After 65 yrs, Opa water works to replace its main pipeline

PONDA: After 65 years, Opa water works proposes to replace the rising main pipeline made of asbestos cement (AC) with a mild steel (MS) pipeline that raises water from the 8-MLD (1.75 MGD) Portuguese-era water treatment plant to Curti hillock based master balancing reservoir. The work was planned during the previous financial year, but since the PWD’s Goa Scheduled Rates (GSR) were revised, the file is pending for administrative approval.
The 8 MLD (million litres per day) of 1.75 MGD (million gallons per day) was constructed during the Portuguese era and was commissioned in December 1957. Acclaimed engineer Mokshagundam Visvesvaraya selected the site and plant design.
Since the 350mm diameter AC pipeline has turned very fragile, the water division wants to replace it with a new 508mm diameter MS pipeline. The cost of the project was estimated at Rs 4.3 crore as per the 2019 GSR (buildings) and (PHE). However, since the GSR has been revised, the project needs administrative approval, PWD executive engineer Nivruti Parsekar said.
The Opa water works complex was originally an 8 MLD plant, but has undergone capacity expansions four times till now. First was 12 MLD plant in 1967, 55 MLD plant in 1972, 40 MLD plant in 2000 and the latest 27 MLD in 2020. These plants together treat and supply 140 MLD water to Tiswadi and Ponda talukas. This includes Panaji, Bambolim, Taleigao, Ribandar and the entire taluka of Ponda.
The Opa weir was constructed in 1972 to raise the water level and also as a storage reservoir during the lean period from March to June. The weir height is 2.42m with a total length of about 82m across the river.