NewsMeter Exclusive: DSRP presses alarm button about 65-year-old Kaddam irrigation project, calls for overhaul

Adilabad: Dam Safety Review Panel (DSRP), which inspected and evaluated the problems at the Kaddam Narayan Reddy Project (KNRP) in the Nirmal district, has warned that the highly successful irrigation facility could "slip out of hands" if it does not see a complete overhaul without losing time.

The DSRP report accessed by NewsMeter revealed that the continuing accumulation of silt in the reservoir, among other issues, threatens the very existence of the about 65-year-old project by posing a great danger of the river sluices giving way eventually to result in total decommissioning of the project "in an instant of time".

The 251-page report of the 6-member Panel headed by former Central Water Commission Chairman, A.B. Pandya was submitted to the government about a fortnight ago.

The Panel carried out the inspection of the dam, popularly known as Kaddam or Kadem dam, on July 28 in light of the peril that the dam structure faced following the flash floods on July 27, 2023, due to heavy rainfall in the catchment area.

The flood inflow was so sudden on that eventful day that within an hour the gauge rose seven feet. The increase in flood inflow was so sharp that records show an increase from 8,693 cusecs to 3,80,071 cusecs, a whopping increase of 44 times in one hour.

Discussing the aspect of the flashy nature of floods proving to be a drawback, the report said the reservoir of Kaddam dam is unique in shape being oblong and narrow like a widened channel. "The rush of heavy inflows and inadequate spillway capacity is leading to a rapid rise in water level," the report said.

Quoting an example, the report further said that on July 27, 2023, water overflowed 3 spillway gates some of which had malfunctioned during the flash floods. Also, the sudden rise in flood level hardly provided any response time for those on duty.

The notes on the question of silt accumulation, on page 21 and 22 of the report, point out the information provided by dam officials on silt accumulation up to the crest level of the spillway. Such siltation has alarming consequences like impacting the disposal ability, leaving the scour sluices gate in inoperable condition resulting in loss of precious storage and ever decreasing lead time for operation of gates, among others.

"The last Hydrographic survey to determine silt accumulation in the Kaddam reservoir was done in 2013. It was revealed that the reservoir had lost 79 percent of its dead storage, 15 percent of the live storage, and 40 percent of its overall capacity.

Arguing for a fresh Hydrographic survey during the current season itself, the report underscores that such a survey is a pre-requisite to fine-tuning interventions. Further, it may warrant training the approach channel depth for existing and any additional spillways.

According to experts, the solution to make the Kaddam dam safe is to add more spillways to handle the quantum of water that rushes into the reservoir thanks to the flashy nature of floods. Besides, the report has suggested correction of the many inherent faults of the dam and its upkeep.

Construction of the KNRP across the Kadem stream originating in Adilabad district began in 1949 and it was commissioned in 1958 with nine gates. The project irrigates about 68,500 acres in six mandals and 98 villages in Nirmal and Mancherial districts.

The dam on either side of the spillway was breached in 1958 itself and the flood was of the quantum of 5.19 cusecs. Nine more gates were added to the dam in 1969 increasing the discharge capacity of the 398 metre-long spillway from the original 2.5 lakh cusecs to 3.72 lakh cusecs.

In 1995 and 2022, the flood level recorded was over 6 lakh cusecs which had resulted in damage to the project and threatened its existence. Though the dam has withstood the flood fury in the current season, experts doubt if it can bear any further.