Sydney could face water restrictions in a little over a year if dry conditions continue as expected and dam levels plummet.
State utility Sydney Water says the NSW capital could be under level-one water restrictions some time between November next year and early 2025 as an El Nino weather event brings lower rainfall.
Level-one restrictions include a ban on the watering of lawns and water play with toys and slides, as well as restrictions on watering gardens to every second day for one hour.
Swathes of NSW including Sydney are predicted to swelter through a hot and dry summer after the state's driest September in more than three decades.
Sydney Water said people were being urged to minimise their water use heading into what could be one of the hottest summers to date.
"Drought in Australia is cyclic and inevitable, and recent advice indicates we are moving into a phase where rain is expected to hit historic lows over the next 12 months," it said in a statement on Monday.
The government-owned company said with no significant rainfall since November 2022, Sydney's Warragamba dam had dropped to 94 per cent capacity.
Large parts of the NSW north coast region are already classified as being in intense drought, while significant segments of the Hunter, greater Sydney and south coast areas are recognised as drought-affected.
NSW Water Minister Rose Jackson said water conservation was important given the predicted dry and hot conditions.
"With El Nino declared, I encourage everyone to take a look at their water habits and assess if there are actions they can take to reduce water use," she said.
On Saturday, the government said investigations were under way to double the capacity of Sydney's desalination plant to bolster drought resilience.
The plant can produce up to 15 per cent of the city's water and upgrading it would boost that to 30 per cent with a daily output of 500 megalitres.
