I realise that, I was just wondering if there was a way to override that so I could get never-ending sand. The Wiki seems to offer some conflicting advice:
Support materials with shader effects such as normal mapping, water, environment mapping, proxies, etc.
Silly Valve! I guess I'll just have to leave it as is.
Habboi: Not allowing players in the water would change the dynamics of the map. Besides, how would not allowing them in the water help? You can still see the water when you're not in it...