A filter assembly that filters water, particularly stormwater, that includes flow regulating, siphon inducing, and surface cleaning features that allow the filter assembly to operate at the design filtration rate for an extended period of time. During filtration, water flows inward through an annular filter medium into a drain manifold. The rate of flow into the drain manifold is controlled by a float valve assembly. A check valve permits air to escape, but not enter, the filter assembly creating a siphon effect when the rate of flow into the drain manifold is increased. The siphon effect draws water through the entire filtration surface and the entire volume of the filter medium. When the external water level decreases to the level of an array of voids in the filter assembly enclosure, the siphon is interrupted by turbulent air streams entering the filter assembly, agitating the filter surface and dislodging particulate matter.