Drainage Of the Site

The close location of moisture-containing soil layers to the surface can seriously damage the condition of your site and home. This is dangerous because due to erosion, the soil subsides, which leads to an increase in loads on the foundation and supporting structures

Drainage Of the Site

The close location of moisture-containing soil layers to the surface can seriously damage the condition of your site and home. This is dangerous because due to erosion, the soil subsides, which leads to an increase in loads on the foundation and supporting structures. Their gradual destruction and deformation occurs. Rotting and rusting of the building structures begins, concrete and brick are washed out.

Moisture does not bring anything positive for the soil and the harvest either. It removes organic and mineral components from the soil. The acidity of the soil increases, the soil becomes unsuitable for fully growing useful garden plants and crops.

Timely drainage of the site helps to effectively regulate the water level, sometimes even completely drain the land. The drainage system is calculated taking into account the terrain features, including pipes with holes (drains), as well as wells. In rare cases, pumping equipment is used for drainage. The liquid in a properly constructed drainage system goes into tanks or reservoirs, drainage pipes must be well washed so as not to clog. You can install such drainage yourself.

Why and when to drain a site

Drainage protects the load-bearing structures of the house, its foundation from erosion, preserves garden plants and landscape. Your garden plot definitely needs drainage if:

it is located in a lowland where water collects from higher points, which becomes especially abundant during the snowmelt period and rainy months;

  • your summer cottage is located on a slope - during rainy seasons, puddles that do not dry up form here, which leads to the soil being washed away under the house, and the foundation is inevitably damaged;

  • your dacha is located near a pond or river;

  • the soil, which is mainly located under the house and surrounds it, is sandy, clayey or crushed stone (they practically do not allow moisture to pass through);

  • next to your house is the most common flat landscape - but drainage of the site may also be required, because puddles may appear on the ground and not dry out for a long time.

The organization of the drainage system will save the soil from stagnant moisture, and will divert it from the foundations of the buildings on your site. If the basement or plinth is not waterproofed enough, the drainage will protect the underground premises from the occurrence of fungal formations and mold. Drainage is also useful because it protects the septic tank: the treatment facility sometimes needs to be reinstalled due to the septic tank being pushed upwards under the influence of groundwater. There will be no such problems with drainage.

Drainage of the site protects against frost heaving - an extremely undesirable process that occurs in the soil in the winter. Frost heaving leads to deformations of the foundation, distorting the geometric proportions of the house.

Surely, you grow something in the beds, but your harvest is threatened by the same moisture, making the soil oversaturated with water. The drainage system removes stagnant liquid, it will stop washing away garden paths, causing rotting of plant roots and garden crops.  

Properly constructed drainage should drain well the sediment water that got onto the site due to heavy rain, flowing down the slope. This process is called soil erosion, and it mainly affects the border areas. If you have a fence in the form of a monolithic fence erected on a strip foundation, the natural flow of liquid is disrupted - moisture begins to accumulate. And in such situations, drainage of the site helps out.

Pro Tip: Looking for expert concrete contractors in Guelph? We specialize in driveways, patios, and custom concrete solutions. Contact us today for a free quote!

Types of drainage systems for the site

Depending on whether the groundwater rises high enough on the site, open or closed drainage is chosen. Now, more about each of these drainage systems.

First, you will need to call a surveyor to the site. He will inspect your and neighboring sites, determine the depth to which the wells are dug, and, based on some other external signs (the presence of certain types of vegetation), he may establish the fact of a high level of groundwater rise. In this case, closed drainage should be performed.  

Open systems

Such drainage systems are also called surface drainage. The name itself is dictated by the fact that moisture during drainage is removed only from the surface of the earth. This is precipitation and melt water. This type of drainage is recommended to be performed on almost every garden, vegetable garden, household and summer cottage plot. Structurally, the drainage design looks like a system of shallow canals located at an angle. 

A distance of about 6 meters is maintained between them. Canals with beveled walls are not deepened less than 40-50 cm. Sewer pipes are laid inside them, rainwater inlets with upper grates and trays are organized that drain moisture outside the site, or into drainage wells. It is important to remember that when organizing drainage near the house and auxiliary buildings, there should be no canals - otherwise there is a risk of damaging the foundation structure. It is the open type of drainage of the site that can really be done with your own hands.

The standard depth of ditching for open drainage to drain spring melt water is 60-70 cm. The same depth is recommended for protection from rain moisture.

