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Sediment transport

All rivers on earth transport both sediment and water from the source to sea across geographical boundaries. Disturbance of the continuity of sediment flow, when for example sediment deposits and accumulates in reservoirs, leads to “sediment hungry” water causing erosion, degradation, and instability in rivers downstream of dams. Maintaining continuity of sediment flows is necessary to ensure stability and maintain geomorphic and aquatic health of river systems.

Reservoir sedimentation

Reservoir storage regulates natural river flows to ensure a reliable supply of water, power, and flood management services. The future demand for reservoir storage to maintain the reliability of these services will increase due to climate change and a growing world population. Current estimates indicate that more reservoir storage is globally lost because of reservoir sedimentation than what is added through the construction of new dams. The continued decline in net global reservoir storage capacity is alarming, with the current per capita global net reservoir storage equalling conditions last experienced in the 1960s. Satisfying future demands for a reliable supply of water, power and flood management services emphasize a clear need to preserve reservoir storage using sustainable reservoir sedimentation management technology addressing both sediment quality- and quantity related issues.

Sustainable sediment management

Continuity of sediment flow in rivers is key to ensure dynamic stability of river basins, which can be accomplished by implementing sustainable reservoir sediment management technology that concurrently preserves reservoir storage. Creation of new reservoir storage through the construction of new dams is hampered by the limited global availability of suitable dam and reservoir sites. Effective reservoir sedimentation management, therefore, becomes a key element to not only increase a project’s resilience to the effects of climate change by preserving reservoir storage but to also maintain dynamic stability of river basins – a win-win situation benefitting both infrastructure development and environmental preservation. Numerous methods exist to prevent storage loss due to reservoir sedimentation while concurrently enhancing continuity of sediment flow in rivers.

Watch the session from the 2021 World Hydropower Congress

The 2021 World Hydropower Congress featured a session on Sediment Management featuring speakers from World Bank, ICE and BOKU. Watch the session now: