Context: This topic is important for UPSE GS Paper 2.

  Controversy over Mullaperiyar Dam

Mullaperiyar Dam built over Periyar River in the Idukki district Of Kerala. However it is operated by Tamil Nadu. But the water limit in the reservoir has been the bone of contention between both the states.

The story so far:

• With heavy rainfall, threats of flood and the reservoirs filling up in Mullaperiyar Dam, a public interest litigation petition filed in Supreme Court over which Kerala and Tamil Nadu have been fighting for long.
• The Supreme Court asked both States to abide by the rule curve for the period set by the Supervisory Committee constituted at its instance.
• Accordingly, the water level in the dam would be limited to 138 feet till October 31 and 139.5 feet till November 10. The court will hear the case again on November 11.

What is the status now?

• Three shutters of the dam were opened on October 30 to release water. While people living downstream were evacuated beforehand, water release from the Mullaperiyar dam did not alter the level in the much larger Idukki reservoir, at over 94% of its storage capacity, located 35 km downstream.

Why is Mullaperiyar dam a sore point?

• The Maharaja of Travancore signed a 999-year Periyar Lake lease agreement with the British government on October 29, 1886, for the construction of the Mullaperiyar dam across the Periyar in the present Idukki district. The dam became a reality nine years later.

• The water supplied from it through a tunnel to the water-scarce southern region of Tamil Nadu, especially the Vaigai basin, would be the lifeline for farmers of Theni, Dindigul, Madurai, Sivaganga and Ramanathapuram districts.
• On an average, 22 thousand million cubic feet (tmc ft) of water is diverted, irrigating about 2.20 lakh acres and meeting the drinking water requirements of people in the region.
• Concerns over the safety of the gravity dam built using lime-surkhi (burnt brick powder) mortar came to the fore in 1979.
• In November that year, a tripartite meeting chaired by the then chairman of the Central Water Commission (CWC), decided that the level had to be brought down from the full reservoir level of 152 feet to 136 feet to enable Tamil Nadu, which owns and maintains it, to carry out dam strengthening works. By the mid-1990s, Tamil Nadu started demanding restoration of the level.

What happened in the legal battles?

• The Central Government set up an expert committee in 2000 to look into the dam's safety. The committee recommended raising the level to 142 feet, which was endorsed by the Supreme Court in February 2006.
• Kerala sought to restrict the level to 136 feet by way of an amendment to the Kerala Irrigation and Water Conservation Act, prompting the Tamil Nadu Government to move the Supreme Court.
• In February 2010, the court constituted an empowered committee to study the whole gamut of issues concerning the dam.
• Based on the committee’s finding that the dam was “structurally and hydrologically safe”, the court, in May 2014, struck down Kerala’s Act and allowed Tamil Nadu to maintain the level at 142 feet. It also asked the Central Government to set up a three-member Supervisory Committee to monitor dam safety.

Why is it a social issue?

• Commissioned by the Kerala Government in the latter part of the 2000s, a study by IIT-Roorkee raised questions about the survival of the dam, located in seismic zone-3, in the event of an earthquake of a fairly high magnitude.
• A series of tremors felt in the area in 2011 caused alarm. Subsequently, the floods of 2018 and the erratic nature of annual monsoons ever since brought the focus back on the 126-year-old dam.

Why is the case in the Supreme Court again?

• PIL litigation filed in the court last year contending that the Supervisory Committee had abdicated its responsibilities to a sub-committee constituted at the direction of the court for water management in the dam.
• They also urged the court to ask the CWC to fix the ‘rule curve’, ‘instrumentation scheme’ and ‘gate operation schedule’ of the dam.
• Massive landslides had devastated the hilly regions in central Kerala and weather prediction was ominous when the court’s attention was drawn to a report prepared by the United Nations University-Institute for Water, Environment and Health, which cited “significant structural flaws” in the dam and reported that dam may be at risk of failure. Leaks and leaching are also concerning, as the methods and materials used during construction are considered outdated, compared to the current building standards.
• The Kerala Government, a respondent, argued for lowering the full reservoir level to 139 feet as the ageing dam was in a ‘deteriorating condition’.
• In the event of a dam failure, it would result in unfathomable human tragedy and submitted a case for decommissioning the dam, in whose place a new dam could be built to cater to Tamil Nadu's water needs.
• However, Tamil Nadu, relying on the Supreme Court’s two judgments, has been opposing any suggestion for lowering the level from 142 feet, apart from rejecting the idea of a new dam.
• It says it is taking steps to complete the remaining works to strengthen the dam, including those meant for the ‘baby dam,’ situated alongside the main dam, for which clearances from the Kerala and Central Governments are required.

