Jalandhar: Even as the authorities managing the dams over Punjab rivers and the water resources department are preparing to face the situation arising out of the predicted heavy to very
heavy rainfall in Himachal Pradesh, Jammu region, and Punjab, significant changes in the India Meteorological Department’s forecasts for the catchment areas of three rivers of the state are
making their job very difficult. According to the IMD forecast on Oct 1, the catchment area of Ranjit Sagar Dam (Ravi river) was to get a cumulative rainfall of 201 mm from Oct 6 to 8, but in the Oct 2 forecast, the weather department predicted a cumulative rainfall of 121 mm. In the Oct 3 forecast, the IMD further reduced the expected rainfall to 75mm for these three days. After the Oct 1 forecast, and after holding a meeting with the IMD officials of the region on Oct 2, the authorities started releasing over 37,000 cusecs from the Ranjit Singh Dam (RSD) from Thursday afternoon and continued to discharge around 35,000 to 37,000 cusecs on Friday. In the case of the Beas river, on Oct 1, the IMD predicted a cumulative rainfall of 182 mm for the three crucial days –
Oct 6, 7 and 8. However, on Oct 2, the prediction came down to 92 mm. On Oct 3, the IMD predicted a rainfall of 95 mm for three days.
For the catchment area of Satluj, the IMD forecasted a cumulative rainfall of 70 mm for the corresponding three days, but on Oct 2, the weather department revised the forecast to 19 mm. And as per the Oct 3 forecast, 23 mm of cumulative rainfall is expected for the period. The biggest variation in the forecast was for rainfall in the catchment area of the Ravi river on Oct 7. On
Wednesday, it was predicted at 152 mm; on Thursday, it came down to 71 mm, and on Friday, the prediction came down to 38 mm. In the case of Beas river, for Oct 7, the expected rainfall came down from 111 mm to 41 mm.
The RSD authorities and officials of the water resources department said they were preparing for the worst-case scenario. However, their biggest worry remains water flowing in big quantities from unregulated streams, which earlier proved disastrous. What is further complicating the situation is that there are breaches in the dhussi bundh along the Ravi.
According to the Sept 30 forecast of the IMD, there was no or light rainfall in the first week of Oct. But things changed completely in the next two days. On Oct 1, the IMD-National Centre for Medium Range Weather
Forecasting Unified Model (NCUM) predicted 15 mm, 11 mm, and 2 mm rain on Oct 6 in the respective catchment areas. The forecast was changed to 21 mm, 24 mm, and 7 mm, respectively, for Oct 7. However, it was not a cause of worry.What put the dam authorities and top engineers of the water resources department on alert was information sent by the BBMB to the Punjab govt Wednesday morning about the European Centre for Medium-Range Weather Forecasts prediction of heavy rainfall in the catchment areas of the Satluj and Beas rivers.Afterwards, the authorities found that for RSD (Ravi) catchment areas, ECMWF predicted a total of 175.4mm from
Oct 4 to 8.
As the Punjab authorities then consulted the IMD, the latter Wednesday evening in line with the Global Forecast System predicted 152 mm rain for Oct 7 and 38 mm for Oct 8, which set the alarm bells ringing