Brief on Old Brahmaputra: Go with Flow

The offtake of the Old Brahmaputra River, a distributary of the Brahmaputra (Jamuna) River, is facing serious siltation. Both the flow from the main river as well as the maximum diversion ratio show a decreasing trend over the years from 1964 to 2017. During the lean period, this flow diversion is drastically reduced and currently, in dry periods it is totally disconnected. To ensure dry season flow in the Old Brahmaputra along with enhancement of the environmental condition, improvement of the navigation facilities throughout the year, increasing irrigation facilities and fish production, whilst ensuring dry season flow in other connected rivers with Old Brahmaputra (such as the Sitalakha, Jhinai, Bansi , Banar), a better offtake management needs to be implemented.

The objective of this project is to assess the morphological characteristics of the Old Brahmaputra off take and to develop suitable off-take management options (structural and non-structural). Furthermore, innovative dredging options will be explored in the river reach to ensure dry season flow in Old Brahmaputra river and its distributaries along with other water usage/ecosystem services in the river are also studied.