If we use only a few verticals, we could miss the high-velocity band of water, and our discharge measurement will be too low. Using at least 20 verticals gives us a good chance of getting a measurement in the high velocity area and therefore having a more accurate measurement of discharge.

Less than 20 verticals can be used, but at the expense of accuracy.

If a stream is 30 meters wide, and we want to compute discharge in a stream using 20 verticals, how many meters wide would each vertical be? meters