Efficiency evaluation of Swiss Sediment Bypass Tunnels

Modeling the morphological response of gravel–bed rivers subject to repeated sediment bypass tunnel operations

“…Among them, sediment bypass tunnels (SBTs) have been designed with the main aim of routing sediment around reservoirs, thereby avoiding accumulation of new or even removing previous sediment (Vischer et al, 1997;Kondolf et al, 2014;Boes, 2015;Sumi, 2017;Chang and Lai, 2019;Hager et al, 2020). Investigations on existing SBTs showed that in some cases, up to 98% of the incoming sediments are diverted to the downstream river reach, considerably increasing the estimated lifespan of interested reservoirs (Auel et al, 2016;Albayrak et al, 2019;Hager et al, 2020). Most SBTs are located in mountainous regions, with small (< 1millionm 3 ) to mediumsized (< 10millionm 3 ) reservoirs, where a considerable amount of coarse material is entrained and transported as bed load (Auel and Boes, 2011;Boes et al, 2014).…”