Streamflow from selected small watersheds has been continuously monitored at the HJ Andrews Experimental Forest since November 1952. The objectives of this research and monitoring include: (1) evaluate long-term changes in hydrology associated with various forest management treatments, notably clearcut logging, selective logging, and burning of predominantly Douglas-fir conifer forests; (2) characterize the hydrologic regimes and evaluate mechanisms influencing water availability from conifer forests; and (3) provide baseline data for affiliated precipitation and stream water chemistry and sediment transport studies. In addition to stage heights and discharge, data on stream chemistry, stream and air temperature, specific conductivity are collected at the stream gages. Models have also been extensively calibrated with these data to characterize the hydrologic regimes of forests at different elevations and following forest management. Many other studies within the watersheds also use these hydrology data.
The original design for the first- and second-order small watersheds used a paired watershed technique to evaluate changes in streamflow following forest management and harvest in conifer forests. A reference watershed remained unharvested within each set (Andrews WS 1, 2, 3; WS 6, 7, 8; and WS 9, 10). Watershed details and treatments are described at https://andrewsforest.oregonstate.edu/research/infrastructure/watersheds and in the 'Gaged watershed description' PDF in Related Materials/Files. Mack Creek is a third-order watershed where the reference was upstream of the harvested section. The fifth-order Lookout Creek has a gage maintained by US Geological Survey. Early discharge data from Lookout Creek gage, including for the period when USFS maintained the gage, are available here. Measurements of stream stage heights are recorded in feet and streamflow data are available in units of cubic feet per second (cfs). Discharge is calculated using rating curves that have been developed over time. Rating curves and flow calculations are also available in PDF in Related Materials/Files. Data are currently recorded at five-minute intervals. Interpolations of older data originally collected at longer-time steps are available in entity 5 below.
Raw instantaneous streamflow data in cubic feet per second (cfs) and mean flow at fine temporal intervals are available. Rating curves for fixed trapezoidal flumes are maintained for all small watersheds except Lookout Creek and allow calculation of mean and total flow. The USGS-maintained Lookout Creek relies on annual rating table development to reflect changes in the open channel for instantaneous flow calculation. Entity 1 includes a reconstructed history of USGS Lookout Creek hourly data beginning in 1950 and more recently 30 and 15 minute interval data. Calculated mean cfs and total flow for each watershed are available at daily (Entity 2), monthly (Entity 3), annual (Entity 4), and stream sampling (Entity 6) time intervals. An interactive program, FLOW (Entity 5), allows the user to download instantaneous, mean and total flow at requested time periods (e.g., 5 minute, 15 minute, hourly) for all watersheds except for Lookout Creek.
Adam M Kennedy, Alfred B. Levno, Benjamin E. Nash, Craig Creel, David A. Post, Donald L. Henshaw, Gordon E. Grant, Greg Downing, Jack S. Rothacher, Julia A. Jones, R. Dennis Harr, Richard L. Fredriksen, Sherri L. Johnson, Steven M. Wondzell, Suzanne M. Remillard
Discharge from sets of adjacent small watersheds with conifer forests has been monitored to examine changes in streamflow following forest management with one experimental watershed in each set (Andrews WS 1, 2, 3; WS 6, 7, 8; and WS 9, 10) serving as a reference watershed. Undisturbed watersheds with old- growth forests are WS 2, WS 8, WS 9, and Mack Creek. Additional objectives include providing data for affiliated nutrient, water chemistry, and sediment transport studies, and more recently studies of aquatic biota hyporheic dynamics, forest succession and ecophysiology. Discharge in larger watersheds of Mack Creek and Lookout Creek are also gaged within the HJ Andrews Experimental Forest. Lookout Creek gage is maintained by USGS.