UNDERGROUND WATER STORAGE STRUCTURE

PROBLEM TO BE SOLVED: To provide an underground water storage structure capable of storing rainwater, which falls on the ground, under the ground in a clean state or of making the rainwater penetrate into a lower ground, eliminating the need of a sediment removal operation, and having superior durability. SOLUTION: This underground water storage structure 1 includes an impermeable sheet member 3 laid down on a ground 2 at a position lower than a ground surface 20 therearound; a water storage layer 4 formed on the upper surface of the permeable sheet member 3; a permeable spacer member 5 and a permeable sheet member 9 laid down on the upper surface of the water storage layer 4; a permeable filtrating layer 6 formed on the upper surface of the permeable sheet member 9; and a permeable water retaining layer 7 formed on the upper surface of the permeable filtrating layer 6. The water storage layer 4 is formed by storing a supporting structure 18 formed by stacking a plurality of space support bodies 8 in a stacked state in a water storage space S formed by laying down the sheet member 3 on the bottom surface 10b and the peripheral surface 10a of a pool-like recess 10 formed in the ground 2. COPYRIGHT: (C)2009,JPO&INPIT