Balancing Sediment Connectivity and Energy Production via Optimized Reservoir Sediment Management Strategies

Abstract

While hydropower can be a reliable and low-carbon energy source, the construction and operation of hydropower dams cause severe environmental impacts. Reservoirs disrupt natural river connectivity patterns that characterize the movement of water, sediments, and organisms (Kondolf, 2000;Ligon et al., 1995;Wohl et al., 2015). In particular, sediment movement is halted by the low hydraulic forces inside the reservoirs, resulting in reservoir siltation (Graf et al., 2010;Vörösmarty et al., 2003) and sediment starvation downstream (Kondolf, 1997). The first process reduces reservoir storage capacity (Palmieri et al., 2001;Wisser et al., 2013), damages hydroelectric equipment, and poses safety hazards (Wisser et al., 2013). Worldwide, an average of 0.5%-1% of total reservoir storage is lost yearly due to sedimentation (White, 2001). The second impact is more insidious since it is not limited to the reservoir's boundaries. Still, it has the potential to affect the river system as a whole, with long-term impacts on fluvial hydromorphological processes (