Abstract: A support device for a downspout extension is provided, comprising a molded assembly having a U-shaped upper portion and an elongated ground stake lower portion. The upper portion comprises a first and second upright member forming a substantial U-shape, wherein the distal ends thereof include an inward tab extending therefrom. The tabs and the shape of the upper portion are utilized to secure a section of a downspout extension, while the lower portion is adapted to be pressed into the ground a measured distance such that the downspout extension is supported in an elevated position. Graduation indicia are placed along the lower portion to measure the upper portion height relative to the ground, whereby the user can properly pitch a supported downspout extension using consecutive ground support devices. The device ensures proper and continued drainage pitch through a downspout extension, preventing distortions which may otherwise impede proper drainage.