The Big Picture: IMD's National Forecast
After an uneven performance in June and July, the IMD's outlook for the second half of the monsoon, covering August and September, points towards a subdued phase. The forecast released on July 31 predicts that rainfall for August is likely to be 'below
normal', meaning less than 94% of the Long Period Average (LPA). The LPA for August, based on data from 1971-2020, is 254.9 mm. This trend is attributed to the strengthening of moderate El Niño conditions over the Pacific Ocean, which typically suppresses monsoon rainfall in India. However, the forecast isn't uniform across the country. Some parts of Peninsular India, Central India, and the Northeast are expected to receive normal to above-normal rainfall, creating a varied national picture.
Checking The Gauges: A Tale of Two Cities
The impact of this forecast is best understood by looking at the water levels in the lakes that supply major cities. For Mumbai, the news is reassuring. As of August 2, the seven reservoirs supplying the city held a combined water stock of 89.08%, nearing the 90% mark. Lakes like Modak Sagar and Vihar are already at 100% capacity, and Tansa and Tulsi are over 99% full, ensuring comfortable water security for the months ahead. In stark contrast, Bengaluru is facing potential stress. In late July, the Bangalore Water Supply and Sewerage Board (BWSSB) warned that the city could face a water shortage in five to six months if rainfall in the Cauvery basin remains inadequate. The Krishnaraja Sagar (KRS) reservoir, a key source for the city, held only about 20 TMC of water, with authorities already having imposed restrictions on non-essential water usage earlier in July.
What It Means For Your Tap: Municipal Supply
For Mumbaikars, the healthy reservoir levels mean that the prospect of water cuts is highly unlikely for the foreseeable future. The Brihanmumbai Municipal Corporation (BMC) has not announced any cuts, and the current stock is slightly higher than on the same day last year. Pune is also in a relatively secure position, with heavy July rains bringing the four dams in Khadakwasla circle to over 90% capacity by the end of the month, prompting releases into the Mutha river. However, for residents of Bengaluru, the situation is more precarious. The BWSSB has already activated tanker supplies for areas facing scarcity and noted that while they can manage for the next four months with current reserves, a poor monsoon from here on could trigger a crisis. Similarly, Chennai's reservoir levels dropped to just under 50% capacity in early July, though officials stated this was sufficient for the next six months. Water was released from Karnataka's Kabini reservoir on August 1 and is expected to reach Tamil Nadu's Mettur Dam by August 3 or 4, which could provide some relief.
District-Wise Alerts: Where to Be Prepared
While the broader August forecast is for 'below-normal' rain, the IMD has issued specific heavy rainfall warnings for several regions in the immediate future. An active monsoon phase is expected until August 8. Heavy to very heavy rainfall alerts are in place for several northeastern states, including Assam and Meghalaya. Orange alerts, indicating very heavy rainfall, have also been issued for several districts in Kerala. These alerts warn of potential waterlogging, flash floods, and landslides, and residents in these areas are advised to be cautious and follow local advisories. The warnings highlight the complex nature of the monsoon, where a nationally subdued forecast can coexist with intense, localised weather events that pose significant risks.
