About River Tapi

The Tapi River basin encompasses an area of 65,145 km², which is nearly two percent of the total area of India. The basin lies in the states of Maharashtra (51,504 km²), Madhya Pradesh (9,804 km²) and Gujarat (3,837 km²).

The basin lies mostly in the northern and eastern districts of Maharashtra state, including Amravati, Akola, Buldhana, Washim, Jalgaon, Dhule, Nandurbar, and Nashik districts, but also includes the Betul and Burhanpur districts of Madhya Pradesh and the Surat and Tapi district of Gujarat.

The total length of the river from its origin / source end at Multai near Betul in the Satpura Range in the state of Madhya Pradesh to its mouth at / confluence to Arabian Sea at Surat, Gujarat is about 724 km. In the upper part of the last stretch, the river passes through less cultivated areas in the east of Surat plains. The river passes through rich and highly cultivated plains that form the central part of the Surat district. Occurrences of floods during every monsoon form a significant feature of the Tapi estuary region. The flow in the river is regulated by Ukai multipurpose dam, which was commissioned in 1972.

Layout of River Tapi from Its origin to confluence to Arabian Sea
Layout of River Tapi from Its origin to confluence to Arabian Sea

The project comprises of a storage reservoir at Ukai village in Songadh taluka. Approximately 29 kilometers downstream of the Ukai dam and 85 km upstream of the mouth of the river, the river flow is regulated by Kakrapar barrage which was commissioned in 1958. The dry weather flow in the river stretch in the study region basically comprises of spillovers and releases from the Kakrapar barrage. Consequently, monthly flows do not vary much except during low and high flow months (May and August). In 1995 a weir-cum-causeway was constructed across the river at the village Rander, downstream of Surat city. Consequently, freshwater of the river now reaches only up to Rander whereas the river stretch downstream of weir is now a mere tidal zone which gets filled and drained during each tidal cycle. Within a period of 5 years after the construction of weir, the lentic water body started showing sign of eutrophication as evidenced by the growth of macrophytes in the river over a distance of about 20 km.

River Survey

The Tapi River was surveyed from the Kakrapar Barrage up to ONGC Bridge (85 km) beyond Surat Municipal Corporation limits where there is no inhabitation and any visible external source of pollution. River has a water flow width of approximately 600 m, which reduced considerably during summer season. All the intake wells are located in the middle of river cross section. The flow velocity in this middle part of the river (also called summer channel) is very low due to pumping of water by intake wells. This portion of the river section is relatively free of floating macrophyte. However, on both sides of this middle portion, water remains more or less stagnant and is full of floating macrophyte. Nearly 70% of the river water body from Singanpore causeway weir to upstream end of the Surat city is covered with three types of macrophyte namely floating (Lemna, Azolla, Pistia), submerged (Hydrilla, Ceratophyllum, Utricularia) and rooted hydrophytes (Nelumba).