The NAWQA study design for surface water focuses on water-quality
conditions in streams using two interrelated components-water-column
studies, and ecological studies. Water-column studies monitor physical
and chemical characteristics and their relation to hydrologic
conditions, sources, and transport. Water column studies are conducted
at sites termed intensive-fixed sites, according to the
frequency of sampling and/or constituents analyzed. The sampling sites
are selected to determine the quality of water in relation to important
environmental setting in the study unit. Intensive fixed sites can be
either indicator or integrator sites. Indicator sites represent
relatively homogeneous, small basins associated with specific
environmental settings, such as a particular land use that
substantially affects water quality in the study unit. Integrator sites
are established at downstream points in larger relatively heterogeneous
drainage basins with complex combinations of land-use setting. Water
samples are also collected at other locations as part of (short-term)
synoptic studies of specific water-quality conditions or issues during
a specific hydrologic period (for example during peak irrigation) to
provide greater spatial coverage.
Intensive Fixed Site Network
From May 1999 to January 2000, the
Yakima River Basin NAWQA study unit began a water-quality study at
three intensive-fixed site locations--Moxee Drain at Birchfield Rd.,
Granger Drain at Granger, and Yakima River at Kiona (site photos). All sites
were sampled for organochlorine pesticides, currently used pesticides,
nutrients, trace metals, fecal-indicator bacteria, major ions,
dissolved organic carbon, suspended organic carbon, and physical
measures of suspended sediment. A continuous record of discharge,
specific conductance, and water temperature were measured at all
sites. Field measurements recorded at the time of water quality
sampling include, turbidity, water temperature, specific conductance,
pH, dissolved oxygen, and alkalinity. The sampling frequency was weekly
at agricultural drains and twice monthly at Kiona.
Moxee Drain at Birchfield Rd. (USGS station
no. 12500420)--This agricultural indicator site is located 2 miles east
of Union Gap and covers a drainage area of approximately 41 square
miles. Most flow is irrigation return from water imported from the
Yakima River at the Selah-Moxee Irrigation Diversion located at river
mile 123.6 on the Yakima River and the Roza Diversion located at river
mile 127.9 on the Yakima River. Long-term mean discharge is 8.3 cubic
feet per second. The upper 68 percent of the drainage is largely
rangeland. The lower 32 percent of the drainage is split between
cropland (27 percent) pasture (4 percent). The basin is less than 1
percent urban. Twenty five samples were collected from May, 1999,
through January, 2000.
Download
water-quality data for Moxee Drain at Birchfield Rd. (Available through
September 1999; data will be displayed in another window)
Granger Drain at Granger (USGS station
no. 12505450)--This agricultural indicator site covers a drainage area
of approximately 63 square miles and is located in the lower reach of
the Yakima River Basin The mainstem Granger Drain receives water from a
agricultural watershed containing a network of both surface and
subsurface drainage systems. The Granger Drain discharges into the
Yakima River after passing through the Town of Granger. During peak
irrigation season, water is diverted from the Yakima River and supplied
by both the Sunnyside Valley Irrigation District and Roza Irrigation
District canals. Long-term mean discharge is 3.7 cubic feet per
second. The major agricultural land-use activities within the Granger
basin are irrigated agricultural (cropland), pastures and CAFOs
(confined feeding operations). The upper 37 percent of the drainage is
largely rangeland. The lower 63 percent of the drainage is split
between cropland (55 percent) and pasture (7 percent). Beginning in
April, 1999, samples were collected weekly during the irrigation season
and monthly during the non irrigation season.
Download
water-quality data for Granger Drain at Granger. (Available through
September 1999; data will be displayed in another window.)
Yakima River at Kiona
(USGS station no. 12510500)--This integrator site is located at river
mile 29.9 and has a drainage area of 5,616 square miles. A continuous
record of streamflow has been collected at this site since 1933. The
flow at Kiona is affected by diversions and by Keechelus, Hachess, Cle
Elum, Bumping, and Rimrock Lakes. Long-term mean discharge is 3,569
cubic feet per second. The upper 41 percent of the drainage is largely
forested. The lower 59 percent of the drainage is split between
rangeland (37 percent), cropland (15 percent), pasture (3 percent) and
urban (2 percent). Beginning in April, 1999, samples were collected
twice per month during the irrigation season and once per monthly
during the non-irrigation season.
Download
water-quality data for the Yakima River at Kiona. (Available through
September 1999; data will be displayed in another window.)
Download
real-time streamflow data for the Yakima River at Kiona.)
Synoptic Sampling-Site Network
Synoptic sampling is sampling that occurs during a short period of
time in order to provide a "snapshot" of water quality in the basin,
which allows a spatial comparison of water-quality conditions at a
particular time of the year.
Basinwide sampling of surface-water sites and wastewater discharges
for pesticides, nutrients, and trace elements will be conducted in
August 1999 and June, July, and October-November 2000. Samples will be
collected from many sites throughout the basin that include main-stem
sites, tributary sites, wastewater-treatment plants, and drinking-water
intakes. To the extent possible, the timing of the collection of the
water-quality samples from all sites will be based on the length of
time required for water to travel from the upper reaches of the Yakima
River to the mouth. This is referred to as Lagrangian sampling, which
can be visualized as sampling a distinct parcel of water at multiple
locations as it moves downstream. The advantage of this design is that
it is possible to account for additions and losses of water elements,
as the parcel moves downstream. In addition, some sites will be sampled
additional times during the basinwide sampling to assess short-term
temporal variations in water quality.
Access synoptic-network data
Yakima NAWQA Home
Surface Water