Beaver deceiver

With my walking group at Loch of Kinnordy, we came across this device. A sign explained that beavers had been damming the drainage channel. The pipes and fence allow the beavers to rebuild a dam without actually blocking the channel.

I'm not sure of they were fooled, because they hadn't attempted to rebuild (yet). Further along the channel there was another blockage that I guess is a dam - see my extra.