Journey of River Kollidam through Time - From the Western Ghats to Mangrove Bay Ecocamp

Cauvery

It all started with the monsoon in the Western Ghats. Rain water seeps through layers and layers of forest, gaining traction with every step, and falls from the hills to the valleys, and then courses down to the plains, curving and looping around the mountains and plains alike, branching off to irrigate new land, depositing the sediments through its path, and finally entering the sea. That river is River Cauvery. Originating from Talakaveri at the Brahmagiri hills where it rains for 8 months a year, the story of Kavery is the story of the Deccan plateau.

About 1800 years ago, the king Karikala of the Early Chola dynasty saw a mighty river that came gushing from the forests. At the same time, the agricultural land of Cholamandalam, or the Kaveri delta region, saw inclement weather conditions. Having to depend only on the rains for irrigation, the farmers had a choice between extreme drought or extreme flooding of the Cauvery. About 1800 years ago, the king Karikalan of the Early Chola dynasty who ruled ancient Tamilakam built a dam across the river, the Kallanai, which literally means stone dam, to prevent flooding of the delta and divert the excess waters of Kavery to its Northern branch, Kollidam. Kollidam literally means place of storage; the kings of the yore had no time for intricacies in naming the structures.

The Cauvery is an interstate river originating in Karnataka before passing through Tamil Nadu and draining into the Bay of Bengal. In its course, Cauvery meanders around the jagged landform of the Western Ghats and becomes relatively straight once it reaches the plains. It has a unique geology, an impact structure or a deformity running through the middle of the basin, which helps contain the runoffs. Both these factors ensure the mineral wealth of the Western Ghats is evenly distributed throughout the river’s path.

While the majority of the river’s total watershed falls in Tamil Nadu, this river basin is an important source of water for agriculture, drinking water and hydropower for both states. The basin, which spans the states of Tamil Nadu, Karnataka, Kerala, and the Union Territory of Puducherry, occupies a sizable portion of peninsular India and accounts for nearly 2.7% of the nation's total land area. With a maximum length of 560 km and a maximum width of 245 km, it covers an area of 85,626.23 sq km. The river basin is bordered on the west by the Western Ghats, on the east and south by the Eastern Ghats, and on the north by the ridges dividing it from the Pennar and Krishna basins

Kollidam

The Mukkombu dam or the Upper Anaicut is located to the North of the Kallanai, or Grand Anaicu. At Mukkombu, Kollidam, Cauvery’s child is born. The Kollidam River is formed by the Cauvery River splitting in the North just west of Srirangam. Kavery and Kollidam have a very beautiful parent-child relationship. Kollidam runs parallel to Cauvery for a while, then almost reunites with it at Kallanai, before parting ways and moving Northward. Here, the river flows unchecked, irrigating the Northern parts of Tamilnadu before draining  into the Bay of Bengal at Pazhaiyar. After being dammed at Kallanai, Cauvery gives rise to multiple branches and streams, irrigating the South-Central part of Tamilnadu before draining into the Bay of Bengal at Poompuhar. 

With Kollidam receiving the surplus waters, the Kaveri delta flourished. Close to 800 years after the Kallanai was built, the Chola capital was shifted from Uraiyur to Thanjavur. This would mark the beginning of the thalasocrassy of the Chola empire. The proximity to the Rivers Kavery and Kollidam enabled the kingdom to expand in ways most other land-locked kingdoms could not. Pattinappalai of Pathupattu describes Kaveri in a way a woman describes her lover. However, much literature on the naval exploits of the rivers are lost, and are left to the readers’ extrapolation.

An archaeological research by Dr. Muthuvairavasamy Ramkumar and co from Periyar University has studied the presence of historic structures in the banks of the rivers Kaveri and Kollidam. Quoting the paper:

The Srirangam interfluve, formed between the Kaveri and Kollidam Rivers in southern India, has been a religious and cultural human settlement for over 2000 years of recorded history. It contains thousands of ancient, yet in use, man‐made structures.The occurrence of flood deposits burying historic structures especially adjoining the regional tectonic structure indicate episodically active climatic and tectonic processes that played a significant role in the burial of ancient‐historic land surface and manmade structures that were under desolation after invasion and desecration by war‐lords of yore.

The surplus rainfall during most of the south west monsoons results in flooding in the Cauvery as well as the Kollidam as around 2 to 3.5 lakh cusecs of excess water reaches the upper Anicut (Mukkombu). From the time the Mukkombu was created, the water is divided into the Cauvery and the river Kollidam. The Mukkombu can withstand the maximum capacity of 3.50 lakh cusecs and it can divide the water letting into river Kollidam with 2.5-3.0 lakh cusecs (Maximum) and the Cauvery with 0.5 – 0.8 lakh cusecs (Maximum).

