Temperature - European Investment Bank

WEST AFRICAN POWER POOL (WAPP) PÖYRY ENERGY LTD.
Mount Coffee HPP ESIA and RAP 2012-09-18
ESIA Report Page 135
19 MAIN IMPACTS
19.1 Impact Categories
Project impacts are shown in a summarised way in the matrix on the following page.
This matrix shows project components and activities in the left hand column and the
affected environmental parameters in the top row. Impacts are then shown in the form
of a number of categories in the table itself.
It has to be emphasised that a matrix of this form is a simplified way of looking at the
issues at hand. Therefore, it is important that the value and the limitations of the matrix
are clearly understood. In a first step, the categories used need to be explained.
In a general way, there are three main groups of impacts: positive, negative or uncertain.
The scale as explained in the following Table was applied in the matrix.
Table 19-1: Impact categories used in matrix
Definition of Impact
+3 Strongly positive: highly beneficial effect, permanent or at least of long duration,
affecting a wide area and/or an important parameter.
+2 Positive: beneficial effect, of long duration or permanent.
+1 Small positive: beneficial effect of lesser importance, either of short duration, limited in
space, and/or affecting a parameter of little importance.
0 None: no or negligible impact, limited in time and space, and not requiring any
measures, or environmental category not present.
-1 Small negative: negative impact of limited duration, affecting a small area, and/or
affecting environmental parameters of less importance. Note that in spite of the small
effect mitigation measures may still be proposed or even required.
-2 Negative: undesirable or harmful effect of limited concern, either temporary, limited in
space or affecting parameters of medium importance.
-3 Strongly negative, mitigation possible: strongly negative or detrimental effects
(permanent, of high intensity, affecting important environmental parameters), for which
mitigation measures can (and have to) be taken in order to reduce them to an
acceptable level.
-4 Strongly negative, mitigation not possible: strongly negative or detrimental effects
(permanent, of high intensity, affecting important environmental parameters), for which
mitigation or compensation is not possible. Such effects could be no-goes for a project.
± Ambivalent: effect can be positive or negative, or a combination of positive and
negative effects is possible.
? Questionable: it is unclear (possibly due to project stage) whether the aspect will be of
any relevance and/or an effect will result.
Without any doubt, the entries in the matrix, to a certain degree, have a subjective
character. Nevertheless, given the information provided in the previous chapters should
enable the reader of the report to check the items and to draw his own conclusions.
Table 19-2: Impact matrix for Mount Coffee hydropower plant
(See following page)