Drainage Terms A-Z
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adoption of sewers
The transfer of responsibility for the maintenance of a system of sewers to a sewerage undertaker.
aesthetic pollution
Solid sewage-related materials that are visible but create little environmental impact.
antecedent conditions
The condition of a catchment before a rainfall event.
antecedent precipitation
The relevant rainfall that takes place before the point in time of interest.
antecedent precipitation index
An index determined by the summation of weighted daily rainfalls for a period preceding the start of a specific event.
anti-flooding device
A device specifically designed to be installed in gravity drains or sewers to prevent backflow from a sewer towards a property or a group of properties.
areal reduction factor
A factor applied to point rainfall depths or intensities to generate values applicable to an area.
attenuation
Reduction of peak flow and increased duration of a flow event |
