"Global racing program paying off for Team Illuminate" -Cyclingnews.com, Dec 2017

COLOMBIA; Bottle duty
For a race like Oro y Paz, with 6 riders, the team will probably go through ~400 bottles over the course of the race. In terms of calculating, you have to figure the race itself is 6-days and all the riders are arriving 3-days before the start. Now, keep in mind, the riders are always going to be asking for bottles. So from the moment the event starts your bottle count is going down. Now at an event like Oro y Paz in Colombia you also have to take into factor the fans and they all want bottles too! So while 400 bottles may seem like a lot at first, once you break it down the bottles go quickly! 
( 400 Bottles / 6 Riders ) / 6 days = ~11 bottles a day per rider
 When preparing the bottles before the race, we know that with 6 riders, we will need 12 bottles to put on the 6 bikes for the start of the race. Usually we make this first round of bottles really strong. There isn't really a proven science behind this, more just that the riders seem to like the first bottles being extra strong.
When we talk as a team before the start of the race, it is often determined who will be on "bottle duty" on that day. While this might not seem like the most glamorous role, it is a really important one because keeping the team hydrated can play a major factor, especially during a multi-day event. The riders realize the importance of this role and often take pride in being able to bring a selection of drinks and nutrition up to their teammates during the race.
While the water-boy position might be assigned to a rookie in some sport, in cycling often the most experience riders on the team will be assigned to bottle duty. Being smart about the timing about when to go back for bottles can be critical and that is why the role is often given to a veteran within the team. The last thing you want to do is go back to the team cars at a bad time in the race, when the pack is splitting up or when a cross wind is starting. Being smart about the timing can be critical and that is why the role is often given to a veteran within the team. When a rider comes back for bottles, we also use this time to communicate with them about the race. Getting information to the riders can be important and it is also good for us to hear from the riders about what is going on in the pack. 
Words; Chris Johnson
Photos; Ethan Glading