Ecological mitigation – practical techniques
Chapter 14: Practical techniques
(UK and Ireland)
Due to the strict protection given to designated sites through legislation and planning policy, it is increasingly unusual for development to occur within designated sites. This publication therefore deals mainly with the more common situation of encountering habitats and species of conservation concern outside of designated sites. We have selected those issues that come up most commonly and outlined an approach to mitigation for each issue. Providing solutions in detail is beyond the scope of this publication and, in any case, detailed design for mitigation will be needed on a case by case basis to ensure that mitigation is appropriate and cost-effective.
Best practice guidelines, based on law and national policy, generally stipulate that the primary aim of the ecologist and developer should be to avoid any adverse impacts on wildlife, achieve no net loss of biodiversity and in particular all reasonable steps should be taken to ensure works do not kill, injure or disturb protected species, as such actions would result in an offence being committed. This can be achieved in many cases simply by considering the potential ecological impacts of a development at the outset, allowing the development plan to be modified accordingly, often at no additional cost to you. The mitigation calendar shows how development activities can be timed to avoid negative impacts upon protected species.
It may not be possible to completely avoid adverse impacts, so in such cases measures can be taken to offset damage that will be caused by a development. Overall, mitigation for protected species should accomplish the following:
- Avoidance of deliberate killing, injury or disturbance of protected species
- No net loss of habitat, species richness, population size, number of structures or places used by a protected species for shelter or protection
- Lost habitat or habitat features should be replaced with habitat or features of the same or better quality
- Assured long-term survival of the habitat or population
Translocation and exclusion methods may be employed where it is not possible for a protected species to remain on site, either in the long or short term. Construction activities may threaten to harm protected species if they are not removed from site, and in many cases it may be possible to allow them to re-inhabit the site once the development has been completed and any necessary habitat enhancements have been carried out. Translocation and exclusion techniques are described for each protected species later on in this publication.
Consultation with an ecologist at the outset of your development will not only benefit the wildlife that occurs on site, but will also reduce the time and expense needed to ensure that your activities do not breach any international or national wildlife legislation or planning obligation.
Potential measures to enhance development sites for biodiversity are listed within this handbook. In addition, some of the works described in the following pages under the heading of ‘Maintaining Habitats’ could bring about biodiversity enhancements, if they are over and above the measures required to offset negative impacts of the development.
Click on the links below to access the various practical technique guidance notes: