A legal requirement that new houses do not pollute nearby wetlands, rivers and nature reserves has halted development across a swath of England.
Forty-two local authorities in England were last month told they must ensure that new homes are “nutrient neutral” and do not add damaging nitrates or phosphates to river catchments and protected areas including the Eden Valley in Cumbria, the River Camel in Cornwall and the Norfolk Broads.
In these areas – close to protected sites such as special areas of conservation (SACs) – planning authorities are unable to permit new applications for any kind of home until developers prove they are not adding to nutrient pollution.
Natural England, the government’s conservation watchdog, has already required developers in 32 local authorities to demonstrate they are causing no additional pollution of protected sites after a 2018 court of justice ruling to protect conservation areas designated by the EU.
Nutrient pollution causes algal blooms that deplete oxygen in the water, killing fish and damaging other aquatic life. Farming is the main cause of excess nutrients washing into rivers and wetlands alongside discharges from overloaded sewage works but rainwater running off roads and new developments can also add to the pollution.
The Home Builders Federation estimates that up to 120,000 new homes have been delayed because of the “nutrient neutrality” rules in 74 local authority areas, with 42,000 new homes delayed in the greater Norwich area alone.
In some areas, such as the Solent, mitigation measures have been established, with developers able to purchase nitrate credits from landowners including environmental charities who use the money to rewild farms or create pollution-absorbing wetlands in the catchment.
But many local councils complain they have not been given adequate notice to enable new developments to continue, so cannot meet their mandatory new housing targets. In Norfolk, there are no mitigation schemes established yet, with all development without full planning permission paused within the catchment of the Broads and the River Wensum, both of which contain damaging levels of nutrient pollution.
The government’s demand for “nitrate neutrality” was welcomed by Rosie Pearson, the chair of the Community Planning Alliance, a grassroots campaign group for sustainable development.
“It’s great to see and a rare example of where the public protective system is doing what it should,” she said. “But with councils bound by their five-year housing supply targets and one government department saying: ‘Build, build, build,’ and then Natural England and Defra going: ‘You can’t build, you’re harming the environment,’ it is a complete mess.”
Mitigating nutrient pollution with the creation of new wetlands was “a sticking plaster” according to Pearson. “All these wetlands will be created that will be great for nature but the government constantly ignores the underlying problem, which is the sewage system.”
Housebuilders are warning the measures could cost developers up to £5,000 per home and affordable homes and council houses will be delayed. A study in Somerset found that the urban environment contributes 4% of nutrient pollution, with the vast majority caused by farming and sewage discharges.
James Stevens, the director for cities at the Home Builders Federation, said: “Developing a consistent and standardised mitigation approach on water neutrality is essential to removing the growing block it is causing to housing supply.
“We are urging government to agree proportionate measures that reflect the contribution of housing delivery to the issue without delay. The situation has already been ongoing for some years and it is imperative that solutions are agreed and implemented urgently.”
In the Solent, where nutrient neutrality rules began in 2018, it took 18 months for mitigation sites to be established but Natural England said it would be much quicker for the 42 new local authorities because there was a nutrient calculator and £100,000 funding to help councils and developers identify solutions.
In South Hampshire, nutrient credits bought by developers have enabled more than 3,000 “nutrient-neutral” new homes to be built.
Hampshire & Isle of Wight Wildlife Trust (HIWWT) has used credits to buy two farms totalling 450 acres in the Solent catchment, rewilding intensively fertilised land that was causing nutrient pollution, restoring biodiversity as well as removing 25% more nitrates than the credits instructed.
“It’s working,” said Debbie Tann, the chief executive of HIWWT. “It means that development is able to mitigate its impact but it’s really important to acknowledge that pollution in the Solent is terrible and just doing this is not going to clean it up. What we really need to tackle is farming, reducing fertilisers, and the water companies need to tackle sewage discharge.
“This is a good step by Natural England but we need government to step up on the other issues as well.”
Melanie Hughes, the director of sustainable development at Natural England, said all of the affected protected wetland sites were in “unfavourable condition” because of nutrient pollution, such as stinking mats of algae covering salt marsh in the Solent, which prevent wading birds from feeding in the mud.
“We can’t carry on polluting in these areas – that’s the line that’s been drawn,” she said. “We’re pleased that we’re using nature-based solutions to help resolve the problem, which have much wider benefits.”
A government spokesperson said: “We want to protect the environment and deal with the build-up of nutrient pollution whilst building the homes this country needs.
“While house building is not the primary cause of nutrient build up, we want to introduce measures quickly to allow development to move forward.”
