Vedic Saraswati
The major rivers of north-west (Punjab, Sindh, Rajasthan & Gujrat) were: Saraswati, Sindhu (Indus), Shatadru (Sutlej), Vipasa (Beas), Vitasa (Jhelum), Parushni (Ravi), Asikni (Chenab), Yamuna, Drishadwati and Lavanavati. All rivers have changed their courses since Vedic times. Of these, three rivers: Saraswati, Drishadwati and Lavanavati no longer exist.

In Vedic times: the rivers Beas, Jhelum, Ravi & Chenab joined Sindhu, to form one channel from Himalayas to the Arabian Sea.

Saraswati and her tributary rivers: Yamuna, Sutlej, Drishadvati and Lavanavati formed the other channel from Himalayas to the Arabian Sea. Saraswati was a mighty river with three sources in the Himalayas. Her bed was as vast as 10 km in some places. The river course was dotted with lakes and ponds.

In the very early days, Saraswati met the Arabian Sea at the Rann of Kachh. After the level of Rann increased, she crossed the Rann to join Arabian Sea at the gulf of Khambat.

Course of Saraswati
Here is the proposed course of the northwestern rivers during Vedic times:

Saraswati: The Goddess of Knowledge
The vedic people had realised the importance of water, and called it life. Obviously the water providing pure streams were no less than a mother, who nurtured life on its banks.

It was on the banks of Saraswati, that the Vedic ashrams thrived. It was on the waters of Saraswati that the vedic culture grew. She was thus called the goddess of knowledge. (Remember goddess Saraswati is always portrayed with water in background, blooming lotus, white swans, and bathing elephants.)

The Rg Veda praises the river as:
     ambitambe naditambe devitambe saraswati
     The best of mothers, best of rivers, best of godesses, Oh Saraswati!

Saraswati-Sindhu civilization:
80% of the sites have been found on the dry banks of river Saraswati, and hence the name Saraswati-Sindhu.

It is suggested that the urbanised and trade oriented Saraswati-Sindhu civilization (3100-1900 BC) suceeded the earlier Vedic civilisation. They built their civilization on the Vedic knowledge. How else could they build towns, navigate the seas, achieve large scale production, have quality standards, and have commercial relations with the Mesopotomia & Egypt cultures? It was the Vedic study that provided them the required knowledge of geometry, algebra, geography, ship building, and navigation.

The Saraswati-Sindhu Civilization represents itself in, about 300 cities (plus so many supporting towns & villages). Huge cities had populations of 100,000. They had two or three storied houses built with bricks of uniform size. The cities had underground sewage system. Networked with grid of roads. Cities had giant reservoirs for water. (Today, only one or two Indian cities can boast to be like those built 5,000 years ago!)

The Decline

Late Vedic Period: Tectonic movements pushed up the Aravali hills, in northern Rajasthan. This changed the drainage pattern of the Northwest drastically. Saraswati lost her major tributaries, Yamuna and Sutlej. Sutlej turned west and joined Beas-Sindhu system, and Yamuna started migrating east to join Ganga.

During Mahabharat times: The volume of water flowing down the Saraswati had reduced. The waters of Saraswati did not make it upto the sea. Yamuna at this time, partly flowed westwards to meet Saraswati and partly flowed eastwards to meet Ganga.

At the time of Krishna's birth Yamuna was not as mighty as it is today. Hence it must have been possible for Vasudev to cross the river, with the new born Krishna in his arms.

It is described in Mahabharat, that Balaram travelled along the almost dry banks of Saraswati, and then along the banks of Yamuna, from Prabhas (Somnath) to Mathura.

After Mahabharat times: Yamuna now pirated Saraswati's sources and flowed into Ganga. Because Yamuna brought the waters of Saraswati to Ganga, the Sagam is called as the Triveni Sangam of Ganga, Yamuna and Saraswati. Ganga now took the importance of Saraswati and the title of goddess.

Saraswati now had neither her sources nor her tributary rivers. She no longer remained the perinnial river. Only floodwaters of Sutlej flowed through her vast channels. As late as the 16th century AD, the floodwaters of Sutlej flowed down Saraswati.

Today, Ghaggar; a puny seasonal river, occupies some parts of Saraswati's dry beds. The dry vast bed called the Hakra-Nara channels lie in the western Rajasthan.

Impact of Saraswati's demise on the population
Saraswati had such an impact on the lives, even after her disappearence, that many rivers were later renamed after her. River Argandab (now in Afghanistan) was named Saraswati. The lower channels of the river Luni in Gujrat were also renamed as Saraswati. Another river born in the Himalayas, (one of the sources of Vedic Saraswati) but flowing down in Assam is also called Saraswati.

The demise of Saraswati, was near fatal for the Saraswati civilization. The scarcity of water forced people to migrate. Saraswati - Sindhu civilization did not vanish. There was a shift of population after the economy around the Sarasvati river collapsed. People moved to east to the Ganga-Yamuna plains, west (giving rise to the Mittani and Kassites, who worshiped Vedic Gods), northwest and south to Godavari plains.

Saraswati Discovered!
1819: Earthquake gives rise to Allah Band. The ground is seen to rise by 5 to 7 meters in some places in Kutch.

1870: Geologist Alex Rogers discovers: The alluvium deposited by a river in the Gulf of Khambat. It also seems that it must be the drainage of the Panjab, that once flowed into Gulf of Khambat.

1886: British officer Oldham saw the dry, vast bed of the seasonal river Gaggar. He concluded that a seasonal river could not create a bed so vast; thus Gaggar must be occupying the bed of an older river. He wrote a paper on the change of river courses in the northwest, and attributed that dry bed to Sutlej.

1886-1999:Many geologists, archeologists and historians some of them being: Wilhemly, Yashpal, Valdiya, Shridhar, Manuk, Mughal, Marshall, Ahmad, S. Kalyanaraman, Roy, Malik, Ghosh, etc. put forth the theory that Saraswati did once flow, in now dry Gaggar, Hakra-Nara channels.

1972: The sattelite images of the northwestern region showed underground channels of water.

1980's: Bhabha Atomic Research Centre (BARC), Mumbai performs carbon testing of the underground waters. It turns out to be 3,500 years old.

1998: Rajasthan Ground Water Department undertook the task to ‘unearth’ the river with the collaboration of BARC and Physical Research Laboratory, Ahmedabad (a wing of ISRO). If the effort is successful, people living in the desert belt of Rajasthan will be supplied with water for irragation.