Infrastructure sustainability has become a major global concern. Massive reservoir siltations (RS) have seriously disrupted the service of many reservoirs worldwide. The dredged siltations are difficult to stockpile, or dispose of, because of their high water content and soft nature. This study explores a novel approach using RS to produce controlled low-strength materials (CLSM), reinforced with geobags that are used for storage and backfill applications. Test results have shown that, initially, geobags provided a significant contribution to the strength improvement of an RS-based CLSM. However, effective reinforcement appears to be highly dependent upon the type of geotextile and the original strength of the RS-CLSM. The results show a promising solution for reusing reservoir siltations and ensuring a sustainable approach for the mitigation of a silted reservoir.