Small Hydro turbine to measure flow

1 cubic foot = 7.481 gallons
1 cubic meter = 35.31 cubic feet
1 cubic meter = 1,000 liters
Measuring Flow
The second major step in evaluating your site’s hydro potential is measuring the flow of the stream. Stream levels change through the seasons, so it is important to measure flow at various times of the year. If this is not possible, attempt to determine various annual flows by discussing the stream with a neighbor, or finding U.S. Geological Survey flow data for your stream or a nearby larger stream. Also keep in mind that fish, birds, plants, and other living things rely on your stream for survival. Never use all of the stream’s water for your hydro system.
Flow is typically expressed as volume per second or minute. Common examples are gallons or liters per second(orminute),and cubic feet or cubic meters per second(orminute).Each can be easily converted to another,as follows:
1 cubic foot = 7.481 gallons
1 cubic meter = 35.31 cubic feet
1 cubic meter = 1,000 liters
Three popular methods are used for measuring flow—container, float, and weir. Each will be described in detail below.
Container Fill Method
The container fill method is the most common method for determining flow in micro hydro systems.Find a location along the stream where all the water can be caught in a bucket.If such as pot doesn’t exist,build a temporary dam that forces all of the water to flow through a single outlet.Using a bucket or larger container of a known volume,use a stopwatch to time how long it takes to fill the container. Then divide the container size by the number of seconds.
For example, if your container is a 5-gallon paint bucket and it takes 8 seconds to fill, your flow is 0.625 gallons per second (gps) or 37.5 gallons per minute (gpm).