Around the world, there are naturally occurring waterways with various physical properties. Because of the large diversity and the subtle differences, there are many different terms for different types of waterways. Three that are often used to describe a similar waterway are river, stream and creek. To further confuse the matter, there are no official definitions for each term that would distinguish between them.[i] However, generally speaking, they do have some differences between them though.
The most commonly cited difference between the terms is in reference to their size. A river is a naturally flowing waterway that usually contains freshwater and will typically flow into an ocean, sea, lake or combine with another river. Rivers typically describe waterways with a relatively strong current and are often large enough to pose a threat or disruption toward human activity if they are unmanaged. For this reason, most rivers in the world have man-made features such as dams, weirs, levees, canals, or other sluice mechanisms. This prevents flooding that can be catastrophic when experience on a large scale. The flow of water in rivers is one aspect of hydrology and the volumetric flow rate is often calculated. While there is no official rate that distinguishes a river from either a creek or a stream, the term would typically be used to classify waterways with a much higher volumetric flow rate.[ii]
Creeks and streams are terms used for waterways that are much smaller than a river. However, the difference between these two is much more subtle. They both refer to a body of water that may have a current (usually much gentler than a river current). Other terms for a creek or stream that are commonly used in different geographical areas are bayou, beck, branch, brook, crick, ghyll, fill, kill, lick, mill race, race, fill, rivulet, run, runnel, streamage, syke, or wash.[iii] The volumetric rate flow for a creek or stream would typically be smaller than that of a true river. When looking at the distinction between a creek and a stream, it is important to realize that a creek is a type of stream and therefore, all creaks are considered to also be streams, but not all streams are creeks. Streams vary in size from streamlets, to brooks, to creeks and eventually if large enough, they eventually become rivers. In North America, New Zealand, and Australia, creeks refer to a small or medium stream or a tributary of a river. The definition for stream, on the other hand, is that it is a linear flowing body of water on Earth’s surface.[iv] Based on this definition, a river would also be considered a stream, technically. However, in typical conversation, a stream would be considered smaller than a river.
A river will begin at a source, or several sources, such as melting ice masses, glaciers, underground streams, or even from rain and snow in high altitudes.[v] Rivers follow a path that ends at the mouth. Larger rivers will also contain a floodplain. They can pass down mountains, through valleys and along plains. Long-lasting rivers may eventually create canyons or gorges. There are also subterranean rivers that flow underground within caves or caverns. When this happens at the beds of glaciers and ice sheets, it is called a subglacial stream.[vi]
Streams and creeks typically get most of their precipitation from rain and snow when runoff starts to concentrate in a channel. Creeks will typically not have any branches, but rather usually exist as a branch of a river.[vii]
Rivers are generally considered a rather permanent geological feature. While some can flow occasionally, then be dry for up to years at a time, the fact that they re-appear when the precipitation is present still distinguishes them as a permanent waterway. Rivers also have a larg ecosystem, including many diverse plants and animals. In some instances, flooding is a natural part of a river’s cycle. Rivers typically flow downhill due to gravity, which means that their path can be long and winding.[viii]
Smaller streams and creeks can be recurring meaning that they only have water in their channel for part of the year or they can be perennial. Ephemeral streams describe streams that flow only during and immediately after precipitation. Intermittent streams, or seasonal streams, only flow for part of the year.[ix]
Because of their much larger size, rivers play a very important role in human civilization and everyday life. Since very early in human history, groups formed along river banks simply because they can provide many of the necessities for life, including water and food. Water is essential for consumption and irrigation for agriculture and fish and other edible aquatic life are a rich source of nutrients. In addition to this, rivers have been used for water navigation since around 3300 BC. Their strong currents mean that they are an effective and cheap transportation method. In larger rivers with strong current, hydroelectric power is often common. Rivers also serve an important function in global politics as they commonly determine political and national boundaries.[x]
Streams, and especially small ones such as a creek, play a much lesser importance. Some will have aquatic life, but the ecosystem may be less diverse than what could be found in a larger river. They may also be used for transportation, as many of them flow directly into a larger river. However, you will see that civilizations prefer to form along much larger, more permanent waterways.