The deficit sharing protocol for Andhra Pradesh and Telangana States to be evolved by the Krishna Water Disputes Tribunal (KWDT-II) should also cover the deficit in the flows in a given year at 75% dependability, witness for Andhra Pradesh M. Visveswara Rao suggested the tribunal at New Delhi on Friday.
During his continued cross-examination by senior advocate appearing for Telangana V. Ravinder Rao, Mr. Visveswara Rao, retired irrigation engineer, explained that 75% dependable flow would have deficit when the actual flow would be below 2,130 tmc ft and similarly 65% dependable flow would have deficit when the actual flow in the river would be between 2,130 tmc ft and 2,293 tmc ft.
Further, there would be deficit in the average flows if the actual flow would be in the range of 2,293 tmc ft and 2,578 tmc ft, the former irrigation engineer added.
Complexities involved
Accordingly, implementing the water sharing protocol at different dependabilities in a given year was very difficult since the changes in the dependability occur in a very short time and lot of complexities were involved in implementing the concept of different dependabilties.
He supported his contention with the example that during 2005-06, one of the extremely good years with the gross flows in the basin crossing 3,624 tmc ft, the dependability changed to 65% (between 2,130 tmc ft and 2,293 tmc ft) in three days after the flows reached 2,130 tmc ft by September 21, 2005 and over the next six days it changed to average (2,293 tmc ft and 2,578 tmc ft).
Mr. Visveswara Rao told the Brijesh Kumar tribunal that the average flow in Krishna within the erstwhile State of Andhra Pradesh was 472 tmc ft.
Downstream flows
He admitted that the average flow in the sub-basins K-10, K-11 and K-12 downstream of Nagarjunasagar was 120 tmc ft and the net flows after meeting the needs in the three sub-basins would flow into the main river course of Krishna.
Another 101 tmc ft at 75% dependability is generated in K-7 sub-basin, also below Nagarjunasagar, the former engineer explained.
Further, a total of 204 tmc ft generated below Nagarjunasagar would be available for utilisation by Andhra Pradesh with average dependability, the irrigation expert said.