Management of Water in Hirakud Dam Project – Part II
Conservation steps
As for the measures taken in the Orissa portion of the Hirakud catchments, 14 out of 44 selected priority watersheds have been brought under the soil conservation scheme since its initiation. But they are yet to be covered totally.
By the end of 1987-88, authorities say, between 19 per cent and 95 per cent of treatable area of these watersheds have been treated with conservation steps like bunding, terracing, tree plantation, pasture development and construction of various engineering structures.
In total, by the year 1987-88, physical area of nearly 2.9 lakh acre have been covered at a cost of Rs. 855.95 lakh, the authorities say.
But an Orissa Remote Sensing Application Centre report points out that the progress in soil conservation work is “very slow”, and says, “there is a lot to be done for treatment of identified critical watersheds.”
Above all, a Rs. 1-crore scheme assisted by the United Nations Development Project for conducting studies on sedimentation in the reservoir, is reportedly to be denied to the project (Hirakud) due to lack of administrative approval from the state government.
The scheme, which aims to introduce high technology in sedimentation survey in order to derive maximum benefits from the reservoir, was reportedly offered to the irrigation and power department two years ago.
The Central Water Commission, the implementing authority of the scheme, is understood to have made it clear that if the state government could not provide necessary funds to implement the scheme in the Hirakud project, the same would be awarded to some other reservoir project.
Other reasons
Besides the emphasis on power generation and soil erosion in the catchment area, Dr Sahu cites two other reasons behind the failure in flood control. They are: absence of control on runoff from the 14 major tributaries and 15 minor rivers feeding the Mahanadi in its central basin and rise in the river bed in the delta due to slow flow of the river.
The river’s flow being slackened by the dam, it cannot carry alluvial matter collected downstream to the estuary and, instead, deposits the same on its bed. When the flood water is released, it cannot flow down to the river’s mouth and erodes its banks and overflows.
In the process, the area around the mouth of the river is deprived of the sand needed to prevent the erosion of the coastline by the sea. In the absence of the protection, tidal batterings are fast eroding the coastline of Orissa and posing a threat to the Paradip port, according to an ORSAC study.
Islet disappearing
The study shows, the port’s northern part and the islet Hukitola, 10 km north of the port, are fast disappearing into the Bay of Bengal. The islet, which measured 15.85 sq. km. in 1929, now has only 2.35 sq. km. of its area left.
The only way to save the delta from increasing flood, says Er Patri, is to construct another flood control reservoir across the river Mahanadi. Besides that, afforestation and soil conservation steps have to be stepped up, stronger embankments to be built and infrastructure to be developed for effective flood forecasting, he adds.
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