Rapid Classification

Are you curious what “CFS” means — or why the same river can feel totally different from one week to the next? River flow plays a major role in how rapids look, feel, and how difficult they are to navigate.

The six-point rapid rating scale used on the Arkansas River is common worldwide. In general, the higher the class, the more difficult the rapids.

River conditions and ratings can change quickly. Whitewater boating involves risks at all levels.

What is CFS?

CFS stands for Cubic Feet per Second — the standard way we measure how much water is flowing down the river. The higher the CFS, the more water moving downstream each second.

Why rapid ratings change

Rapid difficulty fluctuates as flow levels rise and fall throughout the season. Flows usually start lower in the spring, increase as mountain snow melts, then settle into more moderate levels later in the season. Peak runoff often occurs in late May through early June.

Higher flows usually mean bigger rapids

As flows rise, waves grow, currents speed up, and hazards can change. Some rocks may disappear underwater, while stronger currents and hydraulics can make rapids more powerful — and sometimes more difficult.

If you have questions about current river flows or which trip is best for your group, feel free to contact us — we’re happy to help.