Worldbuilding for a series is a tenuous balance between casual references to people, places, concepts, and events that will later be important, and not overwhelming the reader with details that appear (and may in fact be) unimportant to the immediate story. So how prescient does an author need to be to figure out what to mention long before that topic suddenly needs to have been clearly established long before? Part of the answer is that, unless that full outline of a series is known before you start writing, it is exactly those "unimportant" casual worldbuilding details that then inspire future story ideas. In Floodtide, the profession of riverman is a major presence. Liv follows that family trade, and her familiarity with the "water roads" through Rotenek is key to several plot points. Further, we see how water transit is a constant, if often unnoticed, presence in the city. Did I know how important it was going to be so I could set up the reader's knowledge in advance? Absolutely not! So let's look at how the profession of riverman developed through the series so far, such that I could present it as a known fact in Floodtide.
In Daughter of Mystery, when Barbara is attacked on the bridge: “She dodged down the water-steps at the southern end of the parapet to the landing below where the rivermen docked.” She convinces one of them to row her to safety, but he balks at landing her at Tiporsel House, saying, “It’s worth my license to dock there without leave.” And that's it. No mention of regular use of the river for deliveries, no mention at all of the canal system. A slight implication that the rivermen are licensed and organized and that they are bound by certain rules. And an implication that there are regular public landing places where they are availble for hire. But the important reason for introducing rivermen was to give Barbara an escape route.
In contrast to that one lone scene, The Mystic Marriage includes 9 search returns for the string "riverm". (In Daughter of Mystery I alternate between "riverman" and "boatman". At one point I considered standardizing on "waterman". But "boatman" felt like it should be more generic, also applying to those who worked on ships and barges coming up the Rotein from elsewhere. And "waterman" just didn't have the feel I wanted.) The first reference is specifically a worldbuilding pause: Barbara is contemplating her several possible transit options for traveling outside the city down to Urmai in pursuit of a rare book as a present for Margerit. (This of course, is the first clue being planted for Margerit's eventual purchase of property there for her college.)
As she stepped out into the narrow courtyard where the groom was waiting with the horses, Barbara glanced up at the thin afternoon sun. Enough hours of light to get to Urmai and back and enough in between to examine the books Chasteld was said to have on offer if there were no delays. But with Chasteld there was no guarantee. Perhaps it would be better to take the town-chaise instead, despite the delay. No, Bertrut would have taken it already. On a better day she might have considered hailing a riverman to row her downstream. Chasteld’s place had its own frontage and dock on the river. But though the trip down would be swift, it would be slower coming back when there was more chance of rain. Her errand scarcely warranted the trouble of a coach and four, and she preferred to ride in any case.
The next five mentions of the word are all in the context of Antuniet's fevered escape from her nemesis (a somewhat deliberate echo of Barbara's experience in the first book--establishing the river as something of a metaphorical symbol of escape). Like Barbara, she frantically hails a ride so that her pursuers on foot will be foiled. When the riverman discovers she's passed out, he continues downriver to deliver her to a charity hospital outside the city (thereby conveniently taking her out of the story long enough for everyone to be worried).
The rest of the mentions are more background: reference to less well off people hiring a boat to travel up to the Carnival fair in the market grounds; mentioning the calls of the rivermen as part of the background noise of the city--at least for those living along the water; and another casual mention of the public docks when Jeanne entices Antuniet out for a picnic lunch by the river in the heat of the summer.
But The Mystic Marriage talks about other kinds of river traffic: pleasure boats that the more wealthy might hire to host entertainments--the sorts of entertainmens Jeanne has a knack for organizing; the commercial barges that fuel the warehouse district and that prove an attractive hazard for Aukustin's dreams of adventure. Still no mention of the importance of the canal system in Rotenek, though I do mention one nouveau riche family that made their money by investing in canals. But these would be the longer transport canals just being expanded through the countryside that become a bone of personal and political contention in Mother of Souls.
So let's move on to Mother of Souls. Now we have 21 returns for the search string "riverm." We get a better sense that boat transit is viewed as a cheaper alternative to either owning or hiring a carriage. Though, of course, it's only useful if you can get where you're going by water, but especially when traveling along the length of the Rotein. Or if you want the discretion of not arriving somewhere in a personal and clearly identifiable carriage! That's the reason Barbara gives for taking Margerit down to the old Chasteld place by boat for the purpose of claiming first dibs on the late Chasteld's library of esoteric books. (Margerit, of course, ends up buying the entire property instead.)
But now we also get mention of the chanulezes--the canal system. We can use the excuse that they only exist in the lower and flatter parts of the city--the south side and the western area around the Nikuleplaiz--and further that the residents of Tiporsel House do have private carriages and riding horses to get around casually. There are other good excuses for not having mentioned the transit importance of the chanulezes in previous books: Jeanne lives in a part of town with the wrong geography for canals, and Antuniet for the most part was on too strict a budget to opt out of walking (though, in retrospect, her original workshop was definitely in an area where the rivermen must have plied their trade). But Luzie's house is only half a block from a chanulez and she's right at the economic break-point where hiring a riverman is an occasional convenience, but hiring a fiacre is too much of a luxury.
Of course, in Floodtide, introducing and exploring the chanulezes is a vital plot point with regard to the failure of the Rotein to flood as expected. In Mother of Souls we get regular references to the low water levels in the chanulezes, both interfering with transit availability and exposing the foul-smelling sediments that collect when not scoured away regularly. (Although I never mention it in detail, I do have an epidemiological model for why significant flooding after years of low water creates a risk of river fever epidemics. It was important to me to have that model, but it wasn't important to bring it into the plot. We haven't yet gotten to the era of germ theory, and "caused by stirring up the stinking mud in the chanulezes" is the most appropriate level of understanding for my characters.)
The chanulezes get to feature in the "bookends" for Mother of Souls as part of the interconnected water system that stars in the magically-inhibited snowpack of the Alps:
High in the mountains to the east and south of Alpennia, spring rains and warming winds wash the winter’s snow from the peaks and send it tumbling down the valleys. The melt gathers in rivulets; rivulets turn to streams; streams feed rivers. The Esikon, the Tupe and the Innek swell the Rotein, which flows through the heart of the city of Rotenek. And the city flows through the Rotein: in barges bringing goods up from French ports, in riverboats rowing passengers along the banks and up the narrow chanulezes that thread through the neighborhoods of both the upper and lower town.
And all of that preceding information then sets us up to understand both the ordinaryness and the importance of the rivermen that winds through Floodtide in exactly the way the chanulezes wind through the city. Roz--as mentioned in last week's teaser--is the ideal point of view to expand that understanding because she's still figuring out that aspect of Rotenek life for herself, as we see here:
* * *
The garden sloped down from the back of the house to the river. You could enjoy watching the birds skim over the water and listening to the whistles and shouts of the rivermen. Sometimes one of the family would send word down to hail a riverman and then I could see them pass by in all their fine clothes to be handed into the boat and rowed off somewhere. Once Charsintek wanted me to bring a delivery back from the Nikuleplaiz and gave me a coin for a ride. But most times when a boat came to the dock, it was the kitchen delivery from the market out past the east gate. Every morning Cook or her assistant took a hired fiacre off to the market and sent the baskets back by the river. It was like a second set of roads. There’d be a sharp whistle up from the dock and Cook would send whoever was idling about down to fetch things up. Sometimes the riverman would help carry baskets too, just for the extra teneir, or to get the boat unloaded more quickly.