ICIMOD Koshi Basin Programme

Summary

ICIMOD's research programme on the Koshi Basin, covering downstream impacts, agricultural dependency, and flood dynamics. Supports the geopolitical significance of Nepal's eastern river system.

Key Data Points

• Koshi basin supports >40 million people
• Contributes disproportionately high sediment loads to the Ganges system
• Koshi irrigates ~500,000–600,000 ha in Bihar
• The Koshi is known as the "River of Sorrow" in Bihar due to shifting course and catastrophic flooding

Relevance to Project

Central to Hydro-Geopolitics and Nepal's Contribution to the Ganges. Also relevant to Sediment as Design Constraint given extreme sediment loads. .

Limitations

• Programme page, not a single technical report. The source summarizes ICIMOD's Koshi Basin Programme rather than providing one citable methods document.
• Directional sediment framing. The page supports high-level sediment and flood-risk context but does not provide design-grade suspended-sediment parameters.
• Downstream aggregate scale. Population and irrigation figures are basin-scale context; they do not allocate impacts by project, district, or season.
• Programme date ambiguity. The page uses a 2023 source date, but the programme spans multiple outputs with different publication dates.