What’s on the cards?

• The design of a new dam by Kerala’s Irrigation Design and Research Board is in the final stages.
• However, without Tamil Nadu on board, this is not going to be a reality. Meanwhile, in the backdrop of the bad weather forecast, Kerala Chief Minister wrote to his Tamil Nadu counterpart, urging him to draw the maximum quantum of water from the dam through the tunnel so that a large volume release would be avoided altogether.
• Tamil Nadu informed that the level in the dam was being closely monitored and the current storage was well within the level permitted by the Supreme Court.

Way Forward

Both the states must amicably solve the issue as per the agricultural usages and environmental concerns. There is a need to strike a balance between the two by limiting the storage level which caters to the need of both as well as strengthening the dam construction to avoid any future crises.

Context: River-based conflicts are important for UPSC Mains Paper-2 and Essay writing

In the present century water is a new SOCIAL-POLITICAL issue, which has its own Geographical and Historical base. Mullaperiyar is one of the oldest River-water Federal issues.

India ranks third globally with 5334 large dams in operation and about 411 are under construction and there are several thousand smaller dams. These dams are vital for ensuring the water security of the Country but simultaneously bring various Rivers-Dams and associated federal issues. Therefore it’s time to think about Dam Safety and Dam management.

Mullaperiyar dam – Federal issues

Context: T.N. must assure Kerala that all instruments for monitoring the dam’s safety are in place

About Mullaperiyar dam – Federal issues:

• The Supreme Court’s direction to the supervisory committee for the Mullaperiyar dam on the issue of the maximum water level has revived the controversy surrounding the dam.
• Located in Kerala, the water body is operated and maintained by Tamil Nadu to meet the water requirements of five of its southern districts.
• The order was issued while hearing a petition raising apprehensions about the supervision of water levels of the reservoir, especially during the rainy season; Kerala has also been experiencing unusually heavy spells of rain.
• During October 18-25, the dam too received a substantial inflow. Despite the Court’s nod in 2014 to store water up to 142 ft, Tamil Nadu has been careful in drawing as much water as possible so that the level does not reach the permissible level ordinarily.
• A few days ago, Kerala Chief Minister wrote to his Tamil Nadu counterpart, referring to the heavy rainfall in the catchment and emphasizing the “urgent need for the gradual release of water”.

The critical aspect of this River water issue:

• As the issue of dam safety is a recurrent one, it would be in the interests of all stakeholders that the remaining works to strengthen the dam are done at the earliest, for which the approval of the Kerala and Central governments is required.
• Some sections in Kerala may argue that the completion of the works will only make the case of Tamil Nadu stronger in the context of its long-standing demand of raising the water level to the original 152 ft (UPSC Prelims)
• But, what needs to be kept in mind is that the works are meant to strengthen the dam.
• It has been suggested that Kerala give its permission — a pre-requisite for Tamil Nadu to get the Centre’s clearances — while stating that this will not be prejudicial to its position on the issue.
• Tamil Nadu too should ensure that all the instruments for monitoring the safety and health of the dam are installed and are functioning properly.
• As there are sufficient scientific and technological tools to respond effectively to any legitimate and genuine concern, every player should adopt a rational approach while deciding on the storage levels and safety aspects of the dam.

About Mullaperiyar Dam

The Mullaperiyar, a 123-year-old dam, is located on the confluence of the Mullayar and Periyar rivers in Kerala’s Idukki district.

• The dam stands at the height of 53.66 metres and 365.85 metres in length.
• It is operated and maintained by Tamil Nadu for meeting the drinking water and irrigation requirements of five of its southern districts.
• According to a 999-year lease agreement made during the British rule the operational rights were handed over to Tamil Nadu.
• The dam intends to divert the waters of the west-flowing river Periyar eastward to the arid rain shadow regions of  Tamil Nadu.

Mullaperiyar Dam and Federal issues between Kerala and TN

Supreme Court (SC) has ordered the Mullaperiyar Dam Supervisory Committee to issue directions on issues concerning the dam's safety (constituted in 2014 to oversee all the issues concerning the Mullaperiyar dam).

Issues:

• A petition was filed by a resident of the Idukki district of Kerala to lower the water level of the Mullaperiyar dam to 130 feet saying there is a danger of earthquakes and floods in the area as the monsoon progresses in the State.
• The petitioner contended that the Supervisory Committee had become “lethargical” about the safety inspection and survey of the dam.
• It had delegated its duties to a sub-committee of local officials.
• The instrumentation scheme, safety mechanism, etc, have not been finalised for the past six years.

