Emergency Preparedness
DIY Water Collection: Rainwater Harvesting for Emergencies
Set up rainwater collection for emergency water supply. Legal considerations and filtration for UK homes.
Ethan Walker
6 min read
4,954 views
UK Rainwater Harvesting Law
Good news: Collecting rainwater is legal in the UK. No permits needed for domestic use.
Basic Collection System
Components
- Collection surface (roof)
- Gutters and downpipes
- First flush diverter
- Storage tank/barrel
- Filtration system
- Overflow outlet
Capacity Calculation
Rainfall (mm) × Roof area (m²) × 0.8 = Litres collected
Example: 25mm rain × 50m² roof × 0.8 = 1,000 litres
Storage Options
| Type | Capacity | Cost |
|---|---|---|
| Water butt | 100-300L | £30-80 |
| IBC tote | 1000L | £50-100 |
| Underground tank | 1000-5000L | £500+ |
Treatment for Drinking
- First flush to waste (initial dirty water)
- Sediment filter (50 micron)
- Carbon filter
- UV sterilisation OR boiling
- Store in clean containers
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water
rainwater
harvesting
DIY