The Periyar – Lifeline Of Kerala

Being 244 km long with a catchment area of 5396, the Periyar is Kerala’s longest river. It originates from the Sivagiri peaks of Sundaramala in Tamil Nadu. 

Periyar plays an important role in the life of Kerala, as it is the region’s source of drinking water (daily pumping 290 million litres per day)  and the river is also used for other domestic purposes.

Periyar is a reflection of Kerala’s economy because it helps in activities like irrigation,

(Periyar Valley Irrigation Project – 32000Ha and to Tamilnadu for  irrigation 76890Ha

fisheries and is also used for industries. 

It flows through the districts of Idukki and Ernakulam before it joins the Arabian Sea at Cochin with tributaries: Mullayar, Perunthuraiar, Chinnar, Cheruthony, Kattappanayar, and Edamalayar. 

The river generates a good amount of electrical energy from the 6 Units of Pelton-type turbines with a power generation capacity of 130 MW (1 MW can supply 650 average houses) each for the state via the Idukki dam. Periyar’s banks’ also house about 25% of Kerala’s commercial industries. 


Fecal coliform level in Periyar from the sewage monitoring station was well over the permissible limit of 500mpn/100mL, with an average of 113,000mpn/100 mL.

The river directly receives civic effluents from townships like Vandiperiyar, Munnar, Malayattor, Perumbavoor, Kalamassery, Aluva, and Paravur. 

None of these local bodies possesses proper sewage treatment facilities, resulting in the discharge of hazardous pollutants like phosphates, sulphides, ammonia, and fluorides into the river.


The intensive agricultural practice along the banks and watershed area has been enriching the river water with huge amounts of pesticides and fertilizers especially during surface runoff in the rainy season.

Inorganic phosphorus from agricultural activities – whose safe limit is 80-100 µg/l – was registered at a peak value of 955µg/l.

Too much phosphorus can cause decreased levels of dissolved oxygen due to growth of algal bloom or a process called eutrophication, which affects aquatic life. 


While the Idukki section of the Periyar is struggling with contamination from domestic sewage, Angamaly to Kochi is the most industrialized zone of the Periyar river basin. 

There are over 50 large and medium industries and over 2500 small scale industries in this region. 

The industries located in Edayar – Eloor area consume about 189,343 metric cube of water per day and discharge about 75% of it as wastewater along with a large quantity of effluents and pollutants.

The effluents allegedly released by many of these industries have turned the water into a deep black color. For the last 3 years, the river went from red to dark brown to black. 

There are more than 30 unauthorized effluent pipes spewing toxins straight into the river from the industry.

Then there are the regular fish kills. The sight of many smaller kinds of fish lying dead on the surface of the water has now become an all-too-common sight. 

When the Pollution Control Board visited the river, for instance, hundreds of dead Indian anchovies could be seen floating in various parts of the river. 

But there have also been much larger fish kills, in which thousands of larger fishes ended up dead especially during summer, the last incident having occurred in April 2020


As the years go by, Periyar pollution has become the root cause of many social and environmental issues. 

In the Kerala floods of 2018 – which affected nearly 5 million people – the waste chemicals from the river that had overflowed into the residents and nearby low-lying areas caused additional damage, which shows the evidence of the environmental issues.

The floods were caused by rapid rains, but the panic condition of the river made the life of the people much worse. The flood affected a total of 776 villages and 373 lives were lost.

The water polluted with the toxic chemicals from industries around the river that flooded the houses was reported to be acidic and have destroyed the belongings like clothes and plants. 


The Periyar pollution and social issues related to it has always got huge attention and influence from the masses. 

  • The administration of Kerala along with the district administration have made an advanced pollution monitoring committee along with civic bodies. The committee consists of experts, representatives of local bodies and factories, and NGOs. 
  • Periyar River Action Plan has been drafted by the Kerala State Pollution Control Board (KSPCB) to address the persistent issue of the Kochi city’s filthy drinking water source. 
  • The National Green Tribunal (NGT) had ordered the drafting of an action plan to deal with the solid waste and septage polluting the Alua-Eloor-Kalamassery stretch of the Periyar. 
  • The Pollution Control Board has sent notices to the companies with directives to install treatment plants or close down the factories. The Total Ecosystem Restoration Project for Periyar was one of the finest projects built so far. 
  • 24-hour water quality monitoring system for the Periyar was set up by the Pollution Control Board. The results of the water quality from the Eloor-Edayar stretch of the river will be displayed live on the display board set up at Eloor.



