The answer is, it depends on your location on the river. It’s possible that the river is flooding in certain areas and not in others. Right now (Thursday a.m. May 21), using the link at the bottom of this page “NOAA Hydrological Prediction Service” shows why the predict in "prediction" is a problem.
On the link, East Bernard (top graph) is at 17 feet minor flood stage and there is a forecast graph. Sweeny (bottom graph) is at action level so there is a forecast graph for it. But because Boling (middle graph) is not currently at the action level there is no forecast for it, and no way to second guess the forecast for Sweeny. There are only forecasts AFTER a location reaches the action level or higher. The East Bernard crest will move to Boling and then there'll be a Boling forecast, but we need forecasts at each location once the rain has fallen, not after it has already swollen the river.
FOR San Bernard is currently in touch with the NOAA folks and maybe this issue can be addressed.
...so, yes it's flooding somewhere on the river.
Note: The Sweeny area of the river is expected to rise a foot this weekend that could translate to 18" and would be over the docks in that area for the fourth time this spring! As the water flows further south to deeper, wider portions of the river, the level will be minimized.
<< Location of the three flood gauges on the river