Table 5.
Unavoidable real loss (UARL) and Infrastructure leakage index (ILI) in district metered areas (DMA).
| DMA | Before DMA construction |
After DMA construction |
Difference before and after |
||||||
|---|---|---|---|---|---|---|---|---|---|
| UARL1) |
ILI |
UARL |
ILI |
UARL |
ILI |
||||
| L/d | L/conn/d | (−) | L/d | L/conn/d | (−) | L/d | L/conn/d | change % | |
| DMA-1 | 42,610 | 18.2 | 7.04 | 43,651 | 17.7 | 7.95 | 2.4 % | −2.26 % | 12.9 % |
| DMA-2A | 61,000 | 18.5 | 4.42 | 59,077 | 18.3 | 4.99 | −3.2 % | −1.11 % | 12.9 % |
| DMA-2B | 57,934 | 18.2 | 0.90 | 63,940 | 18.4 | 3.06 | 10.4 % | 1.05 % | 239.6 % |
| DMA-3 | 14,309 | 19.7 | 13.24 | 14,477 | 19.1 | 5.94 | 1.2 % | −2.57 % | −55.1 % |
| DMA-4A | 55,116 | 17.4 | 6.09 | 22,940 | 18.1 | 28.16 | −58.4 % | 4.09 % | 362.4 % |
| All DMAs | 226,968 | 17.8 | 5.05 | 200,085 | 17.9 | 7.84 | −11.8 % | 0.23 % | 55.2 % |
| Tokyo (1956, 2021)2) | 26.5 million | 27.2 | 24.07 | 202.0 million | 25.9 | 0.72 | 662.0 % | −4.82 % | −97.0 % |
Note: 1) Non-revenue water (NRW) was unknown in each DMA before their construction. Thus, it was assumed to be the same as the NRW after the DMA construction. 2) Water Statistics Book, Japan Water Works Association, 1956–2021. Tokyo Metropolitan Water Works Bureau.