Water supply pipes should be laid at a minimum depth of 750 mm (30 inches) below ground level to make service connections and protect them from potential disturbances. The maximum depth allowed for service pipes is 1350 mm (53 inches) to maintain accessibility for maintenance purposes. Gas service pipes should be installed at a depth of 600 mm (24 inches) to ensure proper separation from water service pipes. It is important to comply with these depth guidelines or obtain permission from the local water supplier if deviations are necessary.
Please note that these guidelines serve as general recommendations, and it's important to consult local regulations and authorities for guidance on specific requirements in your area.