Opens NutrientMonkey. Pick River Avon (Christchurch) from the catchment list and the phosphorus toggle locks to match.
Stuck behind a River Avon (Christchurch) nutrient condition?
The Hampshire Avon, draining to Christchurch Harbour, is a phosphorus catchment — and a classic trap, because it sits right next to nitrogen-led Poole Harbour. Get the nutrient wrong and the whole assessment is wrong.
If your site drains to River Avon SAC (→ Christchurch Harbour), 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 River Avon SAC is assessed for phosphorus, not nitrogen — the opposite of its Dorset neighbour Poole Harbour. That matters, because the methodology and the credits differ by nutrient — and neighbouring catchments often differ. NutrientMonkey flags the River Avon (Christchurch) catchment for phosphorus and locks the tool to match, so the assessment is right from the start.
How the River Avon (Christchurch) calculator works
- Pick River Avon (Christchurch) from the catchment list — it's pre-flagged for phosphorus.
- 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).
- Add land use & SuDS — current vs future land cover and any sustainable drainage, with editable export coefficients for the Wiltshire, Hampshire & Dorset catchment values.
- 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 River Avon (Christchurch) 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? That's what we're here for.
Frequently asked questions
Which nutrient applies in the River Avon SAC (→ Christchurch Harbour) catchment?
The River Avon SAC is assessed for phosphorus, not nitrogen — the opposite of its Dorset neighbour Poole Harbour. A compliant scheme has to be neutral for phosphorus. NutrientMonkey locks the nutrient toggle to match the River Avon (Christchurch) catchment automatically, so you can't pick the wrong one.
Is the River Avon (Christchurch) calculator free to use?
Yes — selecting the catchment, entering your dwellings and watching the budget update in kg/year is completely free. You only pay £79 +VAT (£94.80 inc VAT) to export the planning-ready PDF report.
How is the River Avon (Christchurch) nutrient budget worked out?
It follows Natural England's published nutrient-budget methodology — waste water, current and future land use, SuDS, then the final budget with the ×1.2 (20%) precautionary buffer. For new homes the waste-water term does most of the work and is computed exactly.
Is this the official Natural England calculator?
No — it's a fast, planning-support assessment that implements NE's methodology, and the report says so. The official NE catchment calculator remains the statutory tool, and your figures should reproduce in it.
In a different catchment?
NutrientMonkey covers every Natural England catchment.
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
- Somerset Levels & Moors 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.