On a road trip through the Pacific Northwest, two travelers crossed running water with names that included “river,” “stream,” “creek,” and “brook.” Especially in the West, undergoing a historic drought, some “rivers” looked like what most people might call “trickles.” Which prompted the question: When does one become another? What criteria determines what is a “river,” or a “rivulet”? What’s the difference between a “brook” and a “stream”?
It’s all water under the bridge.
From an official standpoint, the United States Geological Survey says any flowing water is a “stream.” Its definition doesn’t mention size, flow, distance, or anything else that might help you decide what to call something
At least 121 other generic terms fit this broad category, including creeks and rivers. Observers might contend that a creek must flow into a river, but such hierarchies do not exist in the Nation’s namescape. Near the USGS offices in Northern Virginia, Little River flows into Goose Creek.
How many of those 121 generic terms do you know?
But a posting on the USGS Water Science School site takes the path that many might take: “I tend to think of creeks as the smallest of the three, with streams being in the middle, and rivers being the largest.”
The USGS education site also defines a “river” as “A natural stream of water of considerable volume, larger than a brook or creek.” But it doesn’t define “brook” or “creek.”
Not all rivers are truly rivers: Take the East River in New York City, for example. Some say that it is an “estuary,” but the USGS defines that as “a place where fresh and salt water mix, such as a bay, salt marsh, or where a river enters an ocean.” There’s not much fresh water in the East River, which connects Long Island Sound and New York Bay. Others, like Wikipedia, say the East River is a “tidal strait,” which the USGS doesn’t define, but is generally considered to be a narrow body of water affected by tides.
The USGS also has the Geographic Names Information System database, which keeps track of the names of geographic features (duh!). It’s a handy resource if you want to know the proper name of a river, brook, etc. It calls the East River a “channel”: “Linear deep part of a body of water through which the main volume of water flows and is frequently used as a route for watercraft (passage, reach, strait, thoroughfare, throughfare).”
In short, whoever first named a flowing body of water could call it whatever they liked. If you want to use a generic term for that body, tap the one that seems to best fit in the context, or use what people in the area use. And if they say “crick,” think whether that’s just their accented way of saying “creek.”