Biodiversity Net Gain Mitigation for Developments

With its integration into UK legislation, Biodiversity Net Gain will become obligatory for all future development projects in England. Biodiversity Net Gain is a process in which a development considers its impact on the environment in terms of biodiversity. The goal is to guarantee that biodiversity is improved after the completion of the project by preventing any biodiversity loss. This is also done by preserving various types of habitats and safeguarding any strategically significant assets.

Local planning authorities are increasingly requiring Biodiversity Net Gain (BNG) to inform planning applications. BNG aims to demonstrate how the proposed project will benefit biodiversity in a measurable manner. It is also a planning condition and policy requirement for planning permission. This makes it a crucial factor in the decision-making process of planning authorities when deciding whether to grant or refuse a planning application.

As such, if local planning authorities determine that a proposed project may not meet the required BNG standards, developers may be required to specify key mitigation methods that must be put in place in order to deliver the net gain required to gain planning permission.

Biodiversity net gain is crucial for various reasons and has a positive impact on the environment in multiple ways. Some of the essential benefits of BNG are:

• Enables sustainable production of raw materials
• Supplies water and oxygen to surrounding ecosystems
• Enhances the aesthetic appeal of the environment
• Provides employment opportunities for local farmers and other agricultural occupations
• Facilitates scientific understanding of the natural environment
• Offers recreational activities such as fishing, camping, and hiking

The concept of mandatory biodiversity net gain is a structured and regulated approach to prioritise and ensure the support of all the aforementioned factors in the future. As BNG applies to all projects, it creates a universal approach from governing bodies.

Since BNG is a government policy, it eliminates any potential conflicts with key stakeholders. BNG is especially important to retain sites of special scientific interest or strategic significance.

To achieve BNG, development proposals must adhere to the ‘mitigation hierarchy.’ This hierarchy encourages developers to prevent harm to biodiversity from the outset. Following this, they should mitigate or compensate for any losses on-site or off-site.

Complying with the mitigation hierarchy is critical for projects that aim to achieve no overall negative impact on local biodiversity or BNG. The hierarchy involves a series of steps to be followed throughout a project’s life cycle.

The biodiversity net gain mitigation hierarchy comprises the following steps:

1. Avoidance – The first step in the mitigation hierarchy involves taking measures to avoid negative impacts on biodiversity from the start. This may include timing construction to avoid disturbing wildlife and carefully planning infrastructure placement to avoid affecting habitats. Avoidance is typically the easiest and most effective way to reduce potential negative impacts. However, it must be considered during the early planning stages of a project.
2. Minimisation/Mitigation – This step includes measures taken to reduce the duration, intensity, likelihood, and extent of any impacts that cannot be avoided. Effective mitigation can help eliminate some negative impacts. Examples of mitigation include building wildlife crossings on roads, designing powerlines to reduce harm to birds, and measures to reduce pollution and improve air quality.
3. Restoration/Rehabilitation – This step includes measures taken to create or enhance habitats after development has taken place where mitigation or avoidance was not possible. Restoration aims to return an area to the original ecosystem that existed before any impacts occurred. Rehabilitation aims to restore basic ecological functions and ecosystem services. These steps are typically required towards the end of a project.
4. Offset – This step involves taking measures to compensate for any adverse impacts after the other steps of the mitigation hierarchy have been implemented. Offsetting can often be complex, so the steps beforehand are typically more preferable.

According to the Chartered Institute of Ecology and Environmental Management (CIEEM), there are ten crucial good practice principles of biodiversity net gain. These should help to achieve BNG if they are followed accordingly. The mandatory biodiversity net gain principles include the following:

• Utilise the mitigation hierarchy to minimise the impact on biodiversity
• Eliminate any negative impacts on biodiversity
• Communicate each BNG outcome with complete transparency
• Cover all areas of sustainability, including societal and economic factors
• Involve any stakeholders in creating mandatory net gain solutions
• Focus on producing long-term environmental benefits from BNG
• Understand the variable factors and potential risks in order to achieve biodiversity and deliver biodiversity net gain
• Offer nature conservation that exceeds the stated BNG requirements
• Determine a suitable method in order to secure measurable biodiversity net gains
• Ensure the best possible results from biodiversity net gain

For case studies and a practical guide on biodiversity net gain principles, visit the CIEEM website.

Our team has strong experience completing biodiversity net gain and will provide guidance throughout the planning system process. This applies from the initial land purchase agreements to monitoring assessments.

The Environment Bill was passed as it received royal assent. Therefore, BNG will soon become mandatory through the forthcoming Environment Act in 2023. However, the application of the National Planning Policy Framework (NPPF) also requires a net gain approach which should be achieved in a measurable way.

Within this Environment Bill, it aims to include the development of effective conservation covenants, increase the use of recycling, improve air and water quality and recall products that violate environmental standards. It also aims protect local wildlife species, regulate chemicals that may harm the environment, reduce plastic waste and use resources in an efficient manner.

As a result of this Bill, BNG has been served as a core policy with numerous long term effects on ensuring the preservation of habitat types is maintained for at least 30 years.

Metrics assign every habitat on a project a ‘biodiversity unit value’ according to its relative importance for biodiversity. This enables comparison between the existing value of a designated site and what will be delivered through development or management and post development. This may include an increase in natural habitats through retention and enhancement and/or creation, which goes over and above the environmental habitat originally on the development site.

A developments biodiversity net gain can be calculated through the DEFRA biodiversity metric 3.1, which requires a limited number of factors. These factors include:

• The type of habitat sites (both on and off site)

• Any locations (if they are local environment priorities)
• The size of habitat parcels in kilometres or hectares
• The condition of any habitat parcels

The government website also provides a biodiversity metric 3.1 calculation tool which can help measuring a biodiversity unit score that translates into the standards of your local planning authority.

Our team of ecologists and landscape architects have helped numerous clients over the years. This includes mitigation guidance for biodiversity gain in England. It is important to note that this varies across each Local Planning Authority in the country.

Biodiversity net gain mitigation is something that we are qualified and experienced in, and we can offer advice on your project. We are determined to offer you the support you need in order to reach the required mandatory biodiversity bracket.

Please get in touch if you would like further information about Biodiversity Net Gain development plans or Land Management Plans. We are happy to offer free CPD sessions on the Biodiversity Net Gain 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 services we provide, feel free to contact us using the details below.