Tamil Nadu’s Stand:

• Blamed Kerala for delaying the finalisation of the rule curve for the dam. Rule curve in a dam decides the fluctuating storage levels in a reservoir. The gate opening schedule of a dam is based on the rule curve. It is part of the “core safety” mechanism in a dam.
• The rule curve level is fixed to avoid emergency opening of dam shutters in case of a flood-like situation. It helps in controlling the water level in the dam during peak monsoon.
• Kerala has made consistent efforts to obstruct Tamil Nadu from operating the dam. Tamil Nadu is not able to access data which is in Kerala’s terrain. There is no road built, the power supply has not been restored although Tamil Nadu has paid for it.

Kerala’s Stand:

Accused Tamil Nadu of adopting an “obsolete” gate operation schedule dating back to 1939.

SC’s Ruling:

• Tamil Nadu’s Chief Secretary shall be “personally responsible” and “appropriate action” will be taken on failure to give information on the rule curve for Mullaperiyar dam to the SC -appointed Supervisory Committee. Directed the Supervisory Committee to issue directions or take steps to address the three core safety issues and submit a compliance report in four weeks.

Dam Safety related provisions in India

Dam Safety Bill, 2018

The Bill applies to all specified dams in the country. India ranks 3rd after China and the USA in terms of the number of large dams.

• Onus of dam safety is on Dam Owner. It provides for Penal provisions for violations.
• National Dam Safety Authority (NDSA) as a regulatory authority and a State Committee on Dam Safety by State govt.
• Owners of specified dams are required to provide a dam safety unit in each dam.

DRIP-Dam Rehabilitation and Improvement Project

In April 2012, the Ministry of Water Resources, River Development & Ganga Rejuvenation through the Central Water Commission with an objective to improve safety and operational performance of selected dams, along with institutional strengthening with the system-wide management approach, embarked upon the six-year Dam Rehabilitation and Improvement Project (DRIP) with World Bank assistance at a cost of INR 2100 Crore (US$M 437.5).

• The project originally envisaged the rehabilitation and improvement of 223 dam projects in four states namely, Kerala, Madhya Pradesh, Odisha, and Tamil Nadu. Later Karnataka, Uttarakhand (UJVNL), and Damodar Valley Corporation (DVC) joined the DRIP, and the number of dams in the DRIP portfolio increased to 257; due to the addition/deletion of a few dams during implementation by partner agencies, presently 198 dam projects are being rehabilitated.
• It was started in 2012 and was scheduled to be completed in 2018.
• In September 2018, the Government approved its revised cost estimates along with a two-year time extension from 2018 to 2020, for the completion.
• Apart from its general objectives, it also aims at ensuring the safety of downstream populations and property that are affected in the case of a dam failure or operational failure.
• It was initially taken up for the repair and rehabilitation of dam projects across the seven states of India, namely Jharkhand, Karnataka, Kerala, Madhya Pradesh, Odisha, Tamil Nadu, and Uttarakhand.

Component of DRIP

• Rehabilitation & Improvement: Rehabilitation & Improvement of dams and associated appurtenances,    focusing on structural and non-structural measures at 198 dam projects across 7 states.
• Institutional Strengthening: Institutional Strengthening, focuses on trainings, developement of technical regulations, DHARMA, SHAISYS, Capacity Building of all IAs & selected institutions, establishment of DSOs along with necessary support, Dam Safety Conferences etc.
• Project Management: Project Management deals with activities related to management of ongoing DRIP by all stakeholders.

DHARMA

• Dam Health And Rehabilitation Monitoring Application (DHARMA) is a bespoke web-based software package to support the effective collection and management of Dam Safety data in respect of all large dams of India.
• The software is designed for users at the Central, State, and Dam level, with user permission rights governed by their respective licenses. The access to software is governed through user accounts; and for creation of a new user account, the interested persons may contact appropriate licensee (i.e. any of the Central, State or Other Licensees). 
• General Public can have access to an overview of DHARMA Data in terms of National or State Level Inventory of dams, or in terms of brief report of any individual dam. Development of DHARMA is taken up in phased manner; under the Dam Rehabilitation and Improvement Project (DRIP).
• First phase has been completed, and under implementation initially for DRIP Dams.

Seismic Hazard Assessment Information System (SHAISYS)

• SHAISYS is an interactive program to estimate Seismic Hazard at a point in South Indian region.

The Hindu Editorial-Clearing the air on water

Context: Kerala and Tamil Nadu can overcome hurdles to renew the Parambikulam Aliyar (upsc prelims 2019) Project (PAP) agreement.

