Neighbourhood greywater network
Shared treatment and dual-pipe distribution, serving a whole development rather than individual homes.
In one paragraph
A neighbourhood greywater network collects water from baths, showers and basins across many homes, treats it at a shared plant, and distributes it back through a second pipe network for WC flushing, laundry and irrigation. It achieves better economies of scale than in-home systems, but requires the dual-pipe network to be laid during construction and a clear answer to who will operate it for the life of the development.
What it delivers
- Substantial reduction in mains potable demand across the development
- Better treatment consistency than distributed in-home units
- Lower maintenance burden per home than individual systems
When the decision has to be made
Masterplanning. The dual-pipe network, plant location and storage all need space reserved before the layout is fixed. This measure cannot realistically be added later — retrofitting a second pipe network into a built development is prohibitively expensive.
What to watch
- Stewardship must be settled alongside the design — see the three models
- Demand and supply need balancing; oversized plant is a common and costly error
- Resident communication matters more than the technology, per our engagement research
Evidence
- Greywater reuse at neighbourhood scale — performance, cost and maintenance data
- Knights Park, Cambridge — the measure in a live development