Water supply and sanitation is an important sector of investment supported by the Asian Development Bank (ADB). For the period 2006–2010, ADB-approved investments in water supply and sanitation amounted to approximately $4 billion, representing 7% of ADB’s lending portfolio over the same period. Total investment in water supply and sanitation for the period 2011–2014 reached in excess of $5 billion.
The provision of water supply and sanitation services is particularly vulnerable to projected changes in climate conditions (temperature and
precipitation among others), in the frequency and intensity of extreme weather events, as well as in the projected rise in sea level and the
intensification of storm surges.