Your Guide to Understanding More about Land Drains

If you are suffering from areas of poor drainage on your property, you already know what a nuisance it is. Apart from the inconvenience of dirty water everywhere attracting bugs, you can do nothing with saturated land. Other than making mud. If you find you are spending more time in waders than flip flops outside, perhaps it’s time to consider more drainage options.

Also called perforated drain pipes, land drains are designed for commercial, domestic and agricultural areas to prevent the ground from becoming waterlogged particularly on impermeable soils and in areas of excess rainfall. Land drains direct water elsewhere to alleviate flooding. They also ensure you don’t have to worry about poorly drained fields affecting crops. If you are further interested in this topic, we recommend you to stay with us a little longer and we will explain these processes in greater detail. Without further ado, let’s go.

How Do Land Drains Work?

The basic function of a land drain is to allow the surrounding water to drain into an underground pipe. Whatever the reason for the waterlogging, without a pipe to drain into, the water will stay where it is. Perforations along the length of the pipe sitting on a layer of aggregate ensure water flows down and away from the area. Although slight, you will notice this vital gradient as you install. Using a land drain, you can easily direct water to another water source, a river or stream, provided you have permission from the authorities to do so. It is also possible to direct water into a storm drain or soakaway system in areas of very porous soil.

In areas that are waterlogged, you can accumulate closely packed particles of soil in order to hold the water in one position. The intention is not to allow water to find an exit. You can replace soil particles with a granular material, like a shingle, and you can create a clear path for water to dry out. Shingle proved to be more effective than original soul particles. The gravity will do the whole job for you. You can even land a pipe that could dry out all of the extra water that could accumulate in the meantime. Once the water is in the pipe, it’s free to flow away without any obstacles.

The Installation

When it comes to installation, your best bet is to start the process at the lowest possible point and work backward. You should install the trench to allow for about 150mm of granular material on both sides of the pipe. For example, for a 100mm land drain, you need a trench that’s 400mm wide. When it comes to the clean bedding, it should be deep around 100mm. Above that, you should have a 300mm of free-draining material that’s followed by 100mm of the excavated soil on the surface that can be re-laid. The conclusion is, if you have a 100mm land drain, you need to have a trench that has a depth of 750mm.

Tips for Installing

  • Prevention of sediment entering the pipe

When you are installing a land drain, your best bet is to choose either one or two approaches in preventing the soil from entering the pipe. Choosing between non-woven geotextile or catch-pit that are 100mm long can give you some serious advantage.

  • Sensible gradient

When it comes to the suggested gradient for land drain, we recommend 1 in 150. You should definitely opt for 1 in 100. That way the flow of water will not be too aggressive or too fast.

Different Types of Land Drains

You can find two basic types of land drain – land drain coils and twin wall land drains. Both are made from high-density polyethylene (HDPE) and available in many different lengths and diameters to suit many applications. While 25m and 50m are the most common lengths, you can also find specialist lengths from popular manufacturers. You may want to go to and check the latest price to find the best deal. The best part is that along with finding land drains, you can also go ahead and buy whatever accessories you need to handle the installation on your own.

However, before making a purchase, you may want to consider how much load you’re going to put on the pipe. If the load is substantial, you will be better off going for a twin wall land drain. Although both types of the land drain are very strong because of their rigid design, twin wall land drains have extra rigidity that makes them ideal for use in driveways.

Good drainage can make all the difference to your property and if you raise crops, you’ll already know how good water management can increase yield. Too much water is as bad as not enough. Although digging up the ground to lay land drains sounds expensive, compared to the damage water can do if it’s left to its own devices, it really is not. Once done, if you have made your choices wisely, your land will be sensibly watered for many years to come.



If you are in the process of making an outfall, you should know a thing or two about it before you start making it. It needs to be created out of a rigid pipe. You can even use PVC. This pipe needs to be concreted into the bank and it can extend the bank below. The area of the bank should go directly below the pipe and because of its location will protect you from the potential water flow.

Even though the local authorities will provide you with specifications and instructions, this is a detail that we believe is essential for anybody to know when it comes to land drains. If you choose the option to connect the outfall with a soakaway, our recommendation is that you should use ones that are made of modular plastic water crates. We believe that this is a much more efficient way of connection than some rustic and outdated ways of connecting.