BBOWT acquired the 45Ha Duxford Old River site in 2017 primarily due to its location directly adjacent to its 307Ha Chimney Meadows nature reserve in Oxfordshire. This site lies at the heart of the Upper Thames Conservation Target Area and is part of BBOWT’s Upper Thames Living Landscape Scheme area, both important for landscape scale conservation.

The site was previously managed as commercial pasture for cattle and so had a very low value of biodiversity. Over 30 years of nature-led management, a mosaic of key floodplain habitats will be created, such as floodplain wetland mosaic, other neutral grassland, broad-leaved woodland, and mixed scrub. These habitats will support species of wildfowl, waders, songbirds and specialist wetland invertebrates. An ‘Environment Benefits from Nature’ assessment predicted that in 30 years the project would see increases in a range of services, such as flood regulation, erosion protection, carbon storage, and interaction with nature.

The opportunity for long term investment into this site to improve the biodiversity presented the ideal platform to achieve this through Biodiversity Net Gain as a new Habitat Bank. Through a project funded by Defra’s NEIRF, BBOWT worked with Warwickshire, Cheshire and Surrey Wildlife Trusts and the social enterprise financial advisors, Finance Earth, to pilot the creation of a financial model for Duxford Old River as a habitat bank.  This provided the necessary tools and information to evaluate the commercial viability of the project.

The Trust for Oxfordshire’s Environment (TOE) is an independent place-based environmental funder, whose grant-making included a contribution to BBOWT’s campaign to purchase Duxford. From 2018, TOE had started engaging with Local Planning Authorities, developers and landowners in the area to broker biodiversity offsets (initially on a ‘no-net-loss’ basis) in the pre-mandatory BNG market. From very early in this process, BBOWT and TOE began to look at ways in which BNG units aggregated by TOE could support the ‘natural process led’ approach at Duxford.

While there were many challenges in the project’s developmental process, including the uncertainty associated with a dynamic pre-regulatory environment, TOE and BBOWT agreed to the first transaction of a significant quantity of BNG units from Duxford, which provided BBOWT with some seed funding to support the early management activity across the entire site.

In the pre-mandatory / piloting phase of BNG, TOE was able to employ units from a variety of development sites, aggregating these to support one site of significant value. These kind of small unit transactions (i.e. less than 10 units) are likely to remain a significant proportion of the offsite BNG market.  While it is unlikely that this precise way of working can be replicated after mandatory BNG is introduced, if BNG is to support nature recovery in line with Lawton principles (see Glossary), it is hoped that exemplars models of aggregation such as Duxford Old River will be able to be replicated within the post-January 2024 mandatory BNG regulatory framework .

Duxford Habitat Bank has a large volume of units still available,and these will be sold directly to developers by BBOWT. The creation of Duxford Old River as a habitat bank will generate over £1m of new incremental revenue for the Wildlife Trust with a positive gross operating margin which will be required to fund the monitoring and reporting requirements for the delivery of biodiversity net gain throughout remaining term of the 30-year project. BBOWT and TOE’s partnership has helped to enable a strategically important nature recovery initiative and they hope to continue to work alongside each other to achieve impact using BNG funds as the regulatory framework allows.

BBOWT have used the experience of this project to create a second Habitat Bank site in Buckinghamshire in 2023 with plans for further comparable projects in development.

Read the latest updates on the project here.