Pacific Southwest Research Station

Research Topics Water and Watersheds

Kings River Experimental Watersheds (KREW)

Stream Discharge

Stream discharge is probably the most fundamental hydrologic measurement of watershed studies (Gore 1996). Variation in discharge is a factor that can interact with all components of the watershed ecosystem. Management activities, such as logging and prescribed fire, undoubtedly have the potential to alter discharge on a watershed, so accurate, thorough discharge data are a priority for KREW. Parshall-Montana flumes have been installed on KREW study sites to measure stream discharge. Each watershed, except Teakettle, contains one small flume that measures flow throughout most of the year, and one large flume that is used during high-flow events, such as heavy rainstorms. Flow levels are measured at the small flume using an ISCO® 730 Bubbler that records water height and relays the data to a logger located in a shed on the stream bank. Data are downloaded periodically in the field, or via telemetry, from the Fresno office. In addition, Aquarods® are installed at each flume as a backup flow measurement for the small flume and the only measurement for the large flume. Data from the Aquarods are retrieved manually in the field, as they cannot communicate with the data logger. More detailed descriptions of the instrumentation and their selection process can be found in the KREW Study Plan (Hunsaker et al. 2004). The historic wier at the Teakettle stream was rennovated and retrofitted with the same measurement instruments.

References:

Gore, J.A. 1996. Discharge Measurements and Streamflow Analysis. In: Haurer F.R. and G.A. Lamberti. Methods in Stream Ecology. pp 53. Academic Press.