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At least 1,027 records · Page 57Linked to original sources
USGS1997

Geomorphology of the lower Copper River, Alaska

The Copper River, located in southcentral Alaska, drains an area of more than 24,000 square miles. About 30 miles above its mouth, this large river enters Miles Lake, a proglacial lake formed by the retreat of Miles Glacier. Downstream from the outlet of Miles Lake, the Copper River flows past the face of Childs Glacier before it enters a large, broad, alluvial flood plain. The Copper River Highway traverses this flood plain and in 1995, 11 bridges were located along this section of the highway. These bridges cross parts of the Copper River and in recent years, some of these bridges have sustained serious damage due to the changing course of the Copper River. Although the annual mean discharge of the lower Copper River is 57,400 cubic feet per second, most of the flow occurs during the summer months from snowmelt, rainfall, and glacial melt. Approximately every six years, an outburst flood from Van Cleve Lake, a glacier-dammed lake formed by Miles Glacier, releases approximately 1 million acre-feet of water into the Copper River. When the outflow rate from Van Cleve Lake reaches it peak, the flow of the Copper River will increase between 150,000 to 190,000 cubic feet per second. Data collected by bedload sampling and continuous seismic reflection indicated that Miles Lake traps virtually all the bedload being transported by the Copper River as it enters the lake from the north. The reservoir-like effect of Miles Lake results in the armoring of the channel of the Copper River downstream from Miles Lake, past Childs Glacier, until it reaches the alluvial flood plain. At this point, bedload transport begins again. The lower Copper River transports 69 million tons per year of suspended sediment, approximately the same quantity as the Yukon River, which drains an area of more than 300,000 square miles. By correlating concurrent flows from a long-term streamflow-gaging station on the Copper River with a short-term streamflow-gaging station at the outlet of Miles Lake, long-term flow characteristics of the lower Copper River were synthesized. Historical discharge and cross-section data indicate that as late as 1970, most of the flow of the lower Copper River was through the first three bridges of the Copper River Highway as it begins to traverse the alluvial flood plain. In the mid 1980's, a percentage of the flow had shifted away from these three bridges and in 1995, only 51 percent of the flow of the Copper River passed through them. Eight different years of aerial photography of the lower Copper River were analyzed using Geographical Information System techniques. This analysis indicated that no major channel changes were caused by the 1964 earthquake. However, a flood in 1981 that had a recurrence interval of more than 100 years caused significant channel changes in the lower Copper River. A probability analysis of the lower Copper River indicated stable areas and the long-term locations of channels. By knowing the number of times a particular area has been occupied by water and the last year an area was occupied by water, areas of instability can be located. A Markov analysis of the lower Copper River indicated that the tendency of the flood plain is to remain in its current state. Large floods of the magnitude of the 1981 event are believed to be the cause of major changes in the lower Copper River.

Professional Paper↗
USGS2011

Water-quality conditions near the confluence of the Snake and Boise Rivers, Canyon County, Idaho

Total Maximum Daily Loads (TMDLs) have been established under authority of the Federal Clean Water Act for the Snake River-Hells Canyon reach, on the border of Idaho and Oregon, to improve water quality and preserve beneficial uses such as public consumption, recreation, and aquatic habitat. The TMDL sets targets for seasonal average and annual maximum concentrations of chlorophyll- a at 14 and 30 micrograms per liter, respectively. To attain these conditions, the maximum total phosphorus concentration at the mouth of the Boise River in Idaho, a tributary to the Snake River, has been set at 0.07 milligrams per liter. However, interactions among chlorophyll- a , nutrients, and other key water-quality parameters that may affect beneficial uses in the Snake and Boise Rivers are unknown. In addition, contributions of nutrients and chlorophyll- a loads from the Boise River to the Snake River have not been fully characterized. To evaluate seasonal trends and relations among nutrients and other water-quality parameters in the Boise and Snake Rivers, a comprehensive monitoring program was conducted near their confluence in water years (WY) 2009 and 2010. The study also provided information on the relative contribution of nutrient and sediment loads from the Boise River to the Snake River, which has an effect on water-quality conditions in downstream reservoirs. State and site-specific water-quality standards, in addition to those that relate to the Snake River-Hells Canyon TMDL, have been established to protect beneficial uses in both rivers. Measured water-quality conditions in WY2009 and WY2010 exceeded these targets at one or more sites for the following constituents: water temperature, total phosphorus concentrations, total phosphorus loads, dissolved oxygen concentration, pH, and chlorophyll- a concentrations (WY2009 only). All measured total phosphorus concentrations in the Boise River near Parma exceeded the seasonal target of 0.07 milligram per liter. Data collected during the study show seasonal differences in all measured parameters. In particular, surprisingly high concentrations of chlorophyll- a were measured at all three main study sites in winter and early spring, likely due to changes in algal populations. Discharge conditions and dissolved orthophosphorus concentrations are key drivers for chlorophyll- a on a seasonal and annual basis on the Snake River. Discharge conditions and upstream periphyton growth are most likely the key drivers for chlorophyll- a in the Boise River. Phytoplankton growth is not limited or driven by nutrient availability in the Boise River. Lower discharges and minimal substrate disturbance in WY2010 in comparison with WY2009 may have caused prolonged and increased periphyton and macrophyte growth and a reduced amount of sloughed algae in suspension in the summer of WY2010. Chlorophyll- a measured in samples commonly is used as an indicator of sestonic algae biomass, but chlorophyll- a concentrations and fluorescence may not be the most appropriate surrogates for algae growth, eutrophication, and associated effects on beneficial uses. Assessment of the effects of algae growth on beneficial uses should evaluate not only sestonic algae, but also benthic algae and macrophytes. Alternatively, continuous monitoring of dissolved oxygen detects the influence of aquatic plant respiration for all types of algae and macrophytes and is likely a more direct measure of effects on beneficial uses such as aquatic habitat. Most measured water-quality parameters in the Snake River were statistically different upstream and downstream of the confluence with the Boise River. Higher concentrations and loads were measured at the downstream site (Snake River at Nyssa) than the upstream site (Snake River near Adrian) for total phosphorus, dissolved orthophosphorus, total nitrogen, dissolved nitrite and nitrate, suspended sediment, and turbidity. Higher dissolved oxygen concentrations and pH were measured at the upstream site (Snake River near Adrian) than the downstream site (Snake River at Nyssa). Contributions from the Boise River measured at Parma do not constitute all of the increase in nutrient and sediment loads in the Snake River between the upstream and downstream sites. Surrogate models were developed using a combination of continuously monitored variables to estimate concentrations of nutrients and suspended sediment when samples were not possible. The surrogate models explained from 66 to 95 percent of the variability in nutrient and suspended sediment concentrations, depending on the site and model. Although the surrogate models could not always represent event-based changes in modeled parameters, they generally were successful in representing seasonal and annual patterns. Over a longer period, the surrogate models could be a useful tool for measuring compliance with state and site-specific water-quality standards and TMDL targets, for representing daily and seasonal variability in constituents, and for assessing effects of phosphorus reduction measures within the watershed.

Idaho↗
USGS2019

Groundwater movement and interaction with surface water near the confluence of the Platte and Elkhorn rivers, Nebraska, 2016–18

