I'd like to propose that we fill the sewers in Colonia Nova with some sort of swimmable prim water and small waterfall rollers to the extent that it can be done easily and without an extensive use of prims.
The benefit of such an operation would be creating a stream of water in the sim running along an N<->S axis to correspond with the current W<->E axis that is the river. Apart from creating such visual "symmetry" the water would also increase the recreative value of the cloaca, which is currently limited to walking and taking pictures as the area is too narrow to be used as a builders sandbox.
The downside of the operation might be that it would reduce the attractiveness of the termae as a meeting place and thus a spot of commercial viability but on the other hand we never considered the river to have this effect so why should flooding the cloaca be judged negatively by this criterion.
I haven't yet had the chance to measure the extent of the cloaca but I imagine that the project might be implementable using 1 prim per 3 sqm (loose estimate).
If we want to do a quick implementation we could acquire Zora Spoonhammers multi-layered living creek textures with built-in sound and supplement it with one of the swimmable prims such as those made by Siggy Romulus or the new one by Karandas Banjo.
The creek kit is 900L$ for unlimited use and Karandas Banjo's swimmable waterscript is free. Of course into this should be also factored the cost of hiring someone to do the job. I'd be willing to make a stab at it on a pro bono basis if the community believes it's a good idea and someone will be willing to equip me with the relevant group membership.