The game plan is to get water behind the Oroville Dam below what its engineering designs call “flood control storage,” and keep it there. At that depth, the dam would have a buffer capacity of half a million acre-feet of water. At the current release rate, a pounding 100,000 cubic feet per second, the dam will reach that point by late Saturday or early Sunday, even with another rain system arriving Wednesday, said Bill Croyle, acting director of the state Department of Water Resources.