In the local usage, the lower course [i.e. the Nara] is also given the name Hakra. The local people were probably aware of the continuity of the entire line of valleys and that a single river flowed here once upon a time.
Source, in full
Wilhelmy, Herbert, ‘The Ancient River Valley on the Eastern Border of the Indus Plain and the Sarasvatī Problem’, in Vedic Sarasvatī°, p. 97. in Danino, M. (2010). The lost river : on the trail of the Sarasvatī. Penguin Books India.