Krishna Raja Sagara

Mysore, and Mandya in particular, had always been dry country, and summers regularly pushed people to migrate to wetter areas nearby. A severe drought in 1875–76 killed off a fifth of the population of the Kingdom of Mysore, and crop failures kept recurring for want of irrigation water.^[5] The Kaveri was the obvious candidate to change that. An earlier attempt already existed as a model: the Marikanive project, begun in 1897 under Diwan K. Seshadri Iyer and Queen-Regent Kempananjammanni Devi, had shown that the state could fund and build a reservoir of its own.^[6]

But any major new works on the Kaveri needed the consent of the downstream Madras Presidency, under an agreement signed in 1892 (see below), and getting that consent turned out to be the real obstacle standing between Mysore and its dam.

Mysore's first chief engineer for the project, Captain Dawes, drowned in the Kaveri in 1909 while surveying the proposed site near Kannambadi village.^[7] The Diwan at the time, T. Ananda Rao, then brought in Sir M. Visvesvaraya as Chief Engineer and Secretary to the Government; Visvesvaraya took up the post on 15 November 1909.^[8] Drawing on his earlier work surveying large dams, including the Aswan Dam in Egypt, and on reservoir designs he'd done in the Bombay Presidency and Hyderabad, Visvesvaraya drew up the design for the Kannambadi reservoir.^[9] He ran into resistance from Mysore's own finance ministry, who argued the project would "serve no purpose" and that any electricity it generated would go largely unused for lack of demand. He took his case to Ananda Rao and to the Maharaja, Krishna Raja Wadiyar IV.^[10] Even so, sanction wasn't immediate. In his own memoir, Visvesvaraya recalled that once his project report was ready, "no sanction was forthcoming from His Highness the Maharaja for some time," and that some of the State's own officers had likely talked the Maharaja out of committing so large a sum, ₹253 lakh by his own estimate, on a single project when the State had never spent anything like it before.^[11] Frustrated at his inability to move the Maharaja, Visvesvaraya considered resigning from Mysore service altogether, and went off on leave to Northern India rather than push the matter further.^[11] It was the Maharaja himself who brought him back: noticing Visvesvaraya's changed mood, he sent for him while camping in Bangalore, asked why he'd lost his enthusiasm for new works, and, on hearing the engineer's frank answer, told him simply, "Don't be hasty, I will do what you want." Within the week, meeting Visvesvaraya again at Mysore, the Maharaja sanctioned every proposal that had been submitted, the reservoir scheme chief among them, without changing a single detail.^[11] The order to begin was issued on 11 October 1911, with a sum of ₹81 lakh set aside for it (this later rose to about ₹1.03 crore).^[12]

Visvesvaraya's own account of the original design, submitted as his first project report on 5 May 1911, gives figures a little different from the ones the dam was eventually built to, since further negotiation with Madras (described below) would later revise them: a masonry dam 124 feet high and 8,600 feet long, 130 feet above the riverbed and 140 feet above the lowest foundation, with a base 111 feet wide at foundation level, built to hold about 48,000 million cubic feet of water. He calculated the catchment above the dam site at 4,100 square miles, with an average annual flow through the river gorge of around 220,000 million cubic feet. The reservoir was meant to eventually irrigate 150,000 acres and generate about 80,000 horsepower, well beyond the roughly 13,000 horsepower Mysore's existing Shivanasamudra station could produce at the time, of which 11,000 went to the Kolar Gold Fields alone.^[13] In that same 1911 report, he laid out why he thought the project was worth the risk: "Once commenced, the scheme opens up a vista of possibilities of ever-increasing value to the State... a work like this would be justified even if it paid no more than 3 per cent. But the promise of extraordinary direct returns from power at commencement, and the opportunity it affords of building up a great irrigation project from the sale proceeds of power, form a combination of advantages rarely vouchsafed to such undertakings in any part of the world."^[14]

The dam's construction, its height, and how it's operated have all been shaped by a long sequence of agreements, and later tribunal and court rulings, between Mysore (later Karnataka) and Madras (later Tamil Nadu).

