Parallel drainage is probably as frequent and extensive as rectangular and trellised patterns. This is related mainly to marked gradient making the occurrence of parallel flow of channelized water possible. This pattern is notable in relatively narrow zones as in uptilted coastal zones, which have marked gradients.
The narrowness of the zone helps in the non-integration of the drainage because of the shortness of streams but the marked slope and relative youth of landscape are the main factors behind parallelism of streams. Very striking example of parallel stream pattern is seen on the western coastal region where the streams originate on the slopes of the Western Ghats and course as independent individual rivers through the narrow coastal plain towards the Arabian Sea.
Parallel pattern is also found on the Eastern coastal Plain. Other rejuvenated areas of marked slope, e.g., the northern parts of Chotanagpur plateau and adjoining Gangetic plain also have fairly marked parallel drainage pattern.