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cyanrarroll t1_j6gjhk5 wrote

Reply to comment by waterwitch80 in Eli5....can you dig a well anywhere and hit water...and how did the early ranchers in the West know where to dig for water. Especially in the really dry areas? by pinkshrinkrn

Underground streams are a myth (except those that are literally rivers in caves). Water just kind of permeates everywhere underground and slowly moves towards lower elevation openings to leave as surface waters. Dowsing works as well as asking a frog to jump toward the direction of underground water, and then flipping a coin on whether or not you'll agree to it.

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Hayduke_Abides t1_j6gngv7 wrote

You are partly correct, large amounts of water do move through the pore spaces in rock. However, in addition to that type of flow, almost all rock formations have a network of cracks and fractures, and water often moves preferentially along these pathways. How much porous flow vs fracture flow you get in an aquifer depends on the nature of the rock and the degree of fracturing in the aquifer. In wells, intersecting a few good fractures can be the difference between a productive well and one that does not produce sufficient flow to be useful.

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cyanrarroll t1_j6gpxwn wrote

True but not necessarily useful since most groundwater tables, especially where most humans live, is significantly higher than bedrock.

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