What Is Land Drainage?

Land drainage is the term used to describe infrastructure that is dedicated to the removal of excess water from soil and ground surfaces. There are various systems that can be deployed in this category, using perforated pipes, gravel trenches, geotextile-wrapped channels and more to collect and redirect water. This technique is common in construction and agriculture, but can be applied to properties where waterlogging is impacting soil structure and the foundations of buildings.

At Express Drainage Surveys, we’re going to provide a deeper look into what land drainage is so that you can understand the options available to you.

A brief introduction to land drainage

When faced with oversaturated soil, it can lead to so many different challenges. This is why people turn to land drainage, to deliver a permanent fix that removes unnecessary groundwater and surface runoff. These techniques have evolved over time to make use of more durable and long-lasting materials, but at their core, are designed to redirect and drain away the water.

Proper installation of land drainage is required, with the right depth of trench, the right gradient, the most appropriate aggregate and correct connections all playing their part. Only when all these are in place can aggregate be used to backfill the space, and any topsoil be reinstated.

Why land drainage matters

Land drainage matters for many reasons, including:

The prevention of waterlogging. If your soil is waterlogged, it will lack the necessary airflow to deliver growth for plants and anything else you wish to grow. Firm ground is needed to get a healthy lawn, crop or garden, something that drains surplus water helps to maintain.
The protection of structures. When water becomes trapped in your soil, it creates hydrostatic pressure on any foundations and retaining walls. This is often one of the hidden dangers, so alleviating the pressure and safeguarding the structural integrity of your property is important.
Health and hygiene. Standing water and boggy ground are known to attract a lot of unwanted bugs and pests. This, in turn, creates unhygienic spaces and poses a risk if you end up providing a breeding ground for biting insects such as mosquitoes.

Types of land drainage systems

We mentioned earlier that there are many various interpretations of land drainage. This results in numerous systems being referred to as land drainage. Here is a quick look at the two main systems:

Perforated drains: Also known as French drains, these use perforated plastic pipes buried underground. The small holes in the pipe allow water to filter into the pipe to either be directed away towards an outlet or to gradually soak away into the ground again at a more even rate.
Unperforated drains: These systems use solid pipes to channel or direct water away to either a soakaway, nearby stream or storm drain system. This helps to remove as much water from the ground as possible, as quickly as possible.

How land drainage works

The two systems explored above both rely on gravity in order to function. Whether the pipework is perforated or not, they need the rainwater to filter through a layer of gravel down into the pipe. Gravity is also in play due to the subtle gradient applied, helping the water to naturally flow away to the intended outlet.

Practical applications of land drainage

So, who can benefit from the use of land drainage techniques? Almost any area suffering from oversaturation and waterlogging can implement these systems, including:

Residential gardens: Whether it’s your lawn or your flowerbed, if you know areas of your garden are prone to waterlogging, a French drain could be the ideal way to tackle the problem.
Agricultural spaces: Farmers will be reliant on land drainage in order to maintain their soil, reducing compaction and improving crop yields.
Sports pitches: Implementing land drainage for any sports area means organisers can ensure the safety of players, while also keeping the pitches usable to avoid postponements.
Construction companies: When constructing new buildings, it’s a good idea to plan for the reduction of hydrostatic pressure and to reduce dampness overall. Rigid pipes and gravel trenches near foundations and retaining walls are vital here.

Components and materials

Key components and materials needed to successfully and safely install land drainage include:

Perforated or unperforated pipes: these are often flexible, corrugated pipes of 60-200mm in diameter, or tinwall, which is larger.
Geotextile membranes: a non-woven fabric to help prevent silt from clogging the pipework.
Connectors: using flexible couplers to link any pipes, you can create the flow and connection to a soakaway system.
Channel drains: a surface-level type of land drainage that is available in different load ratings, typically with grates placed over them.

How to maintain your land drainage

If you install land drainage properly, it can typically last around 20-30 years. However, they do require maintenance in order to ensure they remain effective throughout their life. Effective maintenance strategies for land drainage include:

Installing an inspection or catch pit to allow for jetting access
Using a full-wrap geotextile layer to limit the amount of sediment getting inside the pipework
Regular checks, usually in both spring and autumn
Swift repairs if any damage is sustained or if a collapse is noticed

All of the above will help to keep things running smoothly for longer and eliminate the opportunity for minor failures to become a major disaster.

Drainage services from Express Drainage Surveys

When it comes to drains, why look anywhere else? Our expert team at Express Drainage Surveys can answer all your questions regarding land drainage and how to maintain your property, whether you’re a homeowner or a business owner.

We offer a wide range of drainage services to prevent water from impacting your daily routine, including:

Because we deal with drains every single day, we’re well aware of the regulatory and safety considerations that come with drainage, particularly Building Regulations Part H for land drainage and the removal of surface water.

Whichever service you need us for, don’t hesitate to contact our professional team today for more information or to book an appointment.