Sustainable water allocation option has always been a challenge for any overpopulated city. Dhaka, the capital of Bangladesh faces additional challenges due to its phenomenal expansion in the recent decades and huge population has overstressed its existing natural water resource. The surface water bodies being polluted, excessive extraction of groundwater and filling of wetlands have threatened the sustainable water allocation options. Water Footprint assessment can be used as an effective decision support tool in this situation. Water Footprint can be assessed for a process, a product or for a group of consumers and the spatial variation can be classified as in terms of global average, national or regional, or a catchment specific. This paper deals with the potential of using Water footprint assessment as a decision support tool. A proposed model framework has been presented in this paper for assessing the water footprint of a geographically delineated area, Dhaka and how this water footprint assessment approach can be used for water allocation decision. The rationale of the spatiotemporal detail proposed in this approach has been discussed and coherence between blue, grey and green water footprint for Dhaka has been defined. This paper also focuses on future scope of water footprint assessment in national level in Bangladesh.