Duke of Buckingham, the then Governor of erstwhile Madras Presidency ordered a canal to be built parallel to the east coast between Kakinada in Andhra Pradesh and Chennai in Tamilnadu. This 420 km long canal was excavated at a distance of one to two and half kilometer distance from the sea. The close vicinity to the sea was an engineering decision as it facilitated drawing sea water from the pre-existing creeks during the high tide on full moon days. This helped to maintain an optimum water level in the Canal for smooth sailing of vessels. Average width of the canal is 30 m and depth ten meters. The canal was commissioned in 1878 and named after the Duke of Buckingham and was in operation till 1964.
The canal was built to act as a navigable waterway to carry rice, firewood and salt between Kakinada and Marakkanam. The industrial and construction boom of the 'developing' India could only choke the canal to convert it in to a drain for carrying urban waste. The canal apart from urban effluents also carries aquaculture waste. In Andhra Pradesh it is used to divert excess of floodwater.
Despite our apathy the canal served its purpose by acting as a great buffer during the great tsunami of December 2004.
The link between the Adyar and the Cooum rivers in Chennai a part of canal was excavated as a relief measure to provide succor to the residents of Chennai against the terrible famine. At that time perhaps the Governor or even the engineers who built the canal must not have even dreamt that one day this structure will not only save thousands of lives but also save a complete disruption of life in Chennai due to wrath of the sea.
In the year 2002, the Government of India decided to resurrect such canals and an estimated amount of Rs 700 crores was earmarked for the purpose. While carrying the story The Hindu, reported that as late as 1960-61, about 1,250 boats were plying on the canal and had that year carried around 19,000 passengers and 190,000 tonnes of goods valued at Rs. 185 lakhs! It was named as National Waterway (NW)-4. This author was appalled to note in Chennai the hideous pillars of the Metro Rail occupy the middle of the 'dry canal' in 2004. With metro rail running at a height of about 20 m above the canal and pillars occupying almost 50% of the canal width, the 'resurrection' may remain a dream.
Well the tsunami proved the related significance of the canal. The waterway did provide a 'waterway' against the menacing tsunami waves.
The canal was designed in such a way as to draw water from the pre-existing creeks during high tide. In addition, at many other places flood waters of nearby rivers used to diverted in to the canal to maintain a steady level. Thus it was a multipurpose structure which provided a means of transport and flood control both.
Over a period of time thousands of families of fishermen settled between the canal and the sea shore. Though this was very much against Coastal Zone Regulations, yet the respective state governments decided to keep their eyes closed. These were the families that were affected most by the wrath of the tsunami on the ill fated day of 26 December, 2004. But on the other hand there were several families that escaped without even a scratch, just because the tsunami waves were diverted and pushed through the channel of the canal. The canal regulated the tsunami waves over a distance of 310 km from Pedda Ganjim to Chennai. All along this length the canal was filled up with tsunami water, which at places even spilled over the banks. Fortunately the tsunami waters found their way back to the sea within 15-20 minutes.
This saved many a lives in Andhra Pradesh and parts of Chennai. While retreating back the tsunami waters removed all the aquaculture debris along the canal. A thick vegetation cover along certain parts of the canal provided an extra relief to the residents. For example, villages like Puddikuppam, Srinavasapuram and Tuplipalem escaped with minimum damages.
B Ramalingeswara Rao of the National Geophysical Research Institute compiled the heights of tsunami waves that struck the eastern peninsular coast on 26 December, 2004. He wrote in one of his papers that the maximum run up of the tsunami waves was 15 m at Nagapattinam and minimum two meters was at Vijainagram (Bogapuram). He reports that the witnesses informed that the approaching tsunami waves sounded like two or three freight trains chasing one after another and some felt it sounded like Jet Planes crashing on their hutments. It was during the survey of the area for collection of data on the height of the tsunami waves at different localities, he came across the phenomenon of how the Canal saved so many people.
Creeks are a common feature along the sea. At places new creeks were formed. Actually this happens when the excess water erodes and earlier creeks which lie buried normally under a thick cover of sand are exposed. The process of formation of new creeks still needs to be studied. Like the canal the creeks too are shock absorbers as far as the tsunami waves are concerned. They provide natural depressions for the excess water to get diverted.
In the past the kings used to construct a Fort around their Capitals. Often the Fort used to have a mote all around. These were to deter the enemies from sudden attacks. The canal acted as a mote against the tsunami. Had it not been their many more thousands of people would have perished.
It is time that the government takes up a project to clean up the canal, make it navigable and convince the illegal occupants of the land between the canal and the sea shore to move to safer distances.