Closed drainage systems

If the groundwater level rises to such an extent that it seriously threatens to wash away the soil, closed (deep) drainage of the area with a high groundwater level is performed. This method is more complicated, although deep drainage is more effective. To install such drainage, PVC pipes are used, which are deepened into the ground. It is necessary to ensure that they do not become clogged. Therefore, they are wrapped in geotextile. 

The system of perforated pipes of closed drainage is installed quite deep underground, below the level of soil freezing. For this, trenches are dug that go to a depth of up to one and a half meters. They are filled with gravel or crushed stone, and then a system of pipes for drainage is laid in them.

The entire structure of the drainage system with closed drainage must follow the slopes of the natural terrain of the area where the house is located. Such drainage is very difficult to do on your own, we recommend contacting professionals.

Types of drainage wells

Wells are integral components of drainage systems, they are used to store, accumulate, filter and discharge water masses. There are three types of drainage wells: rotary, collector and plugging.

Inspection (rotary) drainage wells+

This type of well is installed in places where drainage pipes turn and connect. In sections of the drainage system where there are only straight pipes, such wells are placed every 20 meters. An inspection well allows you to control the drainage process; to remove the contents from it, you need to pump out the liquid using a pump into a septic tank or simply flush it with a stream. Such wells are also used to clean the area from sludge, which should be done every 10 or 15 years.

Collector (water storage) drainage wells

The purpose of these tanks is to store (accumulate) liquid. It comes here before draining, and it is also taken from the collector well for watering the garden. The process of pumping into the wells is carried out by a submersible drainage pump. It is located underground, in a separate depression. Only when this pump is running does the collector well itself work, which, according to the rules, is placed at the lowest point of the site, since the water should flow into it by gravity, going down the slope.

Cementing or absorption (filtering) wells

Such devices perform more complex functions. Like other types of wells, they collect water, but additionally purify it. Instead of arranging the bottom, large gravel, crushed stone or brick chips are poured into the base of such wells. Filter wells are installed when performing drainage only where there is no natural reservoir for draining liquid into them. Most often, they are installed on sandy, sandy loam soils. The water masses that have passed the filter simply go deep, underground.  

How to determine the groundwater level 

You can predict the rise of groundwater if you know the depth of its location. When it exceeds 5 meters, you don’t have to drain the site at all. We have already mentioned the geodetic work that a specialist carries out on the site before starting drainage work. You can also conduct certain surveys yourself. Here’s what you can do:

  • inspect the surrounding area: if you notice an overgrown pond with stagnant water, its accumulation in low-lying places (ravines, lowlands, pits), puddles that do not dry out for a long time - these are the first signs of the need to organize drainage on the site;

  • inspect wells (especially abandoned ones, from which nothing is pumped out) - the level of liquid in them can indicate to what height the groundwater rises;

  • talk to your neighbors, especially the owners of basements and wells: ask these people how deep they dug their wells, whether the basements in their houses are flooded, whether there is mold on the walls;

  • study the surrounding flora: if, for example, there is a lot of horse sorrel growing nearby, there are reeds, hemlock, or noticeably a lot of sedge, cattails - this indicates an excess of liquid in the soil; the presence of fruit trees, on the contrary, will tell you that the soil is quite dry;

  • drill holes: take a garden drill with extensions or a similar construction tool, try to drill into the soil in several places by two meters - perhaps the hole will fill with water.

Types of surface drainage

There are open (surface) points and linear (storm sewer) drainage of the site. The main difference here is the size of the drainage system coverage of the territory from which liquids will be discharged.

Spot drainage

This type of drainage is organized in places where a lot of water accumulates. These are areas under drains and roofs (houses and auxiliary buildings). The drainage scheme includes a rain receiver (with an external grate) that does not allow large particles, leaves, stones to pass through, but allows water and melted snow to pass through itself and enter the sewer pipe, and from there - into the drainage well.

First, make a pit, right under the drain pipe. The depth should be 30 cm greater than the height of the drain inlet, the other (surface) dimensions should be 5 cm greater than the similar dimensions of the grate. Pour sand onto the bottom (a layer of up to 10 cm), then tamp it down. Strengthen the drain inlet, which should be placed on top of the sand layer, using the same sand. Fill it from all sides, and from above - almost to the very top. After this, tamp it down.

Now you need to install the sewer pipe, one end of it needs to be connected to the storm drain, the other one needs to be brought into the sewer using a coupling. Seal the structure with a sealant for strength. Place the grate on top of the storm drain. All that remains is to fill the pipes with sand and compact it thoroughly.  

