Mitigation and Compensation

When wildlife could be harmed by development, local planning authorities should follow a step-wise approach to reduce that harm, known as the ‘mitigation hierarchy’.

This is required in National Planning Policy (Planning Policy Wales 2021: 6.4.21 and Technical Advice Note 5: 2.4).

Avoid – Can damage be avoided altogether? For example, by using an alternative site or changing the design?

Minimize & Mitigate – Can potential harm be reduced as much as possible? For example, some harm caused by construction can be avoided by changing timings and building methods or by protecting wildlife features during construction.

Compensate – Where harm cannot be avoided or mitigated, damage can be offset by improving existing wildlife habitat or making new habitats. Ideally, compensation habitats should be of the same type and of better quality or greater size than the habitat that is lost. It should also be located as close as possible to the area of lost habitat. Compensation can happen within the overall development site, or outside of it. When off-site compensation is needed, this is often arranged through a payment called a Section 106 Agreement.

Enhance – all developments in Wales are required to cause a Net Benefit for Biodiversity, whether they cause harm to wildlife or not. This means that all developments should include features for wildlife such as new areas of habitat or special planting, often called wildlife enhancements.

Manage – areas for wildlife within a new development will need some ongoing care. Development proposals should include plans for who is responsible for wildlife areas and how they will be managed – both during construction and afterwards.