Pollution from farms has prevented housing developments being approved by 35 councils, analysis by The Times and Watershed Investigations, the not-for-profit organisation, can reveal.

Rachel Salvidge | Leana Hosea www.thetimes.co.uk 

Natural England, the regulator, has issued advice to 74 local authorities where water bodies were already in “unfavourable conservation status”.

The public body told them that new developments should be approved only if they would not worsen the already polluted rivers. Nutrient pollution, in the form of excessive nitrogen and phosphorus from farm fertilisers, animal slurry and human sewage, damages rivers by causing an overgrowth of algae. With the water starved of oxygen, the wildlife is suffocated. In extreme cases, this can lead to dead zones.

The Home Builders Federation estimates that more than 120,000 houses have been stuck in the planning system.

Developers are trying to work out how to show they are “nutrient neutral” — that the extra sewage they bring to an area will not add to the pollution.

The Times and Watershed Investigations used Environment Agency data to determine why rivers failed to meet “good” environmental standards at 64 of the affected councils. Agriculture was found to be the main problem facing 35 councils. Of the known reasons, across all 64 councils, 44 per cent were reported to be due to agricultural pollution and 21 per cent a result of the water sector.

The Times’s Clean It Up campaign has called on the government to maintain the nutrient neutrality rules laid out by Natural England. The campaign is also to encourage farmers to curb their pollution of rivers.

Several housebuilders said they backed the scheme but wanted the burden shared between water companies and farmers. The analysis found farm pollution was a problem in Cheshire and Devon, while the water sector was the main cause in 14 local authorities.

Stewart Baseley, executive chairman at the Home Builders Federation, said his members were “committed to protecting the environment”. He called for measures “that address the contributors to the poor quality of our rivers”.

Mike Burke, director for sustainable development at Natural England, said “comprehensive action across all sectors” was needed. “Pollution in rivers comes from a range of sources,” he said.

Richard Benwell, of the Wildlife and Countryside Link coalition, called for an end to “intensive” agriculture. He said the government should encourage “agro-ecological” farming.

An official at Water UK, the industry body, called for more innovative approaches and partnerships with farmers “to deliver benefits”.

The National Farmers’ Union was approached for comment.