Deep drainage. Drainage surgery. The principle of organizing a horizontal drainage system

It is worth considering that your site needs deep drainage if it is swampy or located in a place with excess moisture. For example, if the site is located in a lowland, then without good drainage system cannot be avoided, because all the melted and rainwater. Before constructing a residential building, the groundwater level must be checked.

If they do not flow deeply enough, then there is a high risk of undermining the foundation of the house and the same waterlogging of the area, rotting of the roots of planted plants, etc. The quality of the soil is also crucial, since if it is dominated by clay, then even with light precipitation your site can turn into one large puddle.

So, if you have discovered one or more factors that determine the need to install a deep drainage system, and have decided to install it, then you can solve the following important problems:

Protecting not only the foundation of your home, but also those laid in the ground engineering communications.
Preventing the penetration of groundwater into basements and basements.
Reducing the humidity level not only on the site, but also in the house itself, especially on the first floor.
Prevention of soil washout, swelling, subsidence of the landscape and death of the root system of trees, shrubs and other plants.
Reducing the risk of pathogenic bacteria, insects (mosquitoes and midges) and even frogs appearing and multiplying in your area.

Closed drainage - its main elements

So, the installation of underground drainage is a set of measures aimed at laying perforated pipes buried in the ground to absorb excess moisture and installing drainage wells for their maintenance. In addition to drainage pipes and wells, one of the main and most functional elements of the system are drainage tunnels.

They are designed to remove rainwater and filter it before discharging it into a well. Such tunnels hold quite a lot of water compared to gravel trenches, so their use in parking areas is most justified.

Modern drainage tunnels can withstand a load of approximately 3 tons per 1 m2!

However, the basis of a deep drainage system is still drainage pipes. Just a few years ago they were made of ceramics or asbestos cement, but today they have been replaced by practical, lightweight and easy-to-install plastic. Modern perforated pipes perform two functions simultaneously - receiving water and discharging it.

This ensures proper water balance in your area and minimizes the risk of negative consequences associated with excessive soil moisture. If there is a natural pond or other location within close proximity to your home where waste water can be discharged, consider yourself lucky. The only nuance that you will have to take care of is the preliminary purification of the water.

If there is no such receiver, then you will have to install drainage wells. They are special containers that are buried in the ground and absorb moisture collected by drainage pipes.

If your site is different small in size, and the degree of flooding is not too great, then it is quite possible to get by with one well. Otherwise, you may need several of them. With the help of drainage wells, not only water is distributed in the system, but also its functioning is monitored.

Installation of deep drainage - we follow the technology for performing the work

Closed drainage can be laid in accordance with one or another scheme. Most often, pipes are laid along the perimeter of the land plot, along its center or diagonally. Another way to install a drainage system is to lay pipes in a herringbone pattern. This allows you to quickly and efficiently collect water from the entire area, preventing it from becoming waterlogged.

To lay drainage pipes, it is necessary to dig a trench of appropriate depth. As a rule, it depends on the quality of the soil and the depth of groundwater. So, for clay soils, the optimal depth for laying pipes is 60-70 cm, and for sandy soils - about 1 meter. Digging trenches and laying pipes, respectively, is carried out at a slight slope towards the catchment (drainage well), which allows water to easily flow into it without any intervention.

Before laying drainage pipes, a sand and gravel “cushion” is laid on the bottom of the trench!

Then, the installation of deep drainage involves filling the laid pipes with crushed stone and sand. Pre-dug soil is poured onto them and turf is laid. Thus, you get an effective closed (hidden in the soil) drainage system for your site. Experts note that when installing drainage, you may encounter a number of problems, but many of them can be easily fixed, but will require additional costs.

For example, if it is not possible to lay pipes on a slope, you will have to purchase and install a drainage pump. But these costs will pay off quite quickly, and high-quality drainage will delight you with its work for a long time.

Owners of plots located in lowlands or in areas with a groundwater level above 1.5 meters need deep drainage of the plot. It will be most effective in case of additional equipment, waterproofing the foundation or even installing ventilation hoods on the ground floor.

In summer, swampy lands usually entail flooding of basements, the spread of dampness and mold throughout the house, rotting of the root system of plants, and the dissolution of gaseous and solid substances in the soil that destroy concrete, brick and cement. In winter, damp soil freezes deeper than 1.5 meters, freezes with the buried parts of the house, and, increasing both horizontally and vertically, causes more or less large-scale destruction - shifts of walls, cracks in door frames and frames. Because of this, the room loses a lot of heat. A drainage system is a way to avoid such problems.

