The Solent water environment in Hampshire is internationally important for its wildlife and is protected under the Water Environment Regulations and the Conservation of Habitats and Species Regulations.
However, as a result of nitrate and phosphorus pollution from agricultural runoff and wastewater from housing, the Solent has already breached its nitrates limits, causing it to fail to meet environmental standards and to suffer from rampant eutrophication in the form of algal blooms, which choke wildlife of oxygen.
Last year, Natural England issued legal advice to councils in Hampshire, urging them to only approve new housing where developers could prove the projects would be nitrate-neutral and would therefore not contribute to nitrate pollution in the Solent.
The advice was prompted by concerns about nitrate levels in the area's protected waterways as well as recent European Court of Justice rulings that tightened the rules on mitigating the impacts of new development schemes on such sensitive habitats.
As a result, 11 local authorities in Hampshire suspended the consideration of new housing applications, which resulted in many applications getting stuck in the planning system.
In a bid to break the housing deadlock, the Hampshire and Isle of Wight Wildlife Trust, working with environment watchdog Natural England, has bought a 40-hectare £950,000 farm in Wootton on the Isle of Wight, where it will rewild the land and prevent fertiliser-heavy soils from entering the Solent.
The trust will then create nitrate credits which can be bought by developers to offset nitrates entering the Solent from new housing projects.
The trust said the conversion of the farm could allow around 400 homes to be built but added that it aimed to replicate the offset project in new areas to eventually allow the delivery of all the housing currently held up by the moratorium, estimated to be about 12,000 homes.
Speaking to local newspaper The Portsmouth News, the wildlife trust's chief executive Debbie Tann said: "It's not our job to facilitate house-building, it's our job to look after nature and wildlife but what we were facing on the south coast was a real logjam.
"From our point of view there was a real risk that because there were no houses being built it would result in legal challenges and developers going to [the] government saying the restrictions are causing a massive problem.
"Legal challenges like that could lead to environmental regulations being ignored or weakened, and that could set a really bad precedent."
According to the newspaper, the trust is looking at further farmland in the north of the Isle of Wight, and south Hampshire.
A Natural England spokeswoman told the newspaper: "We are working hard to improve the vital habitats in the Solent, by enhancing biodiversity and improving water quality.
"As part of our work, we have supported the Hampshire and Isle of Wight Wildlife Trust in developing a nutrient-offsetting scheme to deliver new havens for wildlife and alleviate the housing pressure in the local area. We will continue to work with them as the scheme is developed.
"Natural England is also providing advice and support to local planning authorities who are considering this issue and can provide discretionary advice to developers on request.’
In December last year, Portsmouth City Council announced that it had ended its moratorium on deciding new residential applications after introducing a temporary strategy to offset nitrate output from new development through water-saving measures in the council’s existing housing stock.
A version of this article first appeared on Planning's sister title ENDS Report.