Outdoor 3 min read Updated 15 April 2026 Trade verified
How to Fit a Water Butt Diverter — Rainwater Harvest Guide
A water butt saves 200L of tap water a week in summer. Fitting a diverter to your downpipe takes 20 minutes.
Need parts for this job?
Trade-priced water butt diverter in the Plumber.Parts catalog — next-day delivery.
Step-by-step method
1. Position the water butt
On a stand for gravity-fed watering cans. Adjacent to the downpipe you'll divert.
2. Mark the diverter height
Hold the diverter against downpipe at butt-inlet level (usually 20cm below butt top).
3. Cut the downpipe
Hacksaw a horizontal cut at the mark. Slide the diverter body in, top and bottom of downpipe both push into diverter.
4. Connect to butt
Drill 32mm hole in butt at same level as diverter outlet. Push connector through, tighten locking ring, connect flexi hose.
Frequently asked questions
Do I need overflow protection?+
Most diverters have auto-overflow — once butt is full, water diverts back down the pipe. Confirm your model has this.
Can I use butt water indoors?+
For toilet flushing only via a rainwater harvesting system with UV treatment. Not for drinking or laundry.