River Volume
If you have ever been considering going kayaking at a river you have probably checked a guide to the river and some flow gauges to make sure the river is running at a good safe level. The guides always say something like cubic feet per second or CFS. Well what is cubic feet per second?
Cubic Feet per second is best put as a measure of the amount of water that is coming through a given area on a river in one second. There is a much more complicated formula for this that concerns river velocity not only the volume of the river but it is way to complicated for this basic definition. So when you are measuring cubic feet per second, don't only think about the volume of the river, but also the speed of the river.
When you are kayaking it is important to understand that changes in volume or velocity can make a huge differences on a river. Depending on the river, going up or down by just a few cubic feet per second can make differences of night and day on a river. You should keep this in mind and consult with local experts before running any unfamiliar rivers.
As a general guideline you can tell how large a river is going to be based on the cubic feet per second rating. Although there is more to CFS than just volume, it is more or less an accurate gauge of the river size. A small river such as a creek or stream is going to have a volume of somewhere in the hundreds up to around 1000 Cubic feet per second. A Medium sized river will have somewhere between 1000 and 9000 cubic feet per second while a big river is going to be over 10,000 cubic feet per second. There are some incredibly large rivers that have over 100,000 cubic feet a second.