2015-2016 was not unusually dry. Above average precipitation for the northern half of the state but I guess if you compare it to other strong events it was unusually dry. This is a study done by researchers from UC California of the 2015/2016 El Nino versus the 1997-1998 event which was very wet. Their conclusion was the 2015-2016 was more of a CP event. Based on the comments made by the researchers here I've shared messages with they don't necessarily subscribe to that theory. This is the study that was done. It is a fascinating field of study.

 https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016GL071515