About PAP:

• The prosperity of the Pollachi region (UPSC PRELIMS) of Tamil Nadu is attributed to the Parambikulam Aliyar Project (PAP).
• The project paved the way for surplus waters from eight west-flowing rivers to irrigate eastern Tamil Nadu.
• Of the eight rivers, six — Anamalaiyar, Thunacadavu, Sholayar, Nirar, Peruvaripallam and Parambikulam — are in the Anamalai hills. Two — Aliyar and Palar — are in the plains.
• The project is an exemplar of co-operative federalism, in this case between Kerala and Tamil Nadu.
• Using inter-basin diversion, the project irrigates drought-prone areas in the Coimbatore and Erode districts of Tamil Nadu.
• It also stabilises the existing irrigation system in the Chittoorpuzha valley in Kerala (UPSC PRELIMS).

Historical perspective:

• The PAP agreement was signed between Kerala and Tamil Nadu on May 29, 1970, with retrospective effect from November 1958.
• It provides for the diversion of 30.5 thousand million cubic feet (tmc ft) annually from Kerala to Tamil Nadu.
• It also provides for Kerala 7.25 tmc ft through the Manacadavu weir and 12.3 tmc ft at its Sholayar dam annually (19.5 tmc in all).
• This major project with an outlay of ?138 crore was completed in 1972.
• The agreement ensures Kerala’s riparian share in the Sholayar and Chittoorpuzha sub-basins as a guaranteed annual entitlement without applying the distress-sharing formula.
• It also ensures four months’ flow (from the Northeast monsoons) from the Upper Nirar weir for Kerala’s exclusive use in the Periyar basin. Except for the Kerala Sholayar dam, the Parambikulam, Peruvaripallam and Tunacadavu dams are situated inside Kerala territory but are controlled and operated by Tamil Nadu.

Agreement and Disagreement

The agreement provides for review every 30 years since November 9, 1958. This, however, remains inconclusive.

• Kerala has reservations on
  • the non-realisation of its share of 2.5 tmc of water from the Parambikulam group of rivers for the exclusive use of Chittoorpuzha valley;
  • the failure of Tamil Nadu to give Kerala what it is entitled to at the Manacadvu weir and Sholayar dam in low-yield years from the reservoirs under its control; and
  • construction of some structures in the project area without Kerala’s concurrence.
• Tamil Nadu regrets the non-realisation of the anticipated yield of 2.5 tmc from the proposed Anamalayar project and the expected yield of four months of flow from the Upper Nirar.
• It also proposes new constructions to augment its share — the Nirar-Nallar Project and Balancing Reservoir above Manacadavu — which have not got Kerala’s consent.
• Tamil Nadu expanded its envisaged ayacut from 2.5 lakh to more than 4.25 lakh acres, in the four zones irrigating on a rotation basis.
• The deliberations are so far inconclusive because both States have focused on the total average yield and are not exploring furthering the utilisable yield from the available yield.
• Five decades-long joint gauging data (1970-2020) on yield and utilisation, approved by the Joint Water Regulation Board created inter-governmentally, shows that the actual combined yield of the entire project is more or less equal to the anticipated yield.
• But if we consider the yield on a sub-basin level, there is huge variation between the actual yield, the anticipated yield, and also the yield available for utilisation.

Issue of surplus and deficient water

A closer look at the project hydrology reveals that of the last 20 years:

• Chalakudy basin experienced overflow from PAP in 12 years. Similarly, a sizeable portion of the water is lost through Manacadavu as unutilisable flows.
• These are due to the constraints in the present live storage capacity and the skewed inflow pattern.
• Kerala had consented to the diversion in the 1960s, anticipating enough storage spaces in both the Periyar and Chalakudy basins to meet its needs, but most of those storage reservoirs were subsequently denied environmental approval.
• The way forward lies in trapping the existing spill at Chalakudy and Bharathappuzha through new reservoirs, which will substantially alter the present flow regime of PAP.
• Experts of both States could analyse and create working tables based on the observed flow regime to see how much additional water can be made available in the system through new reservoir systems and how that can be shared.
• Sharing becomes imperative as Kerala has largely transferred its storing options in favour of Tamil Nadu in PAP.

Way Forward

As new systems considerably alter the flow regime it is imperative that proper checks and balances be agreed upon to ensure the guaranteed entitlements at Sholayar and Manacadavu. Once the benefits are established by the technical officers, the political leadership can deliberate on the principles of sharing to review the agreement.

The leaders of both States have clear mandates and a reputation for being decisive. They can overcome hurdles for a mutually acceptable renewal.