With reservoir levels at 10 percent above a 10-year average, gardeners from South Australia can use their hoses and drippers for an extra two hours a week from May 1.

South Australians have responded well to increase flexibility in watering times which is announced last November of last year to the point where consumption went down, Premier Mike Rann said on Sunday.

That means that further increase on watering times will unlikely be a problem.

Currently hand held hoses fitted with a trigger nozzle and dripper systems are used for a maximum of five hours a week between 7-10am or 4-7pm on any given day.

However, starting May 1 it will be increased to seven hours, with the government further easing restrictions when the new desalination plant begins production of fresh water by the end of the year,

Adelaide has used this year about 45.8 billion liters of water which is 3.6 billion liters less than last year, even after the extension of watering times to five hours a week, Mr Rann said.

Reservoir levels in Mount Lofty Ranges are now at a 61 percent capacity, compared with the 10-year average of 51 percent at this time of the year.

The government will keep on assessing the situation on a month-by-month basis.