So there's not much to say here. Cape Town needed to increase its water resources for the summers so they put a dam on the Berg River. I'm assuming those are farms in the 2005 image. Hopefully the farmers had good compensation for that!
You can find it yourself on Google Earth using these coords: 33°55'29.52"S 019°03'51.24"E
Check back soonish to see a traveling geologic feature!