Case studies of EIA in practice - Introduction to Environmental Impact Assessment - page 294

Because of baseline data limitations, not all relevant constraints could be mapped within
the relatively tight timescale of the SEA. In particular, it was not possible to map a
number of important environmental constraints, such as the distribution of certain bird
and fish species and migration routes. Whether these omissions invalidate the conclusions
drawn from the constraint mapping exercise is open to question (see below for a
summary of consultation responses on this issue). However, those factors that could not
be mapped were considered in the later risk-based analysis of impacts.
A scoring system was used in the mapping of constraints, in which each area was
awarded a score between 0 and 3 for each mapped constraint (with higher scores
indicating greater constraints). The scoring system used is illustrated by the following
examples:
Scores for fishing effort:

• 0 None

• 1 Low (less than 500 hours per annum)

• 2 Medium (500-5,000 hours per annum)

• 3 High (over 5,000 hours per annum).

Scores for designated habitats of conservation interest:
• 0 Designated habitats are absent
• 1 Not applicable

• 2 Nationally important habitats are present (including those not yet designated)
• 3 Internationally important habitats are present (including those not yet designated).

Scores for seascape:
• 0 No sensitivity

• 1 Low sensitivity

• 2 Medium sensitivity

• 3 High sensitivity.

The scoring system allowed the identification of locations within each of the three
strategic areas that had several constraints (a high total score) and those with fewer
overall constraints (a lower overall score), subject to the qualification that not all relevant
constraints could be mapped. Broad conclusions from the spatial analysis are summarized
below, for each strategic area (DTI 2003a):

• Liverpool Bay. Overall, the greater amount of constraint and sensitivities occur in the
southern part of this strategic area, due to the presence of bird interests, marine
habitats of conservation interest, seascape, fisheries and marine traffic. Seascape
constraints in the north of the area are significant.
• Greater Wash. The Greater Wash has the largest area of low constraint in comparison
with the other strategic areas and offers the greatest potential capacity for wind farm
development. Inshore areas, particularly in the southern part of the area, have the