Southern Water has issued a hosepipe ban which will come into force for all of the Isle of White and large parts of Hampshire from 9am on Monday.
This comes after Thames Water, Yorkshire and South East Water have announced water restrictions.
Southern Water has revealed that water reserves are at “critically low levels” down 24% for this time of year.
Southern Water’s managing director, Tim McMahon, said, “We have to respond to the widespread and prolonged dry weather affecting our region.
“In our case, this means a hosepipe ban for our customers in Hampshire and the Isle of Wight, to protect the health of our amazing chalk streams, which as one of the rarest habitats on Earth has been compared to the Amazon rainforest.
“We must act now to support the wildlife that live there, including Atlantic salmon and southern damselfly.”