Bulk samples of streambed sediment were collected from two reaches of the lower Merced River in California's Central Valley to support research intended to evaluate the extent to which large-scale restoration projects provided improved salmon spawning habitat. A related goal of this study was to improve our understanding of the geomorphic factors influencing spawning site selection by salmon. The bulk samples were acquired during the summer of 2016 at the Merced River Ranch and Robinson Reach field sites using a McNeil sampler [McNeil and Ahnell, 1964]. Before collecting each sample, the surface layer was removed to avoid including surface grains as part of the sample. Surface material was scraped off to a depth equal to the diameter of the largest particle found on the surface. The subsurface material was collected to a depth of 0.3 m and grain size distribution data were obtained by running the bulk sample through a series of sieves with screens ranging from 0.063 - 128 mm [Bunte and Abt, 2001]. We used existing bulk sample data of the initial sediment stockpile of the Robinson Reach, which was collected by California Department of Water Resources in 2002 [CADWR, 2005]. Additional bulk sample data were collected during the summer of 2016 at the Merced River Ranch and Robinson Reach field sites. References Bunte, K., and S. R. Abt (2001), Sampling surface and subsurface particle-size distributions in wadable gravel- and cobble-bed streams for analyses in sediment transport, hydraulics, and streambed monitoring, Gen. Tech. Rep. RMRS-GTR-74,113, Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, 428 p. CADWR (2005), The Merced River Salmon Habitat Enhancement Project: Robinson Reach Phase III, 159 pp., California Department of Water Resources, San Joaquin District, Fresno, CA. McNeil, W. J., and W. H. Ahnell (1964), Success of pink salmon spawning relative to size of spawning bed materials, U.S. Fish and Wildlife Service, Special Scientific Report – Fisheries 469, Washington, D.C.

Bulk samples of streambed sediment were collected from two reaches of the lower Merced River in California's Central Valley to support research intended to evaluate the extent to which large-scale restoration projects provided improved salmon spawning habitat. A related goal of this study was to improve our understanding of the geomorphic factors influencing spawning site selection by salmon. The bulk samples were acquired during the summer of 2016 at the Merced River Ranch and Robinson Reach field sites using a McNeil sampler [McNeil and Ahnell, 1964]. Before collecting each sample, the surface layer was removed to avoid including surface grains as part of the sample. Surface material was scraped off to a depth equal to the diameter of the largest particle found on the surface. The subsurface material was collected to a depth of 0.3 m and grain size distribution data were obtained by running the bulk sample through a series of sieves with screens ranging from 0.063 - 128 mm [Bunte and Abt, 2001]. We used existing bulk sample data of the initial sediment stockpile of the Robinson Reach, which was collected by California Department of Water Resources in 2002 [CADWR, 2005]. Additional bulk sample data were collected during the summer of 2016 at the Merced River Ranch and Robinson Reach field sites. References Bunte, K., and S. R. Abt (2001), Sampling surface and subsurface particle-size distributions in wadable gravel- and cobble-bed streams for analyses in sediment transport, hydraulics, and streambed monitoring, Gen. Tech. Rep. RMRS-GTR-74,113, Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, 428 p. CADWR (2005), The Merced River Salmon Habitat Enhancement Project: Robinson Reach Phase III, 159 pp., California Department of Water Resources, San Joaquin District, Fresno, CA. McNeil, W. J., and W. H. Ahnell (1964), Success of pink salmon spawning relative to size of spawning bed materials, U.S. Fish and Wildlife Service, Special Scientific Report – Fisheries 469, Washington, D.C.

Dr. Richard Janda of the USGS began a channel monitoring program in Redwood Creek in northern coastal California in 1973. The USGS continued this work through 2013, when the Research Geologist, Dr. Mary Madej retired. This effort produced 40 years of channel change data in rivers that were disrupted by severe erosion following timber harvest of old-growth redwood forests, a portion of the program's data (plus 1953 data) has been preserved in this data release. Original field surveys documented bank erosion, aggradation, and degradation at 60 cross-sectional transects at annual or biannual timesteps. Three river reaches also have long-term longitudinal channel bed surveys which document the distribution and development of pool channel features and other aquatic habitat units. Preserved survey data are provided in CSV format on the Cross Sectional Data and Longitudinal Profile Data ScienceBase child items, along with respective metadata records. Project level metadata and supplementary materials are available on the main ScienceBase page.

