Drainage below ground

5.3.6Ground water drainage

Ground water drainage shall convey excess ground water to a suitable outfall. Issues to be taken into account include:

  1. layout of pipes
  2. pipe construction.

Layout of pipes

Where ground water drainage is required, depending on the site contours and ground conditions, it may be designed as:

  • a natural system
  • a herringbone system
  • a grid system
  • a fan-shaped system
  • a moat system.

Pipe construction

Pipe perforations should be holes or slots to suit the nature of the ground.

Ground water drain systems connected to foul, surface water or combined drains should discharge into the drain through a catchpit. Where suitable, ground water drainage may discharge into a soakaway, preferably through a catchpit or into a watercourse.