Cam is dipping a grilled cheese sandwich into a bowl of tomato soup when he feels the summons. He goes ahead and grabs it. Doesn't even drop the sandwich.
"We're nowhere near the ocean. Tidecatchers may be impractical, and also be in other cities' territory where they can do what they like to them. Is anything involved in the surveying other than flying over it and making maps, possibly with a telescope or other detecting things?"
"I will have to estimate the capacity and speed of the river. Other than that, that's basically it."
"I'd like to come along. Are you going to use a vehicle?"
"Then I will fly with you and attempt to practice Italian, as long as you don't mind."
"Hmmmm," says Cam, "sure, let me just think." A few minutes later he makes a small black rectangle, which then lights up - "Put your thumb on it so it won't wake up if anyone else touches it, and then I think it should be straightforward from there - just poke whatever it looks like you want it to do or show you, and instead of turning pages you slide your finger from the bottom to the top of the screen and the text moves along with you."
She tries it out. It's pretty intuitive, though all the labels are Italian. She opens a book-reading program, and then opens a book. "Thank you. Is it fine if I ask you 'what does this word mean' some?"
She puts the shiny new computer in a pocket, then knocks over a box with one of her wings while turning around. After hovering it back into place, she heads out the front door and flies. "This way to the river."
It takes about half an hour to reach the southernmost part of the river that is still in Opri's territory. Steel turns north after that.
River. What an interesting river. Cam flies low enough to see if there's anything that shouldn't be underwater in the canyon.
"That's the old water station. They would literally fill huge tubs and levitate them from here to the city. I like my way much better."
"Someone might be squatting, but no, not this one. There's another station with real pumps at the top of the canyon a few more minutes up. That's where we get any river water we use these days."
"Okay." Cam makes a note to chase out any squatters in the old water station. "Where's the source of this river?"
"A series of springs forming tributaries in the highlands about two hundred mules north-east. Two cities draw from the springs, Lehr and Knip. Nobody else between Opri and the source draws from the river proper."
"Okay. I'm gonna go up high and get a topology snapshot - don't follow me, I'll be making my own air when it gets thin but it's hard to do that for someone else without tripping them up - and run some programs, see where it'll naturally drain if the river rises and if I need to change that by dynamiting something, etcetera. Forty-five minutes tops."
"I'll determine the presence or absence of our water station squatter, then fly circles around the bridge. See you in a bit."
Cam goes up. He takes pictures and lets his computer assemble them into a topographical map and proposes to a different program that he could put a dam here or there or wherever and plugs in Steel's figures for the water volume. He finds where it's going to drain, overflies the area edge to edge to edge and finds nothing more than wildflowers, and then goes to catch up with Steel - for higher confidence in his software results he needs to know how much it rains around here and upstream, but he's almost ready.
"There are no squatters in the old place. There were a few old files, but nothing important, I burned them. I'd say just let it flood. As to rainfall figures..." She digs through a notebook from her backpack. "Here we go. These are for the local area. Unfortunately I don't have any for prefecture 6, where the springs are."
"Would you expect it to be more than..." He plugs in the figures and his computer spits out results. "...fifteen percent greater per year or thirty in any given month?"
"Probably not... We both get the same weather patterns for the most part, there's no really major geography between here and there to change it up."