How to do the drainage of the site with your own hands: we do the drainage correctly by studying the projects and types of systems. The easiest way to create drainage in a summer cottage What can a drainage system be made of
The main problem that land owners may face is the accumulation of water on the ground. The main sign of stagnant processes is puddles that do not dry out. long time. This problem must be solved, since excessive moisture will lead to wetting of vegetation and the destruction of buildings. There is a solution - installation of drainage. You can do it yourself.
Why do you need a drainage system on the site
Drainage - forced diversion of water. Usually this procedure is carried out before the construction of buildings in order to drain the site. Drainage is a combination of taps, wells that help excess water be removed from the adjacent area.
Before building a house on the site, it must be carefully examined. This will help determine whether drainage is necessary, as well as which system is best to install. You must first collect the following information:
If water stagnates on the site, then a drainage system is required.
After collecting this information, it is possible to determine the need for arranging a drainage system. It is needed if:
You can also determine the need for drainage by plants growing on it. Signs of increased humidity are sedge, cattail and other moisture-loving plants, while cultivated trees develop poorly, usually they simply rot.
Sedge - an indicator of high humidity of the site
Advantages of the dehumidification system
The advantages of drainage are obvious:
If the drainage system is neglected, the consequences can be quite unpleasant. It can be a constant unpleasant smell, water can accumulate in the basement, which will lead to a fungal disease of the house, its destruction.
The drainage system provides an optimal microclimate for human habitation
The drainage system of the land plot consists of:
The most commonly used closed vertical drainage, which consists of a system of trenches several meters high. Drainage pipes are installed at the bottom of these trenches, or the bottom is simply covered with rubble, broken brick, and then with earth. This will allow moisture to collect in this particular place, and not spread to the entire area.
Closed drainage system takes up much less space
Methods for arranging a drainage system on a land plot
Exist different ways arrangement of drainage on a private plot of any area. The choice depends on the characteristics of the terrain and soil. Any of them can be made by hand.
Surface
Open drainage is a system of grooves. Suitable for areas subject to heavy rainfall.
Surface drainage complicates the process of growing crops
The sequence of actions is as follows:
You can equip the system without trays. In this case, the trenches must be covered with crushed stone of a large fraction to 2/3 of the height of the groove, then a layer of crushed stone of a fine fraction, last layer- turf. It is possible to improve the performance of just such a drainage system with the help of geotextiles.
You can make surface drainage very quickly
Video: open iron drainage system
Deep
When arranging it, it is necessary to observe the basic rule - the location of the pipes of the system below the level of groundwater.
There are certain norms for the depth of the ditches of a deep drainage system:
The optimal trench width is 40 cm.
Special perforated pipes must be used. Their diameter should be about 15–50 mm.
In no case should old stale pipes be used to equip the deep drainage of the site. You will not save in this way, since such a system will not perform its functions exactly, and you will have to redo everything again.
Deep drainage lasts a very long time
The order of work for the arrangement of deep drainage:
The advantage of a deep drainage system is that only you will know about its existence, since it is impossible to see the entire trench system with the naked eye.
For the arrangement of soft drainage on the site, geotextiles and tecton are usually used. These materials have big amount advantages:
Pipes are not needed for soft drainage
To arrange soft drainage in a private area, it is necessary to dig a ditch, while the bottom must be at an angle. The bottom of the pit must be covered with tecton, and then with geotextile. The latter must necessarily go beyond the channels by at least 40 cm. This part of the material will later be used for overlapping. Now this material needs to be covered with crushed stone so that the layer reaches half the height of the trench. Now geotextiles can be covered with crushed stone, overlapping it. Now the entire structure can be covered with sand and carefully compacted.
This type of drainage system is the most preferable, since it not only drains water from the site, but also filters it.
Drainage system on a sloping site
Even if the site is located on a slope, it is also necessary to drain water from it, both from the surface of the earth and from the depths. This is necessary in order to prevent landslides in the spring, when the snow melts. A system that combines both open and closed drainage will be effective.
The arrangement of the drainage system on a site with a large slope is not much different from a horizontal system, but there are still certain features that must be taken into account. First of all, it concerns wells. They must be located at the threshold of the slope, that is, at the lowest point of the site. The main trenches are dug along the perimeter of the site, and they try to place them as close as possible to the fence. Auxiliary trenches should be located at an angle relative to the main one, and the angle of inclination of your site must also be taken into account, since it may not always be enough for normal water drainage. The general slope should be 2-4 cm per 1 m of the equipped system.
