Seven Sarasvatis

The sages requested Lomaharshan to reveal about river Saraswati’s origin, which flowed in Kurukshetra.

http://yamunanagar.nic.in/km/temple6.asp 
http://www.ancient-origins.net/news-general/did-mythical-saraswati-river-ancient-vedas-really-exist-002174
http://decodehindumythology.blogspot.in/2011/10/finding-saraswati.html

Lomaharshan said-

“Saraswati originates from Paakad tree (Indian fig tree). She enters Dwaitvan after passing through numerous mountains. While describing about her majesty, sage Markandeya felt that Saraswati was the source from, which everything originated- all the three worlds, three Vedas, Vidya (learning), heavenly bodies like Sun, Moon etc.

Once, sage Markandeya eulogised Saraswati by saying- “O Saraswati! You manifest in the form of cryptic mantra- “OMKAR”. You are the eternal form through which the Almighty God (Brahma) manifests himself in different appearances.” Saraswati was pleased by his devotion and said- “O Brahmin! I am willing to go wherever you want to take me.”

According to Markandeya,

1. river Saraswati was initially known as Brahmasar. 
2. Later on, she became famous as Ramhalad.

Sage Markandeya requested Saraswati to flow in the territory of Kurukshetra where sage Kuru was doing his penance. This way, Saraswati diverted her course towards Kurukshetra.

http://tostrength.blogspot.com/2013/11/seven-sarasvatis.html