Glossary Group: H

A classification used to indicate the permeability of the soil and the percentage runoff from a particular area.

A conduit draining the highway. On a highways maintainable at the public expense it is vested in the highway authority.

A local authority with responsibility for the maintenance and drainage of highways maintainable at public expense.

The government agency responsible for strategic highways, ie motorways and trunk roads.

A graph showing, for a given point on a stream or conduit, the discharge, stage, velocity, available power or other property of water with respect to time.

The computational process carried out by a computer model to analyse the behaviour of a system (sewer network) due to an external influence (rainfall).

The measure of the capacity of the system or part thereof.

The maximum flow that a pipe of given dimensions, slope and roughness can carry (often quoted as pipe-full capacity, which is a little less than the maximum capacity).

Assessment of the hydraulic behaviour of a system. Simulation hydraulic modelling of a sewerage network to determine its performance.

A drain or sewer constructed for the purpose of draining a highway.

Any road, track, bridleway or public-footpath in private or public ownership that is not associated with an individual property.

The relationship between a discharge rate and the water level causing the discharge.