Ecological Impact Assessment (EcIA)

Ecological Impact Assessment (EcIA) is the assessment of the impact of a proposed action on plants, animals, habitats and their environments. This is becoming increasingly mandatory for larger developments. It may be done independently or as part of a wider Environmental Impact Assessment (EIA) or Environmental Statement (ES).

OpenSpace can produce ‘standalone’ Ecological Impact Assessment reports or as an Ecology Section of an EcIA according to specific requirements. OpenSpace specialises in Ecological Impact Assessments and can provide:

  • scoping studies
  • a full range of ecological surveys providing key data
  • concise and accurate reports following Institute of Ecology and Environmental Management (IEEM) guidelines
  • ecological impact mitigation and compensation measures
  • recommendation as to the best way forward to fulfill legal obligations

There is no standard approach to ecological issues in an Environmental Assessment due to the wide variation of habitats and of the proposals that may affect them. Both the methods and the ecological issues under consideration must relate to the particular circumstances of each proposed development and the environmental assessment.

The initial stage of an EcIA would be a scoping study to assess whether the proposal raises issues of ecological importance and where significant impacts may occur. The scoping study should determine whether there is sufficient ecological information already available to assess the magnitude of these impacts or whether further survey information is required.  If this is the case then it should determine what is required and how the surveys and assessments will be done. The initial stage would involve:

  • Reviewing the quality and extent of all existing ecological data collected, including presence/absence of rare or protected species, and recognised sites of nature conservation interest (statutory and non-statutory);
  • Consulting with conservation organisations and others with local ecological knowledge;
  • Visiting the site and identifying general locations of any current areas of specific interest for floral or faunal communities, and also considering the potential effect of the proposal on the wider ecological framework not benefiting from any nature conservation designation.

Some proposals may require more information than can be produced by desk study and a site visit, where the above tasks will not be sufficient to enable decisions to be taken. In these cases, preliminary field survey work should be carried out before decisions are made on the full scope of ecological issues in the Statement. In most cases this will comprise a Phase 1 Habitat and Scoping survey of the site (and often of surrounding land as well), which would highlight at a basic level whether there are important habitats on site or habitats with potential for protected species and/or signs of protected species. The preliminary survey may highlight further surveys that are required such as bat surveys or an NVC survey of potentially important habitats.

The assessment stage of the proposal would involve identifying the ecological receptors, identifying and predicting the impacts (changes) and then assessing the significance of the changes, so the appraisal may contribute to the decision as to whether it should be allowed to proceed, modified or prohibited.

Where ecological receptors are affected by the proposed development then impacts are likely to occur. Impacts may be beneficial or adverse, direct or indirect, temporary or permanent, single or cumulative and may vary in their duration, timing, magnitude and significance. During different stages of the project there may be different impacts. The significance depends on the importance of the ecological receptor, timing, magnitude and duration of the impact. Significance thresholds can be determined from different combinations of sensitivity and magnitude. All of these factors must be considered.

One of the main aims of Environmental Assessment is to avoid significant adverse effects. It will not always be possible to avoid effects, although there will usually be opportunities to reduce or minimise adverse impacts by the use of mitigating measures, such as:

  • locating project elements to reduce adverse effects;
  • using construction and operation methods which reduce adverse effects, for example to avoid disturbance at critical times of the year;
  • introducing specific measures into project design, that will reduce adverse effects.

Ecological mitigation usually focuses on attempts to minimise habitat loss and changes to site integrity, or to minimise disturbance to a habitat or species found within it. Habitat or species translocation may have a role in mitigating for adverse effects. However, such techniques are often of uncertain effectiveness and should only be considered as a last resort.

The ecological effects of mitigating measures themselves should also be assessed and the effectiveness of such measures should be addressed in the Environmental Statement. As a result of the mitigation section of EcIAs, OpenSpace will often design (and if needed, implement) a wide range of mitigation and habitat creation / enhancement measures to minimise the ecological impact of the development so that it is not considered significant.

If you have a query about the Ecological Section of an Environmental Impact Assessment, then call us on 01228 711841 or email

Updated April 2017