Water conservation means water bans and doing without. All municipalities have sewage treatment. Very few toilets leak and those that do don't waste much water.
Automatic dishwashers waste water compared to washing by hand.
If you fill the dishwasher to capacity once per day, you use only about 40 litres of water. There's plenty of water in the summer, so conservation isn't as important. In fact, water demand nearly doubles in the summer, creating a peak demand problem and higher costs for the local water utility. Therefore, water conservation during the summer is crucial to avoid water rationing and keep costs down. You use less water when you shower than when you have a bath.