The IWM Database
Every integrated water management measure we assessed. Search the library, or filter by scale, benefit and the stage at which the decision has to be made.
Water-efficient fittings
Low-flow taps, showers and dual-flush WCs specified as standard to reach 110 litres per person per day.
Greywater reuse (in-home)
Bath and basin water treated within the home and reused for WC flushing.
Neighbourhood greywater network
Shared treatment and dual-pipe distribution serving a whole development.
Rainwater harvesting (communal)
Roof runoff collected, stored and reused across a development for non-potable demand.
Rainwater harvesting (household)
Individual butts or tanks serving garden watering and other non-potable use.
Sustainable drainage systems (SuDS)
Swales, basins and permeable surfaces that slow, store and treat runoff where it falls.
Blue-green roofs
Vegetated roof build-ups with attenuation storage beneath the growing medium.
Constructed wetlands
Natural treatment of surface water before it is discharged to the environment.
Smart metering & resident feedback
Real-time consumption data shared with households to support behaviour change.
Community engagement programme
Structured resident engagement on water use and how the reuse systems work.
No measures match those filters.
Clear filtersCosts are indicative and relative, not absolute — they vary substantially by site. Every measure links to its supporting evidence.
How to use the library
Start from where you are. Filter by "decide by" to see what still has to be settled at your stage — those measures become difficult or impossible to add later. If you are already in detailed design, the filter will show what remains open to you.
See the full framework →masterplan → design → construction → occupation