Water
Store drinking water first; treat harvesting as a separate, non-potable system unless professionally designed and tested.
- Keep sealed drinking water and rotate it by the manufacturer date.
- Plan at least 2.5–3 litres per person per day for survival; around 10 litres allows basic cooking and hygiene.
- Know where your internal stopcock is and keep containers you can carry.
- Add a clean water butt for gardens and toilet flushing.
- Use first-flush diversion and covered, opaque storage for larger rainwater systems.
- Do not assume roof-collected rainwater is safe to drink; contamination can be invisible.