The State of Nebraska requires a sustainable balance between long-term water supplies and uses of groundwater and surface water and requires Natural Resources Districts to include the effect of groundwater use on surface-water systems as part of their respective integrated management plans. Recent droughts in Nebraska (2000–6; 2012–13) have amplified concerns about the long-term sustainability of groundwater and surface-water resources in the state, and concerns about the effect of groundwater irrigation on both streamflow and the water supplies needed to meet wildlife, recreational, and municipal needs. The lower Platte River provides nearly 100 percent of drinking-water supplies to Lincoln, Nebraska, 40 to 60 percent of drinking-water supplies to Omaha, Nebr., and critical aquatic and riparian habitat for threatened and endangered species. The Lower Platte River Basin-wide Management Plan has been jointly developed by the Nebraska Department of Natural Resources and seven Natural Resources Districts to address some of these concerns by managing groundwater and surface-water resources conjunctively. To sustain flows in the lower Platte River that are needed for municipal water supplies, water managers have proposed projects aimed at temporary storage of surface water in upstream parts of the basin to mitigate periods of low flow in the lower Platte River. To increase scientific understanding and provide support for any potential future streamflow augmentation projects, the Papio-Missouri River Natural Resources District, the Lower Platte North Natural Resources District, and the Nebraska Department of Natural Resources, in cooperation with the U.S. Geological Survey, initiated this study to examine groundwater/surface-water interaction along the lower Platte and Elkhorn Rivers upstream from their confluence. The study design described herein focused on understanding seasonal characteristics of groundwater movement and interaction with surface water during periods of high groundwater demand (June through August) and low groundwater demand (all other months). Understanding how groundwater movement and interaction with surface water are affected by streamflow conditions and local groundwater demand is critical to the development of any streamflow augmentation project intended to sustain streamflow and mitigate periods of low flow in the lower Platte River. The characteristics of groundwater movement and interaction with surface water are affected by hydrologic and local climatic conditions. For the study area, 2016–18 conditions can be broadly characterized as above normal precipitation. The flows measured at the Elkhorn River at Waterloo, Nebr., streamflow-gaging station (U.S. Geological Survey station 06800500) were above the long-term median, and the streamflow of the Platte River near Leshara, Nebr., streamflow-gaging station (06796500) remained normal or slightly above normal for the duration of this study. Continuous streamflow and water-level data were interpreted to examine differences in groundwater movement and interaction with surface water between the Platte and Elkhorn Rivers during high and low groundwater demand periods. Although the streamflow for the Platte and Elkhorn Rivers and their tributaries was less during the high groundwater demand period, the hydraulic gradient along a transect of recorder wells was identical (0.0012 foot per foot) during the high and low groundwater demand synoptic water-level and streamflow surveys. The hydraulic gradient between the Platte and Elkhorn Rivers generally remained between 0.0011 and 0.0012 foot per foot. It can be inferred that the hydraulic gradient, which is the only temporally variable factor in Darcy’s Law, is consistent throughout the study period and that groundwater flow does not vary appreciably along this transect. The northern part of the study area (north of the transect of recorder wells) has consistent groundwater and tributary flow from Big Slough, Rawhide Creek (Old Channel), and Rawhide Creek for low and high groundwater demand periods. In the southern part of the study area (south of the transect of recorder wells), tributary flow is more variable and dependent on local groundwater demand and flow conditions of the Platte River. Small decreases (less than 2 feet) in the groundwater levels, such as those measured during the high groundwater demand period, can have substantial changes in the streamflow in an unnamed tributary to the Elkhorn River. The streamflow measured during the high groundwater demand synoptic water-level and streamflow survey had decreased by nearly a factor of 20 when compared to the low groundwater demand period. The volume of groundwater discharge received by the Elkhorn River was estimated by examining the changes in streamflow between measurement locations. Streamflow measurements indicate that the groundwater discharge received by the Elkhorn River in the southern part of the study area was seasonably variable, making it difficult if not impossible to estimate an annual value. In the Elkhorn River, between the Elkhorn River at Waterloo, Nebr., streamflow-gaging station and the Q Street Bridge, streamflow measurements collected during the low groundwater demand period indicated a gain of 80 cubic feet per second, which is comparable to the gain estimated using aerial thermal infrared imagery and water temperature data. Streamflow measurements collected during the high groundwater demand period indicate a loss of 80 cubic feet per second across this same reach. In assessing water supply conditions in the lower Platte River system, the term “loss” in reference to streamflow in the Elkhorn River should be used with caution. Most likely, flow from the Elkhorn River which is “lost” to the groundwater system will later discharge to surface water closer to the confluence of the Platte and Elkhorn Rivers as underflow. A calibrated groundwater flow model of the study area likely is required to predict the fate of this water and to quantify groundwater discharge during varying hydrologic conditions along this reach. Aerial thermal infrared imagery indicated that much of the groundwater discharge in the southern part of the study area is focused across a 3-mile reach where the Elkhorn River turns southwest, perpendicular to the regional groundwater flow direction. Points of focused groundwater discharge were not detected with aerial thermal infrared imagery, indicating that groundwater discharge is diffuse rather than concentrated at focused points. Temperature-based streambed flux estimates indicated that strong regional groundwater gradients are not driving groundwater discharge and hyporheic flow is the dominant groundwater/surface-water exchange process.

Nebraska↗
USGS2019

Controls on spatial and temporal variations of brine discharge to the Dolores River in the Paradox Valley, Colorado, 2016–18

The Paradox Valley in southwestern Colorado is a collapsed anticline formed by movement of the salt-rich Paradox Formation at the core of the anticline. The salinity of the Dolores River, a tributary of the Colorado River, increases substantially as it crosses the valley because of discharge of brine-rich groundwater derived from the underlying salts. Although the brine is naturally occurring, it increases the salinity of the Colorado River, which is a major concern to downstream agricultural, municipal, and industrial water users. The U.S. Geological Survey in cooperation with the Bureau of Reclamation conducted a study to improve the characterization of processes controlling spatial and temporal variations in brine discharge to the Dolores River. For the study, three geophysical surveys were conducted in March, May, and September 2017, and water levels were monitored in selected ponds and groundwater wells from November 2016 to May 2018. The study also utilized streamflow and specific conductance data from two U.S. Geological Survey streamflow-gaging stations on the Dolores River to estimate salt load to the river. River-based continuous resistivity profiling and frequency domain electromagnetic induction surveys made during low-flow conditions indicated a zone of brine-rich groundwater close to the riverbed along an approximately 4-kilometer reach of the river. Under high-flow conditions, the brine was depressed as much as 2 meters below the riverbed, and brine discharge to the river was reduced to a minimum. Direct current electrical resistivity surveys show that the freshwater lens overlying the brine is much thicker (up to 10 meters) on the west bank than on the east bank (less than 5 meters). A large low-conductivity anomaly at river distance 6,800 meters was observed in all surveys and may represent a freshwater discharge zone or a losing reach of the river. Filling and draining of the wildlife ponds on the west side of the river had a negligible effect on salt loads in the river during the study period. Groundwater monitoring showed there was active exchange of water between the river and the adjacent alluvial aquifer. When river stage was low, groundwater flowed towards the river, and brine discharge to the river increased. When the river stage was high, the gradient was reversed, and fresh surface water recharged the alluvial aquifer minimizing brine discharge. Most of the salt load to the river occurred during the winter and appeared to be enhanced by diurnal stage fluctuations. A conceptual model of brine discharge to the river is presented at three scales. Groundwater at the regional scale drives dissolution of salt in the Paradox Formation and flow of brine into the base of the alluvial aquifer. Surface water–groundwater interactions at the scale of the alluvial aquifer control brine discharge to the river seasonally and interannually. At the finest scale, diurnal fluctuations in river stage drive exchange of freshwater with saltier pore water in the hyporheic zone, which appears to increase brine discharge to the river during winter.

Colorado↗
USGS2003

Occurrence and transport of cadmium, lead, and zinc in the Spokane River basin, Idaho and Washington, water years 1999-2001

A water-quality investigation of the Clark Fork-Pend Oreille and Spokane River Basins began in 1997 as part of the U.S. Geological Survey National Water-Quality Assessment Program. As part of the investigation, selected streams in the Spokane River Basin were sampled for trace metals during water years 1999–2001. These data, combined with data collected as part of a U.S. Environmental Protection Agency Remedial Investigation/ Feasibility Study, were used to assess the occurrence, loads, and transport of cadmium, lead, and zinc at 21 streamflow-gaging stations in the Spokane River Basin. Concentrations of dissolved and total cadmium, lead, and zinc varied widely both at and among stations. At most stations, dissolved cadmium and zinc composed most of the total concentrations; dissolved lead generally composed less than 10 percent of the total lead concentration. From the South Fork Coeur d’Alene River near Mullan downstream to the South Fork Coeur d’Alene River near Pinehurst, concentrations of trace metals increased 2 to 4 orders of magnitude. The mean flow-weighted concentrations of total cadmium, lead, and zinc near Pinehurst for water years 1999–2001 were 5.7, 80, and 810 micrograms per liter ( µg/L), respectively. On the Coeur d’Alene River near Harrison, downstream from the confluence of the metal-enriched South Fork and the relatively dilute North Fork Coeur d’Alene River, the mean flow-weighted concentrations of total cadmium, lead, and zinc were 1.6, 88, and 240 µg/L, respectively. Trace-metal concentrations were smaller in the Spokane River than in the Coeur d’Alene River because of dilution and retention in Coeur d’Alene Lake. The mean flowweighted concentrations of total cadmium, lead, and zinc in the Spokane River near Post Falls were 0.32, 3.1, and 71 µg/L, respectively. Regression models relating the mass transport, or load, of trace metals to changes in stream discharge and time were successful in simulating the variability in trace-metal concentrations and loads. The median coefficient of determination for the load models for the 21 stations was largest for total lead (92 percent) and smallest for dissolved and total cadmium (82 percent). Whereas most of the cadmium and zinc loads in the Spokane River Basin were derived from the South Fork Coeur d’Alene River, most of the lead load was derived from the Coeur d’Alene River downstream from the confluence of the North and South Forks. Major tributary sources of trace metals to the South Fork Coeur d’Alene River were Canyon Creek, Ninemile Creek, and Government Gulch. These three tributaries contributed about 3,000 pounds of cadmium, 23,000 pounds of lead, and 310,000 pounds of zinc annually to the South Fork Coeur d’Alene River. Erosion and transport of sediment-bound lead in the Coeur d’Alene River was the primary source of total lead, accounting for almost 400,000 pounds annually during water years 1999–2000. Ground-water discharge in the area of the Bunker Hill Superfund site was a major source of zinc in the South Fork Coeur d’Alene River, contributing more than 250,000 pounds per year. During water years 1999–2000, the average annual loads of cadmium, lead, and zinc transported from the Coeur d’Alene, St. Joe, and St. Maries Rivers to Coeur d’Alene Lake were 8,900, 500,000, and 1.4 million pounds, respectively. The Coeur d’Alene River accounted for more than 99 percent of the total load of each of these three metals entering the lake. About 4,600 pounds of cadmium, 44,000 pounds of lead, and 980,000 pounds of zinc were transported from Coeur d’Alene Lake into the Spokane River. Between the Spokane River near Post Falls, Idaho, and the Spokane River at Long Lake, Washington, there was an annual net loss of about 2,600, 20,000, and 250,000 pounds of cadmium, lead, and zinc, respectively. About 2,000 pounds of cadmium, 24,000 pounds of lead, and 730,000 pounds of zinc were transported annually downstream from Long Lake toward the Columbia River.

