Widening the scope: strategic environmental assessment - Introduction to Environmental Impact Assessment - page 370

November 1993, on the basis of the results of these early appraisals, the DoE published
Environmental Appraisal of Development Plans: A Good Practice Guidance (DoE 1993).
The 1993 guidance, which was widely used in the following years by many local
authorities, recommended that environmental appraisal should involve:
1. identifying environmental components (e.g. air quality, urban “liveability”) that could
be affected by the plan;
2. ensuring that the plan is in accordance with government environmental and planning
advice; and
3. determining whether the plan's objectives/policies are internally consistent, using a
policy compatibility matrix, which resembles a triangular road mileage chart; and
assessing the policies' likely environmental effects, using a “policy impact” matrix
with the plan policies on one axis and the environmental components identified in Step
1 on the other axis.
The second edition of this topic gave an example of an appraisal based on this guidance.
PPG12 was revised in 1999. It advised authorities to consider a range of social and
economic effects as well as environmental ones in a broader “sustainability appraisal”. A
similar approach was taken for Regional Planning Guidance. By October 2001 over 90
per cent of English and Welsh local authorities and all regional authorities had had some
experience with appraisal. About half of the appraisals were “environmental” and the
other half “sustainability” (Therivel & Minas 2002).
Research on the effectiveness of these appraisals (Therivel 1995, 1996; Therivel &
Minas 2002) showed that they were being increasingly carried out during (rather than
after) plan making, were leading to more changes in the plans (Figure 12.3), and were
providing side-benefits such as increased transparency in plan making, and a better
understanding of the plan and the environment by plan makers. The appraisals were most
effective in improving the plan when they were carried out by several people, including
the person who wrote the plan and someone external; during rather than after the plan-
making process; and with enough resources (Figures 12.4 and 12.5).
12.4.2 Implementing the Directive
In the UK, the SEA Directive is being implemented through different regulations in each
devolved administration, 3 and through several additional guidance documents