[1][2] The Mechi-Mahananda interfluve is a transitional area between the hills and the plains and exhibits a wide range of topographical variations.

The rivers originating in the hills attain a braiding character and have well-developed alluvial fans.

[4] Embankments exist of the left bank of the Mechi River for 14 kilometres (9 mi) in West Bengal.

As the Mechi forms the international border, it was agreed at a meeting of the Nepal-India Joint Standing Technical Committee to take due care in aligning the embankments so that they would be at identified distance from the border and the top levels of the embankments should be kept same on both sides, as far as practicable.

Besides the High Dam, a barrage across Kosi river will also be constructed near village Chatra, 10 to 12 kilometres (6 to 7 mi) below the proposed Kosi High Dam, to transfer water to the Mechi through the Kosi–Mechi link canal.