The present study is aimed to develop a GIS based method for “Divide (zoning) the Allahabad city into different wastewater zones to optimize the drainage length using the GIS and Remote sensing”. The study was performed at three different levels of analysis viz. land use/land cover analysis, site suitability analysis and hydrological analysis using remote sensing data to develop the zones. These analyses were carried out using ARCGIS 10 and ERDAS IMAGINE softwares. Land use/land cover (LULC) analysis was performed by supervised classification method using the maximum likelihood classifier. The site suitability analysis was carried out by considering technical feasibility, environment sustainability and social acceptability. Factors such as ground slope, land use, distances from surface water, roads, railway network and dwelling place were considered for site selection analysis. Buffer analysis was performed at these layers and converted it into raster format. Raster data of these layers were overlaid in the GIS and weighted overlay method was performed. The above analysis resulted in identification of suitable site for wastewater treatment plants (WTPs). Hydrological analysis was carried out for determining the slope, flow direction, flow accumulation, drainage network using digital elevation model. The analysis resulted in identification of watershed and its natural drainage network. Finally, these results were combined together to identify the zones for wastewater drainage of the city and suitable sites for wastewater treatment plants.