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CHAPTER 3 3.1.4

Figure 3.10 Figure 3.11

Front cover of Davy-Bowker et al. (2008)describing SNIFFER Project WFD72c final report, Clarke &
the development of RIVPACS IV and RICT (34) Davy-Bowker(2014) covering development of RICT
to incorporate WHPT status classification (47)

The most recent refinement to the river invertebrate classification
occured in 2016 and replaced the classification metrics based
on BMWP indices by equivalent metrics based on WHPT indices
(Figure 3.11). The 5M approach to setting initial class boundaries
was used, with boundaries for NTaxa again slightly adjusted. The
remaining sections of this chapter describe in more detail the
steps to deriving the current classification.

RIVPACS does far more than predict reference values for river
status classification. It can predict the natural invertebrate
community (the species composition and the abundance of
each species) found in any permanently flowing stream or river
in the UK, so it is a far more adaptable tool than those developed
for other quality elements, particularly plants and algae. It
recognises the different natural communities in terms of their
species composition (its original aim) and not just the intensity of
one or more environmental pressures to which the classification
metric is supposed to respond. It is therefore relatively easy to get
RIVPACS to predict the un-impacted or reference value of any
index. This ‘over-engineering’ means that it is a far more capable
predictor than tools designed only to predict reference values
for particular indices or the single pressures to which they are
Figure 3.12 assumed to respond.
Front cover of the proceedings of a conference held
in Brussels in December 1991 at which the RIVPACS The success of RIVPACS and the reference approach to
approach was introduced for the proposed European classification in the UK led to its adoption in the Water Framework
directive that became WFD (46) Directive for all biological quality elements in all water body
categories across Europe (Figure 3.12).

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