From above, the system resembles a river
If the site is quite large, then it can be conditionally divided into several parts by a transverse drainage trench.
Remember that the installation of a drainage system on a sloping adjacent plot requires more thorough and thorough preparation, accuracy of actions, thoughtfulness of each step, as well as larger financial investments.
Drainage of a site with a high level of groundwater
To deal with a high level of groundwater, drainage is indispensable. It is possible to equip both open and closed drainage systems. Open is the presence of ditches around the perimeter and between the beds. The main trenches must be at least 40 cm deep, additional - 15 cm. The disadvantage of such a system is to reduce the useful area of \u200b\u200bthe site, as well as the appearance of some difficulties in growing garden crops.
More complex, but also more effective is a closed system consisting of underground channels and wells-water intakes.
Properly equipped drainage system can reduce the level of groundwater
It is necessary to carry out this work precisely in the spring, when groundwater is at its highest. It is necessary to start digging ditches from a lower site. This is necessary so that groundwater does not interfere with the pipe installation process. The depth of the ditches of the system depends on the size of the drainage well.
In addition, it is necessary to lower the level of groundwater. This can be done using wellpoint installation. It consists of pipes with needle filtrates at the ends, they are connected to a pump and a vacuum convector (it is located on the surface of the site).
There are more complex systems that can lower the groundwater level by 20 m. They include centrifugal pumps and injection water lifts.
Video: drainage of a site with a high groundwater location
The peculiarity of clay soils is that they are heavier, do not let moisture through at all, and therefore dry much longer. Therefore, the arrangement of a drainage system in such a site is mandatory.
The earth near the drainage pipe needs to be loosened
There are certain rules for arranging drainage on clay soils, which should never be ignored, otherwise the efficiency of the system will decrease:
After installing the system, it is imperative to carry out testing, since clay soil is rather difficult to process. The test is considered passed only if the flow passes through the system from beginning to end without encountering any obstacles on the way.
Clay soil is very difficult to cultivate
Budget simple do-it-yourself drainage
Do not think that the drainage system requires the investment of a large amount of money. Pipes can be made by hand from ordinary plastic bottles. You can do this in the following way:
Trenches need to be dug around the perimeter of the site
It is very easy to make pipes from plastic bottles
Bottles need to be covered with sand, which must be compacted
Pipes from plastic bottles are durable
In a swampy area, the drainage system resembles a river in its structure, that is, there is always a channel and tributaries.
The plastic bottle system has certain advantages:
Video: plastic pipe drainage
How to make drainage with your own hands: step by step instructions
You can do the installation on the site with your own hands, and it will be quite fast. The main thing is to correctly calculate the system, taking into account all the features of the soil and the topography of the site.
Calculation rules
When calculating the system, the following parameters of the site should be taken into account:
It is better to request some data from specialists, since it is almost impossible to obtain it on your own.
Most often, the drainage system is equipped according to the ring principle. For its calculation, the main factor is the height of the base of the house. It doesn’t matter what material will be used to insulate the trench, the depth of the groove should be 30–50 cm more from the base of the foundation of the house, while the angle of inclination should be 1 cm per 1 m running system. Therefore, it is imperative that you first notice the lowest point on the site, this is where the water intake (well) will be located. To calculate the depth of the upper trench, it is necessary to measure the distance between the two extreme points system, and then give it the necessary slope of 1%.
Drainage can be located in close proximity to the foundation
An example of the calculation of the drainage system is given, which will help to make it for your site. Suppose that at the top point there is a collector well 30 cm above the ground and at a distance of 10 m from the foundation of the house. The length of the trench located around the perimeter of the house is 6 and 9 m. To this value, you need to add 10 m of the trench from the house to the well. The total length is 25 m.
Now you can calculate the required slope. To do this, you need to calculate 1% of the value obtained, that is, the permissible difference between the extreme points is 25 cm. If this value is greater, then pumps must be introduced into the system.
The pump helps move the water
Additionally, you need to remember to respect a certain distance between the foundation and the trenches. It should be equal to 3 m or more.
