Thousands of homes held up by Somerset's long-running phosphates crisis could begin moving again by the end of this year, councillors have been told.

Around 12,000 homes across the county are currently stuck in the planning system, unable to proceed without costly and complex mitigation to prevent additional phosphates entering protected waterways on the Somerset Levels and Moors.

Now councillors say new legislation and a change in national approach could finally unlock large developments — easing pressure on housing supply and cutting years of delays.

How Somerset ended up here

The phosphates crisis dates back to August 2020, when legal advice from Natural England followed a landmark European court ruling which effectively blocked any development that increased nutrient levels in protected wetlands.

Phosphates enter rivers through sources including fertiliser run-off, animal waste and human sewage. In high concentrations, they cause algae blooms that strip oxygen from rivers and wetlands, damaging wildlife.

The ruling applies to internationally protected Ramsar sites, including the Somerset Levels and Moors — covering catchments such as the Rivers Brue, Parrett and Tone. Somerset rivers also feed into sensitive catchments in east Devon and Dorset, widening the impact.

From that point on, even small developments required developers to prove nutrient neutrality — meaning no net increase in phosphates — before planning permission could be granted.

What's been tried — and why it stalled

Since 2020, Somerset Council and developers have attempted multiple mitigation measures, including:

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• Creating new wetlands to absorb phosphates
• Fallowing farmland or converting it to woodland
• Upgrading sewage treatment works
• Installing advanced treatment systems for septic tanks

Both the council and private providers also created phosphate credit schemes, allowing developers to pay for off-site mitigation — at a cost of around £34,000 per kilogram of phosphate removed.

While these schemes worked in theory, councillors and residents say they proved slow, expensive and inconsistent — leaving homes unbuilt, Section 106 funding delayed, and social housing schemes stuck.

Taunton resident David Orr, a vocal critic of the system, told councillors in January that the policy had caused serious economic harm.

He said it had left "12,000 vitally needed homes unbuilt, including 3,600 social and affordable homes" and described the process as "a spreadsheet deity which is never to be questioned".

A key legal turning point

Momentum began to shift in October 2025, when the Supreme Court ruled that developments with outline planning permission granted before August 2020 did not need to provide additional phosphate mitigation at the detailed design stage.

The ruling, made in relation to the Jurston Fields development in Wellington, has already allowed several stalled sites to move forward — including homes in Martock, Tintinhull and Taunton.

Somerset Council has confirmed that further decisions could now be accelerated as a result.

The big change: environmental delivery plans

The most significant shift comes from the government's Planning and Infrastructure Act, passed shortly before Christmas.

The legislation introduces environmental delivery plans (EDPs), allowing developers to take a strategic, area-wide approach to mitigation rather than solving the problem site by site.

Councillors say this could end the current "standstill" approach, where developments merely offset damage without improving the environment.

Instead, EDPs would allow money to be pooled and managed to actively restore habitats across the Levels and Moors.

Why councillors say this matters

Councillor Henry Hobhouse, who represents Castle Cary and surrounding villages, said the changes could dramatically reduce costs and delays.

He told councillors that mitigation costs currently vary wildly across Somerset — from around £5,000 per home in Taunton, where sewage works are being upgraded, to £25,000–£34,000 per home in rural areas served by smaller plants.

He said the new system would introduce a single, consistent mitigation figure, simplify Section 106 agreements, and speed up planning decisions.

Crucially, he said the funds would be managed centrally to ensure real environmental benefit — rather than being paid to landowners with limited enforcement.

What about water companies?

Water companies have also been ordered to act.

Under the Levelling Up and Regeneration Act 2023, sewage treatment plants serving populations of 2,000 or more must be upgraded by May 2031 to remove higher levels of phosphates.

Wessex Water has committed to completing Somerset upgrades by April 2030 and has agreed enhanced "stretch permits" at sites including Langport, Taunton and Wells.

However, many smaller rural plants — serving communities of fewer than 1,000 people — are not scheduled for early upgrades, meaning phosphate pressures will remain uneven across the county.

When could homes actually be unlocked?

Councillor Hobhouse said the government is expected to identify EDP areas by the spring, with the new system potentially taking effect from autumn 2026.

He said some changes could begin as early as April, though final details are still being negotiated.

Council executive director Chris Hall cautioned that Somerset's current planning position remains unchanged for now, with Natural England's advice still carrying significant weight.

The bottom line

After more than five years of delay, court rulings, stalled sites and spiralling costs, Somerset may finally be approaching a turning point.

If the new system delivers as promised, thousands of homes — including much-needed affordable housing — could begin moving again, while also delivering genuine environmental recovery on the Levels and Moors.

But councillors warn the outcome will depend on how quickly the government finalises the rules — and how robustly the new system is enforced.

Reporting by: Daniel Mumby/LDRS