Part 6 – Water Supply

6.11    Depth of Water Mains

Both principal mains and rider mains shall have the following minimum cover.  Greater depths may be required by specific design of the system:

Principal mains    900 mm

Rider mains        600 mm

The sections of main adjacent to a carriageway crossing shall be gradually deepened, to allow the required cover under the carriageway without the provision of vertical bends.  Similar provision shall be made to ensure the necessary cover over valve and hydrant spindles.

Service connection pipes shall have a minimum cover of 350 mm.