Types of deep drainage

There are two types of deep drainage - local (designed to protect individual buildings- houses, underground canals, pits, roads, basements, drainage of backfilled streams and ravines, etc.) and general (to lower the groundwater level throughout the entire site). Subject to availability sandy soils or significant layers of sand, local drainages can serve as general ones, lowering the level groundwater generally.

Local drainages are of three types: wall, ring and layer.

A wall drainage system is necessary to protect basements located on waterproof clay and loamy soils from excess moisture. It is also recommended to install such deep drainage for preventive purposes even in areas where there is no visible groundwater. This system consists of drainage pipes with filter bedding laid on the ground along the outer perimeter of the structure not lower than the base of the foundation slab. The distance from the walls depends on the placement of drainage manholes and the width of the building foundation. If the foundation is too deep, the wall drainage system can be located above it, but care will need to be taken to ensure that the soil does not sag under its weight.

The ring drainage system is designed to protect the foundation and basements in the event that general deep drainage cannot sufficiently lower the groundwater level in both sandy and impermeable soils, as well as in the presence of pressurized groundwater. Located along the contour below the floor level of the protected structure, the ring drainage protects everything that is inside it from flooding.

How powerful the system will work depends on the area of the fenced area and the level of the groundwater table relative to the depth of the drainage equipment (galleries, drainage pipes, filter part of the wells). A drainage system of this type has one significant advantage: due to the distance from the contour of the ring drains themselves (5-8 meters from the wall), they can be installed after the construction of the building.

Layer drainage of a site can only be organized simultaneously with the construction of structures, combining it with ring and wall drainages. This system, being hydraulically connected to a tubular drain, is laid on aquiferous soil at the base of the protected structure. The underground drain provides collection and an artificial watercourse for drainage of groundwater and is located on the outside of the foundation (with a distance from the wall of at least 0.7 meters). A reservoir drainage system is required in the following cases:

In cases where tubular drainage alone is unable to cope with the drop in groundwater.
In case of development of a site with complex structure an aquifer of uneven composition and water permeability.
In the case of the presence of flooded closed areas and lenses under the basement floor.

The reservoir deep drainage system is good because it effectively fights both ordinary and capillary moisture. What is such a drainage system? Its name speaks for itself: a layer (layer) of sand is poured under a building or canal and cut in the transverse direction by prisms of crushed stone or gravel, having a height of at least 20 cm. The distance between the prisms depends on the hydrogeological conditions of the site and ranges from 6 to 12 meters. Reservoir drainage can be two-layer: on top there will be the same gravel, but in the form of a layer. The depth of the layers should be at least a third of a meter under the base of the house, and at least 15 cm under the channels, but everything depends, again, on the importance of the specific structure and individual calculations.

Common deep drainage systems include head, bank and systematic drainage.

Head and shore drainage

Head drainage is used for drying land plots, flooded by a flow of groundwater, whose source of supply is located outside it. Such drainage crosses the groundwater flow along its entire width. The system can either be located above the aquifer or be buried in it (it all depends on the characteristics of a particular area). If there is a reservoir on the site, it is advisable to install coastal drainage to drain coastal areas. Both head and shore drainages can, if necessary, be combined with other types of drainage systems.

Systematic site drainage

If there is no clearly defined direction of groundwater flow on the site, and the water-carrying layer contains open sand layers, the installation of systematic drainage will be required. Depending on the calculation results, the distance between the drainage drains is determined, and if necessary, this system can be combined with local or head drains.

Drainage on site: wells

If there is no natural slope on the site, you cannot do without drainage wells. Inside them (at the top of the wells) all the drainage pipes are connected, through which the water collected on the site, both groundwater and fallen in the form of precipitation, is discharged here. Inside the wells there are also pumps that pump water outside the site, helping to control soil moisture and without requiring special attention, not counting periodic washing. Wells can be rotary, absorbing (filtering) or receiving water.

A rotary well is usually installed either at the second turn of the drainage system pipe, or at the convergence of several channels. Such wells provide free simultaneous access to the inlet and outlet sections of the drains, allowing you to observe the operation of the drainage system and clean it with a stream of water.

