 Due to the topography of the area, Hideyoshi determined that he could not easily burn this fortress as he had the Negoro-ji; he decided to instead use flood tactics, as he had three years earlier in the siege of Takamatsu.The presence of the Ikki zealots was already straining Ōta's supplies of food and other resources even before the siege began.With the construction of a palisade and series of dikes roughly 300 meters from the castle, Hideyoshi began the process of isolating the castle from supplies, and flooding it, a process bolstered by heavy rains.