PROBLEM TO BE SOLVED : To store and utilize rainwater collected in a large site, and to make good use of a ground structure by installing a system for power-storage controlling electric power generated in the site in the ground structure during a developing process.SOLUTION : The developed ground structure 100 is composed of a water-collection passage 120 disposed in the ground for reaching the ground surface, a water-storage tank 130 connected to the water-collection passage 120 and disposed in the ground, pump equipment 140 connected to the water-storage tank 130, a pump controller 150 for controlling the pump equipment 140 and a water-supply passage 160 connected to the pump equipment 150 and disposed in the ground for reaching the ground surface. The water-supply passage 160 is connected to a water faucet column or the like placed on the ground for the utilization of the rainwater. The pump controller 150 is actuated by the electric power generated by a solar photovoltaic module.COPYRIGHT : (C)2010, JPO&INPIT