The Hunter may be poised for level-two water restrictions next month, but in Sydney they have already arrived.
Greater Sydney, including Illawarra and the Blue Mountains, will start level-two restrictions on Tuesday after average dam levels fell to 45 per cent, significantly lower than the 57 per cent in the Hunter.
The massive Warragamba Dam, which at 2 million megalitres represents about 80 per cent of Greater Sydney's water storage, is at 45.8 per cent capacity, 0.5 per cent lower than a week ago.
Water Minister Melinda Pavey announced on Monday that tighter restrictions would start in the Hunter on January 20 unless the region received more rain than predicted.
The restrictions include a 15-minute limit on outdoor watering, which is permitted only every second day. Cars cannot be washed with a hose, and showers are limited to four minutes.
The penalties for not complying with the restrictions are $220 for individuals and $550 for businesses, but Hunter Water executive Darren Cleary said on Monday that its compliance officers would likely only fine repeat and flagrant offenders.
The Bureau of Meteorology forecasts that December and the first three months of 2020 will be drier than average on the east coast.
This would raise the prospect of Hunter dam levels dropping to 40 per cent in the first half of the year, triggering level-three restrictions and a ban on all outdoor water use.
The bureau's head of long-range forecasts, Dr Andrew Watkins, said rainfall could be "a little bit more towards average" in February.
A positive Indian Ocean dipole, a weather system akin to El Nino, had contributed to the drought but was starting to break down.
"But temperatures are likely to stay really warm, unfortunately, much warmer than average, right through the summer," he said.
"That's partly because the soils and everything are so dry now there's not really much moisture in the landscape to evaporate and cool the air.
"For the next few weeks we're going to still have those westerly winds coming across NSW, more of those periods of heatwave, and that, of course, leads to higher evaporation."
Average water levels across the region's four storage sites are falling 1.1 per cent a week. If that continues, they will hit 40 per cent in March.
Parts of the Hunter already have stricter usage rules in place.
Mid Coast Water has banned all outdoor water use in Stroud, Gloucester and Bulahdelah, and Murrurundi has been on level-six limits since mid-2018.
Other water agencies in the state, including Central Coast Council, have introduced permanent water-conservation rules similar to Hunter Water's level-one limits.
LEVEL TWO WATER RESTRICTIONS
- All hoses must have a trigger nozzle.
- Outdoor watering permitted every second day before 10am and after 4pm for up to 15 minutes per day (odd property number = odd date of the month, even property number = even date of the month).
- Outdoor watering applies to hand watering with a trigger nozzle and drip irrigation systems.
- Wash vehicles and buildings with a bucket only.
- Repair dripping taps and leaking toilets as quickly as possible.
- No sprinklers.
- No hosing of hard surfaces, except for health and safety reasons.
- Limit showers to four minutes.
HUNTER WATER STORAGE LEVELS
Grahamstown Dam: 57.7%
Chichester Dam: 44.8%
Tomago sandbeds: 61.7%
Anna Bay: 55.3%
SYDNEY WATER STORAGE LEVELS
Warragamba Dam: 45.8%
Williamtown average annual rainfall 1942-2019: 1124mm
Williamtown rainfall in 2019: 729mm
Nobbys average annual rainfall 1942-2019: 1121mm
Nobbys rainfall in 2019: 674mm
Data sources: Hunter Water, Bureau of Meteorology.