What the Heck Does CFS Mean?

June 2019

CFS stands for Cubic Feet per Second, and is the main unit used to measure the volume of water passing a given point in a river in once second. The same CFS measurement can look different on different rivers. For example, 400 CFS on the North Platte through North Gate Canyon looks much different than 400 CFS on the Michigan River through the town of Walden. 400 CFS through North Gate Canyon means good wade fishing levels and you will likely be able to completely cross the river at multiple points safely, however it is too skinny to take a raft down without having to jump out and drag it across flatter parts of the river. 400 CFS on the Michigan River through town is raging and likely out of its banks and means you will not be able to safely cross the river at any point. 

Michigan River through town around 400 CFS. Out of its banks, blown, uncrossable.

Understanding CFS also helps to understand where fish will be at in the river at any given time. When there is extremely low flow/CFS, fish will likely be stacked up in a few holes just trying to survive. When you have moderate/average flow fish will be dispersed throughout the river whether thats in the riffles, seams, or under cut banks. When there is extremely high CFS, fish will likely be stacked up on the banks trying to escape the harsh and fast current. 

You can look at up-to-date water flows and CFS levels online to try and get a better gauge on what certain flows look like on different rivers. The best way to really learn and understand CFS and what they look like on different rivers is just to get out on the water. Check the flows before you go out and make mental notes of what the rivers look like.