Mullaperiyar Dam 

Mullaperiyar dam is a masonry gravity dam on the Periyar River in Kerala, India. It is among the oldest and largest of its type in the country and was completed in 1895. The main purpose of this dam is to irrigate croplands; it also produces hydroelectricity and provides water for human consumption.

What is a masonry gravity dam? A masonry gravity dam is a dam built of concrete and stone, with the weight of the dam pressing it down onto the foundation. They were popular in the late 1800’s and early 1900’s because they were cheaper than other types of dams. The downside was that they required much more money to maintain and were prone to structural damage from earthquakes.

Mullaperiyar dam is a masonry gravity dam located on the confluence of the Mullayar and Periyar rivers in Kerala’s Idukki district. The reservoir created by the dam’s construction is one of three major water reservoirs in Tamil Nadu, with a capacity of 443,230,000 cubic meters. It has been in use for more than 100 years, and is currently managed by Tamil Nadu.

The dam was initially constructed by the British during colonial rule in India for irrigation purposes before it became more famous for its use as a hydroelectric power plant.

Even though the dam is situated in Kerala, it is operated by Tamil Nadu under a 999-year lease contract signed in 1886 in between Maharaja of Travancore and the Secretary of State for India for Periyar Irrigation Works.

Mullaperiyar dam issue

The mullaperiyar dam issue is about how much water can be stored in the reservoir which impacts the safety of people living nearby. 

In 2014, the Supreme Court of India established a permanent Supervisory Committee to oversee all Mullaperiyar dam-related issues. The dam has caused conflict between Tamil Nadu and Kerala.

In April 2022, the Supreme Court reformed the supervision committee for the Mullaperiyar dam. The committee will be comprised of one technical expert from each of the two states (Tamil Nadu and Kerala) that are interested in the dam’s safety controversy. The court has said that the panel will have the same functions and powers as the National Dam Safety Authority (NDSA). It has asked the two states to nominate their representatives.

Heavy Rain and Mullaperiyar Dam

• For the first time in 35 years, the water level reached 142 feet in November 2014.

• Following incessant rains in the state of Kerala, the reservoir reached its maximum capacity of 142 feet once more in August 2018.

Kerala states that the water level should not rise above 139 feet, which is the same as what the court ordered on August 24, 2018, when the state was hit by floods. It is because raising the dam’s water level would endanger the lives of 50 lakh people. Tamil Nadu, on the other hand, objected to the decision, citing Supreme Court decisions from 2006 and 2014 that set the maximum water level at 142 feet.

What does Tamil Nadu have to say?

Tamil Nadu claims that, despite taking measures to strengthen the dam, the Kerala government has blocked any attempt to raise the reservoir water level, causing losses for Madurai farmers.

Kerala was blamed for delaying the finalisation of the dam’s rule curve.

Rule Curve

A rule curve is a graph that shows how much storage or empty space should be maintained in a reservoir at different times. This curve is determined by complex academic equations that take into account things like the amount of water currently in the reservoir, the weather forecast, and how much water needs to be released downstream. Maintaining the correct amount of storage in a reservoir is essential for ensuring that the right amount of water is available when it’s needed and that flooding does not occur.

A dam’s rule curve determines the reservoir’s fluctuating storage levels. A dam’s gate opening schedule is determined by the rule curve. It is a component of a dam’s “core safety” mechanism. The level of the rule curve is fixed to avoid emergency dam shutter opening in the event of a flood-like situation. It aids in maintaining a stable water level in the dam during the monsoon season.

Arguments advanced by Kerala

Kerala, on the other hand, highlights residents’ fears of devastation in the earthquake-prone district of Idukki. Scientists argue that if an earthquake measuring more than six on the Richter scale occurs in the region, the lives of over three million people will be jeopardised.

Timeline

In April 2022, the Supreme Court reformed the supervision committee for the Mullaperiyar dam. The committee will be comprised of one technical expert from each of the two states (Tamil Nadu and Kerala) that are interested in the dam’s safety controversy. The court has said that the panel will have the same functions and powers as the National Dam Safety Authority (NDSA). It has asked the two states to nominate their representatives.

