Project Description

Informing the design of fish passes to mitigate the impact of dams on fish migrations in
the Lower Mekong Basin

Donor: Cargill Foundation | Duration: 2013-2015 | Location: Mekong Region – Lao PDR, Cambodia
About: This significant study is the first of its kind for the Mekong River and provided the foundation for understanding fish migration dynamics to inform realistic and sustainable design of fish passes for proposed hydropower dams. The objective of the project is to assess the hydro-geomorphologic requirements of fish migrations using the Khone Falls as a natural laboratory.

The channels of the Khone Falls contain a large variety of hydro-morphological conditions which fish different species use under different water levels. This provides an ideal natural testing ground for assessing the optimal condition for passability; the capacity of a fish pass to foster the passage of all species without stress and injury, and traceability; the success with which fish can find the entrance to the fish pass.

ICEM in association with WorldFish Center, the University of Udon Ratchathani, University of Savannakhet and National University of Laos will assess fish swimming capabilities and the hydro-geomorphologic requirements of fish migrations using the Khone Falls, a waterfall located in Champasak Province on the Mekong River in southern Lao PDR, as a natural laboratory. The assessment makes extensive use of drone photography and technology.

The flow velocities, flow pattern, turbulence level and flow discharge are crucial components which will also be measured throughout the study. The two-year, USD 580,000 study will combine scientific field work with community survey and consultation techniques.

Download the Hydraulic Monitoring Methodology Report.