ZE+warterfall=fail

[thecat]

So I was playing a map called ze prototype and ran into this giant lag spike when I saw this waterfall, the spike was so bad that I had to look down to even move at a resealable speed, after the waterfall was gone the lag spike disappeared.
My computer meets the optimal requirements for the game but this still happens every time I see a fucking waterfall.
My internet connection is just fine and also meets the requirements for the game.
This same thing happens on other maps, like ze ice cap.
I would like to know why this happens and if anyone else is having the problem, or if it is because I have a 4 year old computer.
I would also like to know how to fix it.

[Carmichal]

this might be server lag if there were a lot of people on. Also post your pc specs. CPU, GPU, RAM also how much do you get up and down with you isp.

[thecat]

Processor: AMD Athlon(tm) X2 Dual-Core QL-65 2.10
RAM: 3.00 GB(2.75 GB usable)
32 bit Operating System
Old but works great for CC:S.

[Carmichal]

gpu? or integrated?

[thecat]

It's an ATI Radeon 3100 Graphics.

[phil.™]

Your graphics card/computer can't handle waterfalls, or any other fast moving objects without having horrible FPS. My work computer is same, so I always look down when going through a waterfall.