Land Drainage

Garden Land Drainage In Swansea.

Poor garden land drainage?

If you have a high seasonal water table, you will find that the water sits on or close to the surface during periods of high rainfall. If your soil structure is heavy, this too can reduce soil permeability and cause poor garden land drainage. Low points in the garden, can allow water to collect and drain poorly. Walking on your poorly drained lawn when it’s wet can further add to the problem because the wet soil compacts and loses its structure.

Garden Drainage Contractors

Our garden drainage experts are able to provide the following services:

  • Garden drainage installation
  • Garden soakaway installation
  • Garden drainage maintenance

Covering Swansea and surrounding locations in South Wales, J&F Drainage provides an effective garden drainage solution that will reduce the surface water in your garden. Our expert staff are equipped with the technical know-how and the required tools to find a solution.

Does the problem only exist at a small low point?

It might be worthwhile considering turning a problem into a design feature! If you dig out a border and then by filling it with plants that love their feet to be wet. But if you want a lawn you can actually walk on after the rain without it turning into a mud bath, then you should install an underground garden land drainage system, and that’s where J&F Drains Can Help!!

First, you need to take a good look at your site and decide where you want to drain the water to. The thing to remember here is that water will not travel uphill so your trenches must finish downhill from where they start. It may be possible to ‘daylight’ your pipe into an area beyond your garden but there are certain restrictions attached to this. Even waste ground belongs to somebody so you have to check that the owner of the ground you plan to drain onto doesn’t object.

You can’t drain onto a road either because water running off your property onto the road surface may cause cars to skid, nor should you drain into a river or stream as nutrients from your garden may upset the ecosystem and you definitely cannot drain into your neighbour’s property thus transferring the problem onto them. You can daylight your drain if it is possible to slope the trench downhill until it comes up above the ground and it’s certainly the easiest way of dealing with the excess water.

Types of Pipes

Most land drainage systems consist of lengths of perforated or slotted plastic or clayware pipe laid in a trench with a porous surround. There is a wide range of sizes:

  • 80mm Flexible Plastic
  • 80mm diameter perforated flexible/corrugated plastic pipe is ideal for garden drainage.
  • 100mm Flexible Plastic
  • Up to 1000mm or more for large agricultural or commercial schemes, and they come in a wide variety of materials, including uPVC, clayware, fibre-cement, concrete and ductile iron.

How Garden Drainage Works!

How land drainage works

Land drainage systems rely on a combination of gravity and hydrostatic pressure to create a flow within the pipes. Systems are typically installed with a gentle slope in the region of 1:100-1:200 towards the outfall or disposal point. For this reason, it is best to lay land drainage ‘uphill’ i.e. start at the outfall, which should be the lowest point in the land drainage system.

The trench width is usually calculated as external pipe diameter (abbreviated to OD, as in Outside Diameter) plus 150mm side fill to each side, so, for a pipe with an OD of 115mm, the trench width would need to be 415mm.

The trench should be excavated in advance and lined with geotextile if one is to be used. The bedding material is placed in the base of the trench, and then the pipe itself is laid and checked for alignment and gradient before the side fill is added and finally the backfill.

Ensure clean gravel is used for the surrounding material, and do not use limestone chippings unless nothing else is available. Limestone can precipitate calcium carbonate in wet conditions, depositing minerals that can clog up the drain. Make sure there is at least 75mm of gravel around and above the perforated pipe. The geo-textile filter is not essential but will prolong the life of the drain by filtering out smaller clay and soil particles and deter thirsty roots from seeking refreshment in the land drain. Small rootlets in a land drain can quickly expand to a pipe-blocking mass!

Land drainage diagram - How it works

Blocked Land Drains

Garden land drainage can become blocked over time with silt and debris. Water-jetting methods may not effectively clear a blockage so prevention is the best course of action with new garden land drainage installations. Even finding existing pipes in the first place can be difficult. If however, your garden land drainage has become blocked or ineffectively drains the water, the best course of action over the long term may be to replace the pipework, especially if older materials are being used.

To discuss your garden land drainage requirements and to see how we can help, contact us today.