Warblington Farm Nature Reserve and Havant Borough Council’s Mitigation Plan for Nutrient Neutral Development
Havant Borough Council
This award was sponsored by
The implications of a European Court of Justice ruling in relation to the Habitats Directive (in what is now widely known as the Dutch Case) have been very significant in terms of requirements for
nitrate-neutral development and have led Natural England to review their planning advice in the Solent area, which has a coastline of international conservation importance. In the interim all relevant development was halted.
Havant Borough Council was very quick to recognise the risk that, without a timely strategic solution, less sustainable greenfield developments could secure planning permission, undermining the Local Plan ambitions. In order to enable sustainable development – and make it possible for it to be lawfully permitted – there was a need to secure nutrient neutrality through immediate implementation of a strategic mitigation scheme.
At the heart of the Council’s innovative solution is a change of land use from agriculture to nature reserve to counterbalance the additional nutrients that new housing will generate, but with carefully layered additional multiple environmental benefits.
Original research, modelling and monitoring was used to the inform the nature reserve design, including an Integrated Water Management Study for south Hampshire, and an assessment
of nutrient neutral development in the catchment of the local wastewater treatment works, alongside a formal review of the proposed approach. The scale, location and design of the nature reserve was supported by data but crucially looked to deliver in a way that also delivered multiple benefits for people and nature.
In August 2020, the Council took over the management of a 60-hectare agricultural site situated on the coast of Warblington. It decommissioned the site from intensive agricultural use in order to have a positive impact on nutrient levels along the coastline, which forms part of the internationally important sites currently suffering from eutrophication as a result of excess nitrogen inputs. It has converted the site into a nature reserve, providing a haven for animals and plants and with stewardship of the site funded purely by developer contributions.
All relevant future developments in the area are required to calculate their specific nutrient budget, using a novel neutrality methodology developed by Natural England. They then pay an agreed contribution towards the offsite mitigation offered, counterbalancing the additional nitrate loads they produce. Just under half of the available mitigation has been used or reserved, demonstrating the appetite for the scheme in the development industry.
Havant Borough Council worked closely with Natural England’s Thames Solent team and used funding from the Solent Local Enterprise Partnership (LEP) to develop and manage this innovative scheme. To date, the project benefits have included:
- Providing additional protected areas of direct benefit to the numerous endangered bird species reliant on this specific coastline.
- Enabling sustainable development and providing a range of environmental benefits at no ongoing cost to residents.
- Providing an effective mitigation solution in perpetuity to the provision of nutrient-neutral housing.
- Protecting a world class coastline, fulfilling the Council’s responsibility as a steward of several European-level nature conservation designations.
Moving forward, the Council is seeking to bring forward further phases of the scheme swiftly. This will ensure that nature based solutions at this site can continue to mitigate the impact from new housing and secure further environmental enhancements.
Over the last week, we have been posting further information on each of the 2021 CIEEM Awards Winners over on our blog. Further details on each project/individual is set out in our 2021 CIEEM Awards Booklet.