Landscape Irrigation - Drainage
About Drainage
Introduction
Drainage for a landscape is a serious issue that if not addressed in the development stages of creating a landscape, can cause problems in the future. Just as you must have drainage for your home, you also need drainage for your landscape as well. To keep your landscape looking stunning and beautiful, a drainage system should be in place, especially if you live in a region that receives a lot of rain during the wet seasons. What Causes Poor Drainage?
There are a number of reasons for poor landscape drainage. The most common causes of poor drainage are due to the soil content of your property.
Where there are new housing estates, poor drainage can often be an issue due to the compacted soil from the traffic of large trucks during the development stages, or where excavation of land has brought up heavy soil from below and has then been used as topsoil. Another reason for water drainage problems is just that the soil may by nature be water retentive, materials such as clay soils do not have effective water retention features and can therefore cause poor drainage within a landscape. An indication that you may have drainage problems is if the neighbor’s property slopes downwards towards your property. This means that in heavy rains, the excess water from the neighbor’s property is likely the flow into your property.
How do I Know if My Landscape Needs Better Drainage?
The wet winter months will provide an indication whether your landscape needs better drainage. One definite sign of poor drainage is if there is distinct water patches on the surface from heavy rains. Eventually, if nothing is done to improve the drainage of your landscape, these areas will become dirt patches and nothing will be able to grow.
One way to test if your landscape has poor drainage is to dig a few holes, about twelve inches deep. Fill the holes with water and leave for 24 hours. If you have good drainage, the water should completely disappear within this time. If there is still water, this is a definite sign that your landscape requires a drainage system.
What Kind of Drainage Should I Use?
Depending on the extent of the problem, there are a few different solutions that can be implemented into your landscape to improve drainage. Here are a few ideas:
If you think your landscape may have poor drainage, try the first few ideas and if there is still a serious problem, you may have to look into a complete trench drainage system
- If the problem is in the topsoil, strip six inches off the surface of the topsoil and place new topsoil. If the topsoil is water retentive, another idea is to incorporate large amounts of bulk organic materials.
- If the water logging is not severe, an easy and inexpensive way to improve drainage would be to re-shape the landscape surfaces with slight slopes so as the excess water can naturally flow into ditches.
- Create a soakaway. A soakaway is a large hole at the lowest point in the landscape that can be filled with gravel or rubble and covered with topsoil. This would need to be quite large to be effective.
- If the problem is severe, you may need to install a drainage system consisting of underground pipes leading to a soakaway. To do this, trenches must be dug across the property. The trenches must consist of perforated pipes, covered with gravel up to a few inches from the surface and slightly sloping downward to ensure a good water flow.
