The USGS WaterWatch site gives you lots of gage data including live tracking of flooding. The graph below is a representation of the last 50 days. As I post this it looks like it is easing up, but the forecast looks like there is still a second stage to watch.
The second one is a live 5 day graph. Of course, since it is live, if you see this post in August it might make less sense. But, trust me, the Raritan has been rising.