Permeability (earth sciences)

Permeability in fluid mechanics and the earth sciences (commonly symbolized as κ, or k) is a measure of the ability of a porous material (often, a rock or an unconsolidated material) to allow fluids to pass through it.

The permeability of a medium is related to the porosity, but also to the shapes of the pores in the medium and their level of connectedness.


Permeability is the property of rocks that is an indication of the ability for fluids (gas or liquid) to flow through rocks. High permeability will allow fluids to move rapidly through rocks. Permeability is affected by the pressure in a rock. The unit of measure is called the darcy, named after Henry Darcy (1803-1858). Sandstones may vary in permeability from less than one to over 50,000 millidarcys (md). Permeabilities are more commonly in the range of tens to hundreds of millidarcies. A rock with 25% porosity and a permeability of 1 md will not yield a significant flow of water. Such “tight” rocks are usually artificially stimulated (fractured or acidized) to create permeability and yield a flow.

Latest News for: Soil permeability


California wants to harness more than half its land to combat climate change by 2045. ...

The Los Angeles Times 22 Apr 2024
... practices on the soil, and being [a] carbon sink,' Ross said ... Trees and vegetation also contribute to more permeable soil that creates more opportunities for water to seep into the ground and replenish groundwater aquifers that have been sapped by agriculture, drought and overuse....

Iowa environmental groups ask EPA to protect drinking water from agricultural runoff

The Gazette Cedar Rapids 16 Apr 2024
(Southeast Iowa Union) ... He said the rules protect soil and water without infringing on farmers’ rights ... The version released in September said new CAFOs proposed to be built between 5 and 15 feet from karst would have been required to have a 5-foot continuous layer of low-permeability soil, nonsoluble bedrock or a 2-foot synthetic clay liner ... Sept. 26....

2 foods Michael Pollan always buys organic to reduce his exposure to harmful chemicals

Business Insider 15 Apr 2024
They "are usually grown with some pretty nasty chemicals, soil fumigants and things like that," he said ... Typically, organic strawberries in the US are without soil fumigants or herbicides. "In general, organic soils, they don't get their fertility from chemicals, they get their fertility from compost and manure and things like that," Pollan said....

This Storybook cottage’s native plant wonderland shows how gorgeous no grass can be

The Los Angeles Times 15 Apr 2024
... and permeable gravel paths with a delightful crunch ... So in addition to an all-native-plant landscape, Solberg wanted permeable surfaces that would trap water in the soil instead of sending it out into the street — but he didn't want any gutters to ruin their roof's unusual lines....

The Art of Septic System Placement: Key Considerations for Installation Success

GetNews 01 Apr 2024
"Understanding septic installation involves recognizing the importance of soil assessment and percolation testing ... Soil Assessment and Percolation Testing ... During soil assessment, professionals evaluate the soil composition, texture, and structure to assess its permeability and load-bearing capacity....