Next dig out the run. This is best done with a trenching spade (these can be obtained from your local builders’ merchant). The depth should start at about 400 mm and slope in the direction of the intended flow of water, ideally at 6 mm fall per metre of trench. To test the fall, run some water from a hosepipe to the higher end of the trench and see if that water flows smoothly down the trench. After lining the trench with weed fabric, lay the pipe in the centre. Surround the pipe with small stone which is available from the builder’s merchants and garden centres. Clean stone with an average diameter of 20mm is fine. Land Drain Pipe can also be bought in clay sections but the introduction of plastic has made their use, for the domestic application, virtually obsolete. Pipe can also be bought which only has holes half way round. The size of your lawn (or the area you would like to be drained) affects the size of pipe you will need. Choosing the right size is a delicate balance; too small a diameter and the drainage problem won't be fixed; too large and grass won't have enough water to grow. Laying a smaller diameter in a herringbone layout is much more effective than just switching to a larger diameter. This will be more effective than aeration but still has its limits because the water still may have nowhere to go when it has gone through the top layer of sandy soil.

Perforated land drain is also useful as field drainage, in sport fields, and as lawn & garden drainage in smaller diameters, and can also feature in french drains to improve drainage. Land drain, often known as French Drain, is the name given to flexible coiled pipes which are laid underground to alleviate excess surface water. They are corrugated and can typically flex 90 degrees per 1m, and come in either perforated or unperforated coils, available from JDP in sizes varying from 60mm-160mm in 25m, 50m or 100m lengths. How do land drain pipes work? Help your grass to recover from winter waterloggingand grow a more extensive and resilient root system by applying lawn feed in spring

You will need gravel in the trenches to replace the soil you remove; a pea shingle gravel no larger than 40mm is recommended. In the ground water takes the path of least resistance, and in heavy clay-type soil, stone is much easier to flow through. Water is attracted to the trenches and seeps through into the land drainage system.

Space out the side drains at either 3 metre intervals (for clay soil) or at 7.6 metre intervals (for loamy soil);As you can see from the images, we are using french drains to collect and direct surface water to the pumping station. The pump is sat inside a plastic housing which the french drains feed into. A professionally installed drainage system lasts 15 to 40 years with proper maintenance. To ensure a long-lasting drain: you have placed the pipe in the trench, add more pea gravel until it is completely covered. The pea gravel around the Note that, sometimes, especially after a heavy rain, accumulated surface water may also not drain as fast as usual. This, however, could mean that your soil simply needs to be aerated. Types of garden drainage systems Now wrap the gravel and the pipe up completely with fabric so that no tiny soil particles can enter the gravel from any direction.

This pipe should be laid to a fall of 1 in 100 which means for every 1 m of pipe length the slope should be about 10mm or 1cm. However gradual the slope, water will find its way down it.Allowing water to drain through a surface is the first part but for a garden drainage system to work it needs to go somewhere. The destination of the water needs to be able to handle the quantity which it frequently gets in moderate to bad rain. For smaller gardens a 400L capacity may be suitable. For low points which collect the whole neighbourhoods rain you will need a much larger solution.

The best garden drainage solutions usually consist of a french drain system leading into a pump station which redirects water into a surface drain. Cheaper but less effective methods include soakaway areas, soil aeration and changing the soil composition. The ideal garden drainage solution depends on how bad the issue is, what can fit in your garden and the budget. It’s a good idea to understand why your garden is prone to flooding and waterlogging before diving into potential solutions.

Building a Soakaway in your garden

A cheaper method of achieving land drainage which is, historically, used to remove surface water from the perimeter of a house or patio, is a French Drain. In some parts of England, connecting a drainage system to sewers or storm drains is forbidden, so always make sure to consult your local authorities first to avoid a fine. It should also be noted that drainage work has to be done from late summer to early winter when the soil is usually dry. Simple ditches The answer is to create an easy path for the water in the ground to flow so that the surface water can drain away. There are a number of common methods used to improve drainage, here is a brief overview of them from least effective (but cheapest) to most effective (but most expensive). Drainage pumps are not a solution on their own as they need to be connected to one of the other collection and disposal options. The function of a drainage pump is to move water to a place where gravity cannot get it to. For 80mm land drain the trench width would be 380mm (2 x 150mm + 80mm pipe) and height 630mm (100mm base + 80mm pipe + 300mm drainage layer + 150mm top soil).