PURPOSE: Provided is a water collection apparatus combined with a filter basin and a method for installing the same, the method comprising arranging a plate combined with a plurality of strainer fixing pipes on a support on the bottom of a filter basin, installing a concrete slab on the plate and coupling a strainer to respective the strainer fixing pipes. CONSTITUTION: The apparatus comprises a plate on the bottom of a filter basin(10), a plurality of strainer fixing pipes(220) combined with the plate at right angle and arranged in matrix form, a plurality of steel reinforcements(240) on the plate, concrete slab(250) covering the plate and the steel reinforcements(240), and strainers combined with the respective strainer fixing pipes(220). The method comprises the steps of installing a plate combined with a plurality of strainer fixing pipes(220) on a lower portion of a filter basin(10), arranging steel reinforcements(240) on the plate, and forming concrete slab(250) to cover the plate and the steel reinforcements(240), and combining strainers with respective strainer fixing pipes(220).