Desalination & Reuse Handbook - Flipbook - Page 14
IDA
WATER SECURITY
HANDBOOK
SÃO PAULO
In 2015, municipalities all over São Paulo declared states of calamity: the city was running out of water. Between 2014
and 2015, the combined pressures of endemic pollution in the Billings and Guarapiranga urban reservoirs and prolonged
drought drove levels in the rural Cantareira Water System (CWS) – a water source for 9 million people – below 10%
for extended periods. Additional piping was installed to access the ‘dead water’ from the CWS’s lowest points, but after
decades of neglect, the failure of São Paulo’s water supply was a clear and present danger.
Conventional water security measures – drawing on technical reserves, increases in supply systems, regulation of network
pressures, and tariff incentives – were insufficient to mitigate the crisis’ effects. Short-term water diversions and severe
supply regulation allowed the city to see out the worst of the shortages until heavy rains in February 2016 recharged the
CWS to 52.9%.
São Paolo metered and billed water losses
Total water losses in the Sao Paolo water
network fell from 24.4% in 2013 to 20.1%
in 2017. Key to this was the increase in
regulated connections over the period, which
significantly reduced water losses through
illegal connections known as ‘gatos’. This
represented a 19% reduction in losses per
connection, which fell from 372 L/d in 2013 to
302 L/d in 2017. The sudden drop in 2015 was
a result of supply cuts during the height of the
city’s water crisis.
40%
400
35%
30%
300
25%
20%
200
15%
10%
100
5%
0%
0
2013
2014
Water metered - Loss index (%)
2015
2016
2017
Water losses per connection (L/day)
Source: SABESP
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