The water footprint of Indonesian provinces related to the consumption of crop products

National water use accounts are generally limited to statistics on water withdrawals in the different sectors of economy. They are restricted to 'blue water accounts' related to production, thus excluding (a) 'green' and 'grey water accounts', (b) accounts of internal and international virtual water flows and (c) water accounts related to consumption. This paper shows how national water-use accounts can be extended through an example for Indonesia. The study quantifies interprovincial virtual water flows related to trade in crop products and assesses the green, blue and grey water footprint related to the consumption of crop products per Indonesian province. The study shows that the average water footprint in Indonesia insofar related to consumption of crop products is 1131 m(3)/cap/yr, but provincial water footprints vary between 859 and 1895 m(3)/cap/yr. Java, the most water-scarce island, has a net virtual water import and the most significant external water footprint. This large external water footprint is relieving the water scarcity on this island. Trade will remain necessary to supply food to the most densely populated areas where water scarcity is highest (Java).