Steps in Ecological Impact Assessment

1. Screening - Determination of whether or not an assessment is required, usually embodied in law / policy. Note, EcIA may be done without the need for screening.

2. Scoping - an essential component of EcIA and Environmental Impact Assessment (EIA) (stages from IEEM Guidelines):

Proponent's Ecologist to:
  • obtain information about the project from engineers/designers;
  • identify activities likely to cause ecological damage, stress or disturbance.
  • obtain available information about spatial extent, timing, frequency and duration;
  • concurrently, identify opportunities for enhancing biodiversity and delivering biodiversity objectives;
  • identify stakeholders, consultees and all ecologists who should be involved and establish a
  • consultation strategy;
  • produce a scoping report as a basis for further consultation with the competent authority, statutory consultees and others involved in the consultation strategy; and
  • refine the scope of the assessment based on feedback on the scoping report. Continue to refine the scope - scoping out potential impacts that are no longer considered likely to be significant and addressing newly identified impacts that are likely to be significant. The finalscope provides the terms of reference for the remainder of the EcIA.
All Stakeholders to:
  • identify relevant legislation, regulations and policies and review their requirements. This mayinclude the need for a licence before some activities can go ahead;
  • develop an understanding of the ecological context based on existing ecological information,data gathering, literature searches, site visits and any baseline studies already carried out;
  • determine a threshold for selecting ecological features to be included in the assessment, based on their value (section 3, below), using appropriate measures;
  • identify those ecological resources reaching the threshold value which could be affected by
  • the project;
  • identify the factors affecting the integrity of the relevant ecosystems and the conservation
  • status of relevant habitats and species;
  • identify ecological features likely to be significantly affected and therefore requiring furtherstudy and explain the selection criteria used;
  • consider potential sources of cumulative effects;
  • consider alternatives including the best environmental option;
  • agree details of proposed survey/research methodologies. Confirm the study area and the criteria that will be used to assess its nature conservation value; and
  • consider potential mitigation/enhancement or compensation opportunities.
3. Determining Value

Valuing ecological features or biodiversity is at the heart of EcIA. This is something that proponents and their consultants should never do themselves. Value-judgments cannot be made fairly or independently by proponents or their consultants. Values need to be established based on community concensus about what is important and how this is measured in terms of social, economic and biodiversity value. This must happen before the assessment process begins, or it undermines the process. The focus of EcIA is on measuring change against pre-determined Evaluation Criteria. If the criteria are set by persons measuring the change, they have pre-empted the cost of any change, placed their own bias on the outcome and might as well not have done the assessment.

4. Impact Assessment

This is done throughout the process, both at the scoping stage (which itself is iterative throughout), during consideration of whether mitigation measures are needed and when mitigation measures are evaluated for their likely success / failure. Impact assessment is done by a detailed description of baseline conditions, then a prediction and characterisation of change and the consequence of that change on ecological assets. This is where a strong understanding of the 'science' of ecology is used to determine sensitivity of habitats and species.

It is particularly important that changes are measured in an appropriate way - absolute change is rarely useful. Effects are usually described in terms of their magnitude, extent, duration, timing, frequency and reversibility. Finally, confidence in results must be described and their significance. A large part of this is uncertainty, some of which is measurable or reducable through science, and some is not.

The final significance* of any residual impact may be defined in a number of ways, but is usually measured against the pre-determined evaluation criteria described above.

*Note, the word "significant" may or may not appear in legislation. Nevertheless, assessment of residual impact significance is the end point of all EcIA. The word has important semantic use and cannot be avoided.

Risk assessment is a commonly used process in EIA. It is important not to confuse the need to assess impacts, with the need to assess risk. The two processes may be complimentary but risk assessment does not replace EcIA. Great care needs to be taken to ensure that risk processes do not oversimplify or mislead impact assessment processes.

5. Mitigation, Compensation and Enhancement

Contemporary models for EcIA look to an avoid-minimise-offset-enhance strategy, where:
  1. Impacts are avoided to the greatest extent possible;
  2. Unavoidable impacts are mitigated to the greatest extent possible;
  3. Residual impacts are offset the aim of achieving no net loss outcomes for biodiversity (see for example, NSW Biobanking);
  4. Where possible, additional efforts are made to enhance value (particularly to overcome uncertainty, where there is no guarantee that no net loss can be achieved).

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