Well sorted sediments, evenly distributed sediments of uniform size, typically contain 26% to 48% open space. ... Thus, well sorted sediments have higher porosity while poorly sorted sediments have low porosity. Permeability refers to how easily water passes through sediments and rock.
Coarse-grained sediments such as sands, gravels, cobbles and boulders, are more permeable than fine-grained sediments such as silts and muds. Further, well-sorted sediments (more uniformly-sized) are more permeable than poorly-sorted sediments.
