Page 47 - Freshwater-Biology-and-Ecology-Handbook

4.2 Water bodies

Water bodies form the base units for monitoring a water body within an agricultural catchment would
programmes and river basin management. need to be separate from a water body downstream
of a town where a sewage treatment works discharge
The key purpose of identifying water bodies is to allow enters the river. This would be a different risk and require
ecological objectives to be defined clearly in relation to different measures for improvement. Natural and heavily
the pressures acting upon river basins. Consequently, modified or artificial areas must be designated as
the water bodies must represent appropriate units for separate water bodies.
managing particular pressures or sets of pressures.
One of the first tasks in developing water management Correctly identifying these major natural sub-divisions
programmes is to identify and define water bodies that will make the future management and monitoring
are representative of that particular situation. They more effective and will ensure accurate reporting and
should be discrete and environmentally significant assessment. Figure 1.8 shows the key elements of
elements of a river basin. They can be parts or ‘reaches’ water body identification and introduces the concept
of a river system, a lake, estuary or coastal water, but not of typology.
combinations of these water body categories.
Individual water bodies must be subject to the same risks
for which the same measures are needed. For example,

The Directive requires that rivers, lochs,
A transitional waters and coastal waters
are sub-divided into types based on
characteristics such as altitude, geology
and size, represented as A, B and C.

B
Waters within a type may be
further divided by physical
characteristics, such as a
confluence or major tributary.

C

Water body boundaries will be identified within these sub-divisions
where there are changes, or risks of changes, in ecological status
as a result of human activities. Such a boundary is represented
in the diagram by a major discharge (and the change in status
that this may give rise to). This will ensure that the quality of a river
basin district’s aquatic ecosystem can be properly described by
classifying the status of its water bodies.

Figure 1.8
Identification of water bodies. Source - Scottish Environmental Protection Agency (SEPA), 2002, Future for Scotland’s Waters (11)

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