[Balding_Eagle]

Which means this system was in fact providing food for an average of about 5 Billion people.

Then remains of processing plants, animal lots, cities, roads and other transportation system will be found.

[cripplecreek]

Battlestar Galactica did it when they arrived.

[Lx]

5 billion people???? There are 7 billion people now. Where did they go?

[Fred Nerks]

There are no ‘remains of processing plants, animal lots, cities, roads and other transportation systems’ in Peru or Bolivia either.

http://www.atlantisbolivia.org/canalsperuview.htm

I don’t automatically accept the theory of Atlantis in South America, but the massive evidence of canals (terra-forming?) is quite stupendous.

[okie01]

Which means this system was in fact providing food for an average of about 5 Billion people.

Not to mention it supposedly held 5 trillion cubic feet of water. That's equivalent to 36 Baltic Seas or one-fifth of the Mediterranean.

Given its location -- on the West Coast o Africa, north of the Kalihari -- where the hell did all that water come from?

[BenLurkin]

Zing!

[Kirkwood]

It may have been an idea that simply didn’t work out once it was built.

[gleeaikin]

Just because it could have provided food for that number doesn’t mean that it was. Anyone have information on a possible date for all this engineering. I know that the adjacent area, Zimbabwe had some interesting historical buildings of an unusual size and style. Meanwhile as to the question of where they got the water, the answer is probably the Okavango River/Delta. Here is a site showing a large number of photos, maps, etc. of that area.
https://www.google.com/search?q=okavango+delta+map&num=50&newwindow=1&safe=off&tbm=isch&tbo=u&source=univ&sa=X&ei=qwGpVMPwLIeqggTLkYOACw&ved=0CCEQsAQ&biw=1600&bih=775