Autonomous water supply of a country house: collecting rainwater

Recommendation points

• Water needs
• Rainwater – collection and accumulation
• Installing the Drive
• Conditions for the accumulation, storage and use of rainwater
• Plumbing for rainwater

Own house outside the city limits, near a forest and some water body, in a place where the air is not filled with smog is the dream of any city dweller. Just choosing a suitable site and building a house is not enough, you still need to solve the problem of supplying technical and drinking water. Let’s find out how you can get water outside the city in the absence of central water supply.

Water needs

Regardless of the place of residence, each person needs at least 150 liters of water daily – for drinking, cooking and for other household needs. For watering sq. m of a garden, flower garden or lawn will take about 30 liters of water per week. Central water supply in cottage settlements is ineffective even in summer, and in winter it is completely absent, since otherwise the pipes will freeze and be broken. Of course, the owners of suburban real estate can provide themselves with bottled drinking water, purchasing and bringing it with them every time they visit the country house, but what about personal hygiene, wet cleaning of premises and watering plants on the site?

For domestic needs and for irrigation water can be obtained from the following sources – precipitation, nearby open water bodies and springs, groundwater (pressure and non-pressure). Waters on the surface of the earth (lakes) and those occurring near it (upper water) accumulate due to atmospheric precipitation, in places where they are kept by waterproof layers under them, usually formed by clay. The groundwater and interstratal waters occurring at a greater depth (from 1.5 m) are suitable for drinking, but quickly become polluted if there is a cesspool, a barnyard or a garbage dump near their location. Artesian waters are deeper than others – their horizon begins at a level of 70-100 m and more, they are pressure-bearing and have an almost constant volume.

Rainwater – collection and accumulation

In water of atmospheric origin, salts are almost completely absent, that is, it is softer than that coming into houses from the central water supply. The acidic reaction of rain is most often neutral, its drops contain a significant amount of oxygen, so rainwater is ideal for irrigation. But the composition of such water may contain heavy metals, hazardous chemical compounds, fuel combustion products and dust particles suspended in the lower layers of the atmosphere, which will significantly reduce its quality. However, the percentage of harmful components in the rain is directly dependent on the nearby large enterprises of metallurgical, chemical, oil refining and other industries, large transport hubs, as well as megalopolises.

From a practical point of view, the advantage of rainwater is that it is completely free of charge, and the disadvantage is the inconstancy of rains, which may rain for several days in a row, or may be absent for weeks. The simplest way to collect atmospheric moisture is by placing barrels and troughs under the gutters. However, it has a drawback – the water accumulated in this way for irrigation and communal needs will not be enough for the entire warm season, since the total volume of improvised reservoirs is not large. To provide a country house with technical water collected during rains, it will be necessary to build a system that can accumulate the necessary volumes of rainwater and ensure its delivery to consumers..

The quality of the water collected during rain is influenced by the roof structure and the type of roofing. A pitched roof – with a slope of more than 10 ° – will collect water more efficiently than a roof at a lower angle. In addition, there will be no puddles of water on the pitched roof, acting on flat roofs as a cage for microorganisms that penetrate after the next rain into storage tanks and spoil the water.

It is not recommended to collect rainwater from roofs covered with asbestos slate with lead and copper elements in the sheathing! Slate contains amphibole asbestos fibers, the penetration of which into the human body causes serious lung diseases. The oversaturation of water with lead and copper ions affects the central nervous system of a person, impairs plant growth. In addition to roofing materials, you should pay attention to the means of delivering water to storage tanks – downpipes and gutters, make sure that they are lead-free. The roof and its elements made of galvanized metal, natural tiles, polyvinyl chloride and other materials that do not contain asbestos, lead and copper are quite suitable for collecting rainwater.

To collect the required amount of water that can completely solve the problem of watering the territory of a country house, you will need a capacious container made of galvanized steel, polyethylene, concrete, etc. The materials that form a storage container should not change their properties over time, and also affect chemical composition of water. It is easier to use a ready-made polyethylene container with opaque walls. The rainwater storage tank can be surface-mounted or placed below ground level – buried in the ground or placed in the basement of a house. It will be rational to bury the container in the ground, which will provide natural cooling of the water collected in it, prevent the development of microorganisms and algae in it.

Installing the Drive

The advantage of tanks located in the basement or underground is that they do not need to be emptied in the fall – provided that the temperature in the basement is not below zero, and most of the buried tank is located below the freezing level of the soil. The capacity of the tank installed in the basement can be from 750 to 2000 liters, its width usually does not exceed 800 mm, which simplifies transportation of the tank through standard doorways to the place of placement. If necessary, you can combine several tanks with each other using plastic pipes with a diameter of 50-100 mm, introduced by means of a detachable connection in the bottom of each tank.

