Tutorial
Here's the video of the scene, loaded in CS 1.6
Modeling Atmospheric Realistic Scenes in GoldSrc
Larger number of 512xX textures were used and every texture is scaled down to 0.5x0.5, thus what you see is probably near the limit of what GoldSrc can handle.
Posted by Gojkovic on - Advanced Level Design/Theory
Loving the texture work.