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USGS2004

Hydrologic and water-quality characteristics for Calf Creek near Silver Hill, Arkansas, and selected Buffalo River sites, 2001-2002

The Buffalo River and its tributary, Calf Creek, are in the White River Basin in the Ozark Plateaus physiographic province in north-central Arkansas. A better understanding of the hydrology and water quality of Calf Creek is of interest to many, including the National Park Service, which administers the Buffalo National River, to evaluate its effect on the hydrology and water quality of the Buffalo River. The streamflow and water-quality characteristics of Calf Creek near Silver Hill, Arkansas, were compared to two sites on the Buffalo River upstream (near Boxley, Arkansas) and downstream (near St. Joe, Arkansas) from the confluence of Calf Creek for calendar years 2001 and 2002. Annual and seasonal loads were estimated for Calf Creek for nutrients, dissolved organic carbon, and suspended sediment and compared with loads at sites on the Buffalo River. Flow-weighted concentrations and yields were computed from estimated annual loads for comparison with other developed and undeveloped basins. Streamflow varied annually and seasonally at the three sites. The Buffalo River near St. Joe had the largest annual mean streamflow (805 to 1,360 cubic feet per second for 2001 and 2002) compared to the Buffalo River near Boxley (106 and 152 cubic feet per second for 2001 and 2002) and Calf Creek (39 and 80 cubic feet per second for 2001 and 2002). Concentrations of nutrients, suspended sediment, and fecal indicator bacteria generally were greater in samples from Calf Creek than in samples collected from both Buffalo River sites. Bacteria and suspended-sediment concentrations were greater in samples collected during high-flow events at all three sites. The Buffalo River near Boxley had the lowest concentrations for nutrients, suspended sediment, and fecal indicator bacteria. Estimated annual loads of the nutrients, suspended sediment, and organic carbon for 2001 and 2002 demonstrated substantial variability between the three sites and through time. Estimated loads for nutrients at the Buffalo River near St. Joe were 7 to 27 times the median loads estimated for Calf Creek and suspended sediment loads were as much as 120 times greater. Dissolved organic carbon loads were 16 to 20 times greater at the Buffalo River near St. Joe than for Calf Creek. The Buffalo River near Boxley had the smallest annual loads for all constituents except for suspended sediment, which were slightly greater than suspended sediment loads estimated for Calf Creek. Higher loads would be expected at the Buffalo River near St. Joe because of the larger basin area and larger volume of streamflow. Likewise, estimated loads for all three sites were greater during seasons that had greater streamflow than during seasons with more frequent periods of base-flow conditions. The highest daily loads occurred in the fall and winter of 2001 and the winter and spring of 2002.Flow-weighted concentrations generally were higher for Calf Creek than concentrations for the two sites on the Buffalo River and for typical flow-weighted concentrations found in undeveloped basins. However, the flow-weighted concentrations were lower than concentrations in a developed basin. Annual yields calculated for Calf Creek were higher than the two sites on the Buffalo River and sites that are representative of undeveloped basins but lower than a site representative of a developed basin. The Buffalo River near Boxley had yields that were less than the yields typical of undeveloped basins.

Arkansas↗

USGS2005

Hydrologic and water-quality conditions in the Kansas River, northeast Kansas, November 2001–August 2002, and simulation of ammonia assimilative capacity and bacteria transport during low flow