Idaho;Washington↗
USGS2014

Evaluation of the behavior and movement of adult summer steelhead in the lower Cowlitz River, Washington, following collection and release, 2013-2014

Summer steelhead ( Oncorhynchus mykiss ) produced by a hatchery on the lower Cowlitz River, Washington, support a popular sport fishery during June–September each year. Many of these fish return to the Cowlitz Salmon Hatchery and are held until they are spawned in December. In the past, fishery managers have released some of the steelhead that return to the hatchery at downstream release sites (hereafter referred to as “recycled steelhead”) to increase angling opportunity. The recycling of summer steelhead is a potential use of hatchery fish that can benefit anglers in the lower Cowlitz River, provided these fish are harvested or return to the hatchery. However, recycled steelhead that are not removed from the river could compete against or spawn with wild winter steelhead, which would be a negative consequence of recycling. The Washington Department of Fish and Wildlife (WDFW) conducted an evaluation during 1998 and recycled 632 summer steelhead. They determined that 55 percent of the recycled steelhead returned to the hatchery and 15 percent of the fish were harvested by anglers. The remaining 30 percent of recycled fish were not known to have been removed from the river. Recycling has not occurred in recent years because definitive studies have not been conducted to determine the fate of the fish that remain in the lower Cowlitz River after being recycled. The U.S. Geological Survey and WDFW conducted a 2-year study during 2012–2014 to quantify recycled steelhead that (1) returned to the hatchery, (2) were captured by anglers, or (3) remained in the river. All recycled steelhead were marked with a Floy ® tag and opercle punch, and 20 percent of the recycled fish were radio-tagged to determine post-release behavior and movement patterns, and to describe locations of tagged fish that remained in the river during the spawning period. During 2012–2013, we recycled 549 steelhead and determined that 50 percent of the fish returned to the hatchery, 18 percent of the fish were harvested by anglers, and 32 percent of the fish were not known to have been removed from the river. During October–December 2012, only 9 percent of the radio-tagged steelhead remained in the lower Cowlitz River and none of these fish entered tributaries monitored by fixed-telemetry sites. The second year of the evaluation was conducted during 2013–2014. A total of 502 steelhead were recycled during June–August and releases were conducted weekly with group sizes that ranged from 30 to 76 fish. Results from 2013–2014 were similar to results from 2012–2013. Fifty percent (251 fish) of the recycled steelhead returned to the hatchery, 20 percent (100 fish) were harvested by anglers, and 30 percent (151 fish) were unaccounted for. The median elapsed time from release to hatchery return was 13 days, and the median elapsed time from release to capture by an angler was 11 days. The percentage of unaccounted-for steelhead in the general population was moderately high (30 percent), but detection records of radio-tagged fish suggest that few recycled steelhead were present in the lower Cowlitz River during the spawning period. A total of 109 steelhead were radio-tagged during 2013–2014, and most of these fish (88 percent) moved upstream following release and entered the Trout Hatchery–Salmon Hatchery reach (river miles 44–51). The median elapsed time from release to reach entry was 4.6 days (range of 0.5–65.5 days). After fish entered this reach, they spent a considerable amount of time near the Cowlitz Trout Hatchery (median residence time of 16.7 hours) or Cowlitz Salmon Hatchery (median residence time of 146.3 hours), or they moved back and forth between these two sites. Thirty radio-tagged steelhead made at least two trips between the sites and some fish made as many as seven trips. Detection records showed that 61 percent (66 fish) of the radio-tagged fish returned to the hatchery reach and 21 percent (23 fish) of the fish were captured by anglers. The remaining 18 percent (20 fish) of the radio-tagged fish had various fates. One fish (less than 1 percent) left the Cowlitz River and nine fish (8 percent) died, were harvested, or spit their transmitter near boat launches in the river. The remaining 10 fish (9 percent) had the potential to interact with winter steelhead. Four tagged steelhead (4 percent) entered lower Cowlitz River tributaries (two fish in the Toutle River; two fish in Salmon Creek) during October and November, and five tagged fish (5 percent) were last detected in the lower Cowlitz River in October. One fish (less than 1 percent) was never detected after being released. We measured the diameter of opercle punches in recycled steelhead to determine the temporal effectiveness of these marks. A total of 116 opercle punches were measured—36 were measured at the time of tagging and 80 were measured when fish returned to the hatchery. Opercle punches remained open for less than 1 month. None of the fish that returned to the hatchery more than 30 days after release had opercle punches that were open. All recycled steelhead were marked with a Floy ® tag and opercle punch. However, if a steelhead lost its Floy ® tag and was captured by an angler, or returned to the hatchery more than 30 days after being recycled, it likely would not have been accurately identified as having been recycled because of regrowth of the opercle punch. During 2013–2014, at least 70 percent of the recycled steelhead were removed from the lower Cowlitz River by anglers, returned to the hatchery, or left the river. Radiotelemetry data indicated that a maximum of 9 percent of the radio-tagged fish remained in the lower Cowlitz River during the spawning period and only 4 percent of the radio-tagged fish entered tributaries where wild steelhead are known to spawn. These results are consistent with findings from previous studies. Overall, results from these studies suggest that about one-third of the recycled steelhead were not known to have been removed from the river. However, the radiotelemetry data indicated that only about 10 percent of the recycled steelhead were present in the lower Cowlitz River during late autumn and early winter, and few of those fish (0 in 2012–2013 and 4 in 2013–2014) entered tributaries where winter steelhead spawn. These results have management implications in the lower Cowlitz River where the risks and rewards of steelhead recycling will be weighed to determine the future of the recycling program.

Washinton↗
USGS2022

Relative contributions of suspended sediment between the upper Suiattle River Basin and a non-glacial tributary, Washington, May 2016–September 2017

Concentrations of suspended sediment were measured in discrete samples and turbidity was continuously monitored at four U.S. Geological Survey streamgages in western Washington State, including one gage on the Sauk River; two gages on the Suiattle River, a tributary to the Sauk River; and one gage on Downey Creek, a tributary to the Suiattle River. The Suiattle River is a sediment-rich stream with headwaters on Glacier Peak, a glaciated volcano in the northern Cascade Range. Contributions of suspended sediment to the Suiattle River from unglaciated tributaries, represented by Downey Creek, were compared to the contributions from Glacier Peak in the upper Suiattle River watershed. During summer 2017, a period for which complete records of discharge and sediment data were available for all three streamgages in the Suiattle River Basin, the suspended-sediment load from Downey Creek (drainage area [DA] 93 square kilometers [km 2 ]) was 1,400 metric tons, which is equivalent to a sediment yield of about 15 metric tons per km 2 . During the same period, the suspended-sediment load from the upper Suiattle River (DA 176 km 2 ) was 142,000 metric tons, or a sediment yield of about 800 metric tons per km 2 ; and the suspended-sediment load from the lower Suiattle River (DA 733 km 2 ) was 230,000 metric tons, or a sediment yield of about 300 metric tons per km 2 . The Downey Creek Basin accounts for 13 percent of the drainage area of the Suiattle River watershed but contributed only 0.6 percent of the suspended-sediment load over the summer of 2017 and water year 2017 (October 1, 2016–September 30, 2017). In contrast, the upper Suiattle River Basin, which accounts for 24 percent of the entire Suiattle River watershed, contributed 62 percent of the suspended-sediment load during the summer of 2017. Given the short period for which data were collected, it cannot be known with certainty whether the above values are representative of long-term means. The relatively minor contribution of suspended sediment from Downey Creek, however, is consistent with the expectation that the upper Suiattle River, which drains Glacier Peak, is the dominant contemporary source of suspended sediment to the Sauk River. During summer 2016, the suspended-sediment load in the upper Siuattle River (180,000 metric tons) was more than double the estimated load in the lower Sauk River (80,000 metric tons), even though the upper Suiattle River represents only 10 percent of the total contributing area to the lower Sauk River Basin. This ratio of relative contribution is interpreted as an indication of transient storage of sediment along the Suiattle and Sauk Rivers between the two streamgaging stations. In the glaciated upper Suiattle River Basin, sediment is transported by annual glacial-melt processes in spring and summer months, deposited during the summer base-flow period, and then remobilized by fall and winter floods for delivery to the lower Sauk River.

Washington↗
USGS2014

Sources, transport, and trends for selected trace metals and nutrients in the Coeur d'Alene and Spokane River Basins, Idaho, 1990-2013

