"Lakeside" LOL You make it sound like there was summer houses, docks and ski boats. There was no lake. It was still a river with tons and tons of sediment buildup behind the dam. It was so thick you could literally walk across the face of the dam without going over your knees. No widening and depth increase behind the dam. Just a new man made concrete channel that diverted water for power use at Bull Run.

No need. Mother nature has more power in the 'heavy winter flows' than a truck load of explosives.

You're right. And just like the Sandy river, the Columbia washed it away.

Most of the similar structures I’ve been around have the additional design goal of capturing additional logs over time. Contrary to their comments these are not the only intentionally created structures using near vertical piling. Some have criticized the vertical logs as not looking natural. I think that’s correct. In the rivers the key, anchoring pieces used to be four and six and seven feet dbh logs. Two feet dbh logs may contribute to the jam, but they just aren’t the anchors. In our grandchildren’s lives the trees planted as riparian trees won’t approach the mass needed, So I am in favor of the vertical logs driven into the stream beds. Also those other similar structure along the river edges aren’t anchored to the sides. They’re anchored to the beds, exactly like these.