  • Greenpeace International has appointed Mr. V.J Jose as the Periyar River Keeper to regularly monitor the quality of Periyar water. He has been trying to protect and save the Periyar from the clutches of pollution for the last 3 decades. 
  • In 1992, Prof. S. Sitaraman an environmentalist started the Aluva Environmental Protection Forum and played an important role in the prevention of illegal sand mining and water pollution by afforestation programs. 
  • The different local authorities and communities with the help of student organizations conducted PUNARJANI – a cleaning process of the Periyar river and Tiger Reserves. 400 volunteers divided into six zones collected 700 bundles of waste.


The initiatives and actions of the project and the committee have influenced few industries to improve their pollution control measures. 

For instance, these are the few initiatives taken by the  companies:

  • ‘Merchem’ installed an evaporation plant and reverse osmosis plant.
  • ‘HIL’ installed an effluent treatment plant and a 1500 °C incinerator for hazardous waste.
  • ‘Cochin Minerals & Rutiles Ltd’ has built a hazardous waste pond and initiated new effluent treatment measures. 

However, the report submitted to the National Green Tribunal in February 2017 shows that not much has changed over the years. The report states that many industries dump untreated waste into the river directly and also neglect the maintenance of their effluent treatment plants.

In 2019, fishes were again found dead in the river. A decrease in dissolved oxygen level has caused fish-kills more than 25 times in 2018 and 2019. 


The blackening of the river happens every year. The tests of the river in March 2020 revealed that the dissolved oxygen level was almost nil in the downstream stretch of the river.

The dark color and pungent smell of the river has now become a common thing. 

The standard limit of Colony-Forming Unit (CFU) of coliform bacteria for drinking water is less than 100 CFU per 100 ml for drinking water and 1000 CFU per 100 ml for taking a bath. 

The most recent sample collection taken by the PCB on 10 April 2020 from four different stretches of the Periyar river showed that samples from near the Pathalam bridge showed 1,800 CFU. Water from the downstream revealed a coliform bacteria presence of 1,600 CFU while the Pathalam Kadavu sample had 1,700 CFU.


Despite the installment and strict enforcement measures the administration needs to take, the local community must also contribute. 

By establishing circular economy based programs that have active collaborations with local stakeholders such as city administrations, local communities, universities, and educational agencies, private sector companies, and NGOs / NPOs, local problems can be turned into opportunities for the local community. 


Conducting awareness workshops and programs on domestic waste management and sewage waste disposal to the local residents, such as methods on segregating waste, upcycling and recycling waste, and composting to form a circular economy that benefits everyone and increases community participation.

By conducting a mixed-method study approach and collecting information from the residents and locally available people. A cross-sectional survey questionnaire and in-depth interview will help in collecting data. 


Local bodies with the help of students and the young community can do the wetland construction as a prototype or part of their student project. A constructed wetland is an engineering sequence of water bodies designed to filter and treat pollutants in sewage.

It can be constructed with locally available materials making it cost-effective and also simple operation. It consists of different layers, gravel, and pebble as bed material above the clay base. The sedimented wastewater is passed through the layers, filtering it within layer-by-layer. 

Highly maintained constructed wetlands will have an efficiency of 79-82%.


Creating an awareness program for farmers in the surrounding area to increase the use of green agriculture and reduce the use of pesticides. Green agriculture uses adaptable local farming techniques and practices using post-harvest storage and processing facilitates to reduce waste.

Green agriculture practices environmentally sustainable weed and pest control practices. Making efficient and optimum usage of water thus, making it more sustainable.


Improve communication between the community and local authorities. The communities can help by acting as a citizen scientist by reporting the level of pollution in the quality meter on a regular basis to help the authorities keep check on the effluent disposal by industries.

The communities can also report on other pollution sources such as waste, color of the water bodies, and smell. There are an extensive range of portable single and multi-parameter handheld water quality meters. 

Reach out to Earth5R to know more about solving environmental issues by creating circular economy based sustainability projects.


Earth5R is an environmental organization from India with its head office at Mumbai. It works with the NGO sector, Companies and helps them conduct environmental corporate social responsibility (CSR) programs across India. Earth5R specializes in circular economy based projects. Earth5R also offers short term and long term environmental courses.

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Earth5R’s Global Sustainability Hub is a cross-sector and cross-country collaboration in pursuit of UN Sustainable Development Goals. It is an excellent opportunity for governments and the private sector to engage with communities, use Sustainability-based models to drive economic changes, and create social and environmental impact.

Reported by Gouripriya N, edited by Shafa Azzahra