system
Given the following post, respond as if you're commenting on Reddit:
human
How do lakes, ponds, and rivers, and even puddles retain water without it seeping away into the ground, as if I dug a hole and poured water into it?

I know how people make their own artificial lakes, but they need to put a tarp down to keep the water from draining away. How do rivers and such not have water seep away through the ground?
gpt
All of these have water sources that refresh their losses. The ground under those things is already wet so it drains much slower.

When it starts to rain the ground usually eats up all of the rainfall at start, but after a while places can start flooding.