Irsa signals impending water shortage in winter crop season

LAHORE: Indus Rivers System Authority (Irsa) has warned that inept water management, causing low level in Mangla dam, may beget irrigation adversity during upcoming winter crops sowing season, The News learnt on Tuesday.  

Irsa, in a letter dated 24 July, informed the Water and Power Development Authority (Wapda) that deviation from standard operating procedures (SOPs) related to water storage pattern might affect water conservation.    

Sources said Irsa management fretted over slow filling of Tarbela dam during the last week or so. Irsa, in the letter, expressed reservation on the slow pace of water impounding into lake. It said filling of Tarbela dam has been restricted to one foot per day against the SOPs. 

The provision of filling Tarbela dam up to five feet per day is in line with the SOPs dating back to 1976 when the dam was constructed. The procedures were defined after consultation between Wapda, Irsa and experts/advisors of the National Engineering Services Pakistan (Nespak).

Irsa official said tumbling inflows of Indus River, due to variation of catchments temperature as well as scattered rainfall, may impact water regulation on various counts. Such eventuality, he said, may affect filling of Tarbela dam to its maximum conservation level of 1,550 feet as happened in Kharif 2016.

It may also bring about water dispute regarding operation of link canals amongst the stakeholders, he added. Irsa official advised that existing SOPs, duly signed by all the agencies, including Wapda, Irsa and Nespak may be adopted to ensure filling of Tarbela dam to its maximum capacity.

He said the issues should be given top priority to overcome shortages in Rabi season given below-normal rain forecast in August. Following non-filling of Tarbela dam to full storage capacity last year, water authorities agreed on the ways to ensure water storage in Tarbela dam to maximum conservation level in various flow patterns.

Unlike previous year when Wapda refused to follow its own accelerated dam-filling criteria, leading to water shortage especially during late Rabi and early Kharif 2017, water authorities including IRSA finally agreed to various filling patterns. 

Water regulation and operation bodies have also worked out a formula for ensuring smooth impounding of water in Tarbela lake during construction at site of Tunnel-4 extension project. However, despite agreeing on the formula of water storage, Wapda again reverted to slow filling pattern of one foot per day a week back, which may result in low storage levels in the dam by end of high-flow season, potentially causing huge losses due to water shortage.