Widening the scope: strategic environmental assessment - Introduction to Environmental Impact Assessment - page 379

• more detailed sub-components of the plan (e.g. plan policies on housing density and
design). These may need to be evaluated and fine-tuned once the plan is closer to
completion;
• proposed locations for development (e.g. specific housing sites). These may need to be
evaluated and fine-tuned at a level of detail close to that of project EIA.

As such, this section may need to be repeated several times at different levels of detail
and at different stages in the plan-making process.
Impact assessment involves testing how well each plan option or sub-component
fulfils the SEA objectives/indicators identified in A. Where plan options are proposed, it
should also compare, and inform the choice of, these options. Table 12.4 shows how plan
options can be assessed and compared. Table 12.5 shows how the
Table 12.4 Assessment and comparison of options
(illustrative only)

Option

A. B. C. D.

Maintain the
Green Belt in
area X

Remove the
Green Belt in
area X

Have strategic
wedges in the
Green Belt in area
X

Make the Green
Belt narrower in
area X

SEA objective
(Objectives from Box
12.5 used as example)

Conserve and enhance
biodiversity

0 − ? …

Promote the health of all
residents

+ − I

Maintain and enhance
soil quality

… …

… …

Preferred option and why: C is preferred because... Modifications to the preferred option
(mitigation) suggested by this assessment:
Key:

+ positive impact
− negative impact

0 neutral impact
? uncertain impact
1 depends on how option is implemented

(Based on Levett-Therivel 2004.)