Somerset Levels & Moors Nutrient Neutrality Calculator

Stuck behind a Somerset Levels & Moors nutrient condition?

The Somerset Levels & Moors put a large part of Somerset under a phosphorus neutrality requirement, affecting development across the low-lying catchment and its network of rhynes and rivers.

If your site drains to Somerset Levels & Moors SPA / Ramsar, the planning authority can't grant permission until you've shown the scheme is nutrient neutral — that it won't add phosphorus to a catchment that's already overloaded. NutrientMonkey gets you the number: build the assessment on screen, watch your budget in kg/year update as you go, and export the planning-ready report when it's right.

Which nutrient applies here

The Levels are assessed for phosphorus, which drives the algal growth that damages this internationally important wetland. That matters, because the methodology and the credits differ by nutrient — and neighbouring catchments often differ. NutrientMonkey flags the Somerset Levels & Moors catchment for phosphorus and locks the tool to match, so the assessment is right from the start.

Credits in the Somerset Levels & Moors catchment

Somerset Council runs an official phosphate credit scheme for the Tone and Parrett sub-catchments (one credit = 1 kg P/year, available in tenths). The price was cut to £34,061 per kg in June 2025 (from £53,652); legal and monitoring fees apply on top. Private providers also operate in the catchment. See somerset.gov.uk.

Published scheme prices: £34,061 per kg phosphorus/year for a permanent credit.

The council scheme covers the Tone and Parrett sub-catchments only — sites elsewhere in the Levels catchment need a private provider, so check coverage for your site before relying on it.

One credit is 1 kg of phosphorus/year. The number you need is your governing budget — the greater of the pre- and post-2030 figures, floored at zero; where a 2030 permit change applies you can instead split into cheaper temporary credits (valid to 1 April 2030) plus permanent. NutrientMonkey shows these live so you can gauge how much mitigation you'll need before you commit. Prices and sub-catchment availability change — always confirm the current position with the provider.

How the Somerset Levels & Moors calculator works

1. Pick Somerset Levels & Moors from the catchment list — it's pre-flagged for phosphorus.
2. Enter the dwellings & waste water — occupancy, water use (125 or 110 l/p/d plus NE's allowance) and the drainage route (septic, package plant or mains permit).
3. Add land use & SuDS — current vs future land cover and any sustainable drainage, with editable export coefficients for the Somerset catchment values.
4. Export when ready — a branded, planning-ready PDF with the budget in kg/year and every input documented.

Honest about what it is

This is a nutrient-methodology assessment built to support your Somerset Levels & Moors planning application — fast, clear and ready to discuss with your case officer. The official Natural England catchment calculator remains the statutory tool, and your figures should reproduce in it; the report states this plainly. Want it handled end to end? We also prepare nutrient neutrality assessments for Somerset Levels & Moors as a service — we run the budget, size the mitigation and produce the report your ecologist and case officer sign off. Tell us about the site and we will quote, usually the same day.

Frequently asked questions

In a different catchment?

NutrientMonkey covers every Natural England catchment. If you are not certain which one a site falls in, the catchment map shows all 27 on one map of England, coloured by the nutrient that applies.

Or jump to another part of the country:

• Poole Harbour N
• Solent N
• Tees (Teesmouth) N
• Lindisfarne N
• Stodmarsh N & P
• The Broads N & P
• River Wensum N & P
• Chesil & the Fleet N & P
• Hornsea Mere N & P
• Oak Mere N & P
• Rostherne Mere N & P
• West Midlands Mosses N & P
• River Clun N & P
• River Avon (Christchurch) P
• River Itchen P
• River Axe P
• River Camel P
• Derwent & Bassenthwaite P
• River Eden P
• River Kent P
• River Lambourn P
• River Lugg P
• River Mease P
• Esthwaite Water P
• Peak District Dales P
• Roman Walls Loughs P

Or go back to the main NutrientMonkey calculator.

Wider planning support

Nutrient neutrality is rarely the only condition on a scheme. Our energy statements service and the wider SAP & compliance team cover the rest of the planning and Building Control picture — get a quote and we'll talk it through.