1892 Agreement

Signed between the Madras Presidency and the Kingdom of Mysore. It established that Mysore, as the upstream state, needed Madras's consent before it could undertake any major new irrigation works on the Kaveri.^[29]

1913–1914 Griffin Arbitration

As described above, H. D. Griffin's award of 12 May 1914 let Mysore build the KRS dam to its full planned height and capacity, over Madras's continuing objections.^[23]

1924 Agreement

A more thorough, fifty-year agreement between Mysore and Madras. It formally permitted construction of the KRS dam, by this point largely built, alongside the Madras government's Mettur dam, and it laid out detailed water-sharing and irrigated-acreage terms for both sides.^[29][30] A supplementary agreement in 1929 pinned down the exact quantities of water to be released to Madras.^[31]

Karpur Srinivasa Rao's role in the 1924 negotiations

Karpur Srinivasa Rao had already represented Mysore before the 1913–14 Griffin arbitration as Chief Engineer. After he retired in 1923, he was called back to lead the Mysore Government's technical delegation for the negotiations that produced the 1924 Agreement. Together with the sitting Chief Engineer, Cadambi, he led the Mysore team through meetings at Fort St. George, Madras, between 1921 and 1924, facing a Madras delegation led by W. J. Howley, K. Srinivas Iyengar (later Vice-Chancellor of Madras University), and C. P. Ramaswami Iyer. T. Ramakrishnan's 2024 history of the dispute, published by The Hindu Group, confirms his presence at these talks independently: "apart from Cadambi, Mysore was represented by Karpur Srinivasa Rao, former Chief Engineer."^[25] What the agreement actually produced was technically sophisticated: a set of "Rules of Regulation" and Gauging Tables that fixed the Full Reservoir Level at 124.80 feet and storage capacity at 44.827 TMC ft, while guaranteeing flow rights to the lower Cauvery delta. S. Guhan's standard scholarly history of the dispute calls this a genuine achievement of inter-state water diplomacy, and its principles still shape Cauvery water-sharing calculations today.^[32]

A family memoir by Srinivasa Rao's grand-nephew, Hari Rao R. Chaturvedi, goes further. Written from direct family knowledge though never independently published or peer-reviewed, it says Srinivasa Rao was chosen to lead the delegation specifically for his mathematical and statistical ability, and for his detailed grasp of the Cauvery basin's flow patterns, its seasonal swings between flood and lean months, and Mysore's irrigation and power needs. It also says Visvesvaraya relied on data and analysis Srinivasa Rao had prepared for earlier technical submissions.^{[33] [d]}

In recognition of his service, Srinivasa Rao received the honorific title Rajasabhabhushana from Maharaja Krishna Raja Wadiyar IV. An independent biographical sketch describes this as recognition for his "meritorious service to the State in constructing the Kannambadi Dam and in conducting important negotiations with the Madras Government" generally, rather than tying it specifically to the 1924 settlement.^[34] The Chaturvedi family memoir adds that Cadambi received the same title alongside Srinivasa Rao, specifically for the successful 1924 Cauvery Agreement.^{[35] [e]}

1974

lapse of the 1924 Agreement

The 1924 agreement's fifty-year term ran out in 1974. Karnataka, as Mysore state had by then been renamed and reorganised, treated the agreement as lapsed and began new irrigation and reservoir projects on the Kaveri. Tamil Nadu held that the agreement's terms still defined its entitlement. That disagreement became the modern Cauvery water dispute.^[36]

1990–2007

Cauvery Water Disputes Tribunal

In 1990 the Government of India set up the Cauvery Water Disputes Tribunal (CWDT) under the Interstate River Water Disputes Act, 1956. Its 1991 interim award, directing Karnataka to release specified quantities of water to Tamil Nadu, set off widespread protests in both states.^[36] Seventeen years of hearings later, the CWDT handed down its final award on 5 February 2007. It upheld the 1892 and 1924 agreements as valid and put the basin's total usable water at 740 TMC ft.^[37]

2018

Supreme Court verdict and the Cauvery Water Management Authority

On 16 February 2018, the Supreme Court of India partly revised the CWDT's final award and declared the Kaveri a "national asset." Citing, among other things, Bengaluru's growing need for drinking water, the Court raised Karnataka's allocation by 14.75 TMC ft, while lowering the amount Karnataka had to guarantee at the Biligundlu gauging point from 192 to 177.25 TMC ft in a normal year.^[38] The Central Government then set up the Cauvery Water Management Authority (CWMA) in June 2018 to carry out the verdict, keep track of reservoir levels across the basin, and coordinate monthly releases among Karnataka, Tamil Nadu, Kerala, and Puducherry, working alongside the Cauvery Water Regulation Committee (CWRC).^[36]

Ongoing implementation disputes

Even with the legal framework settled in 2018, month-to-month disputes over how it's carried out have kept coming, especially in years of poor monsoon rainfall, and KRS releases remain the flashpoint. In 2023 the CWMA repeatedly ordered Karnataka to release several thousand cusecs a day to Tamil Nadu, and farmers protested around the dam.^[39][40] In July and August 2026, with the monsoon running weak, the CWRC and CWMA again ordered Karnataka to release water, first 3,500 and later 12,000 cusecs a day, to Tamil Nadu. Karnataka argued it couldn't fully comply given shortfalls in its own command area, farmer and Kannada organisations protested at the dam site, and the Supreme Court told Karnataka to comply with the CWMA's order. Separately, in November 2025, the Court dismissed a Tamil Nadu attempt to stop the Authority from even discussing Karnataka's proposed Mekedatu project.^[41][42]

