On Friday 17th October, we took the train from Liverpool Street to Broxbourne to visit Nattergal’s third wildland site: Harold’s Park in Essex, a 206-hectare site, steeped in history and with views of the London skyline. The trip was all part of Blue Earth’s Summit agenda – and we wouldn’t have known about it or how close it was to the City otherwise.
We learnt about Nattergal’s plans to transform the very recently changed low productivity arable fields, intensive grassland and Christmas tree plantations into an abundance of biodiversity and wildlife. Hearing from their expert site manager Tom Moat left us completely inspired and in awe of the project. What Tom doesn’t know about the site already, and conservation in general, just isn’t worth knowing!
The origins of Harold’s Park Estate
The history of the Green Belt area is interesting and dates back to the 11th century, as the land was once the deer hunting ground for King Harold II. Cut to the 1950s and Scottish farmer and Labour politician John Mackie bought Harold’s Park Farm to produce food post-war, but he was also keen on planting trees and allowing the public to enjoy the benefits of the countryside. He was appointed chair of the Forestry Commission in 1976 and in 1981 joined the House of Lords.
Mackie eventually sold the farm to the Church of England and stayed on as an AHA tenant where his son George succeeded the tenancy. In the 1970s, he began to diversify from traditional farming. He established an equestrian business where he grew and sold Christmas trees. On George’s passing in 2020, the church put the farm up for sale.
In 2024, Nattergal purchased the site for rewilding.
The Nattergal Legacy
Nattergal chose Harold’s Park Estate because of the unique combination of its history and potential for nature restoration. Nattergal will be returning Harold’s Park Farm to wood pasture, reminiscent of the ancient deer parks from 1,000 years ago.
Harold’s Park is ripe for rewilding. Although it is a largely ecologically degraded landscape, there are hotspots of life all around the land: ancient woodland, several ponds, a scattering of smaller fields and a selection of unkept hedges – all of which will help start re-establishing natural processes.
What we learned
As we walked and talked, we kept our eyes peeled for the recent reintroduction of free-roaming pigs (which sadly kept themselves scarce). They will be joined in future years, by ancient breed cattle and ponies to shape and drive the ecosystem.
I would say the thing I found most interesting was understanding in practical and live terms exactly how Biodiversity Net Gain (BNG) works. BNG is a recent policy approach in the UK that ensures development projects leave the natural environment in a measurably better state than before. Easier said than done! It became a legal requirement in England under the Environment Act 2021 with the mandatory framework taking effect for most developments in February 2024. So, it’s really new.
What BNG means for UK land
Under BNG, land developers must measure the biodiversity value of a site before and after development using a standardised Defra biodiversity metric. They then have to deliver at least a 10% net gain in biodiversity value — meaning that after development, the site (or offset sites) must support more or higher-quality habitats than previously.
A site’s existing biodiversity is calculated before development. Developers create, restore or improve habitats either on-site or off-site to achieve a net gain. The improved habitats must be maintained for at least 30 years to ensure long-term ecological benefit and in terms of biodiversity credits. If on-site or off-site improvements are not possible, developers can purchase government-approved biodiversity credits as a last resort, which is possibly what this site will attract from developers in the right catchment area.
BNG helps address biodiversity loss. The UK is one of the most nature-depleted countries in the world. BNG aims to reverse this decline by embedding environmental improvement into the planning system. It encourages developers to consider nature early in design, integrating green infrastructure such as wildflower meadows, ponds or woodlands. It creates ecological resilience because healthier habitats improve resilience to climate change, floods and pollution, and it provides economic incentives. Developers who prioritise sustainability can benefit from smoother planning approvals and improved public image.
It was an incredibly eye-opening day, and we were proud to be a part of understanding more about where the UK can go in its rewilding efforts.
