| 摘要 |
PROBLEM TO BE SOLVED: To provide a rainwater storage system that serves both the functions to store and reuse rainwater and to store rainwater temporarily and prevent overflowing of sewerage conduits, with a significantly smaller number of parts and manufacturing processes compared to when first and second storage tanks are manufactured separately.SOLUTION: A first storage tank 11 covered entirely with a water shielding sheet 14 that blocks circulation of rainwater 13 and provided with a rainwater introduction pipe 51 that introduces the rainwater 13 is installed underground for storing the rainwater 13. A second rainwater storage tank 12 is installed underground adjacent to the first storage tank 11, the second storage tank being covered with a water permeating sheet 16 that allows circulation of the rainwater 13, at least on the outer peripheral surface and the bottom surface. Furthermore, an overflow pipe 51 is installed above the first storage tank 11 so as to penetrate the water shielding sheet 14, for leading rainwater stored in the first storage tank 11 that exceeds the prescribed water level through the overflow pipe 51 to the second storage tank 12. |
