Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:3659416.
These models were created with the generous support of my patrons on Patreon. You can join the fun at patreon.com/sablebadger to get advance access, free models, and support a quickly growing collection of tabletop models. Higher tiers can also participate in polling, and suggest future projects.
I needed a river for my tabletop wargame, so I created what I am calling "Stonebank River" which is a modular magentized river you can print and create all sorts of layouts with. The sections print quickly and the 5mm sphere magnets are easy to get ahold of as they are the common desktop fidget toy size. The tray slides in and friction fits, but you can secure them with a drop of super glue if you wanted.
The river is modeled after streams and rivers I hung around when I was kid with smooth round stones all around. I included a number of arcs and a Y section for making all kinds of arrangements.
If you'd like to purchase a print of this, you can check here are FunBoardGames on Etsy who is the only authorized vendor of these printed models. etsy.com/shop/FunBoardGames If the models aren't up on his site just shoot him an email with a request, he is usually pretty quick to respond.
EDIT: added a version of the insert with a slightly larger hole.