Harvesting in deep waters

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With the spectre of acute water shortage staring at the state due to the weak progress of the monsoon, discussions are emerging as to how to tackle the days ahead up to the next monsoon.

In this context, what comes in sharp focus is the most efficient way of tackling the crisis ahead….where do the projects relating to rainwater harvesting stand and can the state afford to relax in the thought that its current efforts are bound to yield results?

According to the current estimate, rains are deficient by 38 per cent in the state as a whole this season and in some places this is as much as 60 per cent.

According to an estimate of the Kerala Government, when it usually rains 3,000 mm rain in Kerala, a total of 1.16 lakh million metre cube (mmc) of water is showered on the state.

Of this, a total of 70,000 mmc water flows through Kerala’s rivers, of which 40,000 mmc is available for use in the state. Another 6,000 mmc goes down as ground water.

But this year, this is set to go down drastically and extra efforts need to be taken to harness water.

Surprisingly, rainwater harvesting initiatives, one of the best ways to deal with water shortage, launched some eight years ago, have lost steam and nobody seems to realise the urgency of carrying on the effort.

“In Ernakulam district, a total of 50 roof top rainwater harvesting units were launched in 2004-05 alone, but 90 per cent of them are either rusting or abandoned including the one at the district collectorate and at Maharaja’s College, where they were launched with much fanfare.

The one at the district panchayat office is the lone one standing,” says prominent environmentalist Prof S. Seetharaman.

Prof Seetharaman said that a majority of rainwater harvesting units launched in other districts too had met with the same fate. A senior official in the state water resources ministry confirmed it.

He said that the rainwater harvesting projects launched from 2004 to 2007 later fell into a state of inertia with no clear cut government authority to look after their functioning.

“A number of agencies across the state including NGOs and media organisations joined the big campaign for rainwater harvesting during this period and took up their implementation while some of them found this an opportunity to make a quick buck with government aid flowing in.

With monsoon not failing the state in subsequent years, nobody, including the government bothered to enquire about the fate of these projects.

This year, with the monsoon failing, the debate regarding rainwater harvesting has resurfaced,” he said. He said that the Rain Centre set up in 2004 to control rainwater harvesting projects too was left orphaned later.

Interestingly, it was made mandatory in 2004-05 that for obtaining clearance from local bodies, buildings above 2,000 sq ft plinth area should have a rainwater harvesting unit.

Though there was awareness and enthusiasm in the beginning, the rule remained on paper with the local bodies turning a blind eye to its existence.

The government at one point offered subsidy for ferro cement units for rainwater harvesting, but this too has become history, with both the givers and takers not warming up to the project.

Prof Seetharaman said that at one point there was enthusiasm to dig rain holes to harvest rainwater. This too had waned. He pointed to another danger looming large on the horizon: The ground water table is going down by 35 cm every year.

The one positive fact is that there are certain private institutions that still continue to harvest rainwater on their premises and use it effectively.

The scientist who made a difference

The former head of the Geo-Sciences Department of the Centre for Earth Science Studies (CESS), Dr P.K. Thambi, is one name that stands out in the sphere of rainwater harvesting.

He has been able to devise a new, natural method of harvesting that has been adapted by Kinfra at its various parks and also by a few private organisations.

“Ferro cement tanks are not cost-effective when it comes to large storage. While it costs Rs 6 per litre for this facility, the technology of using low density polyethylene films of proper grade for sub-surface dams can reduce the overall cost of storage to less than a paise per litre in rainwater harvesting,” says Dr Thambi who set up the largest rainwater harvesting farm in Asia at Ahalia Foundation, Palakkad.

He said that KINFRA’s textile park rainwater facility was providing 5 lakh litres per day to Bharat Earth Movers Limited while it would soon draw another 5 lakh litres from the facility for its use. At KINFRA’s film video park, it was 6 lakh litres per day. He blamed the KWA for the state’s water woes.