A water separation unit having an inner housing for storm water collection, separation of oils and debris from the storm water, and discharge of clean water. The inner housing is suspended inside an outer housing. The inner housing has a translatable floor with a plurality of hollow tubes extending upward from the floor and downward through the floor for passage of clean water from the inner housing and out the water separation unit. A plurality of conduits collect the clean water as it escapes from the inner housing and carries the clean water to a discharge tube and out the water separation unit.