Something that is impermeable will not allow fluid to pass through it. The canoe is made from an impermeable wood. = waterproof. not allowing liquids or gases to pass through permeable
A surface or membrane through which water, or other liquids, will not penetrate, a layer of solid material, such as rock or clay, which does not allow water to pass through, any material that does not permit fluids to penetrate
rock layer is made of materials that permit water to pass only with difficulty or not at all; pores may not be connected or too small for water to be forced through them
Not easily penetrated The property of a material or soil that does not allow, or allows only with great difficulty, the movement or passage of water, particles or chemicals