As the African Rift Valley spreads apart, Lake Victoria will grow in size, as will the other great lakes east of Victoria beyond the mountains to the west. Just as the rolling of the African Plate will widen the Red Sea, as it has in the past, those parts of Africa that are tearing apart will increase their spread. Since Africa is high land, this will not result in an invasion of seawater. Some elevation rise in the mountains along the tear should be expected, as the plate can bounce up there, being released from the surface tension that existed prior to the rip.
Note Hotspot commentary.
Note 7 of 10 Mediterranean commentary.
Note Hot Springs commentary.