Our stream research team at St. Bonaventure installed this broad-crested weir on a 1st-order stream in order to make continuous measurements of stream flow. An automatic data logger records the depth of water behind the weir wall at 5-minute intervals. These measurements are used to determine the hydrograph of the stream.
We are using the information from this weir for two on-going research projects. The first involves a study of how stream algae respond to rock stability. We have placed 10 sets of marked rocks on the streambed and are mapping their locations after each major storm. At the same time we are measuring algal densities on rocks of different sizes, to find out if algae are more successful on large, more stable rocks. The second project is a long-term study of the adaptations of a stream caddisfly, Pycnopsyche, to both high and low flow conditions.