In Massachusetts, there was an effort, back in 1982, to inventory all the streams listed on the USGS maps, and assign numbers to them for later reference. This was called the “Stream and River Inventory System” (SARIS). It listed 2,027 rivers and streams. I’ve been going thru it and making sure they are on OSM (and adding the reference numbers).
I’ve currently done 312, and I just wanted to tell others about it.
Now finished the first 4 river basins – the three in Hudson, and the (large) Housatonic! A total of 248 codes (some of which weren’t drawn in yet, so I left notes about them).
(edit: To clarify – I previously did a bunch of the larger or more uniquely named rivers across the state, which is why there are 370 total tagged as of now. The 248 are the ones where I’ve checked whether they are already mapped and added notes if they aren’t.)