Krishna Raja Sagara

Survey and plan

Mysore's first chief engineer for the project, Captain Dawes, drowned in the Kaveri in 1909 while surveying the proposed site near Kannambadi village. 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. 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. 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. 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. 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. 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. 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).

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. 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."

Visvesvaraya's promotion to Diwan, and his successor as Chief Engineer

Ananda Rao served as Diwan of Mysore from 1909 to 1912. When his term ended, Visvesvaraya moved up from Chief Engineer to become the 19th Diwan, a post he held until 1918. That left the Chief Engineer's chair empty, right in the middle of the still-unresolved Kaveri Reservoir Project. Visvesvaraya's choice to fill it was Karpur Srinivasa Rao, at the time a Superintending Engineer in the Bombay Presidency's Public Works Department and an old colleague of his there. A contemporary account puts the succession plainly: "when Sir M. Visweswarayya was made Dewan, Karpur Srinivasa Rao was appointed Chief Engineer in Mysore." Srinivasa Rao took charge as Chief Engineer in November 1912. His appointment was formally gazetted the following year, in Mysore Gazette Notification No. 412 (July 1913), which named him Chief Engineer of the Mysore State. The government's own official history of the Mysore PWD records that the appointment came "at the instance of the Dewan, Sir M. Visvesvaraya, for the execution of the Kaveri Reservoir Project." The two men went on working together as Diwan and Chief Engineer through the Griffin arbitration and the construction years that followed. When Visvesvaraya pushed to have the Kannambadi dam's budget raised at a 1913–14 conference of the Mysore Representative Assembly, it was Srinivasa Rao, as the kingdom's chief engineer, who supplied the figures behind that push.

Visvesvaraya's genuine, signed assessment of Srinivasa Rao does survive, in the latter's Promotion Recommendation Roll for the year ending 31 December 1913. As Dewan, Visvesvaraya wrote in his own hand that Srinivasa Rao "is an experienced officer and his professional ability is of a high order," that he "is hardworking, takes a keen interest in his work and bears a high character," and that "the Durbar are quite satisfied with the manner in which he performed the duties of Chief Engineer and Secretary to Government during the year."

The Madras Presidency objected to the scale of the project. It had its own plans for a much larger dam at Mettur, and it refused to consent to the reservoir Mysore initially proposed: about 41.5 TMC ft, held behind a dam roughly 194 feet high. Referred to the Government of India, Mysore ended up with permission for a far smaller first stage of about 11 TMC ft. Construction went ahead anyway on foundations built for the larger design, which reopened Madras's objections and pushed both sides toward arbitration. Visvesvaraya described the decision in his own words: Lord Hardinge, the Viceroy, gave Mysore permission to proceed, but only for a first stage 80 feet high; "we nevertheless started building the dam with the bottom width required for the full height we had originally designed, namely, 124 feet... we took the risk," he wrote, and credited the goodwill of Hardinge and of Sir Hugh Daly, the British Resident in Mysore, with helping Mysore through the dispute. The Government of India appointed H. D. Griffin, a judge of the Allahabad High Court, to arbitrate. Proceedings in what became known as the Kannambadi Arbitration Case opened in July 1913, and Griffin's award, delivered on 12 May 1914, let Mysore build the dam to its full designed height of 124 feet, holding roughly 41.5 to 44.8 TMC ft.

It was in this same period — his appointment, per the Mysore PWD's own official history, came "at the instance of the Dewan, Sir M. Visvesvaraya, for the execution of the Kaveri Reservoir Project" — that Karpur Srinivasa Rao became Chief Engineer of Mysore State, holding the post from November 1912 to June 1917. Srinivasa Rao's own Promotion Recommendation Roll, kept at the Karnataka State Archives, records that he was placed on special duty from 8 July to 18 August 1913, and again from 20 October 1913, "to represent the Mysore Government before the Court of Arbitration appointed by the Government of India" — that is, the Griffin arbitration just described — in the dispute between Mysore and Madras over the Kaveri. The arbitration didn't fully settle things, and after he retired in 1923 Srinivasa Rao was pulled back in, leading the Mysore technical team, alongside Chief Engineer Cadambi, through further talks with Madras officials at Fort St. George between 1921 and 1924. Those talks fed directly into the 1924 Agreement. A separate biographical sketch credits him, too, with "conducting important negotiations with the Madras Government" over the dam. He stayed on to run the department through the years the dam's foundations and lower courses went up, including the wartime cement shortage described below.

Funding: the royal family's personal contribution

Popular and heritage-tourism accounts often repeat a story that members of the Mysore royal family sold their own jewelry to help pay for the dam when state finances came under pressure, though the sources don't agree on exactly who did it. Several credit Maharani Kempananjammani, the queen-regent, who by the time construction began in 1911 had already stepped down from the regency but remained an influential figure at court. A 2025 news report quotes a Mysore royal-family member attributing the sale jointly to "the Maharaja's mother Rajmata Kempa Nanjammanni and his wife Pratap Kumari," prompted by the finance ministry's objections to the project's cost. Yet another heritage account credits the Maharaja himself with selling jewelry from the royal treasury to cover a shortfall.

Cauvery water-sharing agreements

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.

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.

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. A supplementary agreement in 1929 pinned down the exact quantities of water to be released to Madras.

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." 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.

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.

