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Carl G. Kroll

Publications and source records attributed to Carl G. Kroll.

5 recordsLinked to original sources
USGS1976

Sediment discharge from highway cut-slopes in the Lake Tahoe Basin, California, 1972-74

Streamflow and fluvial-sediment discharge data were collected at selected streams and highway gutters in the Lake Tahoe basin to determine the extent of erosion from highway cuts and to attempt to evaluate the effects of various land-treatment practices to reduce erosion. Estimate of long-term annual total-sediment discharge from six streams into the lake is 7,100 tons (6,400 tonnes), of which 2,300 tons (2,100 tonnes) is finer than 62 micrometres. During 1972-74, snowmelt runoff (April-July) accounted for 65 percent of the water and sediment discharge. Approximately 90 percent of the sediment is transported in suspension. Sediment measured at 16 gutterflow stations at the base of highway cut-slopes indicates that less than 100 tons (91 tonnes) of fine sediment per year are contributed to the lake from all California State highway cuts. Sediment-transport rates are highly variable, and an unknown part of the measured sediment was derived from sources other than highway cuts. Data were not adequate to demonstrate the effectiveness of treatments to stabilize cut-slopes.

Lake Tahoe↗
USGS1975

Estimate of sediment discharges, Santa Ana River at Santa Ana and Santa Maria River at Guadalupe, California

The computed sediment discharge of Santa Ana River at Santa Ana for the water years 1968-71 was 11,700,000 tons (10,600,000 tonnes) of suspended sediment and 5,000,000 tons (4,500,000 tonnes) of coarse sediment. The computed discharge of Santa Maria River at Guadalupe for the water years 1969-71 was 9,500,000 tons (8,600,000 tonnes) of suspended sediment and 6,000,000 tons (5,400,000 tonnes) of coarse sediment. Estimated mean annual coarse-sediment discharge for the 31 water years, 1941-71, is 230,000 tons (209,000 tonnes) in the Santa Ana River and 300,000 tons (272,000 tonnes) in the Santa Maria River. Streamflow in the Santa Maria River was adjusted to represent 1971 conditions. The 31-year mean annual volumes of coarse-sediment discharges are 190,000 cubic yards (140,000 cubic metres) in the Santa Ana River and 250,000 cubic yards (190,000 cubic metres) in the Santa Maria River. Only during floodflow is any significant quantity of sediment transported. In the Santa Maria River an estimated 99 percent of all coarse sediment was transported in 1 percent (113 days) of the 31-year period.

California↗
USGS1974

Sediment discharge in the Lake Tahoe basin, California, 1973 water year

Streamflow and fluvial-sediment discharge data are being collected at selected streams and highway gutters in the Lake Tahoe basin to determine the extent of erosion from highway cuts and to attempt to evaluate the effects of various land-treatment practices to reduce erosion. This is the second progress report. Precipitation in the Lake Tahoe area during 1973 was 94 percent of normal. Seventy-one percent of the total annual runoff during the 1973 water year occurred from March through June 1973. Sediment samples were collected during the year at streamflow stations and at gutterflow stations at highway cuts to define the range of transport conditions. The major part (74 percent) of the annual suspended-sediment discharge from streams during the 1973 water year occurred during the snowmelt runoff period, March through June.

California↗
USGS1973

Sediment discharge in the Lake Tahoe basin, California, 1972 water year

Streamflow and fluvial-sediment discharge data are being collected at selected streams and highway gutters in the Lake Tahoe basin to determine the extent of erosion from highway cuts and to evaluate the effects of various land treatment practices to reduce erosion. Precipitation in the Lake Tahoe area during 1972 was 77 percent of normal; consequently, runoff was well below normal. Seventy-six percent of the total annual runoff during the 1972 water year occurred from March through June 1972. Sediment samples were collected during the year at streamflow gaging stations and at gutter stations at highway cuts to define the range of transport conditions. The major part (87 percent) of the annual suspended-sediment discharge during the 1972 water year occurred during the snowmelt runoff period, March through June.

California↗