Large concentrations of ammonia and densities of bacteria have been detected in reaches of the Kansas River in northeast Kansas during low streamflow conditions, prompting the Kansas Department of Health and Environment (KDHE) to list these reaches as water-quality limited with respect to ammonia and fecal coliform bacteria. Sources for ammonia and bacteria in the watershed consist of wastewater-treatment facilities (WWTFs) and agricultural and urban runoff. The U.S. Geological Survey (USGS), in cooperation with KDHE, conducted an investigation of the Kansas River to characterize hydrologic and water-quality conditions and to simulate ammonia assimilative capacity and bacteria transport during low streamflow. This report characterizes the water-quality conditions, documents the calibration of a two-dimensional water-quality model, and presents results of hypothetical simulations of existing and future WWTFs discharging to the Kansas River during low streamflow. Water samples were collected during low streamflow conditions at 50 sampling sites along and near the Kansas River between Wamego and Kansas City, Kansas, during three synoptic surveys conducted between November 2001 and August 2002. The analytical results from these samples indicated that ammonia and other nutrient concentrations and fecal coliform bacteria densities increased in the Kansas River from Wamego to Kansas City. Point sources were the primary contributors of ammonia and fecal coliform bacteria during low-flow conditions. Generally, ammonia concentrations in the Kansas River were largest at sampling sites just downstream from WWTFs. Overall, ammonia concentrations in the Kansas River, tributaries, and WWTF effluent were larger in the winter than during the summer. None of the main-stem sample concentrations exceeded the State of Kansas pH- and temperature-dependent chronic aquatic-life criteria for ammonia during the sampling periods. Other nutrients, such as total nitrogen and total phosphorus, indicated a similar, but less variable, spatial pattern along the main stem of the Kansas River, with concentrations increasing slightly downstream from major WWTFs. The temporal variance defined by the results of synoptic survey III (July 22–August 8, 2002) indicated that ammonia concentrations in the Kansas River sometimes varied daily by as much as 155 percent at a single site. Samples analyzed for densities of fecal coliform bacteria illustrated a seasonal, spatial, and temporal pattern slightly different from that of nutrients. Overall, the bacteria densities measured during the summer were larger than the densities measured in the winter. The only fecal coliform bacteria density to exceed the former State water-quality, single-sample criteria of 2,000 col/100 mL (colonies per 100 milliliters of water) was measured at 4,000 col/100 mL during synoptic III (summer 2002) on the main stem of the Kansas River at Kansas City. Temporal variability measured during synoptic survey III indicated up to a 263-percent difference in bacteria density over a 12-day period. Instantaneous loads of ammonia and bacteria were computed to determine primary inputs to the Kansas River and ammonia and bacteria decay rates in the river. The Oakland WWTF in Topeka was the largest contributor of both ammonia and bacteria on the basis of samples collected during the three synoptic surveys, except for fecal coliform bacteria collected during synoptic survey III when the DeSoto WWTF was discharging the largest concentration of bacteria. The ammonia assimilative process was about twice as effective during the summer synoptic survey than it was during the winter survey. Decay of fecal coliform bacteria density was less evident and appeared to have little seasonal effect on the basis of data collected for this report. The summer low-streamflow water-quality conditions were suitable for nitrification, algae that consume ammonia, and consequently, decaying organic matter that consume oxygen. The consumption of dissolved oxygen due to nitrification and decaying algae contributed to three measurements of dissolved oxygen that were less than the State of Kansas aquatic-life-support use criteria of 5.0 milligrams per liter. CE–QUAL–W2, a two-dimensional, hydrodynamic and water-quality model, was used to simulate ammonia and bacteria transport in the Kansas River from Topeka to Kansas City. The model was calibrated and verified using data from the three synoptic surveys. The calibrated model successfully simulated the hydrodynamics, water temperature, dissolved oxygen, ammonia, and fecal coliform bacteria in the Kansas River. Simulated in-stream ammonia concentrations were compared to measured concentrations upstream to downstream along the Kansas River. The simulated in-stream ammonia concentrations mostly overestimated the measured values for both winter and summer, with a few exceptions. Comparisons between measured and simulated in-stream ammonia concentrations indicated ammonia assimilation was simulated more accurately in the summer than during the winter. Four hypothetical simulations of varied effluent discharges from existing WWTFs and addition of a proposed WWTF near DeSoto were simulated to better understand future water-quality conditions in the Kansas River. Results indicated that ammonia and dissolved-oxygen concentrations in the Kansas River will decrease from the conditions observed during synoptic surveys II (February 25 through March 1, 2002) and III (July 22 through August 8, 2002) except near the proposed WWTF where concentrations of ammonia would be near or exceed criteria for waterborne species. Effects of the proposed WWTF on dissolved oxygen would result in concentrations less than the State of Kansas aquatic-life-support use criteria of 5.0 milligrams per liter for 1 to 2 miles downstream from either of the proposed sites.