Sand and gravel need to be filled up to such a depth that they are able to prevent swelling of the soil when water freezes near the foundation.
Additionally, at a distance of 1 m from the house, it is necessary to equip a concrete blind area.
Video: how to choose a drainage pipe
Charting
To draw up a diagram, you first need to carefully examine the site, and then draw up a so-called project, which should indicate the slope and diameter of the pipes for drainage (if used). In addition, the diagram must contain the following information:
The drainage system itself consists of:
The drainage scheme can be linear and point. The first scheme is more complex. It is a system of shallow trenches, which are located under certain angle. They are made around the perimeter of the site and in places where water accumulates.
Linear drainage is mounted throughout the site
A point drainage system is a water inlet that is installed in isolated areas that are the most problematic.
Spot drainage is installed in the most problematic areas
Well device
There are several types of wells for the drainage system:
The manhole must be large
The swivel pit serves to clean the pumps
Absorption well serves to filter water
The collector well is a water intake
Wells can be concrete and plastic.
Video: overview of drainage wells
Methods for arranging a drainage system
Different drainage systems are in many ways similar to each other. Usually they differ only in the materials that are used during installation. It could be:
Each method of arranging the system has advantages and disadvantages. In the first case, simplicity and speed win, but the system will have to be updated periodically. If you combine several methods at once, you can significantly increase the service life of the system many times over.
Video: how to equip a drainage system with your own hands
If you decide that your site needs a drainage system, remember that you can do it yourself. The main thing is to correctly determine the type of system, draw up its scheme, and follow the sequence of work.
If the site requires the arrangement of a drainage system, but there is no money to purchase materials, you can try an alternative option - to equip the drainage of the site with improvised means.
The problem of flooding the territory during the period of snowmelt or heavy precipitation is familiar to many. If it is not resolved in a timely manner, there is a risk of facing very unpleasant consequences. The fact is that moisture undermines the foundation of the house and outbuildings, adversely affects the root systems of plants and urban crops.
Polyethylene film drainage
If you are wondering what material can be used for drainage, the answer is unambiguous - one that allows the passage of water. Most often, the following available materials are used to create a drainage system:
- plastic bottles;
- Styrofoam;
- branches;
- fascines;
- car wheel;
- construction garbage;
- stones;
- old things.
Note! Before choosing improvised materials for installing a drainage system on your site, you should make sure that during operation they will not rot, decompose, creating an unpleasant odor problem.
Plastic bottles for drainage
Do you have a lot of plastic bottles and you don't know what to do with them? Do not rush to throw it away, as they can be useful for arranging the drainage system on the site. For the manufacture of bottles, high-quality, environmentally friendly polyethylene is used, which has a long service life.
Drainage from plastic bottles
The main advantages of using bottles for arranging drainage on the territory:
- Long period of operation. The container is able to lie in the ground for more than 50 years without decomposing or deforming.
- Availability. Sometimes owners simply do not throw away used bottles, but collect them somewhere in the basement or in the attic. Alternatively, you can buy a container on the market at a very reasonable price.
- Environmental Safety. In the ditches where plastic bottles are laid, an unpleasant odor will not occur, since there are no conditions for the development and reproduction of microorganisms (unlike drainage from wood, textiles).
- Ease of installation. The main complex of works consists of land works. Then the entire installation can be done independently in a few hours.
Important! Drainage using plastic bottles should only be closed. When heated, polyethylene is able to release harmful substances, which can affect the health of residents of the house, so you need to ensure that there are no direct sun rays on the material and the effects of heating elements.
There are two options for arranging a drainage system using plastic bottles: mesh, "natural" drainage. In the first case, the bottom of the bottle is cut off, the neck of the next one is inserted into it. After land work is completed, such a plastic mesh is simply laid in trenches and sprinkled with a sand cushion, then with soil. Use this method It is possible only in areas where there is a small area and a small amount of precipitation.
"Natural" tapping is used much more often, it is considered more effective and convenient. Bottles do not need to be pre-prepared. Before laying in ditches, they are simply tightly covered with crusts.
