In reply to Carpe Diem: are you going with a Guiding Company? If so, everything will be taken care of. Even if not, the local guides and porters that you are obliged to hire will ensure you have more than enough water. There are also many streams to collect water from for the first 3 or 4 days.
Do not worry about the negative comment about a stampede. It would be interesting to know when, whether and which route the commentator took. The Rongai route will be much quiter than an EBC trek.
Enjoy. It will be a great experience.
If you want more detailed and constructive information, you are welcome to contact me.