An in-grade light fixture is described herein. The in-grade light fixture has a main housing having an open top end with a lens covering the open top end. A side car splice compartment is adjacent to the lens along an upper portion of the housing. A hydraulic isolation chamber extends vertically downward from the splice compartment to a receptacle which is an electrical connection to a lamping module contained within the housing. A ballast may be utilized for proper supply of power to the lamp if a non-incandescent lamp is utilized. The hydraulic isolation chamber is filled with the potting material and prevents wicking of moisture through the receptacle into the main housing.