River Tapi rises from the Satpura Mountains in Betul district of Madhya Pradesh and taking a 724-km long course through Madhya Pradesh, Maharashtra and Gujarat finally merges into the Gulf of Khambat. Out of its total basin area of 6 mha 15 per cent lies in Madhya Pradesh. 79.1 per cent in Maharashtra and 5.9 per cent in Gujarat. The river supports a number of class I towns many of which are famous for their industrial activities.
About 80 per cent o|’ domestic and 70 per cent of industrial water is disposed as waste water. The major contributor of pollution loads is the largely untreated urban waste water and industrial effluents. Of the total BOD load (488 tons/day) 39 per cent is contributed by urban domestic waste water, followed by industries (21%). The total carry-over of nitrogen and potassium compounds is about 10 per cent. The problem is aggravated during summer months when the river flow is considerably reduced.