These sustainable water-purification and flood-control sandbags use a high-density sponge material inside to quickly absorb floodwater. At the same time, the polluted floodwater is purified by the sewage purifier underneath the sandbags, converting it into a clean and hygienic potable water source. This design solves the problems typically associated with traditional sandbags: slow water absorption, low drainage efficiency, and the difficulty of transporting sandbags. Getting hygienic drinking water to flood-stricken areas can take days, and steady relief supplies can take even longer. With these sandbags, people no longer have to wait for outside water supplies.