Equipping the drainage of the site from improvised materials, in particular from plastic bottles, you should take care of high-quality insulation. If the system freezes during the cold season, it will not be able to perform its functions during the snowmelt in the spring, so all work can then be considered in vain.
foam drainage
If you plan to equip drainage from improvised materials, use foam. It can be collected, or you can buy it at a hardware store at an affordable price. The material has long been known for its versatility. It is used to protect equipment from damage, to perform a drainage layer indoor plants. Sometimes foam is used to equip drainage systems on small areas.
foam drainage
Work should begin with the implementation of land work. Trenches are dug under a slope towards the location of a prefabricated well, collector or artificial reservoir. A pillow of sand and gravel is laid in the dug trenches, then a layer of pre-shredded foam. The last step is laying the ground. To increase the efficiency of the drainage system, geotextiles can be laid in the ditches.
If the site is flooded abundantly, groundwater is high, which from time to time accumulates in the basement, it is rather difficult to solve the problem using improvised materials. In small areas with slightly increased level humidity improvised materials cope with their functions efficiently.
A modern landscaped plot with a comfortable house/cottage and secondary buildings can hardly be imagined without a system for draining excess water. A do-it-yourself drainage system is built without problems, provided that you read this article.
Do you know the situation when, after a rainstorm or during the melting of snow on personal plot deep puddles stand for a long time, the cellar is flooded, the basement of the building becomes damp, fertile soils are washed out. Have you seen cracks in the foundation and walls of the building?
When the soil, wet from rains or floods, is seized by frost, it is subjected to decent loads of displacement and buckling in various directions. You can avoid the destructive effects of the elements in an elementary way - by building a drainage system.
You can build a drainage system:
- Improvised means and materials.
- Factory modern materials: hiring a team of builders or on their own.
Since we set out to save on the brigade without losing quality, we will consider on our own
- From improvised materials.
- From specially produced materials.
We save on material
Let's say you need to drain garden plot with your own hands. To begin with, we will do the preparatory work.
Along the perimeter of the building, at a distance of 2-5 meters from the foundation, we dig a trench 0.5 meters wide and a depth equal to the level of the base of the foundation. We select the highest point according to the natural level of the soil and the lowest.
We make the level of the lowest point less by the following value: running meter the slope of the gutter is 1-1.5 cm. An approximate diagram is shown in the figure.
Water is diverted to a local gutter, pond, or simply downhill as far as possible.
Trenches for water are called drains. Do-it-yourself drainage is made in a variety of options (see fig.)
Let's consider them in more detail.
All options include:
- Sand.
- Small rubble.
- Large crushed stone (at least 50 mm).
- Turf.
Now consider each design separately (see the figure above):
- The simplest option. Due to the porosity of the structure, water entering the drain flows by gravity to the drain. So that the structure does not compact, they put it on top of the turf reinforced concrete slabs (5).
- A kind of triangular structure is being built from reinforced concrete slabs (5), through which the drains go down the drain.
- A similar design, but already U-shaped, from antiseptic perforated boards (6) or large stones (7).
- A canal built from boards (6), surrounded by large rubble.
- The fascia (8) acts as a supporting structure for drains. To do this, take branches of birch, oak, alder, hazel, coniferous trees. Branches (fascines) are formed from branches in this way: thicker branches are placed in the middle, thinner ones along the edges; beam width not less than 25 cm; the whole fascine is knitted in one piece, not in separate sheaves, with the growth of branches towards the drain, first laying on the ground near the trench, tightly tied with a rope or wire. It is advisable to overlay the fascine with moss.
- Throughput is provided by goats made of bars (9).
- A perforated asbestos-cement pipe (10) acts as a carrying gutter.
- Or perforated ceramic pipe.
With this design, water will not accumulate in the soil, but will go further along the natural slope. The foundation will also be intact.
We use special materials
Do-it-yourself drainage at the site is more convenient and reliable to perform from sewer and special drainage pipes.
Drainage systems are divided into:
- Linear system.
- contour system.
WITH linear system drainage we met in the last section. A frame of drainage pipes around the perimeter of the house will completely protect against the destruction of the foundation and will divert water from under your feet. Moreover, the pipe comes with a filter and without a filter. The filter keeps the holes from clogging, prolonging the life of the system.
The contour system drains a wider area of the site. Build if needed.
Such a system allows you to drain water not only from the foundation, but from the site, preventing blurring. fertile soils, flooding of sidewalk paths. In Figure 1 - road, 2 - gutter, 3 - sidewalk paths, 4 - house, 5 - drainage, 6 - drains, 7 - drain collector.
rain drainage
It is also recommended to build drainage systems with your own hands to receive rainwater flowing from the roof through rain pipes.