Data collected at 18 streamflow-gaging and water-quality sampling sites in the Coeur d’Alene and Spokane River Basins of northern Idaho were used to estimate mean streamflow‑weighted concentrations and annual loads of total and dissolved cadmium, lead, and zinc, and total phosphorus (TP) and nitrogen (TN) for water years (WYs) 2009–13. Chronic Ambient Water Quality Criteria (AWQC) and AWQC ratios also were calculated to evaluate Idaho aquatic life criteria for chronic exposure to cadmium and zinc in streams. At four sites with a longer period of record, a Seasonal Kendall trend test was used to assess historical trends in the concentrations of total cadmium, lead, and zinc, and chronic AWQC ratios for cadmium and zinc during WYs 1990–2013. Concentrations of dissolved and total cadmium, lead, and zinc varied widely both at and among sites. At most sites, dissolved cadmium and zinc constituted most of the total concentrations; dissolved lead generally constituted less than 10 percent of the total lead concentration. Trace metal concentrations increased by 2 to 4 orders of magnitude along the South Fork Coeur d’Alene River (SFCDR) from near Mullan (site 2) downstream to near Pinehurst (site 13). The mean streamflow-weighted concentrations of total cadmium, lead, and zinc in the SFCDR near Pinehurst for WYs 2009–13 were 3.71, 61.4, and 514 micrograms per liter (μg/L), respectively. In the Coeur d’Alene River (CDR) near Harrison (site 15), downstream of the confluence of the metal-enriched SFCDR and the relatively dilute North Fork Coeur d’Alene River (NFCDR), the mean streamflow-weighted concentrations of total cadmium, lead, and zinc were 1.58, 125, and 236 μg/L, respectively. Trace‑metal concentrations were smaller in the Spokane River than in the CDR because of dilution and retention of trace metals in Coeur d’Alene Lake. The mean streamflow-weighted concentrations of total cadmium, lead, and zinc in the Spokane River near Post Falls (site 18) were 0.231, 2.91, and 48.9 μg/L, respectively. AWQC ratios indicate that cadmium and zinc concentrations met the chronic criteria (ratio of less than 1.0) for the protection of aquatic life at only three sites: the NFCDR at Enaville (site 1), the upper SFCDR near Mullan (site 2), and the St. Joe River near St. Maries (site 16). Cadmium and zinc concentrations at sites on the Spokane River (sites 17 and 18) generally were close to the chronic AWQC values. The sites with the largest chronic AWQC ratios in the Coeur d’Alene and Spokane River Basins for both cadmium and zinc were in the Canyon and Ninemile Creek basins (sites 3–6). Concentrations of TP and TN generally were low along the SFCDR downstream to Kellogg. From the SFCDR near Kellogg (site 9) downstream to the SFCDR above Pine Creek (site 11), the mean streamflow-weighted concentration of the nutrients TP and TN increased by 0.036 milligram per liter (mg/L) (200 percent) and 0.124 mg/L (78 percent), respectively. The increases in nutrient concentrations along the SFCDR likely are in response to discharge from wastewater‑treatment facilities. Mean streamflow-weighted concentrations for TP and TN (0.054 and 0.284 mg/L, respectively) were the highest in the sampling network in the SFCDR above Pine Creek (site 11). LOADEST modeling was used to relate mass transport, or load, of trace metals and nutrients to variations in streamflow and time. Results indicate that most of the cadmium and zinc load in the Coeur d’Alene and Spokane Rivers is derived from the SFCDR, and that most of the lead load is derived from the Coeur d’Alene River downstream of the confluence of the NFCDR and SFCDR. Major tributary sources of trace metals to the SFCDR are Canyon Creek and Ninemile Creek. Combined, these two tributaries contributed estimated mean loads of about 0.575 ton per year (ton/yr) of total cadmium, 5.29 ton/yr of total lead, and 90.9 ton/yr of total zinc to the SFCDR during WYs 2009–13. Groundwater discharge and tributaries near the Central Impoundment Area between SFCDR near Kellogg (site 9) and SFCDR near Smelterville (site 10) were other primary sources of cadmium and zinc. Combined, these sources contributed an estimated 1.39 ton/yr of total cadmium and 143 ton/yr of total zinc to the SFCDR during WYs 2009–13. Erosion and transport of sediment-bound lead contained in the CDR flood plain and on the river bottom between Cataldo (site 14) and Harrison (site 15) were the primary source of lead. During WYs 2009–13, the mean load of trace metals delivered to Coeur d’Alene Lake included about 4.66 ton/yr of total cadmium, 398 ton/yr of total lead, and 698 ton/yr of total zinc. About 99 percent of the trace-metal load to the lake was from the CDR as measured near site 15 at Harrison. During WYs 2009–13, about 1.48 ton/yr of cadmium, 18 ton/yr of lead, and 350 ton/yr of zinc were transported from Coeur d’Alene Lake into the Spokane River as measured at the lake outlet (site 17). During WYs 2009–13, the loads of TP and TN delivered from the Coeur d’Alene and St. Joe Rivers to Coeur d’Alene Lake were about equivalent. On average, the CDR transported about 93.6 tons of TP and 369 tons of TN, and the St. Joe River transported about 92.9 tons of TP and 360 tons of TN to the lake during 2009–13. About 52.9 ton/yr of TP and 628 ton/yr of TN were transported from Coeur d’Alene Lake to the Spokane River during WYs 2009–13. Results from Seasonal Kendall trend tests indicate statistically significant downward temporal trends during WYs 1990–2013 for total cadmium, lead, zinc, and chronic AWQC ratios of cadmium and zinc in the SFCDR at Elizabeth Park (site 8) and near Pinehurst (site 13), and in the CDR near Harrison (site 15). Statistically significant downward temporal trends for total lead, zinc, and the chronic AWQC ratio of zinc also occurred in the Spokane River near Post Falls (site 18) during WYs 1991–2013. Seasonal Kendall trend tests for WYs 2003–13 indicated statistically significant downward trends for total cadmium, zinc, and chronic AWQC ratios of cadmium and zinc in the SFCDR at Elizabeth Park (site 8). The Spokane River near Post Falls (site 18) had a statistically significant downward trend for total zinc during WYs 2003–13, and a significant upward trend for the chronic AWQC ratio of cadmium. No significant trends were found in trace-metal concentrations or chronic AWQC ratios in the SFCDR near Pinehurst (site 13) and the CDR near Harrison (site 15) during WYs 2003–13. Results from this study indicate that remedial activities conducted since the 1990s have been successful in reducing the concentrations and loads of trace metals in streams and rivers in the Coeur d’Alene and Spokane River Basins. Soils, sediment, surface water, and groundwater in areas of the Coeur d’Alene and Spokane River Basins are contaminated, and the hydrological relations between these media are complex and difficult to characterize. Trace metals have variable source areas, are transported differently depending on hydrologic conditions, and behave differently in response to remedial activities in upstream basins. Based on these findings, no single remedial action would be completely effective in reducing all trace metals to nontoxic concentrations throughout the Coeur d’Alene and Spokane River Basins. Instead, unique cleanup activities targeted at specific media and specific source areas may be necessary to achieve long-term water-quality goals.

Idaho↗
USGS2017

Hydrogeology and simulated groundwater flow and availability in the North Fork Red River aquifer, southwest Oklahoma, 1980–2013

