Nepal ecology students learn practical applications of freshwater assessments for hydropower development

Applying what you’ve learnt is always rewarding and greatly improves understanding. That’s just what three Nepal ecology students  accomplished at the end of 2019.

In a four-day workshop, experiences were shared, networks were built and methods for environmental impact assessment were applied.

The students, sponsored as part of the flow and ecology project phase II with Australia’s national science agency, CSIRO, were invited to participate in the workshop on ‘Assessing freshwater ecosystems for sustainable hydropower development in Nepal’. Organised by the International Centre for Integrated Mountain Development (ICIMOD), the workshop was held in Dhulikhel, Nepal.

Nepal is rich in water resources and has high potential for hydropower. This workshop provided on-ground assessment tools and procedures for assessing freshwater ecosystems as part of environmental impact assessment in the hydropower sector.

Workshop report

Day 1 covered environmental impact assessment methods and government approval processes. A thorough environmental impact assessment of hydropower project impacts provides a tool for conserving aquatic ecosystems while promoting sustainable development. Energy production can be achieved in conjunction with good aquatic health by maintaining minimum environmental flows (e-flow). A new e-flow calculator developed for western Nepal calculates the minimum flow required to maintain river health. Comparison was made between Nepalese and Norwegian environmental impact assessment for hydropower development through the presentation from the Norwegian Water Resources and Energy Directorate.

Day 2 focussed on ecological indicator species for aquatic health. Aquatic biodiversity assessment (using macroinvertebrates and fish as indicators of aquatic health) draws a picture of the health of aquatic ecosystems. Having an aquatic biodiversity baseline prior to hydropower development is critical. ‘Pre’ and ‘post’ impact of hydropower projects in rivers are assessed using biotic and physico-chemical parameters of water quality.

Day 3 allowed practical application of the methods learned with a visit to Panauti Hydropower Station. The students sampled macroinvertebrates in different habitats, tested water quality parameters and measured discharge upstream and downstream of the hydropower station. Applying a published field screening protocol; sensory features (odour, colour, foam and solid wastes), algae and periphyton (the algae that grow on surfaces such as rocks, wood and plants) coverage and ferrosulphide reduction assessment produced a river quality classification. Upstream and downstream assessment were compared to analyse the impact of hydropower development.

Day 4 led to analysis of data from day 3 to calculate the river quality classification and determine the health of ecosystems. Stakeholder inclusion in environmental impact assessment of hydropower development proposals was covered through a role play to test strategies for inclusion of non-government organisations, investors and other government bodies.

Why it’s important?

Economic development, such as hydropower and agricultural irrigation, accompanied by climate change pressures mean that future water availability for freshwater ecosystems is increasingly threatened.

The key benefit of understanding river flow-ecology relationships is that when river flow changes occur, information is available to support the development of environmental flow policies that recognise the need to protect (and possibly enhance) ecological components and multiple uses of the river(s) into the future.

To protect freshwater flow through river basins and the ecology supported by that flow, it is first necessary to understand what biodiversity exists in aquatic ecosystems.