Land Drainage

What is land drainage for?

Land Drainage in Agriculture

Efficient drainage in agriculture is essential to maintaining a good ground surface. Loss of use due to water logging or turf damage can be eliminated by land drainage, and an improved drainage system can improve soil structure and provide better quality vegetation and grass.

Land Drainage in Construction

In construction, it's important to remove surface water from the ground surrounding a building to prevent flooding. Ground water can also increase static load on underground structures and retaining walls, and land drainage can be used to relieve this pressure.

Types of Land Drainage

Land drainage products from JDP are available in coiled sizes 60mm to 160mm, from 25m to 150m in length. There are two main types of land drain: perforated and unperforated.

Perforated Land Drainage

Land drainage with perforations within corrugations.

Also called filter drain or slot drain; this pipework has small holes cut inside the corrugations of the pipework that allow water to drain into the pipe.

Unperforated Land Drainage

Land drainage with no perforations.

Also called carrier drain; this pipework is solid and has no holes in its corrugations. Used to carry (and not collect) water to a designated discharge point.

Perforated Land Drainage

Pipe Diameter (mm) Coil Length (m) Code
60 25 0504SP6025
60 50 0504SP6050
60 150 0504SP60150
80 25 0504SP8025
80 50 0504SP8050
80 100 0504SP80100
100 25 0504SP10025
100 50 0504SP10050
100 100 0504SP100100
160 45 0504SP16045
160 50 0504SP16050

Unperforated Land Drainage

Pipe Diameter (mm) Coil Length (m) Code
60 150 0504SU60150
80 50 0504SU8050
80 100 0504SU80100
100 25 0504SU10025
100 50 0504SU10050
100 100 0504SU100100
160 45 0504SU16045
160 50 0504SU16050

Land Drainage Installation

Drainage plans should clearly show the location of the drain runs, spacings, levels and other relevant information necessary for the correct installation. The minimum depth of cover on any piped drain should be at least 450mm to protect the pipe from damage due to surface traffic or maintenance operations such as deep spiking.

Inspection chambers and silt traps should be incorporated into the scheme to allow for inspection and maintenance. Consideration should be given as to whether the soil arisings from the works are to remain on site or be removed.

The choice of permeable backfill is imperative to the long-term success of the drainage scheme as, by definition, it allows passage of water from the surface to the pipe. All backfill material placed over drains should be durable, evenly graded and free from pollutants.

All drainage outfalls into watercourses should incorporate suitable headwalls fitted with a vermin guard.