Drainage Terms A-Z
G
gradient
The angle of inclination (of pipe), which dictates its capacity and velocity of flow.
gravity system
A drain or sewerage system whereby flow is caused by the action of gravity and where the pipeline is designed to operate partially full.
greenfield/greenfield site
New development, usually at the periphery of existing urban areas. This creates increased rainfall-runoff and has an impact on existing sewer systems and watercourses.
greywater
Wastewater from sinks, baths, showers and domestic appliances.
gross solids Solids, usually organic in nature, either floating, suspended or deposited, which have a polluting effect on a receiving water. Often restricted to visible solids with one dimension in excess of 25mm.
groundwater Water that is below the surface of the ground within the saturation zone.
gully
A structure to permit the entry of surface water runoff into a sewerage system. It is usually fitted with a grating and a grit trap. |
