A technique facilitates formation of a gravel pack in a wellbore. Gravel slurry is delivered downhole to a desired gravel packing zone located along an annulus surrounding a gravel packing completion. Dehydration of the gravel pack is facilitated by providing a return flow path for a carrier fluid along drainage layers of adjacent screen assemblies. The drainage layers of adjacent screen assemblies are coupled by drainage layer shunt tubes which bypass corresponding couplings between the adjacent screen assemblies. In some applications, the drainage layer shunt tubes facilitate delivery of the returning carrier fluid to a sliding sleeve assembly.