Water restrictions will be relaxed across Sydney in a fortnight following the boost to dam levels from the "biggest rain event in 20 years".
The change from Level 2 to Level 1 restrictions will take effect from March 1 when water quality in the catchment's dams is expected to have improved.
"We recently experienced the biggest rain event in 20 years, which has impacted the quality of raw water in Greater Sydney's bushfire affected catchment," Water Minister Melinda Pavey said in a statement on Tuesday.
"A number of initiatives are in place to ensure the water is safe for use, including extensive testing, filtration and nets to catch debris, but we are allowing an extra two weeks purely as a precautionary measure."
Dam levels in Greater Sydney have spiked after significant rainfalls in February with overall storage now at 80.4 per cent.
Some 200 millimetres of rain has fallen in the catchment in the past week alone.
Sydney's main Warragamba Dam is at 80.3 per cent which is almost 20 percentage points higher than a week ago.
Prospect Dam is at 87.2 per cent while Woronora Dam is at 63.6 per cent capacity.
Under Level 1 water restrictions, residents and businesses are banned from leaving hoses running unattended, washing vehicles and buildings with a hose that isn't fitted with a trigger nozzle or using standard sprinklers and watering systems.
Fines will still apply for breaches - $220 for residential breaches and $550 for businesses.
Under Level 2 restrictions, gardens can only be watered before 10am or after 4pm with a watering can or bucket, hosing of hard surfaces is banned and cars can only be washed using a bucket or at a car wash.