Hi Wean
Voelvlei dam is the local dam for WPALAS the contact person is Urs Schwarz tel. (021) 424-1578 or 083-541-4143.
Albe van der Westhuizen tel. 082-881-4566);
I'm not sure if they will be able to give you all the detail, but he will surely be able to give you the contact if he can't sort you out himself.
There is some big carp maybe 4 - 5 kg range but you are more likely to catch between the 1 and 2kg range.
Hope this helps