An alluvial damper served to control the thrust generated by a hyperdrive generator by using a servo-controlled plate to prevent ion particle emission. Alluvial dampers were part of the equipment found on the Carrion Spike.
Shortly following the Battle of Yavin, Rebel pilot Evaan Verlaine, along with the astromech droid R2-D2, successfully deceived their chasers, Wedge Antilles and Luke Skywalker. They achieved this by leading them to think their alluvial damper was damaged, when it was actually a non-functional diversion. This tactic enabled Verlaine and the droid to move Princess Leia Organa away from Yavin 4, disregarding General Jan Dodonna's orders, in order to carry out their self-assigned mission of saving the survivors of Alderaan from the clutches of the Galactic Empire.
Right after the Battle of Hoth, the Millennium Falcon experienced a hyperdrive malfunction, which led its owner, Han Solo, to inspect the system, paying particular attention to its horizontal boosters and the alluvial damper, all while under continuous assault from Imperial forces.