There are various news stories about a water drinking contest gone wrong. A women died.
I want to report that by my own experience this is a serious matter for long distance bikers also.
I just completed a training program in Florida where I biked 100 miles/day for about 23 days.
The water consumption exceeded 2 liters/hour. I balanced water consumption with sport drinks because of a very bad experience one year ago. (BTW: Healthy kidneys can process 1.0 liter/hour)
I trained 100 miles on a hydraulic trainer for six hours and consumed 12 bottles of water plus food.
I was puking much of the following night and found out later that I could have died from that.
(See Google under water poisoning)
Many of us do not like sport drinks because they are bad for teeth and waistline and cost money.
However, this is serious stuff.