In warmer climates, grass continues growing throughout winter and it is business as usual when it comes to lawn care. In some far northern areas where winter is the dry season, it may even be necessary to water more than usual.
However, in most Australian states in winter including Victoria, most grass is moderately dormant, which means it is still growing but only slightly. During the colder months, soil holds on to moisture for longer as evaporation is very slow. This means water requirements are a lot lower than they are during the warmer months.
Most of the time you won’t need to water at all during winter, as rainfall will be enough to see you through. However, if it’s particularly dry (you can test for moisture levels using the Footprint test), a deep watering once a month will likely be enough. Overwatering your lawn is a waste of time and money and can cause fungal issues. Backing off on the water is healthier for both your lawn and your water bill.
Given that your lawn requires a lot less water during winter, it can actually be a great time to lay new turf. The turf will sit idle, healthily maintaining core functions until it warms up in spring and establishes itself properly in the ground. Turf can be laid all year round in Australia in most circumstances, though areas with high wear or shade may be better off left until spring.