HMWSSB Saves 18 MGD Water During Krishna Phase-II Shutdown

The HMWS&SB said it had diverted around 18 million gallons a day (MGD) of water from the Krishna Phase-II main pipeline to a Phase-III reservoir during a recent shutdown, reducing the wastage of treated water and cutting the shutdown period by more than 12 hours.

The arrangement was made possible through an interconnection at the Nasarlapally pumping station, where the 2,375-mm diameter main pipelines of Krishna Phase-I, II and III have been connected through a 600-mm interconnection pipeline to the respective water reservoirs.

During the recent Phase-II shutdown, the main pipeline held around 23 MGD of water. About 18 MGD, or nearly 80 per cent, was diverted to the Phase-III reservoir for drinking water supply, while only 5 MGD had to be released through scouring.

Board officials said the arrangement reduced the time required to empty the pipeline from around 20 hours to eight hours. This saved more than 12 hours during the shutdown and reduced power expenditure by around `5 lakh. The shutdown was also used to replace 48 air valves on the main pipeline, following which water supply was restored in a shorter period.

The interconnection was developed as existing scouring arrangements along the 24-km Nasarlapally-Godakondla pipeline corridor had become difficult to operate due to construction and development in the area. The new arrangement is intended to reduce water loss and shutdown time during maintenance.

The board said it was examining the possibility of introducing similar interconnections at Godakondla, Kodandapur and other suitable pumping stations to reduce treated water wastage during future shutdowns.