Patent ID: 7101114

Claim:
A storm drain system to prevent upward flow through a storm drain inlet due to rising water, said storm drain inlet opening into a chamber into which water ordinarily drains through said storm drain inlet, said chamber comprising one or more walls, said system comprising: a seat horizontally mounted or substantially horizontally mounted within said chamber around a substantially vertically oriented flow passageway through said chamber leading to the surface and above the top of a drainage conduit ordinarily draining from said chamber water entering through said inlet; and a buoyant door assembly which floats in water, said buoyant door assembly being movably mounted with respect to said seat and being responsive to water rising in said chamber by floating relatively upwardly until said buoyant door assembly engages said seat, said buoyant door being of sufficient size to block said vertically oriented passageway and thereby prevent water entering said chamber from said drainage conduit from flowing upwardly out of said chamber through said storm drain inlet.