To do this, a point drainage system is installed along the perimeter of the building with access to the drain pipe.
To drain rainwater, additional surface drainage is often built. This is an additional gutter along the perimeter of the building near the foundation, covered with a grate, which diverts water flows from the foundation of the house and the surrounding area.
The general picture of surface drainage looks like this
Tip: in case your site is absolutely without slope, there is no drainage ditch nearby, nor urban / rural storm water, it is recommended to install a pumping station. It will be used only in cases of heavy rains or severe floods. This is the only way to quickly remove a large amount of water that does not go away by gravity.
The overall picture of the drainage system may look like this
Drainage system - top view
As you can see, do-it-yourself drainage is not difficult to do. However, with a large area of the drained area, using pumping station When constructing a complex drainage system connecting surface and deep drainage systems, it is necessary to make a rather complex working design. And without a specialist, in this case, it will not be easy.
In some regions, groundwater is very close to the surface. So close that they threaten the integrity of buildings (their foundations) and prevent plantings from growing. All these problems are solved by the drainage of the site. In general, this event is costly both in terms of the amount of funds required and the necessary time costs. A lot of time is spent on planning. If you do everything wisely, then you need data from a hydrogeological study and a project drawn up by a specialist. But, as usual, only a few do this, most make the drainage system with their own hands.
What water is drained
Drainage of the site is a costly and time-consuming event that requires a large amount of land work. Best time for construction - the process of planning and arranging the site. More late dates executions lead to a big mess, which is far from pleasing to everyone. However, if there is water on the site, you have to go for it.
There are several types of water on the site that interferes with us and needs to be diverted. They are different and require different measures.
surface water
They are formed during snowmelt and heavy rainfall, during work on the site (watering, washing paths), discharging water from the reservoir, etc. What all phenomena have in common is their one-time occurrence: surface waters appear after certain events. A more reasonable way to divert them is a device. She copes with the task perfectly, and the cost of arrangement is much lower.
To divert surface water, mainly open channels are installed, water intake is point under storm pipes or linear along the entire roof overhang. From these receivers, water is taken by solid plastic (asbestos-cement) pipes into a sewer or dumped into a river or lake into a ravine. Sometimes let's take it to the ground.
ground water
Those underground waters that have a seasonal level (higher in the spring after the flood, lower in the winter), have a feeding zone (where they come from) and outflow (where they go) are called groundwater. Usually groundwater is present on sandy, sandy soils, less often - in loams with a small amount of clay.
The presence of groundwater can be determined using self-dug pits or several wells drilled with a hand drill. When drilling, a dynamic level is noted (when water appeared during drilling) and a steady level (some time after its appearance, its level stabilizes).
If we talk about the diversion of water from the building, then the drainage system is arranged if the groundwater level (GWL) is only 0.5 m below the foundation. If the groundwater level is high - above the freezing depth - then it is recommended with the measures taken to drain the water. At a lower level, other options are possible, but this requires careful and multi-layer waterproofing. The need for drainage of the foundation should be assessed by specialists.
If high-standing groundwater (GWL above 2.5 meters) prevents plants from growing, site drainage is required. This is a system of channels or special drainage pipes laid in the ground at a certain level (below the GW level by 20-30 cm). The depth of laying pipes or ditches - below the GWL - so that water flows to lower places. Thus, the adjacent areas of the soil are drained.
Verkhovodka
These underground waters are found on soils in highly located water-resistant layers, but their appearance is often the result of construction errors. Usually this is water, which, being absorbed into the soil, meets on its way layers with a low ability to absorb moisture. Most often it is clay.
If, after rain, puddles stand on the site and do not leave for a long time, this is perched water. If water accumulates in the dug ditches, this is also a perch. If a few years after the construction of a house on clay soils or loam in the basement, the walls begin to “cry” - this is also a perch. Water accumulated in rubble pockets under the foundation, in the blind area, etc.
The removal of the top water is easiest to do with the help of ditches, but it is better to prevent its appearance - to backfill the foundation not with crushed stone and sand, but with clay or native soil, carefully tamping it in layers. The main task is to exclude the presence of pockets in which water will accumulate. After such a backfill, it is required to make a blind area, which is wider than the backfill and an obligatory stroke - the removal of storm water.