Absorption (filtering) wells are needed in cases where it is not possible to remove excess moisture to a lower area of the territory. However, they operate uninterruptedly only in sandy and sandy loam soils with a small volume of wastewater, not exceeding 1 cubic meter per day. Unlike rotary wells, which can be of different sizes, filter wells can only be quite large: 1.5 meters in diameter and 2 or more meters in depth. Such a structure is covered inside and outside with broken bricks, crushed stone, gravel, covered with geotextiles and then covered with soil - the water entering the well is filtered through the crushed stone and goes into the underlying layers of soil. Attention: for any type, we recommend following.

Water intake wells are needed in the wettest areas with a high groundwater table, because similar situation does not allow the use of absorption wells. A water intake well is also needed if there is a great distance from a site with a natural reservoir for discharging water - a river, ditch or ravine. The advantage of the system is that the collected water can then be used using a pump to water the garden area.

Materials for deep drainage systems

Drainage wells are either made of several stacked on top of each other concrete rings, or immediately mounted from completely finished plastic or glass plastic structures. The last option is more modern and less labor-intensive.

As for the drainage pipes themselves, the previously used short-lived asbestos-cement and ceramic pipes, which require drilling holes, frequent washing and are not entirely safe for human health, are becoming obsolete. Today, mostly polyvinyl chloride (PVC), plastic and polyethylene drains with different characteristics are used: perforated, corrugated, equipped with stiffeners that allow the load from the overlying soil to be evenly distributed along the entire length of the pipe. This innovation, together with resistant polymer materials, makes drainage pipes durable - their service life is 50 years or more.

When there is too much precipitation or when groundwater lies too close to the surface, it becomes necessary to protect the area from the influence of excess moisture. Excessive moisture can lead to leaching, heaving, waterlogging, flooding of basements, if any, and serious erosion of the foundation of the house and buildings.

Drainage systems have a thousand-year history, during which only the materials used have changed. If our ancestors used clay pipes, today polymer materials dominate in drainage systems.

Types of site drainage

If we summarize all the points, the drainage system can be represented by the following plan:
Drainage of the site can be superficial or.

Surface drainage

Surface drainage is designed to protect buildings and soil from excess moisture, which can be caused by excessive precipitation, melt water or water collected through stormwater inlet systems. Surface drainages can be divided into the following types:

Linear– are systems of trays placed on the surface of the earth, which are inclined to allow water to flow to the water receiving point. For convenient operation, such trays are covered with special protective decorative grilles. Such devices are often additionally equipped with sand traps, which allow you to retain sand, pebbles or small debris found in wastewater and which can lead to storm drain clogging. Such a site drainage system will do an excellent job of protecting the soil from excess moisture, but only if the groundwater lies deep enough.

Spot. They are a system consisting of rainwater inlets or water collectors, which first collect water and then transfer it to the sewer system through pipes laid in the ground. Such catch basins are usually installed under drainpipes, water taps, as well as at minimal points on the site, which allows for the collection of excess water.

Surface types of site drainage work great, but you need to select the right materials and install them wisely, as well as clean the system in a timely manner.

Deep drainage

Deep drainage systems- This is an option for regulating the water balance in the soil by laying perforated pipes in the ground, which are called drains. Such pipes absorb excess moisture from the soil, thereby protecting the site and buildings from the harmful effects of excess water.

In order to properly complete the section, drainage pipes must be laid with a slope towards the spillway point. Such a point can be any reservoir, storm sewer, storage well, etc. The system must be equipped with inspection wells, which can be used to clean the network.

It should be noted that deep systems are needed in areas where groundwater lies quite high (up to 2.5 meters), in soils that have low permeability to moisture and near various structures in order to eliminate increased humidity.

The construction of a deep drainage system involves a significant amount of earthwork. That is why all work on laying drainage must be carried out before the construction of the house begins, as well as the complete arrangement of the site.

One type of deep drainage system is reservoir drainage. It is performed under the base of the house in the form of a filter pad, which is combined with drains. Such a system will protect the house from excess dampness and humidity, as well as from flooding with groundwater or melt water.

Drainage works

It must be said that if you can carry out surface drainage of the site yourself from start to finish, then the deep drainage system must be carried out with the involvement of specialists, because it requires a project that will include testing the soil for moisture content. Deep drainage should begin with a study of the existing level and amount of groundwater, which is quite difficult to do independently without special skills.

