Pike are like any other fish.. They like cover, access to food, and temperature.. Food trumps all other concerns.. Any fish anywhere will always alter its behavior to an extent for food.. They will move off cover, off ledges,out of weeds, into cooler or warmer water than what they prefer for food...
If you are doing well over time in 14 feet lets say, and the water comes up a foot in this good area, and the fishing gets poor, I doubt depth has anything to do with it.. Its more likely the food supply the fish were used to has moved on, or perhaps the temp dropped, etc.. Water clarity is also a consideration with any Esox.. The are ambush predators, and I have never done well with any member of the Esox in turbid water..
Pike also shut down like any other fish during passing cold fronts as well.. Don't ask me how the stupid fish can feel the air pressure change, but they can, and that will shut down many fish really fast... I usually don't even bother fishing during or for a day or so after a cold front..
Often a good rain indicates a front has passed, and yes that can often kill fishing for a few days.. Not sure thats the issue in your case, but its worth considering.
As far as year to year, all I can say is that in my 60+ years of fishing, I have found that in rivers/streams and creeks, abundance can vary from incredible to non existent from one year to the next. So many variables in moving water compared to lakes... In rivers I start where I have always caught fish, but when the aren't there, I tend to move to other areas.. River Pike are somewhat different than lake Pike.. River Pike seldom have the abundant weed cover that lake dwelling Pike have.. I have caught them and Muskies in odd places in rivers such as shallow rocky Smallmouth Bass habitat without a weed anywhere within miles... Also in 60 feet down in 100 feet of water in big lakes with NO weeds.. Why were they there??.. Food...
In the Passaic I would imagine Pike eat stuff like small Carp, Suckers, whatever good size minnows are there, not to mention frogs, birds, whatever small mammals they can grab, ducklings etc...
It may be overly simplistic, but a predator like Pike will be around other life that it can exploit as food.
If there is a lack of suitable prey in an area of a river system, the Pike will find a spot that has what its looking for...
Here's a good read on Pike, and how and what they see.... bob
https://thefisherieslab.com/2018/08/...its-important/