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. The Chaturvedi family memoir adds that Cadambi received the same title alongside Srinivasa Rao, specifically for the successful 1924 Cauvery Agreement.

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.

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. 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.

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. 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).

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. 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.

Construction

Construction began in November 1911. Ten thousand workers were employed.

The wartime cement crisis and Srinivasa Rao's improvisation

When the First World War broke out in 1914, it hit the dam's construction in a very specific way. India's own Portland cement industry barely existed at the time: total domestic output in 1914 came to only about 945 tonnes, all of it from a single factory in Madras, so builders across the country still depended almost entirely on cement shipped in from Britain. Wartime shipping shortages made those imports "rapidly dwindle" right as domestic wartime demand for cement, much of it for military use, was climbing. Major civil projects like the Kannambadi reservoir suddenly found themselves cut off from their usual supply of binder, just as work on the dam's main masonry was getting underway.

As Chief Engineer, Karpur Srinivasa Rao had to find a way around it. Rather than stop or slow construction, the Mysore PWD switched to surki mortar, a mix of hydrated lime and finely ground burnt-brick powder, as a wholesale substitute for Portland cement in the dam's masonry. Surki wasn't just filler standing in for sand. Ground burnt brick is rich in reactive silica and alumina, so mixed with lime it triggers a genuine pozzolanic reaction, producing cementitious calcium-silicate compounds in much the same chemical family that gives ordinary cement its strength. Modern materials-science testing bears this out: the pozzolanic reaction adds strength, cuts shrinkage, and improves resistance to water penetration compared with plain lime mortar, though the mortar's final strength depends heavily on how finely the brick is ground and how well, not over- or under-, it was fired to begin with. The technique wasn't new to Mysore: Visvesvaraya had already used surki masonry at the Vani Vilasa Sagara (Marikanive) dam a decade before. But its use at KRS was on a much bigger scale, and most of what stands today as the world's largest all-surki gravity dam went up with almost no imported Portland cement at all. More than a century on, the dam's surki masonry is still structurally sound and in continuous service, a working demonstration that a properly proportioned, well-cured lime-pozzolan mortar can hold up over the long term about as well as Portland-cement concrete in a mass gravity dam. Engineering writers still point to KRS as an early-20th-century landmark of large-scale surki construction.

By the time construction wrapped up in 1931, somewhere between 5,000 and 10,000 people had lost their homes to the project. The government rehabilitated them and gave them agricultural land nearby.

Operation

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. 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.

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. 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.

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.

Dam

The foundation stone was laid on 11 November 1911, and construction proper began that same month. 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, while the formal inauguration came in 1932 — the year usually given as its "opening" — and the adjoining Brindavan Gardens, begun in 1927, weren't finished until 1932 either. 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. The dam sits across the Kaveri near Kannambadi village; construction ran through the 1910s and 1920s alongside the water-sharing negotiations described above. 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. Water released from the dam flows on into Tamil Nadu and is stored at the Mettur dam in Salem district.

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.

Brindavan Gardens

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.

Diwan Sir Mirza Ismail of Mysore planned and built the gardens alongside the dam. 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.

Significance today: why the 1913–14 height decision still matters

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.

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.

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. 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. 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.

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. 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.

Transformation of the land and rural prosperity

Both contemporary and present-day accounts describe the dam's completion as a turning point for the Mandya–Mysuru region's farm economy, though the sourcing here is qualitative and institutional rather than a rigorous statistical record. No pre-1932-versus-post-1932 series on acreage, yield, or income turned up in this research, and readers should weigh the claims below with that in mind.

Before the dam, farming in the region was almost entirely rain-fed. Villagers interviewed by the long-form journalism outlet Fifty Two in 2019 recalled that their ancestors could only grow drought-tolerant, low-value rain-fed crops such as ragi (finger millet) and maize, and that families switched to higher-value irrigated crops, rice and sugarcane, only once canal water from the KRS project reached their fields. That matches the severity of the pre-dam drought conditions described earlier: the 1875–76 famine alone reportedly killed off a fifth of the kingdom's population, and crop failures kept recurring into 1900.

The Karnataka government's own tourism and district-administration material describes irrigation from the KRS reservoir "during the 1930s" as producing a "substantially marked transformation in cropping pattern" and "better grown yield level, ultimately leading to better economic conditions of the people," and says the district's main cash crop became sugarcane, giving Mandya its lasting nickname "Sakkare Nagara," Sugar City, in Kannada. There's a concrete marker of that shift: the Mysore Sugar Company, the state's first sugar factory, opened at Mandya on 30 January 1933, within a year of the dam's completion, built directly on the strength of the cane-growing capacity the reservoir now made possible. The district is still widely known by the "Sugar City" name today.

A 2020s academic overview of early-20th-century agricultural development in Mysore State likewise credits the KRS Dam with making reliable irrigation possible for paddy, sugarcane, and other cash crops in Mandya, with crop diversification away from rain-fed farming, and with "economic growth in the region, improving the livelihoods of farmers." Present-day government figures show how far that's gone: of Mandya district's roughly 248,825 hectares of sown land, about 116,901 hectares are irrigated, and about 88,000 of those hectares draw directly from the KRS reservoir, with most of the rest coming from the Hemavathi reservoir and local tanks, wells, and borewells.

Current status

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. 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.

Flora and fauna

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 have been recorded here.