Public works ministry changes Semeru sabo dam method to precast outside the river channel
The minister said precast construction outside the active channel should prevent repeated damage from lahars during the volcano's rainy-season flows.
Public works minister Dody Hanggodo said the ministry has changed the construction method for sabo dams on the Semeru volcano's river systems, moving to precast elements produced outside the active channel. The shift is meant to stop the cycle in which in-channel cast-in-place structures are damaged by lahars during the rainy season and have to be rebuilt, sometimes within the same year.
Sabo dams are the main structural control for volcanic sediment flows on Semeru, which regularly produces lahars that threaten bridges, settlements and irrigation intakes downstream in Lumajang and Malang. Building prefabricated segments away from the channel allows installation windows to be shorter and scheduled between flow events, reducing the exposure of both workers and partially completed structures. The ministry did not publish the affected package list, contract values or a revised schedule alongside the announcement, saying implementation details follow in the coming weeks.