The UK Environment Act 2021 makes provision for local planning authorities to demand future development proposals include work to improve the biodiversity of nature supported by the site on completion of the project, so that it is significantly greater than before development began. Some development projects have already been affected by such requirements, and, over the next year or so, we can expect more local authorities to invoke these measures. The current expectation seems to be that a minimum of 10% improvement in biodiversity value will be required.
Experience is already showing that biodiversity net gain measures cannot just be “bolted on” at the end of development work, but must be included in the planning and management processes from very early on in the project. In order to achieve the biodiversity net gain target, it might be necessary to amend the original plans or concepts to preserve particular habitats and to provide the best opportunities to enhance others.
A comprehensive Preliminary Ecological Appraisal will identify the range of habitats included within the site of, or likely to be affected by, the development proposal. Examples of habitat types we have found in many of the sites we have evaluated include semi-improved grassland, marshy grassland, broad-leaved woodland, wet woodlands, hedges, running water in streams and drainage ditches, scrub, standing water in ponds and ditches, tall ruderal growth, bare ground and short ephemeral growth, as well as introduced shrubs. Each of these habitats, or any other of the many possible types, might be regarded as important by the local planning authority and thus merit particular protection measures. In addition, planners must be aware that if a habitat is lost or significantly degraded through their work, it might be almost impossible to recover it after the development is complete.
The precursor to sound biodiversity net gain (BNG) planning is the mapping and calculation of areas occupied by each habitat type, as well as the assessment of each area’s ecological value, prior to the work commencing. The assessment of this base state must be fully justified in the BNG report submitted to the planning authority, so that improvement proposals can be appropriately verified and thus easily approved.
Subsequently, various layouts of the infra-structure associated with the project can be evaluated using the approved BNG computer application. It is thus possible to determine which habitat types will be adversely affected and which areas might be extended or improved in quality to compensate for any lost areas of habitat. The evaluations will also help to ensure that natural corridors of habitat across the local area are preserved. Once a layout, which achieves the development aims and satisfies the required biodiversity net gain, has been determined, short-term measures can be put in place to ensure that important areas of habitat are protected throughout the installation phase. Additionally, long-term management plans will detail how areas will be enhanced and managed over the next few years, in order to achieve the overall improvement. For some development projects, it might be appropriate to improve neighbouring areas as an offset to the losses in biodiversity on the site itself.
It is true to say that Biodiversity Net Gain measures are being developed and improved as more experience is gained, but an experienced ecologist will be able to help you navigate your way through the seemingly complex and potentially changing requirements of achieving the required biodiversity target. If you need BNG advice for your development project, do not hesitate to contact us.
JP Ecological Services 