Placing a storage tank in the ground is possible if the groundwater level is low. For this purpose, containers with a large volume are suitable: 2000–3000 liters. The pit must be dug deeper and wider than the overall dimensions of the tank – a 200–250 mm layer of coarse sand is poured onto the bottom of the pit; the capacity is set; coarse sand is poured between the storage tank body and the pit walls, with a layer of 200–250 mm. The distance from the neck of the tank to the surface of the earth should be from 200 to 500 mm, after entering into it a pipe through which rainwater will flow and a submersible pump that will pump water out of the tank, it is necessary to close the opening leading to it with a lid. Before the start of the cold season, the pump is removed from the tank, and the cavity above the closed neck is filled with sand. A sand cushion under the tank and along the perimeter of its walls will protect the tank from soil pressure, filling the neck from freezing.

If it rains for a long time, water can overfill the reservoir. Therefore, when installing an underground tank, it makes sense to equip it with a drain-overflow pipe capable of draining excess water into the storm sewer – the outlet from the storage tank must be equipped with a siphon (water seal) that prevents odors from entering the sewer system, as well as a check valve that does not allow water from sewers get inside the storage.

In the event of a prolonged absence of atmospheric precipitation and the emptying of the storage tank during irrigation, it must be filled with tap water or supplied from a well – it is not recommended to keep the underground tank empty, since it can be damaged by ground movements. To determine the degree of emptying of the container, it is necessary to apply white paint markings on its inner wall, marking at least 1/3, 1/2 and 2/3 of the internal volume – in this case, the amount of water can be determined visually using a flashlight.

Conditions for the accumulation, storage and use of rainwater

Dry weather without any precipitation, established for several days, will lead to the deposition of dust and fine debris on the roof. The first rain after a drought, of course, will wash away all the dirt, but it will fall into the rainwater reservoir, eventually forming a solid layer of dirt at the bottom of the tank. To prevent this from happening, it is necessary to disconnect the water collection pipe from the drain for about half an hour – heavy rain during this time will wash the roof, after which the inlet pipe to the storage tank can be installed back and water can be collected.

Gusty winds, usually accompanying the rain front, carry branches, leaves and other large debris onto the roof, which should not end up in the rainwater tank – you need to equip the gutters with removable trap grates, and install filter baskets in the drain pipes. You can install a filter element in the neck of the storage tank, the hole diameter in which does not exceed 0.2 mm, but you have to monitor the degree of clogging of this filter, that is, leaving the rainwater storage system unchecked for a long time will not work.

It should be noted that, despite the described filters, the water entering the tank will have a cloudy appearance – in order to use it for domestic needs, you will either have to clean it with a filter with 5 micron holes, or give it time to settle and sediment suspensions to the bottom. The second method is cheaper, but will require work on periodically emptying the tank, manually removing sediment on its bottom and walls (1-2 times a year). Those who have equipped the rainwater supply system with a fine filter will need to disinfect it from time to time in order to destroy accumulated microorganisms.

Plumbing for rainwater

To use the collected water for domestic needs, you need to create a water supply system with industrial water. In most cases, storage tanks are located at or below ground level, so a pump is needed to operate the water supply system. Stationary models of centrifugal pumps should be installed inside the house as low as possible – on the ground floor or in the basement, which will reduce energy costs for pumping water into the water supply system and reduce its length. You can also use a compact submersible or external pump. Regardless of the selected type and model of the pump, the water intake from the storage tank is made only from the water surface, that is, the water intake tube should float on the surface of the water surface, like a float. This method of water extraction will reduce the likelihood of penetration into the water supply of contaminants that have settled on the bottom of the tank and suspended in the volume of water..

It is important to put markings on the taps and pipes inside the house through which industrial water flows – you cannot drink it and cook on it!

The contents of a rain accumulator cannot completely replace human needs for water, since even washing dishes and taking a shower with rain water is permissible only if it is multi-stage filtration. However, for other purposes – watering green spaces and territory, wet cleaning and flushing in the toilet, it is quite suitable. The natural softness of such water ensures effective washing in it with low consumption of detergents.

Research by scientists has shown that in a number of characteristics rainwater is superior to tap water, its quality is much higher than in open reservoirs. And since rains are typical for the territory of Russia, it is quite possible to use free water “from the sky” to partially solve the problems of suburban water supply.