Down To Earth published a small portion of this due to space constraint.........

Cuddapah: As the unprecedented rains triggered by a cyclonic storm in the Arabian Sea led to a deluge and flooding and consequent washing away of Annamayya and Pincha projects in YSR Cuddapah district allegations and counter allegations flew thick and fast among political circles on whether it is a man-made disaster or something which was inevitable.

The reason for the disaster can be gauged from the fact that the perennially drought-hit Rayalaseema districts of Kadapa, Chittoor and Anantapuramu districts received rains in excess of 62.9 percent, 61.5 percent and 39.1 percent respectively. The adjacent coastal Nellore district received rain in excess by 21.7 percent.

Because of good monsoon, in the last two years, the water bodies in Anantapuramu district were full. The rains were the highest in 2021 rewriting history. The irrigation projects are designed taking many parameters into account, flood discharge capacity is the most crucial thing among them, says P. Subramanyam, a retired irrigation engineer and an authority on the historical injustice meted out to the Rayalaseema region.

The reason for the deluge was after so many years the catchment areas of Chitravati and Papagni in Anantapuramu received rainfall of 25 to 30 mm rainfall after it had got 10 mm rain for three to four times already. The catchment area was full by then. Rainfall data for the district mirrors the situation. The percentage of deviation from the normal rainfall of 33 mm was 196 mm, which amounts to a 494.8 percent in the month of November. The excess rainfall was recorded across all the 63 mandals of Anantapuramu district.

Apart from the rains, consistent demands for water to the rain parched region had led to filling of many ponds with Krishna water from Handri Neeva Sujala Sravanthi project and Tungabhadra high level canals. The Parnapalli dam whose capacity is 10 TMC already had some 8 to 9 TMC water. Hence Bukkapatnam pond and Anantapur pond were already full.

The heavy rains led to good flow of water in Chitravati and Papagni rivers after so many years. As it rained well in Karnataka the water from Chitravathi which never flowed beyond Paragodu flowed well. The holding capacity of the land and dams was nil and water had to flow out. The reason for the damage was river bed of Chitravati was encroached for plantations as the river did not flow for many years now. As water was released from the 10 TMC capacity Chitravati dam the river which normally flowed just 200 feet reclaimed its full one kilometre radius and flowed destroying plantations in thousands of acres. The water which flowed was 1.2 lakh cusecs, Mr Subramaniam says.

The episode shows the need to increase the capacity of the Gandikota reservoir which is currently 27 TMC and can be increased to 89 TMC by just increasing the height of the gates of the existing dam. During the Britishers time a plan was chalked out to construct a 240 TMC capacity project. The project is on Krishna river and is part of GNSS (Galeru-Nagari Sujala Sravanthi) and has three sources of water that is Chitravathi, Penna and GNSS canal water from which water is sent to Rayalaseema, he adds.

The damage was more pronounced in Cuddapah district as it received a maximum of 1008.2 mm rainfall from the normal level of 618.8 mm from 1/06/2021 to December 2^nd, 2021, data provided by the district chief planning office shows. The district also saw the maximum number of deaths of 29 and left 13 missing. The maximum damage happened as the earth bund of Annamayya project swept away in the floods.

Responding to allegations of mistakes in design in the Annamayya project, M. Surendra Reddy, retd. superintendent engineer, Irrigation Department, says, “No project is designed for breach of all ponds. This has not been explained properly to the press. Ponds breached from Sodam and Somala the starting points of Pincha and Bahuda which have been designed for maximum flood discharge. The project was constructed factoring in the maximum rainfall in the last 25 years along with water that would accumulate from its catchment areas. The maximum one-day rainfall for Chittoor district is 160 mm. If rainfall exceeds that and smaller projects like the Pincha breached leading to a deluge. Annamaiah project is to the north of Seshachalam forest in Chittoor district. The down pour was unprecedented in 50 years. If the same downpour had happened in Kadapa, Kurnool and Anantapuramu on Penna river, Somasila project would also have not been able to cope.”

The Pincha project on its part designed for a flood discharge of 58,000 cusecs had a flow of 1,20,600 cusecs leading to water flowing over the top bund level. This lead to the caving in of the earth bund part of the 0.8 TMC dam. The concrete structure is intact only the earth bund has given away, officials say.

Questioning the explanation, B. Narayana, state committee member of the Communist party of India (Marxist), queried, “Are projects over Godavari and Krishna built by just factoring in the maximum level of water flow in 25 years. They are designed by taking into account flow of longer period. Is Polavaram being designed so? Why is it different for projects in Rayalaseema region. Moreover, it is a well-known fact that the gates were not maintained properly and the officials could not open a gate even last year. The gate could not be opened even during these floods.” Further proposals were sent by the irrigation department for strengthening the earth bund, he added.

Pooh-poohing any suggestions of fault in design of Annamayya project, N. Ravi Kiran, executive engineer, Annamayya project division of Cuddapah district says, “Proposals sent to the government were to increase the capacity of the project from the existing 2.24 TMC to 10 TMC and not because of any weakness in the earth bund. Projects over Krishna, Godavari cannot be equated with those in Rayalaseema as the flow of water is not the same. The main dam is 94 metres while the earth bund is 336 metres which is built to increase the water holding capacity of the dam. The changed circumstances will be studied and we have to examine whether to go for earth bund or concrete structure even if the cost escalates.”

The water holding capacity of the dam is 2.24 TMC and the discharge capacity is 2,15,000 cusecs. The flood that breached the earth bund was 3,20,000 cusecs, Mr Kiran added.

The officials also rejected allegations of lack of proper communication to the public on the impending flood to Annamayya project after the breach at Pincha dam and other ponds.

The highest rainfall was received by Chittoor district of 1235.4 mm from a normal of 618.8 mm between June 1^st, 2021 to December 2^nd, 2021 data from the district CPO shows.

The main damage in Chittoor district was owing to breach of water tanks built during the Vijayanagara kingdom during Krishnadevaraya era. The flood woes of the people in the district were owing to encroachment of these tanks which are put at 16,000 in the Rayalaseema region a majority of which of around 8,000 are in Chittoor district, says Kandarapu Murali, a CPM leader from the district. The local bodies like the TIirupati Urban Development Authority have permitted construction of residential colonies and even government establishments like the municipal office, government bus stand, vegetable market among others.