Are you wondering how much water is available? Â Here are some pointers to help you check and compute stream flow:
- Â Select a straight run in the stream.
- Â Make several measurements of the depth of the stream to get an average depth.
- Â Measure the width of the stream. Â If the width is not uniform for the run, take several readings to determine the average width.
- Â Customary Example: Â if your stream is 4′ wide and has an average depth of 6″ then (4 feet x 6 inches)/12 inches per foot = 2 square feet.
- Â Determine the average speed of the stream flow
- Â Mark and measure the length of the run to be checked.
- Â Drop a float into the stream and record the time to travel 100 feet.
-  If the float takes 2.1 minutes to travel 100 feet, the surface of the stream is flowing at a rate of 100 feet per 2.1 minutes = 47.6 feet per  minute.
- Â In summary, 2 square feet x 47.6 feet per minute = 95 cubic feet per minute (indicated flow).
- Â A factor of .8 times the indicated speed of flow is used to get the average velocity. Â This takes into consideration the water along the banks being slower thank in the center.
- Â 95 cubic feet per minute x .8 factor = 76 cubic feet per minute x 7.40 gallons per feet factor = 562 gallons per minute.
- Â If it is evident there is not enough water to meet your needs, check other possible water sources.