Southern Water seeks drought permit as River Test levels drop
River levels are so low in part of south Hampshire, a water supplier has had to ask the Environment Agency if it can continue extracting water.
Southern Water says it needs a "drought permit" to continue pumping from the River Test, which provides up to half of the area's fresh water supply.
It follows new rules which aim to protect chalk stream habitats.
The firm said if the permit was granted it would also have to introduce a "phased" hosepipe ban to cut water use.
In March, the Environment Agency updated Southern Water's licences to restrict how much water it could take from the River Itchen and River Test if flows dropped.
Until it is able to secure new supplies, it can apply for temporary permits on the condition it imposes restrictions on customers' use of hosepipes and pressure washers.
A company spokesman said: "Using a drought permit means that we must do everything in our power to reduce water use and so minimise the impact on the river's precious and unique habitat."
The company said it had been working to tackle leaks and help customers become more water efficient.
It said it had also been importing water from neighbouring companies to boost supplies.
The spokesman added: "If the drought permit is granted we will be asking more of our customers by imposing TUBs - temporary use bans, previously known as hosepipe bans - in certain areas.
"If we do have to do this, it will be carried out in a phased way in specific areas which depend on the River Test for water and we'll provide full details in advance."