Yes, you can target flounder in Aug. They tolerate brackish water very well.
Fish along grass or structure where deeper water is accessible. Usually along channels, or slews that feed into the bay.
What you will not find, are mass numbers of flounder in one place, it is more like bass fishing in that once you catch one, move down the bank a little.
As always, it is easier when on a moving tide.
Hope this helps.