Growing up on the farm Dad had a free-ranging flock of one rooster, 25 to 30 hens, and had different groups of chicks growing up. They did not stay in one flock, they really spread out. The only consistent source of water was the farm pond where the cattle and horses also drank. They never died of thirst, even in our ridiculous heat waves. As long as they know where it is I'd expect your 11-week-old chicks to return for water when they need it.
I live in Mesa, Arizona. We let our chickens roam the yard during the summer because there are areas they like to go to cool down. They have their water and feeder in the coop. We also put an extra water dish in the coop, one in the rose bush area, and one in our tropical garden area. We clean them out in the morning and the afternoon. We'll also put a frozen water bottle in each water dish in the afternoon. At night we'll bring in the bottles and put them back on the freezer. We also have a drip system in their chicken run and tropical garden that comes on at least 2-4 times a day, depending on the heat. We also have a fan in their nesting area, two in the coop, and a small one in our little silkie nesting area. It's a lot of work and trust me, once you start doing it, you won't forget the other water dishes. It just becomes a habit. FYI, They love it when the drip system comes on.
One of their favorite hangout spots is fairly close to the house, so I went ahead and put some water close to it (but still in the shade and they have found it!) I think between the two it should be enough as they stay fairly close to coop and house vs open hay field. It should be easy enough to remember and as you said routine.
