Why are underground rivers supposed to be a problem for YECs? Ancient surface landscapes? Ha!

I ran across this argument on another site earlier and it reminded me I've seen it before. I've been aware of underground rivers for years and they never seemed to me to be a problem for my creationist views. I lived in a town that had many underground creeks.

If, as I can only suspect, they have the idea that it's somehow proof of ancient landscapes that were once on the surface I can only groan with disbelief. They're underground, they've always been underground, the water seeks existing space between upper and lower formations and it just runs along like any river where it has that space. It runs like a river, acts like a river, leaves sediments and other evidence just as any river does, right where it is.

If they are talking about dried-up former rivers where only their bed remains deep underground they are either underground rivers that dried up underground or they are the evidence of water running across the surface of a layer before the next layer was deposited during the Flood.

There's no way new sediments could have been laid over an existing landscape and the landscape been preserved. Sometimes I wonder what planet these scientists live on anyway.