|
<br />2. Except for a small number of samples contain-
<br />ing concentrations greater than analytical
<br />detection limits, most values of antimony,
<br />beryllium, cadmium, mercury, and silver, and
<br />dissolved concentrations of chromium and
<br />cobalt were near or less than detection limits.
<br />Total concentrations of chromium and cobalt
<br />commonly were greater than detection limits.
<br />
<br />3. Concentrations of total aluminum, chromium,
<br />cobalt, copper, iron, manganese, molybdenum,
<br />nickel, and zinc generally were about 2 to
<br />greater than 10 times the dissolved concentra-
<br />tions.
<br />
<br />4. Generally, concentration ranges of dissolved or
<br />total aluminum, boron, cobalt, copper, iron,
<br />lithium, manganese, molybdenum, nickel,
<br />strontium, and zinc were greatest downstream
<br />from site 3.
<br />
<br />Comparison of data distributions indicate that
<br />sources of aluminum, arsenic, boron, barium, cobalt,
<br />copper, iron, lead, lithium, manganese, molybdenum,
<br />nickel, selenium, strontium, zinc, and perhaps chro-
<br />mium probably are widespread in the White River
<br />Basin. Concentrations of strontium were least in the
<br />South Fork (site 2); also sulfate concentrations were
<br />least at site 2 (figs. 18-20). Thus, the South Fork Basin
<br />probably contains fewer sources of strontium and sul-
<br />fate minerals such as celestite than does the North Fork
<br />Basin. The generally small concentrations (less than
<br />II J.lg/L as total) of antimony, arsenic, beryllium, cad-
<br />mium, cobalt, mercury, molybdenum, silver, selenium,
<br />and vanadium in the White River indicate that quanti-
<br />ties of these trace constituents probably were scarce or
<br />limited.
<br />
<br />Total concentrations for aluminum, cobalt, cop-
<br />per, iron, manganese, molybdenum, nickel, and zinc
<br />also were greater than dissolved concentrations down-
<br />stream from site 3. Sediment loads increased down-
<br />stream from site 3 (fig. 10). Suspended sediment could
<br />be an important source or transportation medium for
<br />these eight constituents. Conversely, the increases
<br />downstream from site 3 and the general range similar-
<br />ity for concentrations of dissolved and total lithium and
<br />strontium indicate that these constituents, and perhaps
<br />the soluble salts of boron, were transported to the
<br />White River mostly as dissolved ions,
<br />
<br />SUMMARY
<br />
<br />In 1986, the U.S. Geological Survey entered into
<br />a cooperative study with the Yellow-Jacket Water
<br />Conservancy District, Water Users Association No. I,
<br />Rio Blanco County, and the Colorado River Water
<br />Conservation District to compile, review, and analyze
<br />sediment and water-quality data for the White River in
<br />northwestern Colorado. Streamflow, sediment, and
<br />water-quality data for water years 1975-88 were com-
<br />piled and analyzed for six streamflow-gaging stations
<br />(sites) on the White River. Data comparisons for the
<br />main stem White River were improved by combining
<br />data from the North Fork (site I) and South Fork
<br />(site 2) at a secondary data site (site 3A) immediately
<br />downstream from the confluence of the North Fork and
<br />South Fork. Annual data for the two most downstream
<br />sites (sites 5 and 6) for water years 1975-82, a period of
<br />no data, were generated from correlations and combi-
<br />nations of existing hydrologic data from sites 5 and 6
<br />with data from site 4, two tributary gaging stations
<br />(09306222 and 09306255), and a discontinued gaging
<br />station (09306300) downstream from site 6.
<br />Most annual streamflow in the White River
<br />occurred during May and June from melted snowpack
<br />in the eastern part of the basin. The combined stream
<br />discharges of the North Fork (site I) and South Fork
<br />(site 2) accounted for about 78 percent of the total
<br />stream discharge of the White River at site 6. Annual
<br />stream discharge for much of the main stem White
<br />River ranged from about 200,000 acre-ft during low
<br />streamflow years to almost 1 million acre-ft at sites 5
<br />and 6 during high streamflow years. The average
<br />annual stream discharge at site 6 for water years 1975-
<br />88 was about 577,000 acre-ft. The combined annual
<br />stream discharges (site 3A) measured at sites 1 and 2
<br />were correlated with measurements of snowpack.
<br />Daily loads of suspended sediment in the White
<br />River were estimated from least-squares regressions
<br />that related instantaneous suspended-sediment loads to
<br />daily stream discharge. Data were grouped for three
<br />hydrologic events, and from one to three regressions
<br />were developed for each site. Annual suspended-sedi-
<br />ment loads were measured as the sum of the estimated
<br />daily suspended-sediment loads for each water year.
<br />Instantaneous bedload measurements at sites 1-4
<br />and site 6 were compared with instantaneous sus-
<br />pended-sediment loads to determine if bedload was a
<br />substantial component of total sediment transport.
<br />Bedloads in 6 of 7 measurements at sites 1-4 were
<br />3,3 percent or less of the total sediment load, and the
<br />18 measurements of bedload at site 6 were 1.3 percent
<br />or less of the total sediment load. Bedload was consid-
<br />ered as small compared to suspended-sediment loads
<br />
<br />66 Sediment Transport and Water-Quality Characteristics and Loads, White River, Northwestern Colorado, Wat.r V.ars
<br />1975-88
<br />
|