On September 8, 1981, the Oklahoma Water Resources Board established regulatory limits on the maximum annual yield of groundwater (343,042 acre-feet per year) and equal-proportionate-share (EPS) pumping rate (1.0 acre-foot per acre per year) for the North Fork Red River aquifer. The maximum annual yield and EPS were based on a hydrologic investigation that used a numerical groundwater-flow model to evaluate the effects of potential groundwater withdrawals on groundwater availability in the North Fork Red River aquifer. The Oklahoma Water Resources Board is statutorily required (every 20 years) to update the hydrologic investigation on which the maximum annual yield and EPS were based. Because 20 years have elapsed since the final order was issued, the U.S. Geological Survey, in cooperation with the Oklahoma Water Resources Board, conducted an updated hydrologic investigation and evaluated the effects of potential groundwater withdrawals on groundwater flow and availability in the North Fork Red River aquifer in Oklahoma. This report describes a hydrologic investigation of the North Fork Red River aquifer that includes an updated summary of the aquifer hydrogeology. As part of this investigation, groundwater flow and availability were simulated by using a numerical groundwater-flow model. The North Fork Red River aquifer in Beckham, Greer, Jackson, Kiowa, and Roger Mills Counties in Oklahoma is composed of about 777 square miles (497,582 acres) of alluvium and terrace deposits along the North Fork Red River and tributaries, including Sweetwater Creek, Elk Creek, Otter Creek, and Elm Fork Red River. The North Fork Red River is the primary source of surface-water inflow to Lake Altus, which overlies the North Fork Red River aquifer. Lake Altus is a U.S. Bureau of Reclamation reservoir with the primary purpose of supplying irrigation water to the Lugert-Altus Irrigation District. A hydrogeologic framework was developed for the North Fork Red River aquifer and included a definition of the aquifer extent and potentiometric surface, as well as a description of the textural and hydraulic properties of aquifer materials. The hydrogeologic framework was used in the construction of a numerical groundwater-flow model of the North Fork Red River aquifer described in this report. A conceptual model of aquifer inflows and outflows was developed for the North Fork Red River aquifer to constrain the construction and calibration of a numerical groundwater-flow model that reasonably represented the groundwater-flow system. The conceptual-model water budget estimated mean annual inflows to and outflows from the North Fork Red River aquifer for the period 1980–2013 and included a sub-accounting of mean annual inflows and outflows for the portions of the aquifer that were upgradient and downgradient from Lake Altus. The numerical groundwater-flow model simulated the period 1980–2013 and was calibrated to water-table-altitude observations at selected wells, monthly base flow at selected streamgages, net streambed seepage as estimated for the conceptual model, and Lake Altus stage. Groundwater-availability scenarios were performed by using the calibrated numerical groundwater-flow model to (1) estimate the EPS pumping rate that guarantees a minimum 20-, 40-, and 50-year life of the aquifer, (2) quantify the potential effects of projected well withdrawals on groundwater storage over a 50-year period, and (3) simulate the potential effects of a hypothetical (10-year) drought on base flow and groundwater storage. The results of the groundwater-availability scenarios could be used by the Oklahoma Water Resources Board to reevaluate the maximum annual yield of groundwater from the North Fork Red River aquifer. EPS scenarios for the North Fork Red River aquifer were run for periods of 20, 40, and 50 years. The 20-, 40-, and 50-year EPS pumping rates under normal recharge conditions were 0.59, 0.52, and 0.52 acre-foot per acre per year, respectively. Given the 497,582-acre aquifer area, these rates correspond to annual yields of about 294,000, 259,000, and 259,000 acre-feet per year, respectively. Groundwater storage at the end of the 20-year EPS scenario was about 951,000 acre-feet, or about 1,317,000 acre-feet (58 percent) less than the starting EPS scenario storage. This decrease in storage was equivalent to a mean water-level decline of about 22 feet. Most areas of the active alluvium near the North Fork Red River, Elk Creek, and Elm Fork Red River remained partially saturated through the end of the EPS scenario because of streambed seepage. Lake Altus storage was reduced to zero after 6–7 years of EPS pumping in each scenario. Projected 50-year pumping scenarios were used to simulate the effects of selected well withdrawal rates on groundwater storage of the North Fork Red River aquifer and base flows in the North Fork Red River upstream from Lake Altus. The effects of well withdrawals were evaluated by comparing changes in groundwater storage and base flow between four 50-year scenarios using (1) no groundwater pumping, (2) mean pumping rates for the study period (1980–2013), (3) 2013 pumping rates, and (4) increasing demand pumping rates. The increasing demand pumping rates assumed a 20.4-percent increase in pumping over 50 years based on 2010–60 demand projections for southwest Oklahoma. Groundwater storage after 50 years with no pumping was about 2,606,000 acre-feet, or 137,000 acre-feet (5.5 percent) greater than the initial groundwater storage; this groundwater storage increase is equivalent to a mean water-level increase of 2.3 feet. Groundwater storage after 50 years with the mean pumping rate for the study period (1980–2013) was about 2,476,000 acre-feet, or about 7,000 acre-feet (0.3 percent) greater than the initial groundwater storage; this groundwater storage increase is equivalent to a mean water-level increase of 0.1 foot. Groundwater storage at the end of the 50-year period with 2013 pumping rates was about 2,398,000 acre-feet, or about 70,000 acre-feet (2.8 percent) less than the initial storage; this groundwater storage decrease is equivalent to a mean water-level decline of 1.2 feet. Groundwater storage at the end of the 50-year period with increasing demand pumping rates was about 2,361,000 acre-feet, or about 107,000 acre-feet (4.3 percent) less than the initial storage; this groundwater storage decrease is equivalent to a mean water-level decline of 1.8 feet. Mean annual base flow simulated at the Carter streamgage (07301500) on North Fork Red River increased by about 4,000 acre-feet (10 percent) after 50 years with no pumping and decreased by about 5,400 acre-feet (13 percent) after 50 years with increasing demand pumping rates. Mean annual base flow simulated at the North Fork Red River inflow to Lake Altus increased by about 7,400 acre-feet (15 percent) after 50 years with no pumping and decreased by about 5,800 acre-feet (12 percent) after 50 years with increasing demand pumping rates. A hypothetical 10-year drought scenario was used to simulate the effects of a prolonged period of reduced recharge on groundwater storage and Lake Altus stage and storage. Drought effects were quantified by comparing the results of the drought scenario to those of the calibrated numerical model (no drought). To simulate the hypothetical drought, recharge in the calibrated numerical model was reduced by 50 percent during the simulated drought period (1984–1993). Groundwater storage at the end of the drought period was about 2,271,000 acre-feet, or about 426,000 acre-feet (15.8 percent) less than the groundwater storage of the calibrated numerical model. This decrease in groundwater storage is equivalent to a mean water-table-altitude decline of 7.1 feet. At the end of the 10-year hypothetical drought period, base flows at the Sweetwater (07301420), Carter (07301500), Headrick (07305000), and Snyder (07307010) streamgages had decreased by about 37, 61, 44, and 45 percent, respectively. The minimum Lake Altus storage simulated during the drought period was 403 acre-feet, which was a decline of 92 percent from the nondrought storage. Reduced base flows in the North Fork Red River were the primary cause of Lake Altus storage declines.

Oklahoma↗
USGS2023

Comprehensive water-quality trend analysis for selected sites and constituents in the International Souris River Basin, Saskatchewan and Manitoba, Canada, and North Dakota, United States, 1970–2020

The Souris River Basin is an international basin in southeast Saskatchewan, north-central North Dakota, and southwest Manitoba. Sustained exceedances of water-quality objectives for total phosphorus, sodium, sulfate, total dissolved solids, and total iron have been reported since the late 1990s at the two binational sites on the Souris River (Souris River near Sherwood, North Dakota [U.S. Geological Survey station 05114000] and Souris River near Westhope, N. Dak. [U.S. Geological Survey station 05124000]). To understand conditions at the binational sites, it is important to understand water-quality changes on a basin-wide scale. Because streamflow is highly variable in the basin and changes in streamflow affect water-quality conditions, it is particularly important to use a trend-analysis method that accounts for changes in streamflow. Trends in water-quality concentrations can be affected by human-induced changes on the landscape or natural changes in land-runoff interactions that are driven by climate patterns and reflected by changes in streamflow (commonly referred to as “hydroclimatic variability”). In the primarily agricultural Souris River Basin, human-induced changes that are likely to affect trends are widespread changes in agricultural management such as fertilizer application, tilling practices, and crop types, as well as dam emplacement and artificial drainage. Around 1970, there was a long-term natural (hydroclimatic) change in the basin in which a significant transition from a dry climate state to a wet climate state resulted in higher streamflow in the basin. To assist the International Souris River Board in assessing current water-quality conditions in the Souris River Basin and exceedances of water-quality objectives at the binational sites, the U.S. Geological Survey, in cooperation with the International Joint Commission, completed a comprehensive analysis for selected ions, nutrients, and trace metals for many sites in the basin that included descriptive water-quality statistics, trend analysis using a trend method that considers interannual hydroclimatic variability, and an assessment of exceedances of the water-quality objectives for the binational sites. Water-quality and streamflow or reservoir inflow or outflow data were compiled for 34 sites (30 stream sites and four reservoir sites) and 23 constituents with established water-quality objectives from 1970 to 2020 in the Souris River Basin and were used for descriptive statistics and water-quality trend analysis. Median total dissolved solids, sulfate, and sodium concentrations were low in the headwaters of the Souris River and some of the highest median concentrations were measured in the upper basin. At main-stem Souris River sites, all median sodium concentrations were greater than the binational water-quality objective. Median total phosphorus concentrations in the Souris River Basin were highest in the headwaters of the Souris River and all sites had median concentrations greater than the water-quality objective. Median total iron concentrations were highly variable across the basin, and for most main-stem sites, median concentrations were greater than or equal to the water-quality objective. During the recent period (2009–19), the annual flow-averaged concentrations of total dissolved solids and sulfate increased for nearly all stream sites with most sites having mildly significant or significant increases. One-half of the sites had an annual flow-averaged geometric mean concentration greater than the total dissolved solids water-quality objective, and four sites had sulfate increases greater than 100 milligrams per liter. Trends in annual flow-averaged concentrations of sodium and chloride generally were small and nonsignificant. Most sites had concentrations greater than the sodium water-quality objective, whereas all sites had concentrations much less than the chloride water-quality objective. Annual flow-averaged geometric mean concentration of total phosphorus decreased for nearly all sites across the Souris River Basin, but all sites had concentrations greater than the total phosphorus water-quality objective for the entire period. Small and nonsignificant changes in annual flow-averaged geometric mean concentration of total iron were detected at all sites but the binational site at Sherwood, N. Dak., and by 2019 all sites had concentrations greater than the total iron water-quality objective. For the reservoir sites, during 2000–15, mostly significant increases for total dissolved solids, sulfate, and sodium were detected, whereas changes in total phosphorus and total iron were mixed. During the historical period (1976–2019), large and consistent increases in total dissolved solids and sulfate have occurred since the late 1980s, with the largest increases and the most sites with mildly significant or significant increases generally occurring during the middle period (1988–2005). Large and significant or mildly significant increases in sodium concentrations occurred at eight of 10 sites in the middle period (1988–2005), and by the late period (2005–19) changes were small and nonsignificant. Similar to other basins in the region, such as the Red River of the North and Heart River, large and overall consistent increases since the late 1980s in total dissolved solids and sulfate in the Souris River Basin suggest that long-term natural (hydroclimatic) processes are large contributors to increases in the concentration of salts in streams and reservoirs associated with the onset of wetter conditions. The concurrent increases in sulfate and sodium concentrations at all sites during the middle period (1988–2005) suggest that sodium-sulfate evaporite dissolution may be a factor contributing to increases. Total phosphorus concentrations oscillated between increasing and decreasing during the historical period, with concentrations increasing during the first trend period (1976–88) and decreasing in the fourth trend period (2009–19) to the lowest flow-averaged geometric mean concentration by 2019 for most sites. During the historical period, changes in total iron concentrations were mostly nonsignificant and generally small, and variability in total iron concentrations likely affected the ability to detect statistically significant changes in concentration. The probability of exceeding the water-quality objective for total dissolved solids, sulfate, and sodium increased between 1976 and 2019 for the binational sites, especially for sulfate, which more than doubled for Souris River near Sherwood, N. Dak. and increased more than seven times for Souris River near Westhope, N. Dak. Total phosphorus and total iron concentrations for the binational sites were likely to exceed the water-quality objective for most of the year, but seasonal patterns of total phosphorus and total iron concentrations were different between the sites, suggesting that different factors may affect concentrations at different times of the year. For sodium, total phosphorus, and total iron, exceedance of the water-quality objective most of the time is not unexpected given that the flow-averaged geometric mean concentration for these three constituents for most sites across the basin are greater than the water-quality objective for most of the period. If natural processes are affecting total dissolved solids and sulfate concentrations, concentrations would be expected to vary with time, and as a result, extended periods of concentrations greater or less than the water-quality objective are likely to occur depending upon climatic conditions. A better understanding of the state of water quality across the Souris River Basin is beneficial to understanding and interpreting water-quality conditions at the two Souris River binational sites. The most consistent spatial and temporal change observed for this study was large and consistent increases in sulfate and total dissolved solids among tributary and main-stem sites since the late 1980s. For sulfate and total dissolved solids, wetter climatic conditions combined with naturally occurring and abundant sources of sulfate likely contributed to sustained exceedances of water-quality objectives in recent decades, and extended periods of concentrations greater than or less than the water-quality objective are likely to occur depending on climatic conditions. For sodium, total iron, and total phosphorus, sustained exceedances of the current water-quality objective likely will continue because most sites across the basin had flow-averaged geometric mean concentrations greater than the water-quality objective; and during the 43-year period of analysis, regardless of climatic conditions, exceedances were consistently greater than the water-quality objective. Further investigation into the factors causing increasing sulfate concentrations and a better understanding of reservoir dynamics would enhance the understanding of changes in water-quality conditions in the Souris River Basin. The basin-wide approach of this report provided an improved understanding of water-quality conditions in the Souris River Basin, and results can be used to inform the current water-quality objectives, inform potential changes to water management in the basin, and serve as a starting point for tracking future progress. Gaps in understanding of water-quality conditions can be closed through continued monitoring and further investigation into causes behind changes in water-quality conditions identified in this report.

