Measuring how much flows

Getting an accurate cross-section of a small stream can be done with simple equipment. A responsible adult MUST be on hand throughout any field work.

Screen 6/11

Water flow is how much water moves a second.

You need to know the size (area) of the channel with water in. Find the width of the channel using your tape. Then find the average depth of water (see screen 5). Multiply these together.

The water flow is the volume moving each second. Divide the area you have just found by the water speed (see screen 4).