In this article, we will focus on the problem of drainage of damp areas: the device of which systems is necessary, how to include elements of the drainage system in landscape design, is it possible to create landscape design in damp and even wetlands without drainage at all.
Before starting work on the device of landscape design, it is necessary to determine the appropriateness of the device of the drainage system of the site. The purpose of the drainage device is to collect and drain excess water from the site. The laying of surface drainage systems is necessary almost everywhere, this is due to the peculiarities of the weather conditions in most regions of Russia, such as a large amount of rainfall throughout the year and a short summer period.
But the device of underground drainage is necessary only in damp, swampy areas and with a high level of groundwater (from 2 m or less) and if the soil is medium or heavy loam. We talked about the device of a closed drainage in our other article. A well-thought-out and arranged drainage system will help drain the problem area.
Deep drainage pipes, being underground, do not affect the location of landscape design elements, but there is one point to which you need to pay attention. When installing an underground drainage system, rotary, inspection and absorption wells are installed. Their covers must be decorated, while providing free access to them..
Let’s talk a little about some of the ways to decorate these wells:
- If the cover is on the lawn, then it is possible to use the so-called rolled lawn on a film or planting climbing fast-growing shrubs, which, even in case of damage to the branches, quickly recover.
- Installation of pyramids with climbing annuals (sweet peas, dolichos, ornamental beans) over the well cover.
- If the cover is on a flower bed, then you can use geotextiles, on which a layer of soil is poured, and ground cover plants are sown (arabis, stonecrops, gorica, thyme, etc.). If necessary, the geotextile layer moves with the plants.
- If the well protrudes above the surface of the earth, then flower beds in pots are arranged above them, small garden forms are installed.
- Absorption wells made of reinforced concrete rings are laid out with mosaics, small cobblestones, wood and are disguised as ordinary village wells.
- You can buy artificial stones, hollow inside, which are specially produced for decorating hatches and wells.
- If the hatch is located on a path, asphalt or paved area and it is impossible to hide it, then it can be “beaten”. Hardware stores offer decorative hatches in various sizes. But a detachable lid, independently made of wood or multi-colored stones embedded in cement, will look no worse.
Let’s dwell on some of the features of an open drainage system in the light of landscape design.
Linear surface drainage
Linear drainage consists of canals dug out at a slope, filled with a drainage layer, or trays laid at an angle to the sump.
The first option is a cheap and quite effective way of arranging open drainage. It is successfully used by owners of small garden plots. For this, taking into account the slope and direction of the catchment area, a single system of trapezoidal channels is dug. An open drainage ditch can perfectly fit into the design of the site, if you decorate it with a rocky stream, such streams are also called dry. They look great when water runs over them and when they dry out. Decorative bridges can be thrown across the ditch. Also, a very interesting technique is the device of a rocky slide, which is arranged over a large-diameter pipe laid in a ditch..
But most often, when arranging landscape design, the drainage ditch is filled up. The filling ditch has one significant drawback – silting. To solve this problem, geotextiles are used, which are laid over the entire surface of the ditch so that free edges remain on both sides. Next, a layer of fine and then coarse gravel is poured, after which the drainage layer is closed with free edges of the fabric. The ditch is covered with coarse sand. A layer of turf is laid on the sand.
For the device of surface linear drainage, ready-made drainage trays are also used, which are laid in dug trenches on a well-compacted sand cushion. The depth of the trench should be equal to the depth of the tray plus 10 cm for the cushion.
Trays are made of concrete, polymer concrete and plastic. Plastic trays are the best option because they are cheap, lightweight and easy to install. Fasteners are included with the plastic trays. To prevent sand and debris from entering the system, plastic sand collectors are available. Their design includes a removable basket for easy cleaning.
From above, the trays are covered with protective and decorative grilles that prevent large debris from entering them. They can be cast iron, steel, welded, stainless.
Such a drainage system should not be hidden and decorated. It will not attract attention, and a wide selection of grilles will allow you to choose models suitable for any style.
Is it possible to do without drainage at all
As mentioned in the previous article, modern landscape design strives for harmony with nature, for the use of all its beauties and gifts with the maximum preservation of natural balance.
Is it possible to use such a seemingly serious drawback as a high level of groundwater in landscape design? It is possible, and very effective.
Indeed, professionals have long understood that it is better not to fight with nature, but to try to use the features of the natural landscape.
In a wet area, you can arrange a natural reservoir by arranging the drainage system so that all the water is drained into it. Typically, these areas are located on the underlying clay layer. It is in it that you need to dig a pit, having done it in such a way as to go beyond its limits. Otherwise, the water from the reservoir will go to the next aquifer. Such a pond can become a real decoration of the site if you take care of strengthening its banks. If there are several wet places on the site, then you can arrange a system of reservoirs connected to each other by bridges.
It is worth thinking about the construction of a well. At a depth of 4–8 meters, there is the next aquifer, which contains rain and melt water filtered by the upper layer. Your own well will perfectly fit into any style of landscape design, and in case of special luck, if a water vein passes through the site, the well can become a source of drinking water.
Luxurious landscaping can be arranged even in the most swampy areas without drainage, but creating your own fairy tale in the swamp. One of the articles in the cycle will definitely be devoted to this topic..