I’ve fished below the Lac Qui Parle dam a few openers, but never on the lake. The key to the dam on opener seems to be to start at midnight or shortly after. The walleye bite will often slow down or stop shortly after sunrise. Usually the most effective presentation is a 1/4 – 1/2 oz. jig (depending on flow) and minnow. A 3 way live bait rig might also work. The best walleye fishing is usually on the east side of the dam either along the wall or on the dam in one of the first 2 gates. If the water is a little high and dirty the bite may last all day.
If you’re fishing off the dam, it helps to have something to be able to land the fish – reeling them up 15 feet where you can reach them means a lot of lost fish. My dad made a very effective device out of 1/2″ mesh about 24-30″ in diameter x 16″ high with a 25′ rope. It looks like a large mesh pail – you just lower it just below the water level, work the fish over it and lift. You may be the only one with something like this so you may be asked to help land other people’s fish too!
The alternative to fishing off the dam is fishing on the east side from shore as close to dam as you can get. The difference is it’s full of snags and you’re no longer fishing horizontally so you you will break off a lot.
You will also get pike and some rough fish, but it’s usually a sure bet for walleyes if you’re prepared and a night owl.