Drainage Terms A-Z
F
first foul flush
The initial discharge of active sediments and pollutants of a generally higher than average concentration of pollutant caused by rainfall.
flap gate
A gate that opens to let water out but prevents water entering back into the system.
flood storage pond
A pond constructed for the purpose of temporary storage of stream flow or surface runoff, which releases the stored water at controlled rates.
flood studies report
Landmark report in the UK for catchment hydrology. (institute of Hydrology 1975)
flow regime
Typical variation of discharge of a waterway usually over an annual or seasonal period.
foul sewage
Waterborne waste of domestic or industrial origin excluding rainwater and surface water.
foul system
A drain or sewerage system that has been designed to carry only foul sewage.
french drain/ filter drain
The use of a granular trench filled with stone to convey and infiltrate stormwater runoff.
frequency
The number of occurrences of a certain phenomenon per unit time. |
