This means the quality of all the aspects of a water resource including -
- the quantity, pattern, timing, water level and assurance of instream flow;
- the water quality, including the physical, chemical and biological characteristics of the water;
- the character and condition of the instream and riparian habitat; and
- the characteristics, condition and distribution of the aquatic biota.
[Source: National Water Act (Act No. 36 of 1998)].
Numeric or descriptive characterisation of the water resource and should not be confused with the water quality of the resource.
This is a component of Resource Directed Measures used to protect and manage water resources in South Africa.

Source: http://www.dwa.gov.za