Mahanadi-Godavari Flood Moderation Project
Water balance studies done by NWDA reveal that Mahanadi and Godavari basins are water surplus basins. The combined surpluses of these basins after accounting in basin uses in ultimate stage of development can be diverted to meet the water requirement of deficit basins in South upto river Gundar through Mahanadi-Godavari-Krishna-Pennar-Cauvery-Vaigai-Gundar linkages (9 link system)
Accordingly NWDA prepared feasibility study report of Mahanadi-Godavari Link. The link offtakes from the right flank of the proposed Manibhadra dam on river Mahanadi in Odisha and after traversing 828 Km (302 Km in Odisha and 526 Km in Andhra Pradesh) and outfall in Godavari River at 15 Km upstream of the existing Dowlaiswaram barrage in Andhra Pradesh.
The proposed dam was having submergence of 59400 ha. (Odisha) based on Government of Odisha surveys. However, the Government of Odisha did not agree with this proposal as the Manibhadra dam involved large submergence. The matter of M – G link has been discussed with Govt. of Odisha from time to time. During the discussions in January 2015 WRD, Odisha made some suggestion in this regard and consequently NWDA has prepared a revised proposal of Mahanadi-Godavari link with minimum submergence and comparable benefits.
The Present proposal:
It is proposed to have a dam at Barmul 14 km. upstream of Manibhadra on River Mahanadi. The Barmul dam with FRL 80m, height 25m will have a gross storage of 1216 MCM and water diversion of 9182 MCM. Out of which, after meeting the enroute needs 4046 MCM water will be transferred to Godavari.
The Mahanadi-Godavari link will originate from Barmul dam at FSL 75.00m with all the design features of conveyance system as proposed in the FR of Mahanadi-Godavari link and additional length of 14 km. Thus the total length of the link canal be 842 km. Six dam projects at Salki and Ong in Ong sub-basin and Uttei Roul Integrated Project, Khadago, Udanti and Tel Integrated Project in Tel sub-basin in Mahanadi basin will be included in the Mahanadi – Godavari Flood moderation scheme. The six dam projects will utillise 1162 MCM of water within Odisha State. The submergence from Barmul dam will be 13768 ha. and from six dam projects will be 10222 ha. Thus total submergence shall be about 23990 ha.
The annual water balance at Barmul site on Mahanadi is assessed as 11175 MCM which includes storages in six dam projects also.
The Mahanadi – Godavari flood Moderation Project shall provide irrigation to the tune of 3.21 lakh ha. in Odisha through link canal and 1.82 lakh ha. through six dam projects. Thus total irrigation in Odisha shall be 5.03 lakh ha. It is proposed to provide 125 MCM water for drinking water supply. The six dam projects have a potential of generating 240 MW hydro power. There will be flood moderation in Mahanadi river basin. The proposal prepared is preliminary based on remote sensing studies and will be firmed up by detailed studies.
Additional Secretary, Ministry of Water Resources, River Development and Ganga Rejuvenation, Chairman, Central Water Commission and Director General, NWDA have made a presentation of the above proposal of Mahanadi – Godavari Flood Moderation Project before the Hon’ble Chief Minister of Odisha on 29.5.2015. Government of Odisha is examining the proposal and is expected to convey its response for taking up detailed studies in due course of time.