Sports Field Drainage
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Drainage systems can be installed on existing sports fields with very little disruption or damage to the playing surface. A waterlogged pitch can be out of action for as long as 3 months during the winter - mid-season for football and rugby. To solve this problem drainage systems can be installed out of season to prevent disruption to team fixtures. A typical drainage system consists of a lattice of lateral drains linked to a main drain :-  |
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A lateral drain can be installed in one operation using the Shelton Super Trencher - capable of digging trenches 25- 125mm wide. The spoil is collected (to the right of the picture), the pipe inserted and covered with gravel (from the left of the picture) from our purpose built gravel hopper. |
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Lateral drainage systems can be installed under existing turf. To preserve good turf this machine was designed and developed by ourselves. It cuts the turf and neatly rolls it to either side to leave the runs ready for the drain trenches to be cut with the Shelton Super Trencher. The drain is then installed and the turf simply rolled back into place, where it will quickly root back into the soil enabling the pitch to be used after just a few days - the minimum amount of time out of use. |
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Another technique is to completely remove a strip of turf along the run, as seen here. The drain can then be installed and the turf replaced afterwards. This method is used on golf greens where the final turf surface is critical. |
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Alternatively, the drainage trenches can be cut straight through the turf. The drains are installed, and then finished to the surface with topsoil. The runs are then seeded and left to grow back (which takes longer). |
Secondary Drainage
If the lateral drains alone are not sufficient to remove all surface water a secondary surface drainage system can be installed over the primary lateral system. There are two types commonly used: sand slitting and gravel banding. We can install both types, but prefer the latter method of gravel banding as this reduces future problems of soil shrinkage during the summer.
Gravel Banding
Gravel banding is a method of rapid surface drainage. A thin trench of free draining Lytag (4-6mm aggregate) is inserted into the soil. Lytag is a versatile, lightweight aggregate produced from pulverized fuel ash(PFA), a by-product of coal burning power stations. It is considered preferable to stone for sports fields due its non-angular shape and water absorbing properties. These drains are typically 25mm wide and 200mm deep so they connect into an existing lateral drain matrix. They are closely spaced at 400-1000mm apart and therefore allow water to quickly find its way from the surface to the lateral drains.
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They can be installed using a trenchless system when ground conditions are suitable. The turf is simply cut open and the gravel inserted into the crevice. This makes gravel banding more cost effective than sand slitting, and is generally considered a superior technique. |
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Above left, the gravel band is inserted, and, above right, a close up of the band showing the minimal impact to the grass surface. |
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Sand Slitting
Sand slitting is another secondary drainage technique. The slits or trenches, 50-75mm wide and 200-300mm deep, are inserted with the Shelton Super Trencher at 1-2m spacings. They are back filled with 10mm pea gravel and topped with 50-75mm of free draining sand.
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They are be designed to tie-in with existing lateral drains. Heavy top dressings of suitable sand are essential for the successful construction and management of sand slit pitches. |
Sand Dressing
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Sand dressing simply applies up to 10mm of sand to an existing surface. This greatly
improves the surface structure of the soil and increases the surface
drainage. |