Kansas↗

USGS2012

Analysis of trends in selected streamflow statistics for the Concho River Basin, Texas, 1916-2009

The Concho River Basin is part of the upper Colorado River Basin in west-central Texas. Monotonic trends in streamflow statistics during various time intervals from 1916-2009 were analyzed to determine whether substantial changes in selected streamflow statistics have occurred within the Concho River Basin. Two types of U.S. Geological Survey streamflow data comprise the foundational data for this report: (1) daily mean discharge (daily discharge) and (2) annual instantaneous peak discharge. Trend directions are reported for the following streamflow statistics: (1) annual mean daily discharge, (2) annual 1-day minimum discharge, (3) annual 7-day minimum discharge, (4) annual maximum daily discharge, and (5) annual instantaneous peak discharge. The South Concho, Middle Concho, and North Concho Rivers drain the upper part of the Concho River Basin. The North and South Concho Rivers converge in San Angelo, Tex., to form the Concho River. The Concho River flows east from San Angelo to its confluence with the Colorado River east of Paint Rock, Tex. The trend analyses principally focused on application of the nonparametric Kendall's Tau statistical test to detect monotonic trends (dependency) in streamflow with time; in other words, Kendall's Tau is a test of temporal independence of streamflow with time. A positive Tau indicates an upward monotonic streamflow trend; conversely, a negative Tau indicates a downward monotonic streamflow trend. Hence, the trend analysis reported here is limited to direction and not magnitude of streamflow change. Six U.S. Geological Survey streamflow-gaging stations were selected for analysis. Streamflow-gaging station 08128000 South Concho River at Christoval has downward trends for annual maximum daily discharge and annual instantaneous peak discharge for the combined period 1931-95, 2002-9. Streamflow-gaging station 08128400 Middle Concho River above Tankersley has downward trends for annual maximum daily discharge and annual instantaneous peak discharge for the combined period 1962-95, 2002-9. Streamflow-gaging station 08128500 Middle Concho River near Tankersley has no significant trends in the streamflow statistics considered for the period 1931-60. Streamflow-gaging station 08134000 North Concho River near Carlsbad has downward trends for annual mean daily discharge, annual 7-day minimum daily discharge, annual maximum daily discharge, and annual instantaneous peak discharge for the period 1925-2009. Streamflow-gaging stations 08136000 Concho River at San Angelo and 08136500 Concho River at Paint Rock have downward trends for 1916-2009 for all streamflow statistics calculated, but streamflow-gaging station 08136000 Concho River at San Angelo has an upward trend for annual maximum daily discharge during 1964-2009. The downward trends detected during 1916-2009 for the Concho River at San Angelo are not unexpected because of three reservoirs impounding and profoundly regulating streamflow.

Texas↗

USGS2013

Pilot study of natural attenuation of arsenic in well water discharged to the Little River above Lake Thunderbird, Norman, Oklahoma, 2012

