Biodiversity Duty report
5. Biodiversity Net Gain (BNG) Monitoring
5.1The Environment Act 2021 introduced a statutory requirement for qualifying developments to deliver a minimum 10% Biodiversity Net Gain (BNG). This requirement has applied to major developments since 12 February 2024. Accordingly, this report covers the period from 12 February 2024 to 31 December 2025 in relation to BNG delivery.
5.2The Council is in the process of upgrading its planning software to enable more comprehensive reporting on BNG secured across all development types. At present, detailed data on BNG secured since 2 April 2024 (when the requirement was extended to smaller sites) cannot be extracted from the existing system. This information will, however, be fully accessible for future biodiversity duty reporting once the new software is operational.
5.3Where appropriate, the Council applies a standard BNG Implementation condition to secure the delivery of approved Biodiversity Gain Plans (BGPs) and Habitat Management and Monitoring Plans (HMMPs). Due to current limitations within the planning software, reporting on approved BGPs during this period has been restricted to major development sites only.
5.4During the reporting period, the Council determined and approved two major planning applications that triggered BNG requirements. Both permissions were granted subject to conditions ensuring that development proceeds in accordance with the submitted BNG Plans. In addition, each permission requires that, if development has not commenced within 12 months of the decision date, an updated BNG statement and metric must be submitted to and approved in writing by the Local Planning Authority.
5.5No biodiversity units were approved for off‑site delivery, nor were any statutory biodiversity credits utilised, in relation to major development sites subject to BNG requirements during this reporting period.
5.6The overall expected gains and losses across approved BGPs in the reporting period are shown below:
| Overall Expected Gains/Losses | Total |
|---|---|
| Total number of pre-development habitat units on-site | 15.3 units |
| Total number of post-development habitat units on-site | 24.5 units |
| Total net unit change in habitat units, on site | 9.2 units |
| Percentage change in habitat units, on site | 90.62% |
| Total number of pre-development hedgerow units on-site | 3.26 units |
| Total number of post-development hedgerow units on-site | 3.9 units |
| Total net unit change in hedgerow units, on site | 0.63 units |
| Percentage change in hedgerow units, on-site | 19.45% |
5.7The area/length and biodiversity unit values for each habitat, hedgerow and watercourse type, both at baseline and post-development across both on-site and off-site delivery, are shown in the tables below.
| Habitat Group | Baseline | Post-development | On-site change | |||
|---|---|---|---|---|---|---|
| On-site existing area (ha) | On-site existing value (units) | On-site proposed area (ha) | On-site proposed value (units) | On-site area change (ha) | On-site unit change (units) | |
| Cropland | 2.00 | 4.01 | 0.00 | 0.00 | -2.00 | -4.01 |
| Grassland | 0.79 | 8.45 | 1.98 | 18.6 | 1.19 | 10.12 |
| Heathland and Shrub | 0.18 | 0.73 | 0.17 | 1.15 | -0.01 | 0.42 |
| Lakes | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Sparsely Vegetated Land | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Urban | 0.22 | 0.00 | 1.05 | 1.47 | 0.82 | 1.47 |
| Wetland | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Woodland and forest | 0.02 | 0.10 | 0.02 | 0.10 | 0.00 | 0.00 |
| Intertidal sediment | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Coastal Saltmarsh | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Rocky Shore | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Coastal Lagoons | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Intertidal hard surfaces | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Watercourse footprint | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Individual trees | 0.00 | 0.00 | 0.22 | 0.68 | 0.22 | 0.68 |
5.8No Biodiversity Gain Plans (BGPs) approved during the reporting period involved on-site changes that would result in adverse impacts on irreplaceable habitats.
5.9The first monitoring milestones (e.g., Year 1 or Year 2 following completion of habitat creation or enhancement works) have not yet been reached for any BGPs approved within the reporting period that require ongoing monitoring.
