Hunter Water's combined storage capacity is only 13 per cent above Sydney's. That's the lowest level on record since 2006, during the millennium drought.

The state government stepped in this week to put Sydney on water restrictions, saying the ongoing severe drought meant it had to take steps to protect the supply. It also noted predictions of high temperatures and below average rainfall over winter had prompted the decision.

Water Minister Melinda Pavey said Sydney was experiencing some of the lowest dam inflows since the 1940s and "early and decisive action" was vital.

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"Water restrictions are an important drought response because they target the outdoor water use of all households," she said.

"Regional NSW has been experiencing a record drought. Water restrictions in Sydney mean that households across NSW are doing their bit to conserve water."

Hunter Water's combined storage level is 66.4 per cent - down 2.5 per cent since May 2. At this rate the storage will hit 60 per cent in August, which will signal level one water restrictions here.

The region used 4,758 million litres of water in April, Hunter Water data shows. That's almost 1200 litres less than the usage during March.

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The average Australian uses between 190 and 200 litres of water per day, and those in the United Kingdom use 140.

Given that only a small amount is used for drinking water, Hunter Water is urging people to think about their usage and how to reduce it.

"Hunter Water is encouraging everyone to continue to love water and use it wisely," a spokeswoman said.

"Water is a precious resource and we all have a role to play in ensuring we preserve our supplies. Simple measures like reducing showers to four minutes, using a trigger nozzle on hoses and fixing leaks around the home, can collectively make a big difference to reduce our water consumption."

Water saving tips: hunterwater.com.au/lovewater