Perforated pipe collects water from the surrounding soil through small slots, while unperforated pipe simply carries water from one point to another. Perforated coils are used for lowering groundwater levels; unperforated sections act as carriers to the outlet.
Manage Surface Water with Land Drainage Coils & Fittings
Land Drainage covers flexible perforated and unperforated coils designed to manage excess surface water across fields, gardens, landscaped areas and construction sites. Products in the Land Drainage range generally include single‑wall HDPE coils in a selection of diameters such as 60, 80, 100 and 160mm, available in lengths suited to small or large areas. These pipes help move surface water away from saturated ground, supporting better soil stability and reducing the risk of standing water. Within the Civils & Groundwork family, the category aligns naturally with Geotextile & Geogrid for soil separation and filtration, and with Line Drainage for areas where surface channel systems are also required.
Land drainage systems are typically installed in a gravel bed with a consistent fall toward a suitable outlet. Perforated coils collect groundwater through evenly spaced slots, while unperforated options transfer water to another point without drawing in surrounding moisture. When used around buildings or hard landscaped areas, these products help protect foundations and prevent water buildup. Rainwater soakaways and discharge points should always follow established regulations, and land drains should be used only for surface water, not foul drainage. Integrating Land Drainage with related elements such as Sewer Pipe & Fittings for below ground routing or Manhole Covers & Grates for access provides a complete, site wide drainage solution.
Thanks to their lightweight and flexible design, these pipes are straightforward to handle and shape around curves or irregular ground. A range of connectors, multi‑junctions and end caps makes it easy to adapt layouts during installation. Performance can also be improved by incorporating non‑woven geotextiles, either by lining the trench or using pre‑socked pipe, helping to prevent silt ingress and maintain long term flow. Many structured wall plastic components are produced in line with recognised industry standards, supporting durability and consistency across a full drainage network. Mentioning Land Drainage throughout these considerations helps frame how coils and fittings work together to support safe and reliable water management.
Land Drainage FAQs
What’s the difference between perforated and unperforated land drain?
What size land drain pipe should I choose?
Smaller diameters such as 60mm suit garden or light duty applications, while 80mm and 100mm coils handle general landscape or field drainage. Larger 160mm options are used for higher flow or as main collectors.
Do I need a geotextile sock or trench wrap?
A non‑woven geotextile can help keep soil out of the aggregate and pipe system. In finer soils, it improves long‑term performance by reducing the risk of clogging.
How deep should land drains be installed?
Depth varies, but a minimum of around 450mm cover is commonly used to protect the pipe from loads and allow space for gravel bedding and backfill. A consistent fall toward the outlet is essential.
Can land drainage discharge into a soakaway?
Yes, where the soakaway is intended for surface water and meets the relevant design and siting requirements. This differs from foul drainage systems, which must use purpose‑designed drainage fields.