Concern over parched days as Dam has low water level due to excess release
Kushalnagar: Two years after the Karnataka Cabinet accorded administrative approval to release Rs. 130 crore to remove silt from Harangi Dam at Somwarpet taluk in Kodagu district, preparations are in full swing to remove the silt and carry out other allied development works.
Over one tmcft (one thousand million cubic feet) of silt has accumulated at Harangi Dam, the main Cauvery water supply reservoir from the catchment areas to KRS Dam in Mandya, the lifeline of South Karnataka and Tamil Nadu. The accumulation of silt had resulted in a sharp dip in the water level impounded in the reservoir.
The tender has been awarded to Maharashtra-based Shiva Constructions and the groundwork, mobilisation and marking of areas for silt removal will begin by the end of this month. The actual work is expected to begin in January 2023.
Massive task in store
This will be a massive task as most of the mud that slipped and washed away from mountains during the floods and landslides of 2018, 2019 and 2020 have entered the Dam through rivers and tributaries, decreasing its water storing capacity further.
Speaking to Star of Mysore yesterday, Madikeri MLA M.P. Appachu Ranjan said that this was a long-pending project becoming a reality now. “The tender was quoted for Rs. 113 crore and the State has approved 129 crore (extra funds of Rs. 16 crore keeping in mind the cost escalation factor). Of this, Rs. 38 crore will be utilised for silt removal, Rs. 40 crore to construct the retaining wall that has been damaged and collapsed at places around the Dam and Rs. 35 crore will be utilised to restore bridges, clean canals and other related works,” he said.
Gabion wall technology
To prevent silt deposits in the future after the present silt is removed, Gabion wall technology will be used on both the sides of the Dam. “As works at the Dam can be taken up only during five months due to weather conditions of Kodagu, the contractor has been directed to finish off maximum silt removal works before the 2023 monsoon sets in,” Appachu Ranjan added.
Cauvery Neeravari Nigam Limited (CNNL) Assistant Engineer (AE) Siddaraju said that as a Writ Petition (W.P. No.8864/2020) has been filed in Karnataka High Court regarding Harangi Dam storage levels, the Court has asked CNNL to carry out silt removal and development works in a transparent manner.
“This will be Court-monitored work and we need to update the Court at every step. The Court has directed us to complete the de-silting and development works within two years considering that there will be favourable weather only for five months in Kodagu,” he said.
Alarmingly low storage level now
While the de-silting will enable the Dam to store more water that will help Mysuru and Harangi Dam Command Areas at the time of water crisis, concern has been raised now due to the low storage level. While the Dam can hold 8.5 tmcft of water, the present level is only 3.5 tmcft and if it does not rain, the same water has to be rationed and maintained till the next monsoon.
In the hope of good rains in December, the CNNL authorities resorted to excessively releasing water to the downstream KRS Dam and to the feeder canals for the benefit of tail-end farmers of K.R. Nagar, Periyapatna, Hunsur and Saligrama.
Today’s (Dec. 13) data shows that the Dam’s gross capacity is 3.42 tmcft and live capacity is 2.67 tmcft. Inflow of 423 cusecs and outflow of 600 cusecs was recorded. Considering the low storage level, it will be a Herculean task to fulfil drinking water to Kushalnagar, K.R. Nagar and Periyapatna during peak summer if it does not rain.
Excess water release
In fact, the data from Karnataka State Natural Disaster Monitoring Centre (KSNDMC) shows that from June 1, 2022 till Dec. 12,
45 tmcft has flowed into the Harangi Dam and 46 tmcft outflow has been recorded, indicating excess water release and lopsided water management.
As the Chunchanakatte Srirama Sugar Factory is operational now, farmers in the region have been encouraged to grow sugarcane and every farmer is prepared to do so. But their plight will hang in balance if there is no water in the Harangi Dam.