KAVERI 101 – calculating water sharing based on actual inflow

by November 11, 2016 Governance
  1. See the map to Identify the 4 major reservoirs in Karnataka : Hemavathy, Harangi, KRS and Kabini. Inflows and Outflows to all 4 reservoirs are monitored and known and this forms the basis of all calculations
  2. The river flows into TN and at Biligundlu there is a measuring station that tells you how much water flows into TN from Karnataka
  3. The water that flows into the river downstream of KRS and Kabini is measured at Biligundlu, is expected to flow in from about 22,000 sqm and in an average year can contribute about 80TMC.
  4. About 740TMC is the total water that is expected to flow into the river (from all states)
  5. Of this the following allocations have been made (the states are entitled to the following volumes of water
    1. Kerala: 30TMC
    2. Karnataka: 270TMC
    3. TN : 419TMC
  6. The total inflows into the river from Karnataka is 462TMC. Of the 462 TMC, Karnataka can keep 270TMC for itself and has to give TN 192 TMC (this is measured at Biligundlu). For the purpose of this post, we assume that the basis of this split is agreed upon (270 keep, 192 give)
  7. So if you see the only real numbers that matter are, irrespective of rainfall across the catchment, based on the total inflows in Karnataka,
    What Karnataka keeps                                           270
    —————————–                          =              ——
    What Karnataka gives TN                                      192
Hence if the total inflows in Karnataka was 100TMC, Karnataka can keep 58.44 TMC and send to TN 41.56TMC. Hence one would not need to base it on the % rainfall deficit/surplus – but on actual inflows. The inflows can be measured on a daily basis, the corresponding keep and give numbers calculated and released at some predetermined/useful frequency. It seems fair? And simple?
 
Now the inflows to/from all reservoirs are known, the additional inflow from 22,000 sqm at Biligundlu is also known. This should make the actual sharing numbers even in a deficit year – a reasonable and clear calculation.
 
Thanks to zenrainman’s FB post on the same topic for a slightly more elaborate description. And if you ask whats TMC ? That for another post 🙂

The flow of the Kaveri till she reaches Mettur

The flow of the Kaveri till she reaches Mettur

Sections:

About Shubha Ramachandran

Shubha Ramachandran is a Water Sustainability Consultant at BIOME Environmental Solutions Pvt. Ltd.
Read more by Shubha Ramachandran

Leave a Reply

Your email address will not be published. Required fields are marked *

Similar Story

Citizens step up: How South Bengaluru volunteers solved SIR hurdles

by August 20, 2026 Governance
From tracking down 2002 voter details to coordinating with overworked BLOs, community members in Bengaluru are stepping in where the system falls short.

While the Special Intensive Revision (SIR) process aims to clean up electoral rolls, the enumeration forms created innumerable hurdles for existing voters. From tracking down elusive 2002 voter details to coordinating with overworked Booth Level Officers (BLOs), citizens across Bengaluru faced a daunting task completing the registration process. Recognising these challenges in their own neighbourhoods, volunteers led by three active citizens—Poongothai, Aparna Shamanth, and Venkatachalam Subramaniam—took it upon themselves to help people in their community and beyond.   Mapping the confusion in Gottigere Poongothai lives in Gottigere, which falls under the Bengaluru South assembly constituency. Her community consists of around 400…

Continue reading

Similar Story

Bidadi GBIT project: Land acquisition process and compensation raises critical questions

by and August 18, 2026 Governance
As the goverment focuses on land acquisition for the 7,481-acre project, are farmers' rights and crucial social impact checks being compromised?

The Greater Bengaluru Integrated Township (GBIT) in Bidadi, first notified in March 2025, received its final notification in June 2026 under the Karnataka Urban Development Authorities Act (KUDA Act), 1987. The project is branded as India's first and largest AI City, featuring an AI-integrated township. The project will be implemented by the Greater Bengaluru Development Authority (GBDA) under the same act. Three villages, Kempainapalya, Vaderahalli, and Mandalahalli are notified in the Gazette under Section 19(1) of the KUDA Act for the implementation of a development scheme, deemed as public purpose. The development scheme is spread over a total of 7,481…

Continue reading