• A February 2006 Supreme Court decision allowed Tamil Nadu to raise the dam’s level to 152 feet (46 metres) after strengthening it.

• In response, the Kerala Government declared the Mullaperiyar dam an ‘endangered’ scheduled dam under the disputed Kerala Irrigation and Water Conservation (Amendment) Act, 2006.

• In Tamil Nadu, the Mullaperiyar dam and diverted Periyar waters provide a lifeline to the districts of Theni, Madurai, Sivaganga, Dindigul, and Ramnad. Based on the 1886 lease agreement, Tamil Nadu has insisted on exercising unrestricted colonial rights to control the dam and its waters.

Mullaperiyar Dam Map

Current Status

What is the decision of the Supreme Court?

• The panel has been assigned the same tasks and powers as the National Dam Safety Authority by the court (NDSA).
• The Dam Safety Act of 2021 calls for the creation of the NDSA.
• In the event of a failure, “proper action” will be taken against the individuals concerned, not just for breaking the court’s orders but also under the Act.
• The statute punishes refusal to comply with the law’s orders with a one-year prison sentence, a fine, or both.
• The two states are expected to nominate one representative to the supervisory committee, in addition to one nominee each, within two weeks, according to the Supreme Court’s most recent ruling.

Dam Safety Act 2021

• The Dam Safety Act of 2021 took effect in December of 2021.
• The Act is designed to address a long-felt need to address concerns about the safety of major dams across the country.
• It calls for the surveillance, inspection, operation, and maintenance of certain dams in order to avoid tragedies caused by dam failures, as well as institutional safeguards to assure their safe functioning.
• The Act applies to dams with a height of more than 15 metres and those with a height of 10 to 15 metres, subject to specific conditions.

Establish two national institutions.

NCDS and NDSA

The National Committee on Dam Safety (NCDS) works to create dam safety rules and regulations. The National Dam Safety Authority (NDSA) is in charge of dam safety. Its mission is to enforce policies and settle outstanding concerns between the two states. The NDSA will act as a regulating authority.

Create two state-level institutions.

In addition, the legislation asks for the formation of State Dam Safety Organizations and State Dam Safety Committees. Dam owners shall be held accountable for the construction, operation, maintenance, and oversight of the dam.

What effect will the Dam Safety Act have on Mullaperiyar?

The Mullaperiyar dam falls under the scope of the NDSA because the Act states that the NDSA will act as the State Dam Safety Organization for a dam located in one state but used by another. Furthermore, the Supreme Court, which has been hearing petition after petition since its judgement in 2014, has floated the idea of expanding the powers of its monitoring committee to assume responsibility for the structure’s safety and upkeep.

Earlier Position

Tamil Nadu is concerned following the Central Water Commission’s (CWC) decision to re-audit the Mullaperiyar Dam’s safety. Although the CWC stated that the dam is strong, the inspection could be detrimental to Tamil Nadu’s inter-state conflict with Kerala if any safety issues are discovered.

While Kerala supports the CWC’s call for a new safety review, Tamil Nadu is using the old report to argue that the dam is safe and there is no need for decommissioning.

Kerala wants to decommission this “deteriorated” dam and build a new one. Tamil Nadu regards the dam as “well-maintained” and wants to increase the dam’s water storage capacity. While the latter maintains the dam, the structure is still located in Kerala.

Both states have cited numerous studies in an attempt to sway the debate in their favour. However, the outcome of the pending safety audit could prove decisive in this decades-long conflict.

Conclusion

In conclusion, it is evident that the Mullaperiyar Dam issue is a complex and controversial one. While both parties have valid points, it is important to remember that the safety of the people of Kerala should be the top priority. We hope that both sides can come to an agreement soon so that the people of Kerala can live in peace and safety.

The Mullaperiyar Dam issue is a complex one that requires a collaborative solution from all affected parties. Kerala and Tamil Nadu must work together to find a mutually beneficial solution that ensures the safety of the dam and the people living downstream along with fulfilling the needs of Tamil Nadu’s population.