When rivers are diverted to dams or small-scale hydroelectric projects, the quantity of water tends to diminish, which frequently has negative effects on the downstream ecology and livelihood opportunities. Keeping a specific ecological flow is thought to be an effective treatment, but simultaneously, it may also have an impact on the social and economic benefits of dam operation. Thus, to balance the relationship between these two, this research suggests using the concept of ecological flow to assess ecological flow demand in the dewatered river section. River data was tracked for eight years (2015–22), with the aim of calculating ecological flow. Results showed that the average natural flow over the course of eight years (2015–2022) is 7.9 m³/sec. At present 1.9 m³/sec is repudiated in the river and the remaining 6 m³/sec is diverted toward the Baran Dame. But, during high flow season. In low flow season, this calculation is not followed. Water diverted irrespective of proper calculation will have negative impacts on the downstream ecology as well as socio-economic activities. It is therefore recommended to keep the river under the concept of ecological flow.

Keywords: River diversion, Ecological Flow, downstream ecology, Dam