The classification of systems for the collection and effective management of rainwater is based on the features of their designs, which are three basic types that have become most widespread in all areas of construction:
Design of rainwater canal
- - open, meaning timely and effective removal of water from precipitation by special meansequipped with a system of concave trays, cuvettes of special design, open drainage canals and appropriately equipped outlets;
- - closed, when collected rainwater trays rainwater comes initially in the wells, rainwater, connected to underground pipelines, sometimes equipped with their own cleaning systems;
- - mixed, in which separate elements of both open and closed systems of sprinkling are used.
In some cases, rain sewers are installed, directing the flow of water into the existing drainage system near the house. However, such solutions are strongly discouraged by specialists, since the excessive volume of water in the drainage system can have a disastrous effect on the technical condition of the foundation of the building.
Installation of elements of storm sewage.
The rainbow laying is traditionally performed in parallel to the drainage system, with the same technical conditions( inclination angle is at least 5 mm per 1 meter of rainwater).With a sufficiently deep laying of drainage pipes, storm sewer can be laid on top of them with preliminary ramming of the soil to the maximum dense state, which helps to protect the pipes from destruction.
As in drainage, storm pipes are stacked on a cushion made of crushed stone or sand with a height of 5 to 10 cm. The most common material for rainwater pipes is the highly resistant polypropylene, which is impervious even to prolonged exposure to water. In order to increase the strength, the outer surface of such pipes is grooved and the inner one is absolutely smooth to reduce friction. As connectors for pipes, double couplings are used, in order to increase the tightness provided with elastic rubber seals.
Directly under the drainpipe, exactly in the level of its outlet cut, a receiving cone-funnel for water is mounted. This funnel is additionally assigned the role of a kind of filter, guaranteed to retain in itself the branches of trees that came with the roof, leaves and other large debris. Then, along the sloping pipe, the rainwater collected by the system from the allotted area follows to the rainwater harvesting well, either directly connected to the common collector or to the sewage pipe system.
In case of severe flooding or after precipitation of excessive precipitation in which the rainstorm can not cope, there is a risk of rainwater entering the drainage system and the basement of the building. To avoid this, a well for drainage and drainage pipes is fitted with a reliable but structurally simple check valve. The lower part of this check valve is always located at least 12 cm from the outlet of the rainwater tray. The upper part of the well is usually supplied in addition with a coupling, through which, if necessary, a downpipe can be connected in case of necessity.
The fully assembled lower part of the rainwater drainage system, consisting of a water collecting neck with a lid, an extension pipe and a direct well, is filled with a sufficient layer of sand or small gravel, which is then carefully rammed.
Open water drainage installation
The rain collector outlet leads either to a centralized high-efficiency sewer system or to some distance from the building to the ground or to an open turf for subsequent soil absorption. In the latter cases, a mound of crushed stone is used to break up the water flow. In addition, in the same cases, the exhaust pipe is provided with a simple but reliable protective grid, preventing the penetration of small animals into it.
Problems to be solved in the design of storm sewer systems.
Without effective removal of rainwater, there is no way to exist either large cities or compact cottage settlements. However, the amount of water withdrawn in each case will be completely different, so the construction of storm sewers always begins with careful calculations. These calculations include the following activities:
- - tracing;
- - design development of the main components and components;
- - hydraulic calculations.
Closed-type rainwater drainage installation
Despite the seeming complexity of such calculations, it is quite possible to do this for an individual apartment house on its own. To do this, it is necessary to relate the catchment area, the terrain, the likelihood of possible contaminants, the length and diameter of the water lines, and the expected amount of precipitation, taking into account the climatic features in this locality.
Tracing includes planning the placement of nodes and elements of rainwater drainage in such a way that the water can freely flow by gravity along the most meek and free path. To do this, the entire catchment area is divided into several basins, each of which in the general scheme is provided with its own collector, connected to a sewage system of sufficient capacity.
Example of a closed-type rainwater drainage system
Also read about installing a storm sewer.
