Sydney Water has rejected a Caringbah South resident's plea for everyone over 70 to be exempted from the rule requiring the use of a bucket or watering can during level 2 restrictions.
However, the authority said the application process had been simplified and, after initially refusing the resident's individual request, gave her an exemption.
Level 2 restrictions, which apply from tomorrow (December 10), effectively ban the use of hoses for lawn and garden care and car washing.
You can only water your garden before 10am or after 4pm with a watering can or bucket.
Cheryl Jackson said many seniors were unable to lift and carry a heavy bucket or can of water, and there should be a blanket exemption.
Seniors could be relied on to use water sparingly, she said.
Ms Jackson wrote to Sydney Water, advising she was granted an exemption during previous restrictions because of spinal surgery in 1998.
"As I am now 21 years older now at 75 years of age, I obviously still require same exemption," Ms Jackson wrote.
"I will only be using a Hoselink (high quality trigger nozzle system) by which to occasionally water my garden and wash vehicle on my front lawn."
Sydney Water asked Ms Jackson to provide a medical certificate, to which she replied it would be very difficult to obtain verification of 1998 surgery.
After Leader inquiries, Sydney Water advised Ms Jackson she would be exempted.
However, the authority rejected a blanket exemptions for over '70s.
A Sydney Water spokesman said Greater Sydney was "experiencing one of the most severe droughts on record and we all need to do our bit to ensure we are using water wisely".
"Under level 2 water restrictions, people will be required to use a bucket or watering can to water their gardens before 10am and after 4pm, cars can only be washed with a bucket or taken to a commercial car wash, and topping up of pools and spas is limited to 15 minutes a day with a trigger nozzle," he said.
"Even though the general rule is that exemptions are intended to enable business activities to continue, there will inevitably be special situations that need to be considered, such as elderly or disabled people.
"These customers can contact Sydney Water and we will reasonably consider their mental and physical health in making informed and compassionate decisions based on the circumstances of each case.
"As each exemption request asks for water restrictions rules to be relaxed in a specific situation, we require appropriate supporting justification for each request.
"This may include a medical certificate or other relevant documentation that will allow us to properly assess each request on its merits.
"Based on feedback from our customers, we've now simplified the process to make it easier for any customer to apply for an exemption on special grounds."