Our first priority when there are water restrictions is to use as little water as possible and to conserve as much as possible. The two biggest ways to conserve water is to recycle your grey water (up to 30% water savings) and to flush less down the toilets (another 15-20% saving).
After you are conserving water, you can then move on to the next phase of gathering rain water into rain water tanks and piping that into your house as primary water. That way, you get to use free water in the house, and watch it come out after use onto the garden. Harvested, used conservatively, and then recycled onto the garden. Now that’s the answer everyone can listen to.