underlying problems caused by the drought and we are continuing to plan for the possibility of a third dry winter."