Please note that incorrect installation of pipes can lead to waterlogging in the area and even lead to flooding in the area. That is why you can independently install a deep drainage system only according to a project prepared by specialists.

The surface fertile soil layer should conduct water well. In cases where it is clayey, water transfer will not occur. In such cases, it is necessary to improve the site by delivering black soil. If you look at a cross-section of the soil, you can clearly see the layers. Most often, the top fertile layer occupies about 20 cm, and after it there are layers of sand or sandy loam, under which lie dense layers of clay that will no longer allow water to pass through. Drains should be installed just at the border between clay and sand.

The most common method of laying drainage system channels is a system of one main and several side channels.

The slope of the pipes must be maintained at least 3 cm per meter. The water that will enter the side channels flows into the main channel, and from it flows to the water collection point. In cases where the exit from the main main canal is located below the level of the receiving well, then another intermediate well must be laid at the exit of the system. The depth of installation can be different, everything will depend on the level of the main receiving well. The best, and cheaper, fit for installing drains is plastic pipes, which must be perforated, however, you can also use existing old pipes by making holes in them along the entire length. Additional drains are also connected to the main drains, and at their joints there should be gaps 3 cm thick, which are filled with coarse crushed stone.

Please note that the site drainage system can be implemented without pipes at all. You can simply fill the prepared channels with large crushed stone. However, such a system will be characterized by low efficiency.

It is advisable to lay drains not immediately into the ground, but at intervals from gutters made of fine mesh, into which gravel should be poured, in which the pipes are already laid. This must be done to ensure that the holes in the pipes do not become clogged with silt. In this case, gravel acts as a filter.

If the house is located in a lowland or marshy area, then you cannot do without a good drainage system. This can be done in several ways, but only deep drainage of the house and site can effectively dry the soil and protect the foundation from destruction. The installation of this type of drainage is labor-intensive, but in some cases it is the only correct option for draining the local area.

Even at the design stage of an honest house, it is necessary to provide a drainage system. It will not be possible to “hide” from rain and melt water; precipitation will still occur. It is necessary to somehow remove moisture away from the foundation, otherwise the home will not last long.

Installation of deep drainage is a labor-intensive process

With the local area the situation is almost identical. If excess water accumulates on it, then it won’t be long before it becomes waterlogged. And this is rotting of roots with subsequent death of plants, and corrosion of utilities laid in the ground.
All storm sewers are divided into two types:

Open (superficial).
Closed (underground, ground).

Advice! If clay soils predominate on the site, then you must take care of constructing deep drainage near the house. Otherwise, even with minimal precipitation, the territory of the estate will turn into a huge puddle.

An important factor when choosing the type of drainage system is the composition of the soil. Sands themselves drain water quite well from the surface layers into the aquifers without additional means. Clays, on the contrary, retain moisture and prevent it from going deeper.
The second nuance is the level of soil freezing. Deep drainage pipes and storm sewer wells must be immersed below this point, otherwise they will freeze and cease to perform their functions.

Scheme of ring drainage around the foundation of the house

An open storm drain in the form of surface trays can cope with the drainage of only rain and melt water. If moisture has penetrated into the soil, then you cannot do without an underground deep drainage system. Only it will dry the soil from the inside, diverting the water into special wells and reservoirs.
Deep drainage has to be installed when:

the house is in a low place;
the soils on the site are clayey or loamy;
aquifers lie close to the surface;
floods flood the basement or underground garage;
The cottage stands on a deeply buried foundation.

A deep drainage system will protect the foundation of the house and adjacent communications that are laid in the ground. It will prevent the accumulation of water in basements and basements, and will also prevent swelling and washing out of the soil.

Construction of a deep drainage system

To properly make deep drainage, you need to clearly understand what elements it consists of and how they interact with each other. In some cases, it can be installed only near the house, but it is better to drain water on the scale of the entire estate.

The deep drainage system includes:

drainage pipes with perforation for collecting water from the ground;
main pipelines;
inspection wells for monitoring and cleaning storm drains;
catch basins.

All these components must be present in the deep drainage system on the site near a private house. Perforated pipes serve to drain water, which then flows by gravity through the mains into the water intake tank. From there, the wastewater is pumped into a nearby reservoir or a centralized storm sewer system.

Advice! For small volumes of discharged water or for purely seasonal periods of precipitation with short-term rains, it is better to arrange drainage on the site in the form of separate vertical wells. This is easier and cheaper to do, but they need electric pumps to work.