Manitoba, North Dakota, Saskatchewan↗
USGS2000

Method to identify wells that yield water that will be replaced by water from the Colorado River downstream from Laguna Dam in Arizona and California

Accounting for the use of Colorado River water is required by the U.S. Supreme Court decree, 1964, Arizona v. California. Water pumped from wells on the flood plain and from certain wells on alluvial slopes outside the flood plain is presumed to be river water and is accounted for as Colorado River water. The accounting-surface method developed for the area upstream from Laguna Dam was modified for use downstream from Laguna Dam to identify wells outside the flood plain of the lower Colorado River that yield water that will be replaced by water from the river. Use of the same method provides a uniform criterion of identification for all users pumping water from wells by determining if the static water-level elevation in the well is above or below the elevation of the accounting surface. Wells that have a static water-level elevation equal to or below the accounting surface are presumed to yield water that will be replaced by water from the Colorado River. Wells that have a static water-level elevation above the accounting surface are presumed to yield river water stored above river level. The method is based on the concept of a river aquifer and an accounting surface within the river aquifer. The river aquifer consists of permeable sediments and sedimentary rocks that are hydraulically connected to the Colorado River so that water can move between the river and the aquifer in response to withdrawal of water from the aquifer or differences in water-level elevations between the river and the aquifer. The subsurface limit of the river aquifer is the nearly impermeable bedrock of the bottom and sides of the basins that underlie the Yuma area and adjacent valleys. The accounting surface represents the elevation and slope of the unconfined static water table in the river aquifer outside the flood plain of the Colorado River that would exist if the river were the only source of water to the river aquifer. The accounting surface was generated by using water-surface profiles of the Colorado River from Laguna Dam to about the downstream limit of perennial flow at Morelos Dam. The accounting surface extends outward from the edges of the flood plain to the subsurface boundary of the river aquifer. Maps at a scale of 1:100,000 show the extent of the river aquifer and elevation of the accounting surface downstream from Laguna Dam in Arizona and California.

Arizona;California↗
USGS2001

Source identification and fish exposure for polychlorinated biphenyls using congener analysis from passive water samplers in the Millers River basin, Massachusetts

Measurements of elevated concentrations of polychlorinated biphenyls (PCBs) in fish and in streambed sediments of the Millers River Basin, Massachusetts and New Hampshire, have been reported without evidence of the PCB source. In 1999, an investigation was initiated to determine the source(s) of the elevated PCB concentrations observed in fish and to establish the extent of fish exposure to PCBs along the entire main stems of the Millers River and one of its tributaries, the Otter River. Passive samplers deployed for 2-week intervals in the water-column at 3 1 stations, during summer and fall 1999, were used to assess PCB concentrations in the Millers River Basin. The samplers concentrate PCBs, which diffuse from the water column through a polyethylene membrane to hexane (0.200 liters) contained inside the samplers. Only dissolved PCBs (likely equivalent to the bioavailable fraction) are subject to diffusion through the membrane. The summed concentrations of all targeted PCB congeners (summed PCB) retrieved from the samplers ranged from 1 to 8,000 nanograms per hexane sample. Concentration and congener-pattern comparisons indicated that the historical release of PCBs in the Millers River Basin likely occurred on the Otter River at the upstream margin of Baldwinville, Mass. Elevated water-column concentrations measured in a wetland reach on the Otter River downstream from Baldwinville were compatible with a conceptual model for a present-day (1999) source in streambed sediments, to which the PCBs partitioned after their original introduction into the Otter River and from which PCBs are released to the water now that the original discharge has ceased or greatly decreased. Two four-fold decreases in summed PCB concentrations in the Millers River, by comparison with the highest concentration on the Otter River, likely were caused by (1) dilution with water from the relatively uncontaminated upstream Millers River and (2) volatilization of PCBs from the Millers River in steep-gradient reaches. A relatively constant concentration of summed PCBs in the reach of the Millers River from river mile 20 to river mile 10 was likely a consequence of a balance between decreased volatilization rates in that relatively low-gradient reach and resupply of PCBs to the water column from contaminated streambed sediments. A second high-gradient reach from river mile 10 to the confluence of the Millers River with the Connecticut River also was associated with a decrease in concentration of water-column summed PCBs. Volatilization as a loss mechanism was supported by evidence in the form of slight changes of the congener pattern in the reaches where decreases occurred. Exposure of fish food webs to concentrations of dissolved PCBs exceeded the U.S. Environmental Protection Agency's water-quality criterion for PCBs throughout most of the Millers River and Otter River main stems. Because the apparent source of PCBs discharged was upstream on the Otter River, a large number of river miles downstream (more than 30 mi) had summer water-column PCB concentrations that would likely lead to high concentrations of PCBs in fish.

Water-Resources Investigations Report↗
USGS1992

Sediment transport, particle sizes, and loads in lower reaches of the Chippewa, Black, and Wisconsin Rivers in Western Wisconsin

Hydraulic and sediment data were collected at three sites on the Chippewa River (near Caryville, at Durand, and near Pepin); at one site near Galesville on the Black River; and at one site at Muscoda on the Wisconsin River during water years 1976-83. This report summarizes an interpretation of those data by providing (1) a description of the relation of suspended sediment, bedload, and total-sediment discharge to water discharge; (2) a description of particle-size characteristics of bed material, bedload, and suspended sediment; and (3) estimates of annual and average annual suspended load, bedload, and total-sediment load for water years 1974-83. Direct measurement with a Helley-Smith bedload sampler and calculations by the modified-Einstein procedure were used to estimate bedload. Single equations describe the suspended- and totalsediment transport-rate relations for Chippewa River at Durand and main channel at Pepin, and the Black River near Galesville. Two equations were needed to define the transport- rate relations for the Chippewa River near Caryville and Wisconsin River at Muscoda. Bed material at all sites except Chippewa River near Caryville were of similar particle size and exhibited little variation with time or location in the river cross sections. Median diameter at these sites ranged from 0.35 to 0.84 mm (millimeter). At Chippewa River near Caryville, median diameter ranged from 0.42 to 15 mm. Helley-Smith bedload at Chippewa River at Durand and near Pepin, Black River near Galesville, and Wisconsin River at Muscoda were of similar particle size. About 57 to 65 percent of bedload at all sites except Chippewa River near Caryville was in the 0.4- to 0.6- mm size range. About 50 percent of bedload at Chippewa River near Caryville was in the 0.5- to 1.0-mm size range. Suspended sediment at all sites except Chippewa River near Caryville was in the sand-size range; the average median diameters were between 0.17 and 0.22 mm. At Chippewa River near Caryville, 60 percent (on the average) of suspended sediment was finer than 0.062 mm. Average annual total-sediment load and the percentage transported as bedload were determined for a 10-year period (water years 1974-83)(October 1,1973-September 30, 1982). These loads and percentages were, respectively, 123,000 tons and 35 percent at Chippewa River near Caryville; 1,073,000 tons and 61 percent at Chippewa River at Durand; 940,000 tons and 44 percent at Chippewa River near Pepin; 277,000 tons and 43 percent at Black River near Galesville; and 558,000 tons and 49 percent at Wisconsin River at Muscoda.

