Excess Protein could cause Kidney Stones long-term.
Also it would increase Nitrogen to Uric Acid Conversion, which if not dealt with properly by say flushing out with good water levels, would contribute long-term to things like Gout.
Yes increased water could relieve potential problems like that I would think, but if you don't need huge amounts of Protein for your needs don't have it.
I.E. not having the same Protein intake of a 200lb person, when you're <180lbs
