USDA Forest Service

Pacific Southwest Research Station

Pacific Southwest
Research Station

800 Buchanan Street
Albany, CA 94710-0011
(510) 883-8830
United States Department of Agriculture Forest Service. USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.

Research Topics Water and Watersheds

Study explores stream nitrogen concentrations

For the first time, a collaborative study [] has compared water quality trends in forested streams across the country that are largely undisturbed by land use or land cover changes. The study draws on 559 years of stream nitrate and 523 years of stream ammonium data from 22 streams in 7 experimental forests across the country. The study found that even near-pristine forested streams are subject to change.

Southern Sierra Critical Zone Observatory

The Kings River Experimental Watersheds hosts the Southern Sierra Critical Zone Observatory--a National Science Foundation effort to gain a better understanding of the zone of earth where "rock meets life." The critical zone extends from the tops of the trees to the groundwater and covers the entire earth where there is land. Download the video created by a UA Flandrau Science Center team to introduce the motivation and science involved in the National Critical Zone Observatory research program.

Kings River Experimental Watersheds (KREW)

Stream Discharge

Small Flume (Providence 301) measures stream flow throughout the yearStream 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 Large flume (Providence 301) measures high stream flowtelemetry, 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.

Water year 2000 discharge data for four streams

Annual stream discharge divided into four water sources or "casual mechanism"


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.

Last Modified: Jun 21, 2013 08:30:10 PM