Wisconsin↗
USGS1992

Distribution and variability of fecal-indicator bacteria in Scioto and Olentangy rivers in the Columbus, Ohio, area

This report presents the results of a study by the U.S. Geological Survey, in cooperation with the City of Columbus, Ohio, to determine the distribution and variability of fecal-indicator bacteria in Scioto and Olentangy Rivers. Fecal-indicator bacteria are among the contaminants of concern to recreational users of these rivers in the Columbus area. Samples were collected to be analyzed for fecal-coliform and Escherichia coli (E. coli) bacteria and selected water-quality constituents and physical properties at 10 sites-- 4 on the Olentangy River and 6 on the Scioto River during the recreational seasons in 1987, 1988, and 1989. Measurements of streamflow also were made at these sites at various frequencies during base flow and runoff. The concentrations of fecal-coliform and E. coli bacteria in the Scioto and Olentangy Rivers spanned a range of five orders of magnitude, from less than 20 to greater than 2,000,000 col/100 mL (colonies per 100 milliliters). In addition, the concentrations of fecal coliform and E. coli bacteria are well correlated (r=0.97) in the study area. At times, relatively high concentrations, for fecal-indicator bacteria (concentrations greater than 51,000 col/100 mL for fecal-coliform and E. coli ) were found in Olentangy River at Woody Hayes Drive and at Goodale Street, and in Scioto River at Greenlawn Avenue and at Columbus. Intermediate concentrations of fecal-indicator bacteria (from 5,100 to 50,000 col/100 mL for fecal coliform and (from 510 to 50,000 col/100 mL for E. coli ) were found in Scioto River at Town Street and below O'Shaughnessy Dam near Dublin, Ohio, and in Olentangy River at Henderson Road. The lowest (median) concentrations of fecal-indicator bacteria (from 20 to 5,000 col/100 mL for fecal coliform and from 20 to 500 col/100 mL for E. coli ) were found at Olentangy River near Worthington, Ohio, Scioto River at Dublin Road Water Treatment Plant and below Griggs Reservoir. Fecal-coliform concentrations exceeded the geometric mean and single-sample Ohio Water Quality Standards for recreation less frequently than E. coli concentrations. The E. coli numerical water-quality standards are more difficult to meet than the fecal coliform standards because they are as much as an order of magnitude lower in some instances. The geometric mean bathing-water and primary-contact standards for fecal-coliform and E. coli bacteria were exceeded in more samples for Olentangy River at Goodale Street than for any other site. The single-sample bathing-water standard for fecal-coliform bacteria was exceeded in 83 percent of all samples and for E. coli in 91 percent of samples for Olentangy River at Goodale Street. Compared to Olentangy River at Goodale Street, geometric means and single-samples exceeded the bathing-water standards somewhat less frequently for Scioto River at Town Street and far less frequently for Scioto River at Dublin Road Water Treatment Plant. In contrast to results for fecal-indicator bacteria, the differences between sites for pH and for concentrations for total alkalinity, total chloride, total nonfilterable residue, total nitrate plus nitrite as nitrogen, total phosphorus, and total organic carbon were small. The large contribution of streamflow and discharge of fecal-indicator bacteria from Olentangy River to Scioto River has a major effect on the Scioto River downstream from the confluence of Olentangy River during periods of rainfall and runoff. Fecal-indicator discharges were calculated for times before, during, and at 24-hour intervals for 48 to 72 hours after two runoff-producing storms. Fecal-coliform and E. coli concentrations were lower in samples collected before runoff and during receding streamflows at 24- to 48-hours after the storms than in samples collected during runoff. The fecal-indicator discharges entering Scioto River from Olentangy River ranged from 22.6 to nearly 100 percent of the total for two storms studied. Controlling nonpoint, unregulated,

Water-Resources Investigations Report↗
USGS1995

Quantity and quality of ground-water discharge to the South Platte River, Denver to Fort Lupton, Colorado, August 1992 through July 1993

Water-quality studies conducted by the Metro Wastewater Reclamation District have indicated that during low flow in segments of the South Platte River between Denver and Fort Lupton, concentrations of dissolved oxygen are less than minimum concen- trations set by the State of Colorado. Low dissolved-oxygen concentrations are observed in two reaches of the river-they are about 3.3 to 6.4 miles and 17 to 25 miles downstream from the Metro Waste- water Reclamation District effluent outfalls. Concentrations of dissolved oxygen recover between these two reaches. Studies conducted by the U.S. Geological Survey have indicated that ground-water discharge to the river may contribute to these low dissolved-oxygen concentrations. As a result, an assessment was made of the quantity and quality of ground-water discharge to the South Platte River from Denver to Fort Lupton. Measurements of surface- water and ground-water discharge and collections of surface water and ground water for water-quality analyses were made from August 1992 through January 1993 and in May and July 1993. The quantity of ground-water discharge to the South Platte River was determined indirectly by mass balance of surface-water inflows and outflows and directly by instantaneous measurements of ground-water discharge across the sediment/water interface in the river channel. The quality of surface water and ground water was determined by sampling and analysis of water from the river and monitoring wells screened in the alluvial aquifer adjacent to the river and by sampling and analysis of water from piezometers screened in sediments underlying the river channel. The ground-water flow system was subdivided into a large-area and a small-area flow system. The precise boundaries of the two flow systems are not known. However, the large-area flow system is considered to incorporate all alluvial sediments in hydrologic connection with the South Platte River. The small- area flow system is considered to incorporate the alluvial aquifer in the vicinity of the river. Flow-path lengths in the large-area flow system were considered to be on the order of hundreds of feet to more than a mile, whereas in the small-area flow system, they were considered to be on the order of feet to hundreds of feet. Mass-balance estimates of incremental ground-water discharge from the large- area flow system ranged from -27 to 17 cubic feet per second per mile in three reaches of the river; the median rate was 4.6 cubic feet per second per mile. The median percentage of surface-water discharge derived from ground-water discharge in the river reaches studied was 13 percent. Instantaneous measurements of ground-water discharge from the small-area flow system ranged from -1,360 to 1,000 cubic feet per second per mile, with a median value of -5.8 cubic feet per second per mile. Hourly measurements of discharge from the small-area flow system indicated that the high rates of discharge were transient and may have been caused by daily fluctuations in river stage due to changing effluent-discharge rates from the Metro Wastewater Reclamation District treatment plant. Higher river stages caused surface water to infiltrate bed sediments underlying the river channel, and lower river stages allowed ground water to discharge into the river. Although stage changes apparently cycled large quantities of water in and out of the small- area flow system, the process probably provided no net gain or loss of water to the river. In general, mass balance and instantaneous measurements of ground-water discharge indicated that the ground- water flow system in the vicinity of the river consisted of a large-area flow system that provided a net addition of water to the river and a small- area flow system that cycled water in and out of the riverbed sediments, but provided no net addition of water to the river. The small-area flow system was superimposed on the large-area flow system. The median values of pH and dissolved oxygen

Water-Resources Investigations Report↗
USGS2000

Role of lake regulation on glacier fed rivers in enhancing salmon productivity: The Cook Inlet watershed south central Alaska, USA

Rivers fed by glaciers constitute a major part of the freshwater runoff into the Cook Inlet basin of south-central Alaska. This basin is very important to the economy of the State of Alaska because it is home to more than half of the population and it supports multi-million dollar commercial, subsistence and sport fisheries. Hence an understanding of how glacial runoff influences biological productivity is important for managing rivers that drain into Cook Inlet. This paper examines the ways in which the regulation of glacier-fed rivers by proglacial lakes affects salmon productivity, with particular reference to the Kenai River. Salmon escapement per unit channel length on the Kenai River is between two and ten times that found for rain-and-snowmelt dominated rivers and glacier-fed rivers lacking lake regulation. Lakes are shown to influence biological processes in glacier-fed rivers by attenuating peak flows, sustaining high flows throughout the summer, supplementing winter low flows, settling suspended sediment, and increasing river temperatures. Downstream from large lakes, glacier-fed rivers are less disturbed, channels are relatively stable and have well-developed salmonid habitats. The positive influences are indicated by the high diversity and abundances of benthic macroinvertebrates, which are important food resources for juvenile salmonids. High summer flows allow access for up-river salmon runs and lakes also provide both overwintering and rearing habitat. Copyright ?? 2000 John Wiley & Sons, Ltd.Rivers fed by glaciers constitute a major part of the freshwater runoff into the Cook Inlet basin of south-central Alaska. This basin is very important to the economy of the State of Alaska because it is home to more than half of the population and it supports multi-million dollar commercial, subsistence and sport fisheries. Hence an understanding of how glacial runoff influences biological productivity is important for managing rivers that drain into Cook Inlet. This paper examines the ways in which the regulation of glacier-fed rivers by proglacial lakes affects salmon productivity, with particular reference to the Kenai River. Salmon escapement per unit channel length on the Kenai River is between two and ten times that found for rain-and-snowmelt dominated rivers and glacier-fed rivers lacking lake regulation. Lakes are shown to influence biological processes in glacier-fed rivers by attenuating peak flows, sustaining high flows throughout the summer, supplementing winter low flows, settling suspended sediment, and increasing river temperatures. Downstream from large lakes, glacier-fed rivers are less disturbed, channels are relatively stable and have well-developed salmonid habitats. The positive influences are indicated by the high diversity and abundances of benthic macroinvertebrates, which are important food resources for juvenile salmonids. High summer flows allow access for up-river salmon runs and lakes also provide both overwintering and rearing habitat.