Option for a drainage system design for a private estate

Horizontally laid perforated pipes can always be replaced with several drainage wells located around the site. But the water will have to be pumped out of them using pumps.
Such a design cannot function without electricity and is rarely used anywhere. But if there is little moisture or storm tanks only need to be used for a few weeks a year, then this is a completely suitable option.

Selection of materials for the drainage system

When arranging deep drainage for a site with your own hands, the main attention should be paid to drainage pipes and their installation. They should have many holes so that moisture can seep into them from the soil. You can make the holes yourself using a drill, but it is better to purchase factory-made perforated pipe products.
Drainage pipes can be:

Asbestos-cement is an outdated option.
Ceramic - durable, but expensive.
Plastic ones are the cheapest and most popular.

For storm drains, plastic pipes are made from polypropylene, polyvinyl chloride and polyethylene. The latter option is optimal for street sewerage; it can easily withstand negative temperatures and does not crack in frost.

Advice! For buried drainage, it is recommended to use plastic pipes with long and narrow slots. They collect moisture better and are not as clogged as their counterparts with round holes.

Pipes for drainage and water drainage should be corrugated. They withstand greater soil pressure and do not push through when it swells. For deep drainage, depending on the installation depth, pipes with the following stiffness class are suitable:

SN 2 or SN 4 – will withstand 3 meters of soil from above.
SN 6 – can withstand a 5-meter layer of soil.

Perforation on the pipe can be made in a circle, halfway, 120 and 240 degrees. All options will do. Much depends on the planned volumes of collected water and soil characteristics.

The perforated pipe is covered with a layer of crushed stone and wrapped in geotextile

Wells can be made from:

bricks;
gland;
concrete;
plastic.

The best option is to install the entire deep drainage system (pipes and wells) from plastic elements. Nowadays they sell ready-made parts that just need to be put together like a construction kit.
Also, to arrange deep drainage, you will need geotextiles and fine gravel with sand. The first will protect the perforation from small debris, and a cushion under the pipes will be made from a gravel-sand mixture.

How to make underground drainage yourself

The main difficulty in designing and arranging deep drainage is its individuality; for each site, calculations have to be done from scratch. It is necessary to take into account the structure and composition of soils, the level of their freezing and the depth of soil water.
Correctly calculating the diameter of pipes and volumes of wells can only be done after hydrogeological and geodetic surveys. It is recommended to independently prepare a project for deep drainage of a house and site only if you have the appropriate knowledge.

Scheme of laying drainage pipes in the ground

You can only install the system yourself. Even a novice master can lay pipes and arrange wells in accordance with the diagram.
The arrangement of deep drainage is carried out in four stages:

Marking of drainage ditches and wells in the area.
Excavation work.
Construction of wells and pipe laying.
Backfilling of ditches with soil.

When digging trenches, it is important to maintain the slope from the house to the final water intake. The water flows by gravity; nothing should interfere with this. It is necessary to exclude even the slightest possibility of its accumulation and stagnation in the pipes.

Important! If the soil on the site is clayey, then geotextiles must be laid, otherwise the perforation will clog immediately.

A crushed stone-sand cushion 10–30 cm thick is first poured onto the bottom of the dug ditches. Geotextile is laid on it with a filter layer up and another 10–20 cm layer of gravel is added. Then a perforated pipe is laid and covered with crushed stone on top and on the sides by 10 cm Then all that remains is to wrap the fabric and sprinkle everything with soil.
Drain pipe must be wrapped in needle-punched geofabric
In order not to bother yourself, you can take factory pipes already in a geotextile filter. They are manufactured in accordance with GOST and are intended for installation in any soil.
Inspection and drainage wells are made using a similar technology, only geotextiles are not needed. First, a cushion of gravel and sand is made. Then a well structure is installed on it and everything is covered with earth.
Wells will have to be installed both at the final, lowest point of the drainage system, and at the places where pipes turn and connect, so that their condition can be monitored and cleaned if necessary.

Video: drainage installation in the local area

The general scheme of deep underground drainage for a private house is extremely simple: drain pipes and a water intake well. You can install everything yourself from plastic elements. But it is better to entrust the preparation of a project for such a system to a competent specialist. It is necessary to carry out research and take into account a lot of nuances, otherwise it will be difficult to choose the optimal solution for a particular site.