Water level is measured in the number of cubic feet that pass any point on the river every given second (CFS). The higher the CFS number the quicker the water is moving and the higher the river will flow. The CFS that indicates high water is not universal for all rivers because it depends on the width of the river. THe CFS for Clear Creek will always be lower than the Colorado River, but that does not mean the flows aren't high. Learn more here.