I have to agree with Phantomjug ... when walleye fishing in August into September, you have to fish at 20 -30 feet to consistently catch fish during the day. It is certainly tougher to fish deeper at 20-30 ft  in August vs 10 -20 ft in late June or July ( when I usually go).

Mid lake reef stucture near deep water and rocky points that taper into deep water are key. Focus on areas that get hit with wind. I concentrate on walleyes when and where there is the "walleye chop". If there are calm waters I move to focus on smallies.

I like to jig and take the aforementioned advice of other QJ fisherman and go as light as you can. However, I often use 3/4 oz. Northland Whistler jigs a lot with a Gulp minnow or leech a lot...especially when fishing in August when fish are deeper. The "extra" sound and vibration of the blades on these jigs seem to help attract walleyes. I also use 3/4 oz Lindy slip sinker setups with floating worm harness with a Gulp worm, minnow or leech to cover a lot of deeper  water and find fish. ( in June and July 1/2 oz slip sinker) I will then go to a jig when I find concentrations of active fish. I have begun to follow the ways of many QJ folks like Mastertangler and use Reef Runners and Deep Taildancers to troll deep structure. They are very effective.

Early morning and towards nightfall you should hit 5 to 10 feet depths reefs near windswept shorelines and narrows between islands or weed edges. Walleyes will come to these spots during low light times. But during the day...head DEEP ... thats where they are in August.

Heed the advice of the many good fisherman that frequent QJ and you can find walleyes during the "dog days" of August.