The automatically operating weir structures presented are simple, largely maintenance-free structures which, when used as control elements in storm overflows, offer considerable advantages over the fixed weir sills. Irrespective of the intensity of rainfalls, these weirs do not discharge any surplus water into the receiving water, unless a maximum possible water level has been reached, which is then maintained at a virtually constant level until the floods subside. The maximum possible water level, the so-called impounding head, will be determined in such a way that, on the one hand, the sewer capacity will be fully utilized, and, on the other, any undesirable backwater in the sewer system can be precluded. The weirs are not only suited for installation in new structures, but may also be integrated in existing ones. Time and cost consuming constructional measures can be dispensed with, as the weirs can, owing to their configuration - they are composed of individual segments - be passed through the existing manholes. They allow considerable additional sewer capacities to be activated, in particular in low-head sewer systems, so that the installation of high-cost retaining basins, which normally require a high degree of maintenance, can either be limited or dispensed with altogether. As the receiving water will be affected only when a given impounding head has been reached, the amount of combined sewage discharged can be reduced to a minimum.

This content is only available as a PDF.
You do not currently have access to this content.