BNG Rivers: Assessments and Guidance

Biodiversity Net Gain (BNG) is now required by local planning authorities for all proposed developments. Under this requirement, if a project’s perimeter encompasses a river or stream, regardless of whether it is directly influenced by the proposed actions, there is a requirement to ensure mandatory Biodiversity Net Gain (BNG), specifically tailored for rivers and streams.

Conducting River Condition Assessments (RCAs) is crucial for evaluating the potential effects of the proposed development. Local planning authorities frequently request these assessments as part of the planning application process. Planning permission for a development might be postponed or denied until mitigation measures are implemented.

What is included as part of a river condition assessment survey?

Here are key components of a river condition assessment survey for BNG:

  1. Baseline Assessment: A Modular River Physical (MoRPh) field survey is conducted to collect information on vegetation, sediments, and water-related features. A river type desk-based survey is also carried out. This desk study is used to gather existing data and information related to the site area.
  2. Impact Assessment: Assessing the potential impacts of the proposed development or land use change on the river ecosystem. This includes considering direct impacts (e.g., habitat loss, pollution) as well as indirect impacts (e.g., changes in hydrology, sedimentation).
  3. Biodiversity Net Gain Calculation: Calculating the expected change in biodiversity resulting from the proposed project using the Defra Biodiversity Metric 4.0. This involves comparing the baseline biodiversity of the river or stream with the predicted biodiversity after implementation of the project, accounting for any mitigation or enhancement measures.
  4. Mitigation and Enhancement Measures: Identifying and implementing measures to mitigate any negative impacts and enhance biodiversity within the river or stream. This may include river restoration for habitats, installation of fish passages, and implementation of erosion control measures.
  5. Compliance and Reporting: Ensuring compliance with regulatory requirements for Biodiversity Net Gain and providing transparent reporting on the outcomes of the river condition assessment, including the predicted biodiversity net gain and effectiveness of mitigation measures.

By conducting a thorough river condition assessment survey for Biodiversity Net Gain, developers and planners can ensure that development projects contribute positively to the conservation and enhancement of rivers, thereby meeting BNG requirements.

Implementing BNG for rivers

Under the Environment Act 2021, a planning project must provide a biodiversity net gain increase for at least 30 years. If the required BNG levels are not met initially, a mitigation hierarchy should be followed until the project reaches the required standard.

If you are unsure of how mandatory BNG may affect your planning application, you should contact your local planning authority immediately. They can discuss your development plans in detail and whether they align with BNG.

If they indicate that your development could be significantly impacted, we recommend that you contact an experienced ecologist as soon as possible. Our ecologists can discuss whether your development plans meet the required standards. They can also recommend any measures you may need to take in order to meet the biodiversity standards.

At Collington Winter, our team has strong experience completing BNG for rivers and will provide guidance throughout the planning process. We can ensure that one of our experienced biodiversity ecologists visits your development site to create and develop any necessary BNG plans and any required BNG reports.

How can Collington Winter assist with BNG for rivers?

Our team of ecologists and land managers have helped numerous clients with river condition assessments for planning and development.

We can also assist with biodiversity net gain by providing: 

Please get in touch if you would like further information about BNG rivers and RCA methods. We are happy to offer free CPD sessions on the BNG principles and how we can help your schemes achieve this.

Our Ecology Director, Olivia Collington, holds a Natural England license. If you would like to find out more about the BNG rivers services we provide, feel free to contact us using the details below.

Contact Us

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23 Bark Street East, 1st Floor, Bolton, BL1 2BQ

Cambridge Office

Future Business Centre, Cambridge Campus, Kings Hedges Road, Cambridge, CB4 2HY


Head Office: 01204 939 608

Dumfries Office: 01387 378208

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