Linear drainage facilities include both closed and open gutters. Open channels direct the water superficially to a drainage point, so the channel itself must have a corresponding depression and slope at the surface.
Closed channels, on the other hand, lead the precipitation to be drained below the surface to runoff. They consist of the gutter body (e.g. concrete, polymer concrete, plastic, steel) and the cover grating. The slot channel is a special design. The nominal diameters (NW) are 100 mm, 150 mm, 200 mm or larger, up to 1000 mm.
Channels have either a slope at the bottom or steps or no slope at all, the water runoff is then regulated by the water level or by installation with a slope. Components with and without a natural slope can also be combined, for example to keep the installation depth low. To drain the water, an inlet box or a pipe connection in the bottom of the channel must be provided at the end of the channel (in the case of longer channels also in between).
installation of drainage channels and drains is carried out on a concrete foundation. On roof surfaces, balconies and terraces with permeable structures, special shapes are used, which are placed directly on the ground. Park and side paths are also drained via transverse tees (simple gutters in timber construction).
The choice of cover depends on the location (streets, pedestrian areas) and the design requirements.
Cast covers generally offer the greatest load capacity. Gratings or longitudinal and transverse bar gratings have maximum inlet cross-sections. Perforated grates have rather small inlet cross-sections and are only able to withstand a small load. Special elements can be made of concrete or natural stone.
Source: Zimmermann, Astrid; Landscape Constructing – Materials, Techniques, Building Elements. Birkhäuser, Basel. 2011.