If the site has a slope, consider arranging terraces and retaining walls, with the obligatory installation of drainage ditches along retaining wall. The most difficult thing to deal with perched water is in low areas that are lower in level than neighboring ones. Here a reasonable solution is to add earth, since there is usually nowhere to dump water. More possible variant drain outlet through neighboring areas or along the road to the point of possible discharge. You have to decide on the spot, based on the existing conditions.
Not to drain
The installation of a drainage system is an expensive undertaking. If it is possible to get by with other measures, it is worth doing it. Other measures include the following:
If after all these activities the situation does not suit you, it makes sense to make a drainage system.
Types of drainage
Site drainage is a complex system with many nuances and features. By structure, it can be local (local) - to solve a problem in a particular area. Most often it is the drainage of the foundation, basement and semi-basement (basement) floors. Also, water drainage systems on the site are common - to drain the entire site or a significant part of it.
By installation method
According to the installation method, the drainage system can be:
- open. Concrete or stone trays are used, ditches are dug around the site. They remain open, but can be covered with decorative grilles to protect the system from large debris. If you need a simple retraction solution surface water in the country - these are precisely the ditches along the perimeter of the site or in the lowest zone. Their depth should be sufficient so that at maximum flow the water does not overflow. So that the unreinforced walls of the drainage ditches do not collapse, they are made at an angle of 30 °,
- closed. Water is caught by laid special permeable - drainage - pipes. Pipes are led into a storage well, into a sewer, a ravine, a nearby reservoir. This type of drainage on the site is good for permeable soils (sandy).
- Zasypnoy. Drainage of this type of site is usually used on clay soils or loams. In this case, the pipes are also laid in ditches, but a layered sand and gravel backfill is arranged in them, which collects water from the surrounding soils. The worse the soil conducts moisture, the more powerful the backfill is required.
Drainage option for a summer cottage - cheap and cheerful
The specific type of site drainage is selected based on site conditions. On clays and loams, an extensive gravel-sandy zone is needed, into which water will drain from the surrounding soil areas. On sands and sandy loams, there is no need for such a pillow - the soils themselves drain water well, but only a specialist in the results of geological research can specifically say.
By type of implementation
There are several types (schemes) of drainage devices on the site:
When draining the site, the central drain or collector is made of pipes of a larger diameter (130-150 mm versus 90-100 mm for conventional drains) - the volume of water here is usually larger. The specific type of drainage system is selected based on the tasks that need to be solved. Sometimes you have to use combinations of different schemes.
Site drainage - device
The drainage system consists of a network of interconnected pipes that are located along the perimeter (or area) of the territory protected from water. Drainage wells are placed at intersections or turns. They are necessary to monitor the condition of the system and clean silted pipes. From all drained areas, water enters the collector well, where it accumulates to a certain level. Then it can be dumped or used for irrigation and other technical needs. The discharge can go by gravity (if there is somewhere), and submersible ones are used for irrigation and other technical needs.
Drainage pipes and wells
Pipes for drainage are used special - with holes ranging in size from 1.5 to 5 mm. Water flows through them from the surrounding soil. Holes are located over the entire surface of the pipe. They come in different diameters, for private houses and plots the most used size is 100 mm, to divert large volumes of water, you can take a cross section of up to 150 mm.
They are now made mainly from polymers - HDPE, LDPE (low and high pressure polyethylene) and PVC (polyvinyl chloride). They are used for laying to a depth of 2 meters. There are also two and three-layer combined ones, which are made from combinations of these materials, they are buried to depths of up to 5 meters.
Pipes for drainage are selected taking into account the depth of occurrence. It is required to select according to the ring stiffness. It is indicated by the Latin letters SN and the numbers following them, displaying the ring stiffness (resistance to loads). For laying to a depth of up to 4 meters, the rigidity should be SN4, up to 6 meters - SN6.
The surface of the drain pipe is wrapped with filter materials. Filter layers can be from one to three. The number of layers is selected based on the composition of the soil - the smaller the particles, the more layers are required. For example, on clays and loams, pipes with three filter layers are used.
