The term ‘mitigation’ is widely used to mean the avoidance or minimisation of ecological impacts caused by human actions, such as development proposals, and for the compensation of impacts that cannot be avoided.
Mitigation strategies are methods for avoiding, minimising and compensating for any adverse impacts to protected species or important habitats that are likely to be caused by a project. Appropriate mitigation methods will be included within survey reports, and will often need to be developed through consultation with the relevant stakeholders.
It is important that the client understands the mitigation requirements, and can commit to their implementation, as frequently evidence will need to be provided to the planning authority or statutory body.
Mitigation Approach
The least disturbing approach is always favoured. In many cases it is possible to avoid causing impacts by timing works to a particular season when a protected species is not present (eg. avoiding the bird nesting season), or by excluding an important area from the construction zone (eg. a badger sett).
However, this is not always possible – and further measures must be taken. This often involves measures taken to exclude a species from the construction zone and provision of an alternative habitat nearby. In some cases this will require a ‘development’ or ‘derogation’ licence from the statutory body ( Natural Resources Wales, Natural England, or Scottish Natural Heritage).
A detailed method statement will be required describing how the proposed measures will protect the species from harm and maintain the population at a favourable level. Usually habitat enhancement works will be included to provide additional benefits to the target species population and wider biodiversity.
Please contact Gould Ecology to discuss you Mitigation or Licensing requirements.
Case Study 1:
Development at a fish farm with great crested newt (gcn) present in a complex of unused ponds. The development required extensive works to the area including drainage of the ponds. A survey of the ponds revealed a small population of gcn in one pond of three surveyed. The licensed works included a period of trapping and removal of newts from the pond, followed by slow pond drainage and capture of remaining newts as the water level fell. These were moved to a recently created pond nearby. In addition, three new ponds were created and woodland management was undertaken to enhance the surrounding habitat.
Case Study 2:
Redevelopment of a derelict house required a bat survey and reptile survey. Mitigation and licensing for great crested newts (gcn) was also required as we had recently conducted surveys on nearby ponds and found them. However, Natural England was happy to accept the results of the previous surveys, so no further surveying was required for the licence application. The site was fenced and trapped for reptiles and gcn for 30 days, after which a destructive search was conducted. Trapping revealed low numbers of gcn, however, several more were found beneath paving slabs and pathways in the vicinity of the existing house. Amhibians and reptiles were released in areas of natural habitat on the far side of the exlusion fencing. An artificial hibernacula was created as a habitat enhancement.
Case Study 3:
A proposed conversion of a derleict stone barn required bat surveys which revealed that several species of bat were using the barn in different way, including night roosting for greater and lesser horseshoe bats, and day roosting for common and soprano pipistrelle, brown long-eared and whiskered bats. Surveys were conducted during May, June and September. The project required licencing through Natural Resources Wales, including a detailed mitigation plan showing how bat roosts would be retained or created within the building. Sensitive works were conducted outside of the main active season for bats under supervision of the ecologist and a designated bat loft was installed within the barn, and other roosting options were integrated into the walls and roof. A small amount of new hedgerow planting was implemented in order to help ‘guide’ bats to the entrance of the bat loft.