In this video, we explain how to assemble and use our flowmeter to measure the velocity (speed) of water in a stream or river. By taking several velocity measurements at different points and depths in a stream, it's possible to calculate an average velocity, and from this the flow rate. The flowmeter in this video is a Valeport Model X which was kindly gifted to JBA Trust by the Canal and River Trust. It's an impeller device which means it works by counting the number of revolutions of the yellow impeller over a fixed time period. We hope you find the video helpful, if you would like to borrow the flowmeter to support research or education, please get in touch!