Construction of water regulatory structures has led to a worldwide increase in the number of low-level weirs (barriers across rivers), which impede fish movements. Almost all freshwater fish are migratory and undertake small and large scale migrations to access spawning, feeding, and nursery habitats. As such, any water development activity must allow the free passage of fish to enable completion of essential life stages. Criteria for the design and operation of water management structures have been well defined in North America and Australia, but no similar data currently exists which demonstrates safe passage of any Lower Mekong fish species through a hydro plant. This incomplete information regarding potential ‘baseline’ environmental impacts at existing structures, and the possibilities of using innovative technologies to minimize impacts, is a major impediment to the informed management of sustainable irrigation and mini hydro systems.
The Mekong project on ‘Optimizing fish-friendly criteria for incorporation into the design of mini-hydro schemes in the Lower Mekong Basin’ (MK15) worked to determine the preliminary, but very necessary, work to determine the engineering design criteria needed to allow fish to migrate past in-stream barriers with minimal injury or mortality in the Lower Mekong Basin (LMB). The project was a critical first step in ensuring mini-hydro development can proceed, thus helping to reduce rural poverty, in a way that maintains fisheries sustainability and diversity.
MK15 was led by the National University of Laos, in partnership with the Living Aquatic Resources Research Centre (LARReC – Lao PDR), Electricite du Lao (EdL) and Waratah Power Company (Australia).
Oudom Phonekhampheng (oudomp[at]yahoo.com)