Hydrological Processes↗
USGS2008

Survival and migration behavior of juvenile coho salmon in the Klamath River relative to discharge at Iron Gate Dam, Northern California, 2007

This report describes a study of survival and migration behavior of juvenile coho salmon in the Klamath River relative to discharge at Iron Gate Dam in 2006. This was the second year of a multi-year study with the goal of determining the effects of discharge at Iron Gate Dam on survival of juvenile coho salmon downstream. The study was a collaborative effort among U.S. Geological Survey (USGS), U.S. Fish and Wildlife Service (USFWS), and the Yurok and Karuk Tribal Fisheries Departments. The goals of the study included: 1) estimating the survival of wild and hatchery juvenile coho salmon in the Klamath River downstream from Iron Gate Dam, 2) determining the effects of discharge and other covariates on their survival and migration, and 3) determining if fish from Iron Gate Hatchery could be used as surrogates for the limited source of wild fish. The major findings of the study in 2006 include: River discharges during the 2006 study period (4 April through 21 July 2006) were among the greatest on record. Average daily discharge at Iron Gate Dam was 3,956 cubic feet per second (cfs) and ranged from 997 to 10,300 cfs. Discharge at Iron Gate Dam was positively correlated with discharges of tributaries downstream due to the above average water year and frequent occurrence of spill at Iron Gate Dam. Average daily discharge near the estuary was 25,789 cfs and ranged from 4,740 to 50,600 cfs. This study was based on hatchery fish taken directly from a tank at Iron Gate Hatchery and wild fish captured in a rotary trap on the Shasta River. Releases of both groups began on 4 April when the catch of wild fish in California Department of Fish and Game‟s Shasta River rotary trap increased, but trap catches varied throughout the study period, resulting in differences in release dates of hatchery and wild fish. A total of 211 hatchery fish were released from 4 April through 26 May. Wild and hatchery fish released on a regular schedule between 25 April and 16 May 2006 were used in comparisons of the survival and migration of hatchery (N = 120) and wild (N = 162) fish. Additional analyses were performed using hatchery fish from all dates. The data and models did not support clear differences between survivals of hatchery and wild fish released on common dates, so estimates of reach survivals were made after pooling these data. Estimates of survival were lowest in the Iron Gate Dam to Scott River reach (0.813) and greatest in the Salmon River to Trinity River reach (1.000). The overall survival from river kilometer 309 (Iron Gate Hatchery) to river kilometer 33 was 0.653 (95% CI 0.578 to 0.729). Estimates of survival based on all hatchery fish releases were similar to those from release dates common to hatchery and wild fish and are similar to those in other river systems over similar distances. The migrations of hatchery and wild fish were different in the uppermost sections of the study area and were similar thereafter. A lag between release and migration, primarily upstream from the Scott River (river kilometer 234), was present in hatchery fish to a greater extent than in wild fish, resulting in differences in migration rates. Fish from both origins spent more time between release and the Scott River than in individual reaches downstream, and this was the only reach in which travel times of fish increased as discharge decreased. The travel times of hatchery and wild fish between sites were statistically similar downstream from Indian Creek (river kilometer 178). There were differences and similarities in the analyses of the effects of covariates on survivals of hatchery and wild fish. The models of covariate effects based on hatchery and wild fish released on common dates indicated effects on wild fish survival that were not supported in data from hatchery fish. However, when the entire suite of hatchery fish releases were used the results of the analyses were similar to those based on wild fish. In both instances the effects of temperature and release date were primarily in the first reach, the reach fish of both origins spent most of their time within. The signs of the effects of these covariates differed among the fish origins (negative for wild and positive for hatchery fish), presumably due to differences in their migrations in the first reach. The effects of dam discharge on survivals of hatchery and wild fish were generally similar (positive relation), and the effects on hatchery, and to a lesser extent wild, fish were largely downstream from the Scott River. This is likely due to the prolonged residence of the naïve hatchery fish, and to a lesser extent, migrant wild fish between release and the Scott River. Inasmuch as the differences between hatchery and wild fish we observed were likely those of migrants vs. non-migrants, the use of hatchery fish captured as they are migrating downstream, rather than those directly from hatchery tanks (i.e., naïve), may improve similarities between hatchery and wild fish in future studies. The data and models used in 2006 do not support the use of naïve hatchery fish as surrogates for migrant wild fish in determining the effects of discharge on survival upstream from the Scott River. This conclusion is based on the different effects of covariates in this reach that were likely attributable to the differences in hatchery and wild migration behaviors in this reach. The results of this second year of research provide insight to the migration and survival of hatchery and wild juvenile coho salmon in the Klamath River, but the results are from a single unusual water year. The results may be different during other water year types. The current information supports a positive relation between discharge at Iron Gate Dam and survival of juvenile coho salmon downstream, but additional data should be used to refine this relation. Discharge at the dam was correlated with discharges of Klamath River tributaries during this above average water year. The data and models from the 2006 study provide the first estimates of survival of these fish in the Klamath River and can be used with data from years with other water year types to examine the effects of discharge on survival. This will only be possible over a period of years in which the correlations between discharge and other factors, such as water temperature and date, are diminished. An experimental approach in which discharges are varied at Iron Gate Dam is the most direct method to determine if survivals are affected by discharge, but this may not be feasible given the limited storage capacity of the project.

California↗
USGS2012

Dissolved oxygen analysis, TMDL model comparison, and particulate matter shunting—Preliminary results from three model scenarios for the Klamath River upstream of Keno Dam, Oregon

Efforts are underway to identify actions that would improve water quality in the Link River to Keno Dam reach of the Upper Klamath River in south-central Oregon. To provide further insight into water-quality improvement options, three scenarios were developed, run, and analyzed using previously calibrated CE-QUAL-W2 hydrodynamic and water-quality models. Additional scenarios are under development as part of this ongoing study. Most of these scenarios evaluate changes relative to a "current conditions" model, but in some cases a "natural conditions" model was used that simulated the reach without the effect of point and nonpoint sources and set Upper Klamath Lake at its Total Maximum Daily Load (TMDL) targets. These scenarios were simulated using a model developed by the U.S. Geological Survey (USGS) and Watercourse Engineering, Inc. for the years 2006–09, referred to here as the "USGS model." Another model of the reach was developed by Tetra Tech, Inc. for years 2000 and 2002 to support the Klamath River TMDL process; that model is referred to here as the "TMDL model." The three scenarios described in this report included (1) an analysis of whether this reach of the Upper Klamath River would be in compliance with dissolved oxygen standards if sources met TMDL allocations, (2) an application of more recent datasets to the TMDL model with comparison to results from the USGS model, and (3) an examination of the effect on dissolved oxygen in the Klamath River if particulate material were stopped from entering Klamath Project diversion canals. Updates and modifications to the USGS model are in progress, so in the future these scenarios will be reanalyzed with the updated model and the interim results presented here will be superseded. Significant findings from this phase of the investigation include: * The TMDL analysis used depth-averaged dissolved oxygen concentrations from model output for comparison with dissolved oxygen standards. The Oregon dissolved oxygen standards do not specify whether the numeric criteria are based on depth-averaged dissolved oxygen concentration; this was an interpretation of the standards rule by the Oregon Department of Environmental Quality (ODEQ). In this study, both depth-averaged and volume-averaged dissolved oxygen concentrations were calculated from model output. Results showed that modeled depth-averaged concentrations typically were lower than volume-averaged dissolved oxygen concentrations because depth-averaging gives a higher weight to small volume areas near the channel bottom that often have lower dissolved oxygen concentrations. Results from model scenarios in this study are reported using volume-averaged dissolved oxygen concentrations. * Under all scenarios analyzed, violations of the dissolved oxygen standard occurred most often in summer. Of the three dissolved oxygen criteria that must be met, the 30-day standard was violated most frequently. Under the base case (current conditions), fewer violations occurred in the upstream part of the reach. More violations occurred in the down-stream direction, due in part to oxygen demand from the decay of algae and organic matter from Link River and other inflows. * A condition in which Upper Klamath Lake and its Link River outflow achieved Upper Klamath Lake TMDL water-quality targets was most effective in reducing the number of violations of the dissolved oxygen standard in the Link River to Keno Dam reach of the Klamath River. The condition in which point and nonpoint sources within the Link River to Keno Dam reach met Klamath River TMDL allocations had no effect on dissolved oxygen compliance in some locations and a small effect in others under current conditions. On the other hand, meeting TMDL allocations for nonpoint and point sources was predicted to be important in meeting dissolved oxygen criteria when Upper Klamath Lake and Link River also met Upper Klamath TMDL water-quality targets. * The location of greatest dissolved oxygen improvement from nutrient and organic matter reductions was downstream from point and nonpoint source inflows because time and distance are required for decay to occur and for oxygen demand to be exerted. * After assessing compliance with dissolved oxygen standards at all 102 model segments in the Link River to Keno Dam reach, it was determined that the seven locations used by ODEQ appear to be a representative subset of the reach for dissolved oxygen analysis. * The USGS and TMDL models were qualitatively compared by running both models for the 2006–09 period but preserving the essential characteristics of each, such as organic matter partitioning, bathymetric representation, and parameter rates. The analysis revealed that some constituents were not greatly affected by the differing algorithms, rates, and assumptions in the two models. Conversely, other constituents, especially organic matter, were simulated differently by the two models. Organic matter in this river system is best represented by a mixture of relatively labile particulate material and a substantial concentration of refractory dissolved material. In addition, the use of a first-order sediment oxygen demand, as in the USGS model, helps to capture the seasonal and dynamic effect of settled organic and algal material. * Simulation of shunting (diverting) particulate material away from the intake of four Klamath Project diversion canals, so that the material stayed in the river and out of the Project area, caused higher concentrations of particulate material to occur in the river. In all cases modeled, the increase in in-river particulate material also produced decreased dissolved oxygen concentrations and an increase in the number of days when dissolved oxygen standards were violated. * If particulate material were shunted back into the river at the Klamath Project diversion canals, less organic matter and nutrients would be taken into the Klamath Project area and the Lost River basin, resulting in return flows to the Klamath River via Lost River Diversion Channel that may have reduced nutrient concentrations. Model scenarios bracketing potential end-member nutrient concentrations showed that the composition of the return flows had little to no effect on dissolved oxygen compliance under simulated conditions.

Oregon↗