The target
Reusing half of every drop by 2045.
The Global Commission on the Economics of Water suggested we should aim to "reuse half of every drop of water that we use." What might that mean in practice?
How much water do we use?
Global freshwater demand, broken down.
We estimate global freshwater abstraction at roughly 4,000 km³ per year. Reuse is difficult to apply to agriculture, once-through cooling and mine dewatering — so the target focuses on municipal supply and on-site industrial process water.
The opportunity is in industrial and domestic wastewater.
Future demand, 2025 → 2045
km³. Process water grows 30%; domestic supply grows 45%.
2045 demand: who supplies the water?
Total domestic + industrial process water demand in 2045 — 1,120 km³ — split by source. Municipal utilities supply all domestic demand plus an estimated 255 km³ of industrial process water; the remaining 265 km³ comes from direct industrial abstraction.
A municipal target
428 km³ of municipal reuse capacity by 2045.
Municipal utilities supply both domestic and some industrial water. By 2045 total municipal supply is expected to reach 855 km³. Reusing half of every drop means scaling installed reuse capacity from today's 67 km³ to 428 km³ — a 6.4× expansion.
Installed municipal reuse capacity, 2006–2025
km³. Source: GWI DesalData.
Reuse by application
Share of installed municipal reuse capacity. Agricultural and industrial use dominate.
Annual additions to reuse capacity — historic vs. required
km³ added per year. The build-out must accelerate sharply: from ~3.5 km³ today to nearly 38 km³ in 2045.
Monitoring municipal progress
Global Water Intelligence tracks all major water reuse projects worldwide. Through its collaboration with the International Desalination and Reuse Association, it conducts an annual sweep of smaller projects and reported additions to capacity, published each year in the IDRA Desalination and Reuse Handbook.
Onsite industrial reuse
Halving the freshwater industry abstracts.
Industrial users abstract around 400 km³ of process water annually — roughly half from municipal utilities. They also use ~17 km³ of reclaimed water from municipal reuse facilities and ~3.4 km³ of desalinated supply.
Why a single industrial target is hard
Onsite industrial reuse is not currently calculable. Most cooling water is recirculated many times. Many industries cascade uses (influent water cools condensate, then makes steam). What counts as "reuse"? The line between reduce, recycle and reuse blurs — what matters is total abstraction and total consumption, not the technique.
A possible solution
The Scaling Water Reuse Initiative is working with industrial partners to agree definitions on a sector-by-sector basis and to promote a standard for reporting reuse. A global target for reducing total freshwater abstraction for industry by 2045 could be met through onsite reuse, reclaimed municipal wastewater, and broader efficiency gains.
An inspirational target
Inspiration, not legal mandate.
Whatever target is eventually adopted, it should serve as inspiration rather than regulation. It will be achieved by changing public attitudes — and by changing the economics of water reuse.
See the economics of water reuse →