I think they were always there. That whole area of plants is hotwired, so the chimps can't get near the moat. I'd guess they can't get any closer than about 4 metres from the waters edge.
I can understand the planted area being hotwired to prevent damage, but if they can't use the area near the moat either, it begins to look like they are rather restricted in wher they can go. Although I've never been a great fan of water moats for Apes, I'd rather see the animals allowed access to it if there is a moat- for the enrichment it provides-'fishing' raking out leaves, dabbling with sticks etc. I think that outweighs the danger from accidents IF you have a moat in the first place.
