Harvesting timber from trees submerged by the creation of reservoirs is a viable business, I believe, on account of rising prices, particularly for high-quality lumber that is becoming scarce.
It certainly can pay off. My dad was involved in a project removing old logging roads and in doing so they salvaged a lot of old growth timber that had been buried in swampy ground to make corduroy roads, beautiful straight grain, knot free wood. Buried as it was it was very well preserved, and he stockpiled some off to the side in our shed.
Now one piece adorns my parents new house as the lintel board above the fireplace, and its absolutely gorgeous. I think a some chunks were gifted to an acquaintance who builds guitars, and some more were given to a Salish descended carver.
I suspect there's still plenty of much, much easier to access trees. The macro-economic effects of the wars, and covid, often causing gasoline prices increases (which is used a lot in forestry) that are still adding pressure to almost all commodity prices, including lumber
It's not "access to trees" so much as "access to large, old growth trees". The old ones with tight growth rings, large widths and long straight trunks are actually kinda rare these days. The farmed stuff is not the same, compare the growth ring per-inch
There is a very noticeable difference between the lumber of our house (not to mention my in-laws' home) and that being sold by even specialist lumber yards.
