Slide 12 of 75
Notes:
In addition to the increase in flood peaks and peak discharge, the frequency of bankfull flows also increases with increased urbanization. Bankfull flows are simply runoff events that fill the normal channel of a stream to the top of the banks. Bankfull flows are significant because they are the channel forming flow condition in a stream and they are highly erosive, turbid, and damaging to the natural morphology of the stream.
Bankfull flooding (or the condition of the flow that "fills up" the channel) occurs much more frequently in highly urbanized areas and has the potential to be extremely erosive and damaging to the natural morphology of the stream.