Damodar Valley Dams role in W Bengal Floods – DVC Dams could have helped reduce the floods, they increased it

As at least 222 blocks of 13 districts of South Bengal suffered massive floods with over 51 lakh people affected and crops on 5 lakh hectares ruined, questions have once again been raised if Damodar Valley Corporation[1] dams played a role in increasing this flood disaster. Available information and the statements of the DVC officials leave no doubt that DVC dams indeed released water into the rivers and this release worsened and prolonged the flood situation in South Bengal. If DVC had held back the water while cyclone Komen was active in the region, bringing heavy rains, then the flood intensity, its impact area and the flood duration could have been reduced. The DVC operators should also have kept in mind that this was high tide period when the rivers’ capacity to drain out the water was significantly lower in the delta area. The DVC dams had sufficient storage capacity to hold this water during the period. However, instead of holding back the water during this crucial period, DVC increased water releases from the dams during the flood disaster.

DVC admits they released water Damodar river has five major dams, four of them in Jharkhand, are under DVC, these are: Tilaiya, Konar, Maithon and Panchet Hills. The Maithon Dam (catchment area 6293 sq km) on Barakar, a major tributary of Damodar and the Panchet Hill dam (catchment area 10966 sq km) on Damodar, are just upstream of the point where these rivers enter W Bengal[2], so releases from these dams would have direct impact on floods in W Bengal. The DVC has said in their defense[3]: “The flooding over the past few days is mainly due to the high tidal effects and Komen depression related rainfall. The combined release on August 3 was 95,000 cusecs, which is lower than the safe downstream channel carrying capacity of the Damodar river which is 1,10,000 cusecs.” This statement is an admission of DVC’s blunder. The fact is that DVC operators knew that downstream areas were facing heavy rainfall during Aug 1-4, 2015 under the influence of Komen and that this was also the high tide period. So the river needed space to drain out the rainwater. And yet they released water equal to 86% capacity of the river as per their own admission! They have thus admitted the blunder.

They need not have released this water as both Panchet Hill and Maithon dams had sufficient capacity to store this water which could have been released at a latter date. Even on Aug 5, 2015 (at 12 noon), Mathon water level was 148.68 m, way below its flood cushion level of 150.88 m and MWL of 151.79 m as per DVC website. Panchet Hill dam has water level of 128.28 m at 12 noon on Aug 5, 2015[4], when its flood cushion level is 132.5 m as per DVC website[5].

WRIS map of Damodar Basin

DVC increased the releases in floods The reality is that if we look at the power generation from Maithon and Panchet Hill Dams, the two dams that have most of the hydro power generation capacity of the DVC, the power generation at these dams went up from 1.81 Million Units on July 31, 2015 to 2.64 Million Units on Aug 3, 2015[6], which is a 46% increase! Power generation quantum is directly decided by height multiplied by flow. Since the head (dam level) would not have changed significantly in these four days, we can assume that about 40% more water was released from DVC dams when the downstream areas were facing floods due to the rains and high tide. So instead of stopping water releases, DVC dams actually INCREASED the water outflow by about 40%. This was clearly avoidable and this must have hugely contributed to the floods in downstream W Bengal areas.

Questions DVC needs to answer: So the correct questions to ask are:

• Could DVC have stopped water releases when downstream areas were facing floods? Ans: Yes.
• Did DVC dams have the water holding capacity to hold back water during flood period? Ans: Yes.
• Did DVC do what it could to reduce the water releases to help reduce floods in W Bengal? Ans: No.
• Did DVC increase the water flow to the downstream areas during flood period compared to water releases before that period? Ans: Yes.

We hope DVC dam managers will he held accountable for theses lapses.

DVC has also been claiming that the dams have been regulated as per the directions of the Damodar Valley Reservoir Regulation Committee, in consultation with Central Water Commission and that DVRRC members include Chief Engineer (Irrigation) of W Bengal. The trouble is there is no information about DVRRC functioning or even DVC dams functioning on DVC website or anywhere else. This need to be corrected immediately and the information about operation of the DVC dams and functioning of DVRRC should be in public domain on daily basis. Secondly, in that case the DVRRC and CWC should also be held accountable.

So when W Bengal Chief Minister Mamata Banerjee said[7] that “the flooding had worsened in Burdwan, Hooghly and Howrah districts because DVC released water from its dams”, she seems correct. This is not the first time that DVC operators have been guilty of such blunders, but they have never been held accountable for such mistakes. We hope this time the DVC should be held accountable and W Bengal CM should not stop at just public statements. The WB CM also needs to hold the state Chief Engineer (Irrigation), member of DVRRC, accountable for the mismanagement at DVC dams.

Himanshu Thakkar (ht.sandrp@gmail.com), SANDRP

WRIS map of Damodar Valley Projects

END NOTES:

[1] Under Union Ministry of Power

[2] For a basin map with location of dams, see: https://sandrp.in/basin_maps/Hydro_Projects_on_Damodar_River.pdf

[3] http://www.business-standard.com/article/pti-stories/water-from-maithon-panchet-dams-not-causing-floods-dvc-115080400994_1.html

[4] As per flood forecasting website of Central Water Commission, see: http://www.india-water.gov.in/ffs/current-flood-forecast/, unfortunately, CWC does not archive its flood forecasts, so only current forecasts are available at any given time.

[5] http://www.dvc.gov.in/dvcwebsite_new1/dams-barrages/

[6] Based on Daily Power Supply Position reports on Eastern Regional Load Despatch Centre Website, see: http://www.erldc.org/Daily_report.aspx?menusel=PSP

[7] http://timesofindia.indiatimes.com/city/kolkata/Death-toll-rises-to-69-Mamata-blames-DVC-for-worsening-crisis/articleshow/48337095.cms