A water-degradable sheet undergoes biodegradation and prevents drainage facilities (e.g., a sewage treatment tank) from clogging. The sheet includes a water-degradable substrate and a water-resistant layer, along with an enzyme that acts to decompose the substrate. The water-degradable sheet can reconcile water resistance with water solubility. The water-degradable sheet dissolves in water after immersion in water. The water-resistant layer can also contain a biodegradable substrate. An excretion receptacle having a pouch that includes the water-degradable sheet is also provided.