At the turning points and in places where several pipes are connected, revision wells are installed. They are needed for easier cleaning in case of blockage, as well as for the possibility of monitoring the condition of the pipes. As a rule, all pipes converge into one collector well, from where water is either sent by gravity to the discharge point, or pumped out forcibly.
There are special wells - for drainage systems, but it is quite possible to bury concrete ring with a bottom and a lid of small diameter (70-80 cm) and bring pipes into it. Depending on the depth of laying the drainage rings, several rings may be required. Another option is to make a large manhole and drainage pipe, but in this case you will have to come up with something with the bottom. For example, you can fill the bottom with concrete.
bias
In order for the collected water to drain on its own, it is necessary to observe a certain slope towards the direction of movement. Minimum slope is 0.002 - 2 mm per meter, the main one is 0.005 (5 mm per 1 meter of pipe). If the drainage is shallow, the slope of the pipe can increase to 1-3 cm per 1 meter, but it should be done as little as possible. At a flow velocity of more than 1 m/s, fine soil particles are “sucked in”, which contributes to a more rapid silting of the system.
The slope is changed (in relation to the "duty" of 5 mm per 1 meter) in two cases:
- If it is necessary to divert a larger amount of water per unit of time without increasing the diameter of the drain. In this case, the slope is increased.
- If you want to get away from the backwater (when the pipe laid with a given slope is below the GWL, i.e. water simply will not drain). In this case, the slope is reduced.
In the practical design of the system, questions may arise about how to provide a given slope. This can be done with the help of using a water level (not very convenient) or a flat board paired with a conventional building bubble level. Having leveled the bottom of the trench, a board is laid, a level is placed on it. Moving it along the board, they check and correct the slope of the bottom of the trench in a certain area.
Drain installation technology
Pre-dig trenches of a given width and depth. The bottom of the trench is leveled and compacted. Do not forget about the slope, but at this stage it makes no sense to withstand it exactly. Next, about 100 mm of coarse-grained washed river sand is poured, it is also rammed (spilled, then rammed), leveled. Sand is desirable fraction Dsr 1.5-2.5 mm.
It is laid on sand with a density of not more than 200 g / m2. The edges of the canvas are lined along the walls of the trench. A layer of granite rubble is poured on top. The size of the crushed stone fraction is selected depending on the size of the holes in the drainage pipe. For the smallest holes, crushed stone with a grain of 6-8 mm is required, for the rest - larger. The thickness of the crushed stone layer is 150-250 mm, depending on the type of soil. On clays and loams, 250 mm is required, on soils that drain water better - sands and sandy loams - about 150 mm.
Crushed stone is rammed, leveling into a given slope. It is laid on compacted gravel drainage pipe. Further, the pipe is sprinkled with gravel in layers, each layer is rammed. There should be at least 100 mm of gravel on top of the drain. After that, the ends of the geotextile are wrapped, their overlap should be 15-20 cm. A layer of sand with grains of 0.5-1 mm is poured on top. The thickness of the sand layer is 100-300 mm, also depending on the water permeability of the soil: the worse the water is drained, the thicker the sand layer. The “native” soil is laid on the compacted sand, and then plants can be planted.
A little about backfill materials
Crushed stone should be granite or other hard lime-free rocks. Dolomite (lime) or marble are not suitable. Testing the existing one is simple: drip vinegar on it. If there is a reaction, it does not fit.
Once again, we pay attention: the crushed stone is laid washed - so that the new pipes do not immediately silt up.
Sand is required coarse-grained. Grain size from 0.5 mm to 1 mm. The sand must also be clean. Some part of the sand is poured with clean water, shaken up, they wait until the sand settles and evaluate the purity of the water. If the water is cloudy, with a lot of suspended particles, the sand needs to be washed.
Some nuances of construction
When draining the site, the central drain or collector is made of pipes of a larger diameter (130-150 mm versus 90-100 mm for conventional drains) - the volume of water here is usually larger.
The drainage device on the site starts from the lowest point and moves gradually up. First, a collector well is installed. At high level groundwater or if the top water has not yet descended, water may accumulate in the ditches. This muddy slurry will roll down the well, clogging it. In addition, the presence of water in the ditch greatly interferes with work: drains must be laid in dry ditches. To drain them along the ditch, side pits (sumps) of greater depth are made. Crushed stone is poured at the bottom. The accumulated water is pumped out of these pits.
