The Index of Drinking Water Adequacy (IDWA) was first introduced in the Asian Water and Development Outlook 2007, a report issued by the Asian Development Bank. The computation of the index (more recently christened IDWA-I) calls for data on five different parameters—resources, capacity, access, quality and use. For 28 Indian states, we could manage to obtain data on four parameters (resources, access, capacity and quality) and for an additional 15 states on ‘use’ also. All data refer to 2001 or years close to that. Access, however, has two variants—general access that refers to access to water via taps, hand pumps and tube wells; and ‘optimal access’ via taps within residential premises. The two variants provide the basis for computing IDWA-I and IDWA-II. Inter-relationships between the two and between them and a couple of development indicators are also explored and implications noted. It is gratifying to note from the inter-correlations that there is really no second best to a tap in a house when it comes to human development.