As Kollidam was born, a large volume of water flowed through the river, proportionately larger than the Kavery itself. Thus, the Anaikkarai or the Lower Anaicut was built in 1902, diverting some of the waters southwards. The source waters being Cauvery in the Western ghats, everytime there is influx of water in Kavery due to monsoons, every tributary of Kollidam gets a surge of the freshwater.

In the translation of the Pathu Paatu by J.V. Chelliah, the author expresses his opinion on the changing times leading to changing interpretations of the written word. Kollidam meant Kaveri-yin Koll-idam, Kaveri’s storage, so literature referring to Kollidam might have called it Kaveri - it was considered to be the same river after all. Also, it has been thousands of years, and we cannot expect the landform to be the exact same, can we? 

The great Chola capital is only a memory now. It has wiped off the face of the earth, and its location is a matter of conjecture. The difficulty of identifying the site is increased by the fact that the river Kaven has changed its course during the centuries. The river is no more a broad and navigable river where it enters the sea. As the result of the construction of a dam the river breached its banks and formed a new branch known as Kollidam. The waters of the old river are now shrunk into a small channel before it reaches the sea.

Veeranam

At Kattumannarkoil, the Vadavaru River, a branch of Kavery, takes water from Kollidam and provides it to the Veeranam lake. The Veeranam, or the Veeranarayana Mangalam lake is a man-made lake built by the Rajaditya Chola at around 907–955 CE. It was considered to be one of the longest man-made lakes in the world with a length of 14 kilometres. It is from here that the city of Chennai receives around 30 to 35 percent of its water through a 230-kilometer long water pipe system. A lake that was built over a thousand years ago, weathered through multiple changes, bore the brunt of various regimes both native and colonial, went through dry periods, and yet, continues to provide for the capital city. 

The foresight of the Chola kings is unmatched. From building dams to utilizing an entire river for storage, and on top of that siphoning waters from the storage to a back-up storage - the ingenuity and thought that goes towards the love of the land. Today, those who live on the very land the kings walked on might not have read the mei-keerthi’s and sangam literature. Whatever we read about them in history, we might even have dismissed it as the past. However, as we reap the benefits of Kallanai, Kollidam, and Veeranam, we must remember - the seeds were sown by the kings of ancient Tamilakam.

Pichavaram

The 1478 hectare Pichavaram mangrove is situated between the Kollidam estuary in the south and the Vellar estuary in the north of the Cuddalore district. The Killai backwater and Pichavaram mangroves are formed by the Vellar-Coleroon estuarine complex. The Vellar and Coleroon river systems link the backwaters, providing a wealth of opportunities for water sports like canoeing, kayaking, and rowing. In addition to providing backwater and waterscape cruises, the Pichavaram forest is home to an extremely uncommon sight: mangrove forest trees that are permanently rooted in a few feet of water. 

The Pichavaram mangroves support a distinctive diversity of flora and fauna, just like other mangrove wetlands in India. The mangrove ecosystem functions as a buffer zone between land and sea, holds and stabilizes shorelines, slows erosion, and aids in climate change adaptation. It also serves as a bio-shield during natural disasters

Mangrove Bay Ecocamp

At Kavarapattu, the Kollidam River makes one final curve to end its meandering journey. It is wide and bountiful, as the river slows down for one last time. After this, she would flow straight into the sea. At the same time, the proximity to the sea causes the saline waters to backflow into the stream, creating a freshwater-saltwater hybrid. The soil is always flooded to the point of saturation, creating the perfect conditions for a wetland ecosystem. The salinity of the waters periodically changes with the tides, thus the only species that can not only survive in such conditions but also thrive - the Mangroves - grow here in abundance. That place is where Mangrove Bay Ecocamp is situated.

While there is absence of specific recorded history, we can put two and two together and conclude that Kollidam was a strategic administrative and military path. As we know, not just from the historical fiction novel Ponniyin Selvan but from history, Melakadambur was a very important location from Thanjavur, and both are on either sides of the Kollidam river.  

Located in the sweet spot between the freshwaters of Kollidam and the salt waters of the sea, the camp is home to dense mangrove vegetation. Also, North of the camp, waters from Kollidam and River Vellar form the Killai backwaters where the Pichavaram Mangrove wetland is located. The mangroves seen at River Kollidam near the camp are a continuation of the system. The very same mangroves which we call home.