I know this has been asked about twice in the last couple of weeks. I found one of the posts, but I couldn't find the other.
Someone had suggested using old topographic data to determine what the depths of the reservoir are: the argument being that the depths should not have changed with the filling of the reservoir.
I agree, and as such I decided to generate 2.5m contours for the Pine Coulee Reservoir area, using surface data from before the filling of the reservoir.
When I overlayed the contours on the maps I'm working on (which I posted in a different thread) . . . things don't look good.
There were some significant changes to the topography in the southern portion of the reservoir when it was filled.
I was going to take it down to 1m, but for the length of time it would take my computer to process the data, and the poor accuracy (given the topographic changes), it just isn't worth it. I certainly wouldn't put my name on it.
If someone is up to collecting points using his/her fish finder in the spring, I'm more than happy to clean up the data (not in Lowrance, please) and generate depths.