HYDERABAD, Sept 12: Desilting of one of the two lagoons of the Water and Sanitation Agency has been postponed because this may result in mixing of sub-soil water with fresh water in the lagoon.

This correspondent has learnt that this decision was taken on the basis of opinions expressed by consultant Shafi M. Lakho, appointed by the district government. The desilting of the lagoons and four other water works of Wasa is part of a Rs120 million package of the Sindh government.

South lagoon's desilting was to begin after tenders were opened on Sept 18 whereas work orders for other water works were also to be issued soon. These water works have been providing untreated water to people of the City and Latifabad talukas as there is no treatment plant.

The consultant proposed that the north lagoon should be desilted by one foot and one more lagoon be created. Earlier, desilting up to three feet had been proposed. The south lagoon will not be desilted because its bed is parallel to the ground level, increasing chances of mixing of sub-soil water with fresh water.

The desilting of the north lagoon and setting up of another lagoon, which will cost Rs12 million, will result in an increase in Wasa's storage capacity that was expected from the desilting of both the lagoons, for which Rs40 million was needed.

The amount saved will be utilized on alternate sources of electricity supply to seven points of water supply in the city as power shutdowns affect water supply. A survey conducted by the consultant has revealed that majority of water supply lines are broken and are causing leakage of water.

Besides, they are also mixing with sewage as sewerage lines and drains are passing over water supply lines. The situation aggravates in areas where people use water sucked through pumping machines.

It has been planned that these water supply lines will be bypassed through new lines over drains to ensure supply of clean drinking water to people. Over 100 air-valves will also be fixed to avoid gathering of vacuum in the lines.