In my opinion, the scud is very under utilized fly when it comes to tailwaters, it’s not very glamorous pattern to tie or to fish, but man, can it be effective for catching trout
I can tell you from my lake fishing experience that a body of water that has a healthy population of scuds also has a fish population that heavily prey on it. This also means that tail waters below those reservoirs have a population of fish that are use to eating scuds as a part of there diet, and in some cases a very significant and year round part of there diet. These patterns work particularly well in the winter months when there are less bug hatches, or when the flows are bumped up, as this often sweeps food down stream. Here’s a link to one of my favorite scuds patterns to tie/fish.
Curved hook (sz 16-18)
Ultra thread Grey (70-140)
Dubbing (semi seal with rusty rabbit fur)
Copper Wire (Small)
Solarez thin UV resin