It is an extraordinary project that involves building a 64 km dam and turning a part of the Arabian Sea into a freshwater lake. It will take at least 20 years to build and if it ever gets off the ground, it will cost around Rs 50,000 crore (Rs 500 billion).

The mind-boggling figures and the complexity of the task ahead aren't stopping the Gujarat Government. Last month the state Government took one step closer to turning the ambitious-beyond-belief Kalpasar project into larger-than-life reality.

Chief Minister Narendra Modi took his top cabinet ministers and bureaucrats to the seashore to kick off a series of what are called bathymetry surveys which involve charting the bottom of the ocean and figuring out the composition of the seabed.

"Kalpasar water will eventually lead to a quantum jump in living standards of the people in the region," says Rajiv Kumar Gupta, secretary, Department of Water Resources, Water Supply, Narmada and Kalpasar.

Gupta was a key figure in the Sardar Sarovar project and he's reporting only to the chief minister on the Kalpasar project.

What is the Kalpasar project? It involves building a giant 64km dam across the Gulf of Khambhat, (it was called the Gulf of Cambay) from Ghogha in Bhavnagar district to Hansot in Bharuch district.

That will trap the water from 12 rivers that flow into the gulf -- including big ones like the Narmada, the Mahi, the Sabarmati and the Dhadar -- and create a huge freshwater lake.

The Kalpasar reservoir will be 2,000 sq km which will be 50 times bigger than the existing Bhadar Reservoir in Rajkot. It will store more water than all existing major, medium and minor dams in the state.

It will store three times the water in the Sardar Sarovar reservoir. Importantly, the government says that hardly anyone will be displaced from their homes, unlike the Sardar Sarovar project.

The giant lake can be harnessed in lots of different ways. It will be able to generate 5,880MW of tidal power. Most importantly, it will solve the state's acute water problem for a long time to come.

Travelling along a 660 km network of canals, it  will provide around 5,61 million cubic metre of water annually to irrigate 1,054,500 hectares of land of Southern Saurashtra, where water is a scarce commodity.

Besides that it will provide 900 million cubic metres of water for domestic usage and 500 million cubic metres of water for the industrial development of Saurashtra and Kutch.

There will be other  benefits. Haskoning, an international company that carried out a survey on the project, has suggested that a multi-lane highway and a railway line should be built across the length of the dam.

That would slash the distance between South Gujarat and Mumbai and also Saurashtra by about 225 km.

The freshwater lake and its rising water levels will probably make it possible to build more ports in the region -- there are even suggestions that as many as three or four new ports could be built.

Also, it will be possible to improve existing ports like Ghogha and Bhavnagar because of the higher water levels. Also, the Government believes that fish could be introduced into the freshwater lake and that this alone could generate an income of Rs 68 crore (Rs 680 million).

If all that isn't enough, the Government reckons it will be able to reclaim 1,100 square kilometres of saline land along the coast that is currently unfit for cultivation. Once the dam is built the salinity levels will decline.

There's still a long way to go before the first brick is put in place. But, let's step back and see how this super-ambitious project has even come this far. It was the brainchild of Anil Kane, a former Vice-Chancellor of MS University, Vadodara who first came up with it 18 years ago.

Kane, a mechanical engineer, points to other projects like Kalpasar in other parts of the world -- though even he admits that none are quite as ambitious. He has been indefatigable.

Says Kane: "I approached over half-a-dozen chief ministers but only Keshubhai Patel and Modi have taken this project seriously. Some of the people whom I met called me a madcap."

Over the years Kane has studied other giant projects like Kalpasar. There's the La Rance project in France and the Annapolis project in Canada which have attempted something along these lines.

But the most ambitious is probably the Ijsselmeer project in The Netherlands which has a 32 km-long dam. The once marshy land in the vicinity has been used to create Lelysted a city with a population of 500,000.

"Other such projects are being implemented on experimental basis in the UK, Russia and China," says Kane.

For the time being, however, the National Institute of Ocean Technology (NIOT) run by the Central Government has picked up the baton. NIOT is in charge of the bathymetry survey, which is essential before any drilling work can start on the seabed.

To handle the task, the NIOT has opened a centre at Bhavnagar only for this project. A 12-member team using two tugboats will sail across the gulf at least twice a week to conduct the necessary surveys. The bathymetry study itself will cost about Rs 2.5 crore (Rs 25 million) and will take three months.

That will be followed by geo-technical studies which will examine the seabed and whether it will be able to take the weight of the dam's pillars.

That survey will only take a month, according to Government sources. The NIOT researchers carrying out the bathymetry studies will try to pinpoint the position where the dam should start and finish.

Says Gupta: "Our ships are going back to the site once again this month and the work of bathymetry survey and sub-bottom profiling will be over by the end of this month."

Once the geo-technical survey is completed the action will get serious. The Government will have to get an Environment Impact Assessment (EIA) carried out. The Government has already floated a global notice for this purpose.