Field measurements of saturated hydraulic conductivity were used to characterize the streambed permeability for two reaches of the lower Merced River in California's Central Valley to support research intended to evaluate the extent to which large-scale restoration projects provided improved salmon spawning habitat. A related goal of this study was to improve our understanding of the geomorphic factors influencing spawning site selection by salmon. Saturated hydraulic conductivity, denoted by K, was measured with a backpack permeameter and modified Mark VI groundwater standpipe using the constant head method of Terhune [1958]. For each reach, permeameter measurements were collected at ten sites spanning a single pool-riffle transition.

This data release provides updated borehole information to build upon and further refine a three-dimensional (3-D) texture model of valley-fill deposits in the Central Valley created by Faunt and others (2009). This model aids in understanding the aquifer system of the entire valley and will be later utilized in a groundwater flow model. The original database contained approximately 8,500 boreholes and with the addition of new data, the model now contains 14,683 boreholes. The new borehole lithologic data was sourced from the California Department of Water Resources (DWR) Online System of Well Completion Reports (OSWCR) and the California Central Valley Groundwater-Surface Water Simulation Model (C2VSim). This dataset contains (1) tabular data of individual borehole general location and construction information, (2) downhole lithologic interval data derived from well driller’s lithology logs and parsed to a series of textural descriptors.

This data release provides updated borehole information to build upon and further refine a three-dimensional (3-D) texture model of valley-fill deposits in the Central Valley created by Faunt and others (2009). This model aids in understanding the aquifer system of the entire valley and will be later utilized in a groundwater flow model. The original database contained approximately 8,500 boreholes and with the addition of new data, the model now contains 14,683 boreholes. The new borehole lithologic data was sourced from the California Department of Water Resources (DWR) Online System of Well Completion Reports (OSWCR) and the California Central Valley Groundwater-Surface Water Simulation Model (C2VSim). This dataset contains (1) tabular data of individual borehole general location and construction information, (2) downhole lithologic interval data derived from well driller’s lithology logs and parsed to a series of textural descriptors.

The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S. Fish and Wildlife Service, the USGS and University of Oregon conducted a study to evaluate channel and floodplain processes for the 131 km of the Sprague River and its major tributaries, including the lower 20 km of the South Fork Sprague River, the lower 16 km of the North Fork Sprague River, and the lower 62 km of the Sycan River. The study involved multiple analyses, including assessments of historical channel change, riparian and floodplain vegetation, and surficial geology. To support these analyses, digital floodplain and channel maps were prepared from historic notes, maps, and aerial photos to depict channel and floodplain conditions at different times between 1866 and 2005. The geospatial database of current and historic channel and floodplain conditions will also enable evaluation of long-term trends pertaining to aquatic and riparian habitat conditions.

The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S. Fish and Wildlife Service, the USGS and University of Oregon conducted a study to evaluate channel and floodplain processes for the 131 km of the Sprague River and its major tributaries, including the lower 20 km of the South Fork Sprague River, the lower 16 km of the North Fork Sprague River, and the lower 62 km of the Sycan River. The study involved multiple analyses, including assessments of historical channel change, riparian and floodplain vegetation, and surficial geology. To support these analyses, digital floodplain and channel maps were prepared from historic notes, maps, and aerial photos to depict channel and floodplain conditions at different times between 1866 and 2005. The geospatial database of current and historic channel and floodplain conditions will also enable evaluation of long-term trends pertaining to aquatic and riparian habitat conditions.

This digital dataset includes three sets of observational data (groundwater level, streamflow, subsidence) used to calibrate the updated Central Valley Hydrologic Model (CVHM2). CVHM2 is a tool that can be used to quantify the sustainability of groundwater resources in the Central Valley.

This digital dataset includes three sets of observational data (groundwater level, streamflow, subsidence) used to calibrate the updated Central Valley Hydrologic Model (CVHM2). CVHM2 is a tool that can be used to quantify the sustainability of groundwater resources in the Central Valley.