You need gutters. It always amazes me how many people don't get gutters. They're crucial for many reasons - The most immediate is keeping the water off the walls/windows/deck. But also, consider the foundation after years of water runoff.
Consider gutters to be taking the place of the eaves of a house. You wouldn't end the roof just over a wall, right?

I'd like to see more yurt manufacturers focus on that challenge and really encourage buyers to get them. Otherwise, many clients don't know to ask and they're a often best to be installed from the start, as a part of the roofing system. I haven't been thrilled with any of the hard gutters I've seen for the circle. But I keep hoping and they're certainly better than nothing.