Nutrient Neutrality Calculator
Calculate nutrient loads and mitigation requirements across all 27 Natural England catchments. Enter your postcode — the tool identifies your catchment and runs the budget automatically.
Nutrient neutrality is a hard constraint in 27 catchments across England.
Where new development could increase nitrogen or phosphorus loads to internationally protected habitats (SACs, SPAs, Ramsar sites), planning authorities must be satisfied that the development will be nutrient neutral. This often requires a detailed nutrient budget prepared by a qualified environmental consultant.
This calculator uses Natural England's published WWTW coefficients and loading data to give you an early-stage budget across all 27 catchments currently in force.
Catchments covered
- Solent (82 WWTWs)
- Somerset Levels (116 WWTWs)
- River Eden, Teesmouth, The Broads
- Poole Harbour, River Avon, River Itchen
- 23 further NE-designated catchments
From postcode to nutrient budget in minutes.
Enter your site postcode
The tool identifies which catchment your site falls within — or flags if you're outside a nutrient neutrality zone.
Input development parameters
Number of dwellings, occupancy, and current land use. The tool selects the appropriate WWTW coefficients for your catchment.
Review your nutrient budget
See your nitrogen and phosphorus load calculations, baseline comparisons, and indicative mitigation requirements.
Get the full report
Request a full planning-ready nutrient budget from Aegaea's environmental team — delivered in 5 working days.
From calculator to planning-ready evidence.
This tool gives you an early-stage budget. For planning submission, you need a full nutrient budget report prepared and signed off by a qualified environmental consultant, with catchment-specific WWTW apportionment and an approved mitigation strategy.
Aegaea prepares nutrient budgets for all 27 catchments. We can also source and arrange mitigation credits where required.
Full nutrient neutrality services
- Catchment screening and nutrient budgeting
- Planning-ready technical report
- Mitigation strategy and credit sourcing
- Liaison with Natural England