The other dam about 300m to the south is at a good capacity so my guess would be they emptied this one in order to perform maintenance. The mud at the bottom is very close to the outlet pipe (the round thing in front of the two ducks)
I say outlet but I have seen them pump water into the dam from that pipe.
Van Reenen's Pass just south of Harrismith - not that bad as the N3TC makes it out to be
The farms in the vicinity of Spionkop Dam
The Maize farm next to the waffle hut on the R600, just south of Winterton - I can highly recommend this restaurant, its food was incredible (I think I may have posted this pic already, but whatever just be sure to visit the region before winter!)
EDIT: The reason I posted these pics, look how green SA is at the moment!!!!