Check with your municipality on proper disposal. An EcoAction2000 message. Collect rain water in barrels for the garden or washing the car. An EcoAction2000 message. During periods of drought, you are better off cutting your grass to 6 or 7 cm.
Longer grass retains water better.
Another tip is to leave freshly cut grass clippings on your lawn, the clippings help to protect your lawn from burning and also serve as fertilizer. Wasting drinking water is like throwing your money to the wind. Wasting drinking water is like throwing your money to the wind. Reduce the quantity of chemical products that you use for the lawn and the toxic products you use for gardening. Sooner or later these products will contaminate the water.