Shortage of water at the Bhoothathankettu barrage has affected water supply in areas of Ernakulam fed by the Periyar Valley irrigation scheme and led to rise in salinity in the Kadambrayar river, according to Irrigation Department officials.
Tailrace discharge from the Idamalayar hydroelectric project mainly feeds the Periyar Valley canals that run a length of 750 km across Kothamangalam, Muvattupuzha, Aluva, Paravur, Kunnathunad and Kanayannur taluks. The canals mostly meet irrigation purposes in these areas when the barrage is opened in early January every year.
“A minimum level of 34.95 metres must be maintained at the Bhoothathankettu barrage to ensure distribution of water through the canals under the Periyar Valley project. Only if the level is maintained can the various sluices and channels, particularly those at an elevation, be filled,” said an official associated with the project. “But power generation at the Idamalayar power house has reduced, particularly since last week after the hartal, leading to a drastic fall in the level of water at the barrage to around 32.85 metres.”
Repeated requests to the Kerala State Electricity Board (KSEB) to increase power generation did not yield results till two days ago, when the level rose by around 40 metres. “The KSEB is required to ensure that the Irrigation Department’s need of 4 million metre cube per day for the Periyar Valley canals is met, but they have cited repairs of a generator as the reason for shortage,” another Irrigation Department official said.
However, a KSEB engineer in charge of the Idamalayar dam maintained that electricity production levels had not dipped recently, and that they had experienced no shortage of water.
Several rural water supply schemes under the Perumbavoor section, in which pump houses draw from the Periyar Valley canals, have been affected for the past few weeks, said a Kerala Water Authority (KWA) official.
Water to Kochi could be indirectly affected by this shortage. Since the canals flow into the Kadambrayar and the Periyar, the shortage of water could lead to a reverse flow of saline water and a consequent increase in salinity in the two rivers. The recent water shortage at Infopark which relies partly on the Kadambrayar that has seen an inflow of saline water in the past few weeks, could be attributed to this, the Irrigation Department official said.
“The shortage we experience in the later summer months has set in now. Since the water table dipped after the floods, the demand has gone up, and cultivators are dependent on the Periyar Valley project for water supply,” the official added.
