Most of the major reservoirs in the southern States of Karnataka, Tamil Nadu, Andhra Pradesh, and Telangana are filled to only 25% of their capacity or less. This is worrying as peak summer is round the corner. Some large dams such as the Tungabhadra in Karnataka and the Nagarjuna Sagar on the Andhra Pradesh-Telangana border are filled to 5% or less of their full capacity. Other large dams such as Mettur in Tamil Nadu and Srisailam on the Andhra Pradesh-Telangana border are also filled to less than 30% of their capacity. The water crisis in Bengaluru may soon hit other urban centres and rural areas if this situation continues in the following days.
Across India, the current water level in 150 primary reservoirs put together as a share of their total capacity stood at 38%, according to the latest weekly bulletin by the Central Water Commission.
Chart 1 | The chart shows a region-wise comparison of the current storage levels as a share of the total capacities of reservoirs. It also compares the current water levels with last year’s levels, as well as with the 10-year average.
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The chart shows that the southern region is impacted the most. All the reservoirs put together are filled to only 23% of their capacity in this region, which is about 17% points lower than the levels recorded last year and 9 points lower than the 10-year average. No other region — central, west, east, or north — shows such a drastic difference in levels compared to last year as well as the 10-year average. For instance, in the northern and central regions, the reservoirs are filled to 33% and 46% of their capacities, respectively, similar to the 10-year average levels recorded in those regions. In the western region, the reservoirs are filled to 45% of their capacity, slightly higher than their 10-year average, while the 49% recorded in the eastern region was only marginally lower than the 10-year average.
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Among the southern States, a comparison of the capacities of individual reservoirs with their current storage shows that water levels in many are dangerously low. Charts 2, 3, and 4 show the current storage levels as a share of the total capacity of major dams (chosen based on their capacities), in Andhra Pradesh-Telangana, Karnataka and Tamil Nadu. The list is limited to those reservoirs observed by the Central Water Commission in these States.
Chart 2 | The chart shows the current storage levels as a share of the total capacity of major dams in Karnataka.
The Linganamakki reservoir in Karnataka’s Shivamogga district, with a total capacity of 4.3 lakh crore litres of water, is currently filled to just 22%. The Supa reservoir in Karnataka’s Uttara Kannada district, with a total capacity of 4.1 lakh crore litres, is filled to only 36%. The Tungabhadra dam in Vijayanagara district of Karnataka, with a total capacity of 3.2 lakh crore litres, is filled to only 5%.
Chart 3 | The chart shows the current storage levels as a share of the total capacity of major dams in Andhra Pradesh-Telangana.
The Srisailam reservoir on the Andhra Pradesh-Telangana border, with a capacity of 6 lakh crore litres, is filled to only 15%, whereas the Nagarjuna Sagar dam on the same border, with a capacity of 5.1 lakh crore litres, is filled to a mere 4%.
Chart 4 | The chart shows the current storage levels as a share of the total capacity of major dams in Tamil Nadu.
The Mettur dam in Salem district of Tamil Nadu, with a full capacity of 2.65 lakh crore litres, is filled to 28%.
Chart 5 | The chart shows the current storage levels as a share of the total capacity of major dams in Kerala.
Kerala is the only exception among the southern States, with most of its major dams filled to at least 50% of their capacities, as shown in Chart 5. The Idukki reservoir is filled to 47%, the Idamalayar dam to 48%, and the Kallada and Kakki reservoirs to 50%.
Table 6 | The table shows the percentage of districts, across various levels of rainfall deficits, during the 2023 South-West monsoon. For instance, in about 27% districts of Kerala, rainfall deficit during last monsoon was 40% or more.
It is important to note that, like Andhra Pradesh and Telangana, most districts in Kerala too recorded deficient rainfall during the south-west monsoon last year, as shown in Table 6.
rebecca.varghese@thehindu.co.in, vignesh.r@thehindu.co.in
Source: Central Water Commission
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