You mean the tunnels after you left the Central Underground Waterplant?

There are a few sequences like that. We need to know which one you're in.

One of them is set off when you play a tape recording. The person who set it up thinks he trapped someone else.

One of them is set in a small but tall room in a sewer. You hop over water and you use a brick to get a big chain-cutter to open a gate.

One of them has you standing in a big tunnel, on a bridge where you can raise and lower shutters to let water pass underneath you.

Can you describe where you are, or what you did recently ?

I mean the sequence, where a tape recorder is placed on a desk and I have to wait for collapse of the railing - to enter the corridor in the first floor. The walkthrouh looks so easy, but I get overwhelmed every time

oh, that should be possible just be running quickly, yes.

I run very quickly :-)

https://www.youtube.com/watch?v=0vlwfuc8Dww
at 10:11, in case that helps
You can try and learn how to bhop to get some speed; or be naughty and enable noclip if you really cant get through

Sorry, what is noclip?
Ok ... I understand
never seen this

Thank`s - i did it