The dam was built at a 1/50th scale and four meters high. The miniature mountains around the dam were built with concrete to withstand the pressure of the water, a decision that upset Tsuburaya due to being unable to move the set in order to set up cameras. The dam was also designed to realistically crumble under the weight of the water but due to this, only a small amount of water came out during the first try. Three attempts were made to force the water out and the dam had to be weakened for the effect to succeed. Since Tsuburaya was unable to move the cameras, all three takes were edited together. Several props of various scales were created for the caterpillar and adult Mothra, including one caterpillar prop used specifically for water scenes.