Water · Guide Companion

Greywater Systems: The Complete Walkthrough

This guide covers greywater systems, rated a moderate to hard task, typically taking 1–3 days setup.

Our printable card on greywater systems covers the essentials at a glance — here's the fuller walkthrough.

From laundry/shower to garden

A simple greywater system diverts water from the laundry, shower, or bathroom sink out to garden beds or trees, rather than sending it straight to the sewer — significantly cutting overall water use.

What You'll Need

Keep these points in mind:

  • A diversion valve or dedicated greywater plumbing
  • Greywater-safe (low-sodium, phosphate-free) soaps and detergents
  • Mulch basins or a subsurface irrigation setup at the garden end
  • Check on local regulations before installing

The Method

Worth paying attention to:

  • 1. Check local regulations — greywater rules vary significantly by location and system type.
  • 2. Choose a source: laundry-to-landscape systems are typically the simplest starting point.
  • 3. Install a diversion valve so you can switch between sewer and garden as needed.
  • 4. Direct water to mulch basins around trees or garden beds — never store greywater, use it promptly.
  • 5. Switch to greywater-safe products for anything feeding the system.

Common Issues

Keep these points in mind:

  • Plants showing stress — check detergents are genuinely greywater-safe; many common products harm soil and plants over time.
  • Smell or standing water — greywater should be used promptly, not pooled or stored; check the outlet is draining well into mulch or soil.
  • Blocked outlets — lint and hair from laundry/shower can clog lines; fit and clean filters regularly.
  • Regulatory issues — some areas restrict or require permits for greywater systems; confirm before installing anything permanent.

Ongoing Timing

Best time — install any time; a permanent, passive addition to water infrastructure. Duration — a basic laundry-to-landscape system can be installed in a day or two. Maintenance — clean lint filters regularly; monitor plant health at the outlet points. Signs of success — healthy plant growth around outlet points and a visible reduction in mains water use.

For the condensed printable version, head to the main guide page linked below.

→ View the printable A4 guide for greywater systems