OTHERS

Little drops that count

If the aim is to make rainwater harvesting a movement, it should not burden the citizens with a huge bill, says GOUTAM GHOSH.

AN ESSAY can prod people to think, but the issue tends to be forgotten quickly, whereas door-to-door, person-to-person contact motivates people much more than the written word. In a world where a lot more attention-grabbing events happen than can be featured in a day's newspaper, one cannot blame the readers. Most of the people Dr. Shekar Raghavan and I spoke to during a few days' tour round the city finally agreed that rainwater harvesting (RWH) could relieve the water scarcity.

When I was invited to attend an interdepartmental meeting on April 17 called by Ms. Sheela Rani Chunkath, chairperson, Tamil Nadu Pollution Control Board (TNPCB) to focus on RWH among other issues, I wondered why the bureaucracy had suddenly woken up to the prospects of RWH. And why the TNPCB?

The PCB can only be indirectly involved with the issue, from the environment protection angle. The pollutant load that the rainwater carries as it washes over oil slicks staining the ground; chemicals from leaking batteries dumped into and around garbage bins; used mosquito repellent mats carrying more than traces of allethrin which is toxic and has no antidote to date - all headed either to the Bay of Bengal or to our water source down below. These issues directly concern the TNPCB as much as vehicular and noise pollution or the effluent discharge near Ennore.

Not that there haven't been enthusiasts among bureaucrats in the past. A former managing director of the Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB), who now holds a crucial portfolio in the State Government, has been, and still is, a strong proponent of RWH. Despite such enthusiasts, not much has been achieved as far as RWH goes.

Mr. Rajesh Lakhani, additional commissioner, Chennai Corporation, firmly believes in RWH and tries his best to implement it wherever possible. He has implemented RWH schemes in some parks and some Corporation schools in the city. Not long ago, he had said enthusiastically that each of the flyovers in Chennai had RWH provisions, but it was an unsustainable claim. Only a few of the present nine flyovers have RWH facility, with a number of shortcomings in each.

So when Ms. Chunkath said that every building - old or new - must provide for a RWH system within two years from the date of notification, and responded positively when there was a suggestion to cut the permissible period to a year, one wondered if the people would respond. When she added, "...failing which water and electricity connections will be withdrawn," the move made more sense.

None would like to live in darkness just because of one's antipathy towards the RWH system, but if the notification is challenged in a court of law, can it survive legal scrutiny and pre-empt legal stays? If a citizen can obtain a stay, the aim - to solve the water scarcity permanently - would be defeated.

The representatives of Metrowater said they had issued press notes stating how deep the borewells can be for different soil profiles (cf. April 16, page 3, The Hindu, "Recommended borewell depths in the city"). Meant to prevent overexploitation of groundwater and extraction of salt water, the directive does not clarify at what level the unsaturated and saturated zones lie, and how the water seeps to the aquifer. You will have noted the difference between the "present average water level in ft" and the "depth of borewells recommended in ft." but there is no explanation why you should dig deeper, for instance in areas with hard rock formations. If you recollect the diagram published on April 12 (Metroplus, page 1), the hydrostatic equilibrium along a linear interface and as a cone from the coastline assumes that the soil is uniform everywhere. In reality, it is not. And the freshwater aquifer is not distributed uniformly at a specific depth. That is why even neighbouring houses may get water of different quality at the same depth.

As the aquifer chart prepared by the Central Ground Water Board shows, the level varies widely even between adjacent areas. Therefore, if a rough guide were taken seriously it could in all probability upset the hydrostatic equilibrium.

To implement RWH, consultants are needed. "We must identify consultants who are above board. They should be good consultants," Ms. Chunkath said. If the aim is to make RWH a movement, it should not burden the citizens with a huge bill. Most of the RWH consultants work for a fee which could sometimes be high. A RWH system is cheap, but the actual expenses can vary from building to building, from one residential plot to the next, between one factory premises and the other. The number of filtration pits to be prepared or recharge wells to be dug and the length of pipes needed to tap rainwater can vary. It all depends on where the well is, how far the downlet pipes from the rooftop are from the well, and the substratum soil profile, among other technical factors.

As far as consultants are concerned, the aim, ideally speaking, is to identify someone with no vested interest in the movement. I could only think of Dr. Shekar Raghavan, physicist-turned-RWH activist, and suggested his name.

That the TNPCB seems to be serious was obvious as Ms. Chunkath directed that letters should be sent to all heads of department and secretaries, asking them to "Kindly ensure rainwater harvesting, and report compliance." A technical wedge remains between the plan that will work and its implementation - the enthusiastic plan must be approved by the Board. As the proposed step is radical - but which will work - you must wait and watch if the plan remains afloat or sinks sooner than a boulder in the Bay of Bengal.

That the State Government had to wait till the end of its tenure to realise the importance of RWH and that the knee-jerk response to the issue is probably an attempt to cover up its ineptitude and lack of foresight will probably be an issue historians would try to explain decades from now. But what matters is, the step has been taken. But its success?

Only time can tell.

Recommended for you