Quantitative status by geological formation

The availability of groundwater is linked to the type of rock and soil in aquifers through which water flows. Different geological formations affect how much water can be stored and how easily it can be accessed. Porous aquifers contain spaces that store more water and allow it to flow. Fractured aquifers have less permeability, while fissured aquifers are typically least permeable.
Productivity shows the ability of the aquifer to sustain a flow of groundwater.