Indian key reservoirs’ storage rises rapidly as monsoon coverage improves

The water level in the major 150 Indian reservoirs continued to rise for the fourth consecutive week even as the storage increased by 10 percentage points this week, data from the Central Water Commission (CWC) showed as the south-west monsoon’s coverage improved.

The CWC’s weekly bulletin on live storage status of 150 reservoirs in the country, the level was 39 per cent of the 178.784 billion cubic metres (BCM) capacity at 69.27 BCM. The situation has improved rapidly from last week, when the reservoirs were filled to 29 per cent of the capacity.

From a situation when at least 7 reservoirs went dry a month ago, five reservoirs are now filled to capacity. However, 13 States continue to have lower than normal storage still. 

25% excess rains in south

The water level has increased more quickly in southern and western regions by 16 and 10 percentage points to 50 per cent and 41 per cent of the capacity, respectively. A month ago, the storage in the southern region dropped below 15 per cent of the capacity. 

A major reason for the rise in storage is the 25 per cent excess rainfall in the southern region during the current south-west monsoon. According to the India Meteorological Department (IMD), the country has so far received 2 per cent excess rainfall with Central India receiving 15 per cent more than normal precipitation. 

Despite excess rainfall, the coverage of the monsoon has been uneven with 36 per cent of the 723 districts from where data had been received have received deficient rainfall, IMD said. As a result, the level in 85 of the major reservoirs is still below 50 per cent with storage in 64 of them being below 40 per cent. 

Among the States, Tamil Nadu (25 per cent higher than normal), Karnataka (37 per cent) and Kerala (20 per cent) have better storage than other States. The Krishnaraja Sagar dam, which serves the Cauvery delta, is filled to capacity, while Sholayar, which turned dry two months ago, is also full. 

At 2-year high

Basavaraj Hampali, a dry chillies trader, posted on LinkedIn that the storage in Tungabhadra and Almati reservoirs are at a two-year-high. In a social media posting, Tamil Nadu Weatherman said the Mettur Dam (Stanley reservoir) may be filled to capacity by August 15.

According to the bulletin, of the 42 reservoirs in the southern region with a capacity of 53.334 BCM, the level was 26.538 BCM or 50 per cent of the capacity. 

Reservoirs such as Kabini, Hemavathy and Harangi have are filled to 90 per cent of the capacity. The situation is improving in Andhra Pradesh (-52 per cent of normal) and Telangana (-16 per cent), though the level is still in the negative.

In all the 10 reservoirs of the northern region, the storage was below 50 per cent of capacity. This week, the level was 29 per cent of the 19.663 BCM capacity at 5.786 BCM. The level in all the three States — Himachal (-26 per cent), Punjab (-75 per cent) and Rajasthan (-31 per cent) — were below normal. 

Bengal level 47% lower

Of the 23 reservoirs in the eastern region, the storage capacity was 28 per cent of the 20.430 BCM capacity at 5.630 BCM. Among the States, the level in Odisha (-31 per cent), West Bengal (-47 per cent) and Jharkhand (-12 per cent) was lower than normal.

The level in the 49 reservoirs in the western region was 31 per cent of the 37.130 BCM capacity at 11.330 BCM. The storage improved to four per cent above normal (-14 per cent last week) in Maharashtra and to 8 per cent (4 per cent) above normal in Gujarat. 

In the central region, the storage in the 26 reservoirs was up at 33 per cent of the 48.227 BCM capacity at 16.042 BCM. Reservoirs in Madhya Pradesh (-17 per cent), Chhattisgarh (-28 per cent), Uttar Pradesh (-29 per cent) and Uttarakhand (-4 per cent) are lower than normal but the situation is improving with the storage in the region increasing by 5 percentage points.