system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How can a natural spring be capped without causing overflow somewhere downstream?

I ask this because we live near a park that boasts a natural spring.  There is a section/seating area where you can sit and watch water pour out of this rock continuously.  It is supposedly safe to drink, play in, etc.  However, every now and again, this spring will have a large metal cap on it, and the water will not be flowing.  I'm wondering how this is possible without causing a sinkhole or flooding somewhere back in the flow of water?  I hope this makes sense, thanks in advance for any explanations!
gpt
A spring is not like a river or creek. Water isn't going from one place to another. It's more like a swimming pool with a small hole in it. A spring is feed by the water table. Think of a massive lake underground mixed with all the rocks, sand a gravel down there. Their are parts of the water table that can find them selves above ground. So there, water will leak onto the surface. Putting a cap on it plugs this leak. That water table is so large that there is no noticeable effect.