Also, a strategy report is being prepared by the Gujarat Infrastructure Development Board, a state-run enterprise. GIDB has been asked by the govt to work out a framework for Public Private Partnership arrangement for this project -- mainly guidelines about how the private companies will take part in this project. That will be followed by a structural report.

How have the people of the state reacted to the project? The answer is that, so far, reactions have been muted. The state government has announced the launch of the project just before the state elections but still it is keeping it fairly low profile.

That's because it doesn't want to attract the ire of environmentalists until it has concrete evidence in hand that the project is doable - and that it's the least harmful option in environmental terms.

Also, the government was strapped for cash and because of that it wasn't able to get the project off to a flying start earlier, even though Modi has always been strongly in its favour.

But the government is determined that it will go it alone to some extent on this project. It says that the money won't come from the Centre but from organisations like the Asian Development Bank and the World Bank.

Also, it wants to woo the private sector and persuade it to take part in the project in a big way.

"We are not waiting for the Centre's fund for Kalpasar as we want this project to have the maximum private participation. And businessmen have already shown positive response even before we could complete the survey works," says I K Jadeja, state Infrastructure Development Minister.

But it is still a $64 million question whether the project will ever be completed. Kane believes it will take only six years from the day that drilling starts in the seabed.

Modi, on the contrary, reckons it will take a decade. But industry experts say that unless the private sector comes forward in a big way the project will never see the light of day.

Obviously, the greatest risk is the environmental one. P P Patel, the head of the Geology Department at MS University, Vadodara believes that the project is on the intersection of the 400-km wide and 150-km long Cambay fault line running in the north south direction and the Narmada-Sone geo.

This, he says, will: "Contribute towards the creation of bigger tectonic stress areas in the region."

He believes that this and a combination of other factors mean that the region is susceptible to earthquakes of between 5.5 to 6 on the Richter Scale. Therefore, building a dam there would be extremely risky.

Kane discounts such a prediction. "I have checked all these factors and found that this project is out of the threat of earthquake. Anyway, we will definitely consult the best experts across the world before finally constructing the dam," he says.

The environmentalists are also coming up with other objections. They say that the mangrove swamps on the coast will be destroyed by the freshwater lake. Around the world, mangroves are of crucial importance because that's where many seawater fish head at spawning time.

There were, in fact, a handful of mangrove regeneration projects on the coast that have been stopped currently by the government.

Says environmental activist Nafisa Barot: "Mangroves prevent salinity increase and also have rich fodder content."

The environmentalists also say that large numbers of people -- especially, the fishermen -- will lose their livelihood as a result of the dam.

Also, they are firmly convinced that it would be better to build a series of small dams to block the rivers that run into the sea in Gujarat.

Most importantly, they say there should be a public debate on the project. Says Barot: "Many of us feel there is no transparency. No one here has a clear idea of what plans have been made for distributing the water equitably."

An even greater fear is that the level of water flowing in the rivers may reduce over the years. That's already happening all around the country because of water overuse.

The name Kalpasar comes from the Hindu mythological Kalpa Vriksha -- a wishing tree. For the Gujarat government it could be the gigantic project that almost magically solves the state's water problems. But, there will be long and hard battles ahead before that ever happens.

Gujarat's water woes Consider a few statistics: In Gujarat's Saurashtra district there are 750,000 deep tubewells drawing water from under the earth. Or, head to Mehsana district in north Gujarat where there are 25,000 deep tubewells. Gujarat is suffering from an acute water crisis that hasn't been solved even after the completion of the controversial Sardar Sarover project. Demand is climbing and, as the state industrialises, the levels of water pollution are also soaring. Worst hit are the Saurashtra region and Kutch, on the border with Pakistan. In these regions there are water shortages even in years when a normal monsoon takes place. What's more, the experts say that by 2025 the water crisis will get much worse. They reckon that by then, even in years when there's a good monsoon, the state will be short of about 7,294 million cubic metre (MCM) of water. The experts say there are a mix of reasons for the current crisis. For a start, they blame the excessive use of sub-soil water and the rapid industrialisation which has caused heavy pollution of the surface water. The levels of pollution are climbing at terrifying speed specially in the 450-kilometre-long "Industrial Golden Corridor'' from Mehsana in north Gujarat to Vapi on the border with Maharashtra. The state government has been trying to improve the situation. Last winter it extended the Narmada canal network till Rajkot and then all the way to Bhuj. Over the years the government has made various moves to alleviate the water crisis. In 2000 it enacted a law to restric the haphazard use of subsoil water and declared 40-odd sub-divisions as 'scarcity zones'' where the underground water level was fast depleting. The excessive use of underground water is also creating potable water problem in over 9,000 of the 18,000 villages in the state. That's despite the fact that more than Rs 1,200 crore has been spent on water resources in the last decade. The giant question now is whether Kalpasar, if it ever comes into being, will solve the state's water woes.