What are 'significant' adverse effects?

The Department of Conservation’s Policy 13 Guidance Note sets out the following guidance for determining whether an adverse effect is ‘significant’:

Status of resources: The importance of the area—locally and regionally. (Effects on rare or limited resources are usually considered more significant than impacts on common or abundant resources).

Proportion of resource affected/area of influence: The size of the area affected by the activity will often influence the degree of impact (i.e. affecting a large area will generally be significant). Affecting a large proportion of a limited area or resource will tend to be significant

Persistence of effect: The duration and frequency of effect (for example, long-term or recurring effects as permanent or long-term changes are usually more significant than temporary ones. The ability of the resource to recover after the activities are complete is related to this effect).

Sensitivity of resources: The effect on the area and its sensitivity to change. (Impacts to sensitive resources are usually more significant than impacts to those that are relatively resilient to impacts).

Reversibility or irreversibility: Whether the effect is reversible or irreversible. Irreversibility will generally be more significant (depending also on nature and scale), and reversibility the converse.

Probability of effect: The likelihood of an adverse effect resulting from the activity. Unforeseen effects can be more significant than anticipated effects. (Adopting a precautionary approach may reduce the likelihood of adverse effects occurring).

Cumulative effects: The accumulation of impacts over time and space resulting from the combination of effects from one activity/development or the combination of effects from a number of activities. Cumulative effects can be greater in significance than any individual effect from an activity (for example, loss of multiple important sites).

Degree of change: The character and degree of modification, damage, loss or destruction that will result from the activity. Activities that result in a high degree of change are generally more significant.

Magnitude of effect: The scale and extent of possible effects caused by an activity (for example on the number of sites affected, on spatial distribution etc). Activities that have a large magnitude of effect are generally more significant.

Last updated at 2:14PM on February 25, 2015