nidaplast ® rain
Traditional sewer management no longer meets modern needs
Drainage of rain is a necessity in a modern town.
Why? Urbanisation results in an expansion of paved surfaces, meaning that it is difficult for water to penetrate the substrate in the event of heavy rain. Traditional sewers that drain rain and waste water together are showing their limitations.
Economic limitations
In order to guarantee that rainwater is drained, storage is normally designed in or around the sewer system. This means the sewers are too large in periods of normal precipitation.
The investment and operating costs of sewers and storage basins that are too large are slowly becoming unacceptably high for the sewer managers who want to optimise their investment.
Technical limitations
A number of sewers are overloaded and cannot handle the rainwater from new extensions without major reinvestment.
Ecological limitations
It is no longer ecologically viable to contaminate the surface water with fast-flowing overflowing sewer water. A separation of rain water makes overflow structures unnecessary.
Alternative methods of solving the problem
In order to prevent flooding in the event of heavy rain, the expansion of the paved surface must be offset in new collection/infiltration systems.
Nidaplast® rain provides the answer: water overflow on roads and pavements is prevented. "Various" methods can be used depending on the situation:
Storage basins:
In the event of excessive rainfall, the water is stored and then drained via the smaller sewers.
Infiltration basins:
Water is stored in the same way but infiltrates the groundwater via a permeable base. This is possible if there is no risk of soil contamination.
Storage basin with option of infiltration
Principle of how a storage basin works
The storage basin consist of blocks that can store large volumes of rainwater in the event of a heavy storm. If the ground is permeable, the stored water can infiltrate the soil up to the groundwater level. Rainwater that is not infiltrated is drained to the watercourse after a delay. There is therefore no need to make the sewers larger which results in substantial cost savings.
Nidaplast ® rain storage basins enable pipes with much reduced diameters to be used.
Calculation of the capacity
The necessary storage can be calculated from tables of rain intensities. If infiltration is possible, this calculation can be refined which can lead to a minimum necessary storage capacity.
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 Advice on implementation
In order to optimise the water storage and drainage nidaplast ® rain can be placed over a drainage system which in turn lies on a bed of draining material. The collection tank has a coarse contaminant strainer basket and a sand trap, all enclosed with a geotextile.
A cost-saving and high-performance system for storing rain water
Nidaplast ® rain is made of polypropylene and consists of a honeycomb with a mesh size of 20 mm. The open sides of a nidaplast ® rain block, top and bottom, are covered with geotextile. Dimensions of a standard block: 2400 x 1200 x 480 mm.
Other dimensions are available on request.
95% Absorbent
Its hexagonal structure means that nidaplast ® rain can store up to 95% of its volume with rainwater.
Today it is the highest performance product in its field.
Self-cleaning and low maintenance
The buffered rain water exits the nidaplast ® rain blocks along the same channels as those used to fill the block. The familiar "counterflow" cleaning method is therefore applied in a natural way. This makes the storage structure self-cleaning and low maintenance.
Lightweight and manageable
nidaplast ® rain weighs just 40 kg/m3. nidaplast ® rain is easy to transport by hand, quick to install and can be filled and finished immediately.
The structure of a nidaplast ® rain basin keeps overload on the environment to a minimum.
High mechanical resistance
The pressure that the cells can withstand at 20oC is 40 tonnes/m2 in the longitudinal direction and 2 tonnes/m2 in the lateral direction.
These mechanical resistances allow nidaplast® rain to be installed under roads too. The minimum soil coverage required is 25 cm.
Resistance to chemicals and micro-organisms
At ambient temperature, polypropylene is not sensitive to most chemicals that might be present in the water to be drained.. It has excellent resistance to micro-organisms, mould, rodents and insects.
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 Principle of how a storage basin works
During a storm, the water runs into the storm drain and thence to a draining distribution system (1) fitted in a bed of draining material (2). The water rises and enters the nidaplast® rain blocks (3) where the water is temporarily stored.
When the rain has stopped, the stored water then flows to the distribution system under freefall, and then infiltrates the substrate (4) and/or is drained in a controlled way (5). (6) ventilation pipe.
Infiltration basin under the road
(permeable road surface and water from the roofs)
Infiltration pit
 Infiltration basin with nidaplast ® rain in green areas
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