The City of Norman, Oklahoma, wanted to augment its water supplies to meet the needs of an increasing population. Among the city’s potential water sources are city wells that produce water that exceeds the 10 micrograms per liter primary drinking-water standard for arsenic. The City of Norman was interested in investigating low-cost means of using natural attenuation to remove arsenic from well water and augment the water supply of Lake Thunderbird, the primary water source for the city. The U.S. Geological Survey, in cooperation with the City of Norman, conducted a preliminary investigation (pilot study) to determine if discharge of water from those wells into the Little River over a 12-day period would reduce arsenic concentrations through natural-attenuation processes. Water in the Little River flows into Lake Thunderbird, the principal water source for the city, so the discharged well water would improve the water balance of that reservoir. During this pilot study, 150–250 gallons per minute from each of six city wells were discharged to the Little River over a 12-day period. Water-quality samples were collected from the wells during discharge and from the river before, during, and after well discharges. Streambed-sediment samples were collected at nine sites in the river before and after the well-discharge period. Water discharge from the six wells added 0.3 kilogram per day of arsenic to the river at the nearest downstream streamflow-gaging station. Dissolved arsenic concentration in the Little River at the closest downstream sampling site from the wells increased from about 4 micrograms per liter to as much as 24 micrograms per liter. Base flow in the river increased by about 1.7 cubic feet per second at the nearest downstream streamflow-gaging station. Streamflow in the river was two-thirds of that expected from the amount of water discharged from the wells because of seepage to soils and evapotranspiration of well water along drainage ways to the river. Arsenic concentrations at the nearest downstream streamflow-gaging station were less than arsenic concentrations measured in many of the well-water samples during the well-pumping period. Arsenic concentrations, loads, and yields in the Little River generally decreased downstream from the closest streamflow-gaging station to the wells by 50 percent or more, indicating removal of about 0.25 kilogram or 0.53 pound per day of arsenic during base-flow conditions. Measured river-water arsenic concentrations near the confluence of the Little River with Lake Thunderbird were in compliance with the primary drinking-water standard. Arsenic concentrations measured at four downstream stations in the Little River also were less than established criteria set for protection of aquatic biota. After well discharges to the Little River were stopped, arsenic concentrations, loads, and yields in the river gradually decreased over 14 days to concentrations measured prior to the well-water discharges. Cumulative loads of arsenic discharged at the wells and the closest and farthest downstream streamflow-gaging stations indicated removal of about 2.5 kilograms of arsenic as well-water flowed to and down the river. Arsenic concentrations in streambed-sediment samples collected before and after the well-water discharges were not significantly different. Results of this pilot study indicate that using natural-attenuation processes to remove arsenic from water and supplement city water supplies may be a viable, relatively low-cost method for attenuating arsenic in well water and for augmenting the water supply of Lake Thunderbird.

Oklahoma↗

USGS2013

Groundwater contributions of flow, nitrate, and dissolved organic carbon to the lower San Joaquin River, California, 2006-08

