Here is a screenshot from the OPW’s online waterlevel gauge for Athlone Weir. It shows the levels for the past 35 days. In recent days the waterlevel website has ceased to show the names or locations of the gauges, but 26333 is Athlone Weir.
Note the odd discontinuities: the level jumped up on 13 February and fell back on 13 February. Does the gauge get stuck every so often and have to be thumped to free it?
I do not know. I have reported both the discontinuities and the disappearance of the station names to the OPW.