This morning I decided to explore that ditch I mentioned yesterday. It snakes round the back of Kovalam Junction and I had presumed it would only be a few km long and served to stop excessive surface water reaching the plantations in the valleys. Now, having walked 5 or 6km of it I have to admit I don't know what it is!
It's like a mini canal with no water in it. It's not big enough to take boats except, perhaps, skinny ones. At its shallowest it would be one metre deep. At its deepest, about ten metres! It's a substantial bit of engineering and must have taken a lot of planning. There's at least one proper sluice gate and even an aqueduct. There are little bridges across it but no locks - well, none that I came across anyway.
A rough path runs alongside it which made it easy enough to walk but a mountain bike would have been better and would have allowed me to explore further. I passed two prayer halls within shouting distance of each other, each emitting loud Hallelujahs. Near one I had a conversation with a bible-carrying lady. She said the ditch went to Neyyar Dam - which turns out to be 40km away and is, frankly, highly implausible.
I passed the huge "Animal Rescue Kerala" Centre. It had some impressive buildings, some possibly residential, and the website boasts a beautiful setting. I hope the animals appreciate it! Two crazy-looking, wild-haired women came out with a bunch of out-of-control dogs, none on leads, and proceeded to yell at them in European English. Didn't they know that these Indian dogs speak only Manglish?
At one point a bridge crossed the ditch, and the path from it immediately climbed about fifteen metres. I wondered if there might be a lake up there so took a look. It turned out to be a quarry; a huge hole in the ground, with a road spiralling down the walls from the top. I had the mad idea that the "canal" might have been used to convey rocks on miniature barges to somewhere like Vizhinjam Harbour which has a huge artificial sea barrier. Vaguely possible I suppose... but there were no passing places for barges... unless they returned by road. And it would have to be very flat - which it appears to be. And there would have to be a good water source - which there is in the form of old flooded quarries. I suppose it just might be feasible.
Or could it be to carry surface water to a drinking water reservoir near the coast. Extracting water near the heavily-populated beach areas would surely lower the water table and allow salt water to pollute the drinking water. This now sounds the most plausible explanation to me.
As the ditch is very long and continuous I now don't think it can be to deflect surface water from the lower plantations. Why not just have a number of small ditches at convenient locations and avoid the palaver of aqueducts and sluice gates.
I'm intrigued! I wonder if I'll ever discover the correct explanation!