ABSTRACT
The author has 30 years’ experience in designing sediment removal equipment for intakes, desanders, tunnels and reservoirs. Hydrosuction dredging has proven to be an effective way of maintaining reservoir storage, and gravity powered hydrosuction dredges has been supplied tom among others to Tinguiririca and Tricahue reservoirs in Chile in 2022. The capacity of the remotely and automatic operated 400 mm hydrosuction dredge was measured to 183 m3sediments per hour. In 2001 the author designed an ejector dredge with a 160 kW water jetting system and mechanical cutter to disintegrate cohesive clay. The dredge was used to reopen lower parts of the intake at 116 years old Necaxa reservoir in Mexico. Since 2020 the author have developed a boulder excluder which is capable of removing boulders of more than one in size meter from intakes. The boulder excluder is completely without movable parts and still operates autonomously during floods, using only the excess water. A 1,2-meter diameter boulder excluder has been successfully tested at Ulvik power plant in Hardanger in Norway and has since 2020 kept the intake completely clean and free from sediments without any human intervention at all.
