Landscape Irrigation - Drainage System
About Drainage Systems
A drainage system will ensure your landscape is kept healthy and beautiful for many years to come. There are different types of landscape drainage systems that can be implemented into a landscape where there is excess water causing muddy patches and retarded lawn growth. The most common and most effective for landscape drainage problems is the French Drain System.
French Drain System
The French Drain system is used for excess water found on lawns, especially near the home which can cause all sorts of problems. This can occur if the land is completely flat and water cannot naturally flow to the lowest point in a landscape, or if the neighbor’s property slopes downward toward your property. A traditional French drain is basically a trench through the backyard filled with gravel. This system will allow more efficient soaking up of the water from the surface, down into the trench where the water is collected into pipes and transported to a ditch or soakaway. How to Install:
1. Determine where the highest and lowest point of the landscape is. The highest point will be where the trench begins and the lowest will be where the soakaway is located. Make sure that this location of the soakaway will not affect anyone else’s land. Also check with the local authorities to find out where any underground cables are laid so you know where not to dig. 2. Draw a sketch of where the French drains will be laid and direct them to lead to the soakaway. Dig out a horizontal trench along the length of the slope, an excavator can be used. The depth of the trench will depend on the extent of the excess water problem. Small trenches should be 6 inches wide and 12 inches deep.
3. Once the trenches have been dug, compact any loose soil in the bottom of the trench. Place a layer of landscape fabric into the trench. If the land is completely flat, the trench should slightly descend toward the soakaway to ensure the water will naturally flow to that area. A slight descend of 10mm for every meter is sufficient.
4. Use plastic pipes with perforation on one side and lay with the holes facing downwards. The reason the holes must face down is that water will enter the pipes sooner if they are facing downwards, as most of the water would miss the holes and spill down the side and also because the gravel would block the holes.
5. After the pipes are installed, lay 1 inch or larger sized washed gravel. Fill the trench with gravel 1 inch from the surface. Cover with a top soil together with coarse sand. The sand will allow the water move more freely through the layer of top soil to reach the gravel.
The French drain is now complete. Lay turf to disguise the trench. When it rains the excess water should now flow down through the gravel, into the pipes and directly to the soakaway.