Construction began in November 1911. Ten thousand workers were employed.^[10]

Instead of the spillways that most dams use to stop water topping the dam, Visvesvaraya fitted 48 automatic gates, in six sets of eight, that open and close on their own as the reservoir rises and falls. The design wasn't new: he'd invented and patented the same basic mechanism roughly a decade earlier, to solve an almost identical problem at Lake Fife near Khadakvasla in the Bombay Presidency, where the reservoir feeding Poona's water supply and the Mutha Canal kept overflowing every year. His automatic gates there let the lake's storage level rise about eight feet higher without raising the dam itself, adding some 25 per cent more capacity, and opened and closed on their own as the water rose and fell, with no one needing to operate them by hand. He refused to take any royalty from the Bombay government for the invention, since the work had been carried out under his own supervision, and by his own account the same design was later adopted, in consultation with him, at the Tigra Dam in Gwalior and then at the KRS surplus weir.^[49] Each gate is made up of a sill, lintel, side grooves and plates, a balance weight, a float, chains and pulleys, and inlet and outlet pipes. The gates themselves are cast iron, manufactured at the Visvesvaraya Iron and Steel Plant in Bhadravati.^[50]

Each set of eight gates connects, via chains and pulleys, to a dead weight, which in turn connects to a float; together they form the "balance weight," working inside a masonry well at the rear of the dam. ^{[citation needed]} The deadweight and float sit one behind the other, four gates to each side. When all eight gates close the sluice, the balance weight rises to the top of its swing and the float sinks to the bottom of the well. An inlet pipe, 1 ft (0.30 m) across, lets water into the well from the reservoir once it reaches the maximum permissible level; that raises the float, drops the balance weight, and pulls the gates open to let water out. The same well empties out through an exit pipe once the reservoir level falls again.^[50]

Today the dam's outflow is measured downstream at the Biligundlu gauging station on the Karnataka–Tamil Nadu border, which is what the CWMA and CWRC use to check compliance with the Supreme Court's 2018 water-sharing formula. Officials say water released from KRS takes roughly 48 hours to reach Biligundlu.^[51]

The foundation stone was laid on 11 November 1911, and construction proper began that same month.^[10] Sources don't fully agree on when it was finished. Most, including a 2025 report citing Mysuru historians, say the dam itself was built by 1931,^[7][10] while the formal inauguration came in 1932^[52] — the year usually given as its "opening" — and the adjoining Brindavan Gardens, begun in 1927, weren't finished until 1932 either.^[53] This article's infobox and categories go with the more commonly cited 1932 inauguration date, though readers should know the underlying masonry was largely finished a year earlier.^[g] The dam sits across the Kaveri near Kannambadi village; construction ran through the 1910s and 1920s alongside the water-sharing negotiations described above.^[10] It's the main water source for Mysore and Mandya districts, and it's the principal source of drinking water for Mysore, Mandya, and nearly all of Bengaluru; roughly 2.1 TMC ft goes out from KRS each month to Bengaluru, Mysuru, Mandya, and other districts.^[54][55] Water released from the dam flows on into Tamil Nadu and is stored at the Mettur dam in Salem district.^[56]

The dam irrigates more than 100,000 acres in the Mysore and Mandya region, and it also underpinned the growth of the Mysore sugar industry.^[57]

Brindavan Gardens is a show garden below the dam, with a botanical park, fountains, and boat rides. Maharaja Jayachamarajendra Wadiyar had it built, and the German botanist Gustav Hermann Krumbiegel designed it.^[58]

Diwan Sir Mirza Ismail of Mysore planned and built the gardens alongside the dam. ^{[citation needed]} KRS was among the first dams anywhere to install automated crest gates, in 1920, under British chief engineer Sir Erwin. Its attractions include a musical fountain, and various biological research departments are based there too.

Winning the fight for the dam's full designed height, 124.80 feet and roughly 49.45 TMC ft of gross storage, rather than settling for the 11 TMC ft first allowed, wasn't just a historical footnote to the Griffin arbitration and the 1924 Agreement. That extra storage is what lets the reservoir do everything it does today for irrigation, drinking water, power generation, and flood control. A dam built to the smaller original allowance would hold only a fraction of today's water, nowhere near enough for the uses below.

