LAHORE, Dec 12: The Punjab on Thursday again insisted on its exclusive legal and historic rights over the Mangla Dam water and claimed that the assertions of the Indus River System Authority (Irsa) to the contrary belied ground realities.

In a letter to the Irsa, the Punjab said water from Mangla was exclusively meant for the eastern canals, all of which were situated in the Punjab. This, in practical terms, means that only the Punjab has right over its water.

Punjab’s exclusive right over Mangla is legalized by the Indus Basin Treaty signed by the federal government, which deprived the province of its eastern rivers — Ravi, Sutlej and Bias.

Following the treaty, the government set up the Indus Basin Advisory Board (IBAD) to assess the total loss of water and explore various possibilities to meet the same.

According to the board assessment, dams to store nine million acre feet of water were required to compensate the province for the loss it had suffered. No site was available on River Chenab for a dam. Jhelum had only one, Mangla, which however could store only 5.8maf of water.

In order to compensate the remaining loss, the Punjab said, Tarbela Dam was built, which had a storage capacity of 9maf, out of which 4.2maf was meant exclusively for the Punjab and the rest for generating money to maintain the national irrigation system. Thus, the province not only had exclusive rights over Mangla Dam, but also over 4.2maf of Tarbela water.

The treaty also dealt with the problem of future silting of the dams, for which, it provided for a 40-foot raise in the Mangla design and identified other sites for dams on the Indus, it maintained. The provision of raising the Mangla Dam level was again aimed at compensating Punjab’s loss.

Wapda in its project cost document dubbed Mangla-raising a replacement rather than a development. The Punjab agreed to the project only when it was assured that the raised dam would not be considered to contain additional water. This showed that the raised dam was also meant to compensate the province for the water it had lost in the Indus Water Treaty, it maintained.

The controversy about rights over Mangla Dam started when Irsa promised Balochistan water from the raised Mangla Dam for the Kachi Canal. The Punjab protested against the decision, pointing out that the Mangla water joined Indus 100km downstream from the Kachi Canal offshoot. There was no way to take water from Mangla 100km upstream to feed the canal.

The Punjab also claimed that linking the Balochistan water supply with the raised Mangla Dam was tantamount to endangering its rights over the dam.

It also demanded clarification as to what would be the source of supply of water to Kachi Canal if Mangla Dam was not raised for any reason. The Irsa recently rejected Punjab’s exclusive rights over Mangla water.