This is often the most difficult question to answer. The standard answer is: when there is a reasonable likelihood that a planning proposal will adversely affect important species or habitats (that is those species, sites or habitats protected under national or international legislation; or a UK or Local Biodiversity Action Plan species or habitat). In practical terms this is most developments that are not small householder developments.
In the majority of cases the results of this survey will need to be submitted with the planning application.
Larger or 'major' developments may require an Environmental Impact Assessment (EIA). Applicants should seek pre-application advice from the planning authority if they believe their development may fall into this category.
Surveys should be carried-out by appropriately qualified ecologists with experience of undertaking the survey required. Surveys should include credible data, be undertaken at the appropriate time of year and follow a recognised methodology. The British Standard on Biodiversity (BS42020:2013) sets out a number of areas that should be followed for best practice.
Under the government's code for sustainable homes, an ecologist is described as:
Depending on the type of site and survey required, the ecologist may need to hold a number of protected species survey licences. CIEEM list the competencies required to survey various protected species by ecologists and are a useful guide for anyone not familiar with this area.
Credible data is a key building block augmenting an ecological survey. Accessing all the recorded data for the site enables a more complete picture of the site to be generated. Species may have been recorded on the site in the previous months or years which were not found on the site during the survey. These species may still be using the habitats or buildings on the site and it is therefore important to consider them during the development.
In Greater Lincolnshire this data can be requested from the Lincolnshire Environmental Records Centre. It should be noted that using data from NBN Atlas for these purposes is a breach of the NBN terms and conditions.
Seasonality is important, many surveys can only be undertaken at particular times of year. As such it is best to plan the surveys as early as possible in the development project plan. This will also allow for any design adjustments that may result from the ecological survey to be encompassed easily.
Methodology is important to ensure the survey is adequate, could be repeated and that both the applicant and the planning authority can be confident in its conclusions. The report submitted should state the methodologies followed. These could be compared to the list of standard methodologies for survey listed by the CIEEM.
Reporting standards, reports should be written by the ecologist who undertook the survey. There are several references for good ecological reports, including the 2015 guidance from CIEEM. In addition the British Standard on Biodiversity (BS42020:2013) sets out a number of areas that should be followed for best practice.