There are now around 800 houseboats in the district. Without holding tanks the toilet waste goes directly into the canals and the diesel and kerosene waste are also polluting the waters. Another problem is the erosion.
Going on a houseboat may be very romantic and an experience in itself but you can see as much if not more of backwater life in other ways. As there are so many it has now become a parade with little chance of you being out of eyesight of another boat. Prices are around Rs 4500 to Rs 10000 per couple per night (including food).
The most environmentally friendly alternative is to take a canoe and let yourself be paddled around the backwaters, Rs 150 an hour. You will find that you are closer to the banks of the canals and being at water level you get a really good view of village life. You can also go down the smaller and narrower canals and get away from the noise of the houseboats to enjoy a very tranquil trip. You sit on a mattress with a backrest which can get uncomfortable. A 4 to 5 hour trip would be about right.
Alternatively you can take a motorised small boat, Rs350 hour. Again you are able to travel close and down the small canals and would probably do as much in 2 hours as a canoe in 6.
There is also the local ferry boat running down to Kollam but this goes much faster and not down the small canals.