Whether you are planning a float trip, a fishing guide, a kayaker, a bank bound fisherman or a property owner monitoring a rising river, a river gage is an important piece of information. It may be a large measuring stick affixed to a bridge support that measures the rising waters or more sophisticated gages that measure height and CFS (Cubic Feet per Second). NOAA has such gages across the U.S. I am sure other countries have similar systems as a means of monitory flows. Become familiar with these systems for safety or whether a planned trip should be canceled due to projected blow outs of a river system. A helpful suggestion: keep a journal or note somehow the fishable/floatable levels. Note when the river is blown out and note those levels. Note the historic floods and what is considered flood stage. Home Page NOAA. There are other excellent NW resources too: USGS Gages & Westfly.