A rainwater collection apparatus is formed with an outer sleeve member that is adapted to connect with upper and lower downspout portions, and with an internal colander that is operable to collect and filter the rainwater flowing through the upper downspout portion. The colander has an upper flanged edge that removes water flowing along the inside surface of the downspout, a filter area including a plurality of apertures for the passage of rainwater into a catch basin, and a support flange that rests on a base ledge formed on the outer sleeve to define the catch basin. A discharge spout drains the collected rainwater from the catch basin to a remote storage container. An internal opening in the colander allows the passage of debris and the overflow of rainwater from the catch basin through apertures in the colander for discharge through the lower downspout portion.