Stormwater drainage for drainage

This drainage technology (along the perimeter of the house) is used when there is a lot of moisture. Structurally, the system of such drainage is represented by drainage channels (concrete or plastic) with an upper grate and sand traps (with a basket for collecting garbage). The channels are rectangular in shape. Water enters through the grate, from above. Then it goes to the sand trap, the location of which should be where the channel and the sewer pipe connect.

The sorted sand goes into the wastebasket. Remember: it should be emptied regularly. The work on organizing drainage in the form of a storm drain begins with digging a ditch around the perimeter of the house. Step back from the foundation by 50 centimeters, no more. The depth of the ditch is determined so that there is a reserve (30 cm deep) compared to the height of the drainage tray.

The excavation work will continue with digging a trench. Which has a small, gradual (2-3 degrees) slope and leads to a collector well, it should be located at the lowest point of the site. Follow the rule: for every meter of the trench length, make it 2 centimeters deeper. This will allow the liquid to flow by gravity. It is not necessary to install a well, it can be replaced by a simple drainage ditch or a natural reservoir.       

Then, at the lowest point, you need to dig a hole for the collector well (at least 2 meters deep). If the area is almost completely flat, choose any random point for this. But then dig a hole so that its depth exceeds the level of the sewer pipes by 40 cm.

Mix 30% sand and 70% gravel, pour this mixture into the bottom of the ditch (along the perimeter of the house) by 20 centimeters. After ramming, you need to fill everything with a ten-centimeter layer of concrete. Do not wait for drying - immediately put two trays in the concrete base. Fasten the trays together with a sealant applied to their edges. The drainage system is almost ready. 

All that remains is to install a sand trap, it is placed between the trays. Close it with the upper grate. Then put the pipe in the trench, sprinkle it evenly almost to the top with sand and fertile soil layers (you recently dug it). Finally, connect the sewer pipe and the well with a rubber sealing cuff.

Pro Tip: Discover durable precast concrete stairs in Guelph! Perfect for homes and businesses, our stairs offer strength and style. Contact us now for expert installation.

Types of deep drainage

This type of drainage is carried out on a land plot to protect it and a country house from groundwater that comes close to the surface. Closed (deep) drainage systems are layered, wall-mounted, and ring-shaped. The last type of drainage is used when the house has already been built; ring drainage of the plot is organized along its entire perimeter. Layered closed drainage is carried out only at the construction stage, because it is carried out directly in the foundation. Let's talk in more detail about the two types of deep drainage.

Wall drainage

Such drainage of the site is available for implementation even when your house is already built. But you will have to dig a trench around the house. Perforated drainage pipes are laid along the perimeter. They are laid at a slight slope of 2-3 degrees and lead to a collector well.

 

Washed sand, 10 cm thick, is poured onto the bottom of the trench. After compaction, a geotextile layer is formed, and on top of it - a layer of granite rubble, also about 10 cm. Then drainage pipes are laid, which are supplemented with inspection wells in the turning areas. Couplings and tees are used to fasten the pipes together, and they are attached to the collector well with rubber cuffs. 

When the drainage installation is complete, everything is covered with crushed stone (until the pipe is completely covered), the pipe is covered with strips of geotextile, and the trench is filled with sand. For the sake of aesthetics, the last 10 cm can be filled with soil - then the drainage will not disturb the harmony of the surrounding landscape.

Ring drainage

In fact, this is also a wall drainage, only executed a little differently. This type of drainage can be done before or after pouring the foundation. The main difference from the wall type is that the pipes themselves are placed further from the house - at a distance of 1-3 meters. Moreover, they are laid deeper, half a meter below the level of the foundation sole.  

As a result

Finally, let us note some features that distinguish the drainage of the site. It is very important to remember that the drainage system is built according to a previously prepared project or drainage plan. The drainage project must contain surface markings, this is necessary to correctly ensure the desired slope.  

The point is that any drainage system described in this article is non-pressure. The liquid must move freely by gravity. Therefore, it is extremely important to ensure a slope when laying drainage pipes. The required slope is also observed when installing a drainage system deep in the ground. Depending on the type of drainage, the slope is from 1 to 5 centimeters per linear meter of the trench length. Let us remind you that before starting work on the construction of drainage, it is necessary to conduct a geodetic survey. Its purpose is to determine the level of groundwater, the degree of danger that moisture will pose for the house, garden, plot. If the water from the soil rises high enough, deep drainage of the site should be performed.

What's Your Reaction?

like

dislike

love

funny

angry

sad

wow