Guide
Check if nutrient neutrality affects your site
Find out if your development site is in a nutrient-affected catchment. Lists all 27 affected catchments across 74 local planning authorities and explains how to check your site.
Nutrient neutrality requirements affect development in 27 river catchments across England. If your site drains to a protected habitat that is sensitive to nutrient pollution, you must demonstrate that your development will not increase nutrient loading.
This affects approximately 14% of England's land area and 74 local planning authorities. Use this guide to determine whether your site is affected.
Affected catchments and local authorities
The following 27 catchments currently require nutrient neutrality:
How to check your site
Step 1: Contact your local planning authority
Your LPA is the definitive source. They will confirm:
- Whether your site is in an affected catchment
- Which protected habitats site applies
- Whether nitrogen, phosphorus, or both require neutrality
- Any local mitigation schemes available
Step 2: Check Natural England's catchment maps
Natural England publishes maps showing the boundaries of affected catchments. These are available on GOV.UK and help you identify which catchment your site drains to.
Step 3: Understand your drainage
Nutrient neutrality relates to where your wastewater ultimately discharges. Key questions:
- Where does your site connect to for foul drainage? Identify the receiving wastewater treatment works.
- Where does that works discharge? The receiving watercourse determines which catchment applies.
- Are you proposing private treatment? If using a package treatment plant, where will it discharge?
What if you're on a catchment boundary?
If your site is near a catchment boundary, the determining factor is where your wastewater flows, not where your site sits geographically. A site physically outside an affected catchment but draining into it will still require nutrient neutrality.
Development types affected
Most affected:
- New residential development (any size)
- Agricultural building conversions to residential
- Student accommodation
- Care homes and nursing homes
- Hotels with overnight stays
Less affected:
- Commercial development without significant wastewater (warehouses, storage)
- Extensions not increasing bedroom numbers
- Replacement dwellings with same bedroom count
- Agricultural buildings remaining in agricultural use
Note: Even "less affected" development types should be checked with your LPA. Local interpretation varies.
If your site IS affected
You will need to:
- Calculate your nutrient budget using Natural England's catchment-specific calculator
- Identify mitigation to achieve neutrality (on-site, off-site, or credits)
- Prepare a Nutrient Neutrality Statement for your planning application
- Submit evidence of secured mitigation with your application
See Nutrient neutrality compliance for development for detailed guidance on achieving compliance.
If your site is NOT affected
If your site is outside affected catchments, you do not need to demonstrate nutrient neutrality for planning purposes. However:
- Check for other environmental constraints: Your site may still have biodiversity, flood risk, or other environmental requirements.
- Catchments can be added: New scientific evidence may designate additional catchments in future.
- Development in currently unaffected areas is welcome: LPAs outside affected catchments are keen to process applications while nutrient-affected authorities are constrained.