Water permeability through membrane is the ability of a material to allow water to pass through it. It is a measure of how easily water can flow through a material’s pores. And is denoted by Lp. Water Permeability Through Membrane is usually measured using the Cubic Meter per Square Meter per Second per Pascal for Water Permeability. Note that the value of Water Permeability Through Membrane is always negative. Typically, the value of Water Permeability Through Membrane is greater than 0.