Critics say rules of China and Vietnam in particular have bowed to the aspirations of their citizens in a big way in the last two decades.
India, which started to give increasing economic freedoms to citizens from 1991, has seen sweeping urbanization, through infrastructure is creaking under the demand.
Sri Lanka's current administration has started to upgrade city infrastructure.
Meanwhile the ADB said its 300 million dollar loans will have tranches targeted at different aspects of a 400 million Us dollar state program to expand water and sanitation in the greater Colombo area.
The first tranche of 84 million US dollars will focus on cutting water losses at state-run National Water Supply Drainage Board, which is suffering losses due to so-called 'non-revenue' water.
Each year the water agency is estimated to lose 13 million US dollars worth water.
The ADB said the program aims to make 24 hours a day water available throughout greater Colombo by 2020 with a focus on improv