21 December 2018
If your garden becomes waterlogged after heavy rain, it may benefit from some kind of drainage solution. Without too much effort, a garden land drain, soakaway or other form of drainage can remove standing water and prevent your garden from becoming a waterlogged marsh. Proper drainage can also prevent problems with damp both inside your home and can also prevent damage to masonry and brickwork.
Water, water everywhere…
Water is essential for life on Earth, but too much water can cause many problems in our gardens. Not only does it spoil the appearance of our lovingly maintained outdoor living spaces, but excess water can also cause root rot and diseases among trees, plants and flowers.
Does your garden turn into a marshy wetland after heavy rain? If so, it may be a sign that your garden is in dire need of some kind of drainage system.
In this blog we’ll discuss what a waterlogged garden looks like, how to find out if yours is retaining too much water, and what you can do about it.
Do you have a waterlogged garden?
Most of us can recognise a soggy garden when we see one. Some of the symptoms include multiple puddles caused by rain that have trouble draining, squelching sounds when stepping on turf, reeds or similar plants growing in the lawn, and the presence of moss.
Some common causes of poor drainage
There are many possible reasons why your garden isn’t draining water properly. Here are some of the most common causes of your garden’s swampy appearance:
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Your garden has an uneven surface that allows excess water to form puddles.
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The level of the natural groundwater under your garden (the water table) is too high to allow easy drainage.
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Your garden is situated at the bottom of a hill or on a lower elevation than surrounding properties.
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Your garden has a paved driveway, patio or another impermeable surface that interferes with water drainage.
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Your neighbour’s garden has a drainage system that diverts water into your property.
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The guttering of your house is blocked or not connected to a drainage system. Outbuildings like greenhouses and sheds may have no guttering at all.
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Underground springs may have changed the direction of their water flow after heavy or continuous rainfall.
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Subsoil and topsoil may have been mixed together when your house was built, creating compacted soil that prevents easy water drainage.
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Your house and garden may have been built on top of a water-retentive clay layer. This is common in the UK.
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You or your neighbours may have built a home extension, swimming pool or other structure with foundations that are deep enough to divert water.
How to check if your garden has poor water drainage
Before investing time and money into drainage solutions, we strongly encourage you to confirm that your garden indeed has trouble draining water. Here’s an easy test:
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Dig a hole into the soil approximately 60cm (2 feet) deep;
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Fill the hole with water and leave it for four hours;
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If the water is still there after four hours, then it’s a good sign that you need drainage.
Note that sometimes, especially after heavy rainfall, accumulated surface water may not drain as fast as usual. This, however, could mean that your soil simply needs to be aerated.
Types of garden drainage solutions
Before digging up your garden, it’s important to plan ahead. The first thing to think about is when to do it. We recommend that you do it in late summer or autumn, when the soil is generally quite dry.
The next step is to think about where you want the water to drain away to. You’ll need to locate a ditch, stream or soakaway in order to redirect your excess garden water there.
In some parts of the UK, connecting a drainage system directly to sewers or storm drains is prohibited, so if this is something you’re considering, make sure you consult your local council first to avoid any problems (not to mention fines).
Simple ditches
To create these, find a slope and dig the ditches about 90cm (3 feet) deep with the help of trenching equipment. The ditches should feature sloping sides and should be dug out at the lower end of the slope. Although basic, this type of drainage system will usually do the trick and should divert extra surface water away from your garden.
French ditches
A French ditch or dry well is a sloped ditch that redirects stagnant water into a drain. They are usually around 15cm (6 inches) wide and 30cm (12 inches) deep. This is how to create one:
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Find a slope and dig a horizontal trench across its length in the direction of the drain.
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Use a string and a string level to adjust the slope of the trench and check it constantly.
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Line the trench with landscape fabric for improved water percolation.
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Fill the bottom of the trench with gravel and fold the fabric over it.
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Add gravel on top of the fabric and make sure to spread it evenly to preserve the slope.
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Cover the ditch by evenly distributing topsoil across its entire length.
Land drains
As with a French ditch, this also involves digging out a sloped trench, lining it with landscape fabric, and filling it with gravel. But here, you will also need to buy and install perforated plastic or corrugated land drain pipes inside the ditches.
Why would you want pipes with holes in them when you could go with a regular non-perforated one? If you have only one spot where water forms a puddle after rainfall, then this method is probably not for you. But if your soil is uneven and you have several spots, then perforated drainage is the way to go.
Because the pipes are perforated, water will get inside from every angle and will be more easily distributed. It’s important to remember that the holes need to point down. Otherwise, the water needs to fill the entire ditch before it can reach the holes.
It’s worth saying that designing and installing piped drainage systems is a big job and should only be handled by certified landscapers.
The final word
Fixing a waterlogged garden is not impossible, nor should it break the bank. But it can do wonders for the appearance of your garden during periods of heavy or persistent rain. You just need to do a bit of careful planning, and the solution will depend on what is causing the flooding, and how severe a problem it is.
For only slight or occasional waterlogging, you may think that creating ditches or installing pipe drainage is too much effort. In these cases, you can help reduce excess water from affecting your garden by picking the right plants.
In fact, one of the easiest and cheapest garden drainage solutions is to plant vegetation that is compatible with your soil type. For instance, some Hydrangea species are great for regulating wet soils, while clay soil gardens will benefit from species like Geranium and Fuchsia.
Another solution is to install a rain barrel to collect water from any outbuildings. Your house already has a guttering system in place, but what about your shed or greenhouse? Installing guttering on outbuildings is relatively simple, and once the gutters are in place, redirect the downpipes to overflow barrels. This is an excellent way not only to reduce garden flooding, but it will also provide an extra water supply that you can use during the dryer months.
FirstLight can help you with all your garden drainage needs. If you live in the Leeds area and you’re looking for some help and advice, feel free to get in touch with us and we can arrange a consultation to discuss your needs.