Visvesvaraya himself seems to have grasped early on what the project would become. Looking back on it in his 1951 memoir, he described the Krishnarajasagara scheme as "in essence a miniature T.V.A. (Tennessee Valley Authority) Scheme in America," pointing to its combination of irrigation, power generation, and the industries that grew up around both, and noted that some three years before he wrote, the capital invested in the whole scheme came to about ₹10.5 crore, against direct and indirect benefits to the population he put at roughly ₹15 crore a year, with the government's own annual revenue from it, direct and indirect together, running to about ₹1.25 crore, or close to 15 per cent on the capital laid out.^[59][h]

Irrigation

The KRS project irrigates roughly 339,136 acres across Mysuru and Mandya districts today, on a seasonal rotation, an "18 days on, 12 days off" cycle for sugarcane, for example, coordinated by the Irrigation Consultative Committee.^[60]

Drinking water

Together with the Kabini reservoir, KRS supplies drinking water to Bengaluru city, Mysuru city, and a reported 47 towns and 625 villages across the Cauvery basin.^[61] Officials put the region's combined drinking-water need at roughly 3 TMC ft a month, around 300 cusecs a day for Bengaluru and 150 cusecs a day for Mysuru, which works out to something like 9 TMC ft of stored water needed to get through a typical three-month dry spell.^[62][63] A reservoir capped at the original 11 TMC ft would leave almost no cushion for that demand once irrigation and power needs were also drawn from it.

Hydroelectric power

Water released from KRS flows on down into the Shivanasamudra hydroelectric station, commissioned in 1902 as Asia's first hydroelectric power plant. It once supplied the Kolar Gold Fields and, in 1905, made Bengaluru the first Indian city with electric street lighting. Its ten turbines add up to 42 MW of installed capacity and a yearly generation target of around 225 million units, though what it actually produces depends heavily on how much water is left over from KRS and Kabini after drinking-water and irrigation needs are met. In drought years, generation has fallen to as little as 20 million units in a bad summer, which shows just how directly the reservoir's storage limits power output downstream.^[64]

Flood moderation

The reservoir's storage also gives operators some room to catch monsoon peak flows and release them in stages, instead of letting a whole flood pass downstream at once. That role has real limits, though: in years of very heavy inflow, the dam has still had to open its gates and release tens of thousands of cusecs, and the Central Water Commission and Cauvery Neeravari Nigam Limited have had to issue downstream flood alerts and close riverside areas around Srirangapatna when inflow got close to or exceeded what the dam could release.^[65][66] Still, the larger, 124.80-foot design gives Cauvery Neeravari Nigam a good deal more room to absorb and stagger a flood pulse than the 11 TMC ft design ever would have, even if it can't rule out downstream flooding in an extreme year.

As of 2026, the KRS reservoir runs under the framework the Supreme Court set in 2018, administered by the CWMA and CWRC. Water levels rise and fall through the year against a full reservoir level of 124.80 feet, and monthly releases get split among drinking water, irrigation, and Tamil Nadu's downstream share.^[73] Karnataka's proposal for a new balancing reservoir downstream at Mekedatu, meant partly to shore up Bengaluru's drinking-water supply, remains contested by Tamil Nadu; as of late 2025 it sits before the CWMA and the Supreme Court, unresolved.^[74]

The images below, all on Wikimedia Commons, show the dam, the gardens, and the main historical figures behind its construction. Where no verified photograph of a figure could be found on Commons, that's noted below rather than guessing at a file.

• 
  Maharaja Krishna Raja Wadiyar IV of Mysore, circa 1902, who sanctioned the dam
• 
  Sir M. Visvesvaraya, Chief Engineer of Mysore (1909–1912) and later Diwan, who designed the dam
• 
  Karpur Srinivasa Rao, Chief Engineer of Mysore (1912–1917), who oversaw much of the dam's construction
• 
  The principal officers' plaque at the KRS Dam entrance gate, recording the chief engineers and other officers who oversaw the dam's design and construction
• 
  Maharani Kempananjammanni Devi (Vani Vilasa Sannidhana), the queen-regent and dowager credited in several sources with helping fund the dam through the sale of personal jewelry (see above)
• 
  Maharani Lakshmivilasa Sannidhana Sri Pratapa Kumari Ammani, consort of Krishna Raja Wadiyar IV, the other royal woman named in some accounts of the jewelry-funding tradition (see above); photographed by Barton, Son & Co., Bangalore, 1900
• 
  Brindavan Gardens by day, adjoining the dam
• 
  Brindavan Gardens' illuminated musical fountains at night

^[i]

The area around the dam mixes farmland, villages, scattered trees, and pockets of original vegetation near the Ranganathittu Bird Sanctuary, which draws large numbers of both local and migratory birds. Close to 220 species^[75] have been recorded here.

• List of dams and reservoirs in India
• Karpur Srinivasa Rao
• Sir M. Visvesvaraya
• Maharaja Krishna Raja Wadiyar IV
• Cauvery water dispute
• Cauvery Water Management Authority