Over the lifetime of a hydropower dam, sediment will be trapped behind the infrastructure and deposited in the reservoir.
Dams are traditionally designed to provide enough reservoir storage to offset at least 50 to 100 years of sedimentation, which is caused by natural erosion and activities such as construction, deforestation and agriculture.
As the reservoir accumulates sediment, its storage capacity will decrease. Sedimentation also causes operational and maintenance challenges, resulting in the obstruction of water intake, the abrasion of mechanical equipment, and reductions in power supply.
Downstream environmental impacts can include increased erosion, reduction in nutrient deposits inland and retreat of deltas. Changes in sedimentation due to climate change can also compromise the performance of a facility.
Effective sediment management is essential for ensuring storage capacity for water and renewable energy supply, and for protecting the health of the ecosystems that a river system supports.
Our strategy and action
IHA is building awareness and disseminating knowledge on successful sediment management strategies.
Working in collaboration with a group of industry experts and our partner organisations, we are identifying and sharing good practices on managing sediment in a variety of geographies and environments.
In December 2017, we launched a Sediment Management Knowledge Hub on the IHA website. The hub presents a range of strategies and resources, including more than 20 case studies from around the world. Resources on the hub include relevant publications and tools which aim to minimise the impacts of sedimentation and extend the life of hydropower facilities and reservoirs.
In 2019, we will continue to update the knowledge hub by sharing resources and case studies on successful applications of sediment management strategies.
Our ongoing work focuses on researching the effects of hydropower development to river connectivity and lessons learned from our sediment management case studies.
IHA members can access the Freshwater Management Knowledge Network in Hydropower Pro, our online member community.
In the online group, network members can connect with each other, exchange experiences and access essential resources, briefings and case studies.
For any questions, please contact IHA senior analyst María Ubierna at email@example.com
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