The influence of groundwater on surface-water quality in the San Joaquin River, California, was examined for a 59-mile reach from the confluence with Salt Slough to Vernalis. The primary objective of this study was to quantify the rate of groundwater discharged to the lower San Joaquin River and the contribution of nitrate and dissolved organic carbon concentrations to the river. Multiple lines of evidence from four independent approaches were used to characterize groundwater contributions of nitrogen and dissolved organic carbon. Monitoring wells (in-stream and bank wells), streambed synoptic surveys (stream water and shallow groundwater), longitudinal profile surveys by boat (continuous water-quality parameters in the stream), and modeling (MODFLOW and VS2DH) provided a combination of temporal, spatial, quantitative, and qualitative evidence of groundwater contributions to the river and the associated quality. Monitoring wells in nested clusters in the streambed (in-stream wells) and on both banks (bank wells) along the river were monitored monthly from September 2006 to January 2009. Nitrate concentrations in the bank wells ranged from less than detection—that is, less than 0.01 milligrams per liter (mg/L) as nitrogen (N)—to approximately 13 mg/L as N. Nitrate was not detected at 17 of 26 monitoring wells during the study period. Dissolved organic carbon concentrations among monitoring wells were highly variable, but they generally ranged from 1 to 4 mg/L. In a previous study, 14 bank wells were sampled once in 1988 following their original installation. With few exceptions, specific conductivity and nitrate concentrations measured in this study were virtually identical to those measured 20 years ago. Streambed synoptic measurements were made by using a temporarily installed drive-point piezometer at 113 distinct transects across the stream during 4 sampling events. Nitrate concentrations exceeded the detection limit of 0.01 mg/L as N in 5 percent of groundwater samples collected from the in-stream wells as part of the synoptic surveys. Only 7 of the 113 cross-sectional transects had nitrate concentrations greater than 1 mg/L as N. In contrast, surface waters in the San Joaquin River tended to have nitrate concentrations in the 1–3 mg/L as N range. A zone of lower oxygen (less than 2 mg/L) in the streambed could limit nitrate contributions from regional groundwater flow because nitrate can be converted to nitrogen gas within this zone. Appreciable concentrations of ammonium (average concentration was 1.92 mg/L as N, and 95th percentile was 10.34 mg/L as N) in the shallow groundwater, believed to originate from anoxic mineralization of streambed sediments, could contribute nitrogen to the overlying stream as nitrate following in-stream nitrification, however. Dissolved organic carbon concentrations were highly variable in the shallow groundwater below the river (1 to 6 ft below streambed) and generally ranged between 1 and 5 mg/L, but had maximum concentrations in the 15–25 mg/L range. The longitudinal profile surveys were not particularly useful in identifying groundwater discharge areas. However, the longitudinal approach described in this report was useful as a baseline survey of measured water-quality parameters and for identifying tributary inflows that affect surface-water concentrations of nitrate. Results of the calibrated MODFLOW model indicated that the simulated groundwater discharge rate was approximately 1.0 cubic foot per second per mile (cfs/mi), and the predominant horizontal groundwater flow direction between the deep bank wells was westward beneath the river. The modeled (VS2DH) flux values (river gain versus river loss) were calculated for the irrigation and non-irrigation season, and these fluxes were an order of magnitude less than those from MODFLOW. During the irrigation season, the average river gain was 0.11 cfs/mi, and the average river loss was −0.05 cfs/mi. During the non-irrigation season, the average river gain was 0.10 cfs/mi, and the average river loss was -0.08 cfs/mi. Information on groundwater interactions and water quality collected for this study was used to estimate loads of nitrate and dissolved organic carbon from the groundwater to the San Joaquin River. Estimated loads of dissolved inorganic nitrogen and dissolved organic carbon were calculated by using concentrations measured during four streambed synoptic surveys and the estimated groundwater discharge rate to the San Joaquin River from MODFLOW of 1 cfs/mi. The estimated groundwater loads to the San Joaquin River for dissolved inorganic nitrogen and dissolved organic carbon were 300 and 350 kilograms per day, respectively. These loads represent 9 and 7 percent, respectively, of the estimated instantaneous surface-water loads for dissolved inorganic nitrogen and dissolved organic carbon at the most downstream site, Vernalis, measured during the four streambed synoptic surveys.

California↗

USGS2016

Generalized sediment budgets of the Lower Missouri River, 1968–2014

Sediment budgets of the Lower Missouri River were developed in a study led by the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers. The scope of the study included the development of a long-term (post-impoundment, 1968–2014) average annual sediment budget and selected annual, monthly, and daily sediment budgets for a reach and period that adequate data were available. Included in the analyses were 31 main-stem and tributary stations of the Lower Missouri River and two Mississippi River stations—the Mississippi River below Grafton, Illinois, and the Mississippi River at St. Louis, Missouri. Long-term average annual suspended-sediment loads of Missouri River main-stem stations ranged from 0.33 million tons at the Missouri River at Yankton, South Dakota, station to 71.2 million tons at Missouri River at Hermann, Mo., station. Gaged tributary gains accounted for 9–36 percent of the local reach budgets and cumulative gaged tributary contributions accounted for 84 percent of the long-term average suspended-sediment load of the Missouri River at Hermann, Mo., station. Although the sediment budgets for seven defined main-stem reaches generally were incomplete—missing bedload, reach storage, and ungaged tributary contributions—the budget residuals (net result of sediment inputs and outputs) for six of the seven reaches ranged from -7.0 to 1.7 million tons, or from -9.2 to 4.0 percent of the reach output suspended-sediment load, and were within the 10 percent reported measurement error of annual suspended-sediment loads for large rivers. The remaining reach, downstream from Gavin’s Point Dam, extended from Yankton, S. Dak., to Sioux City, Iowa, and had a budget residual of -9.8 million tons, which was -88 percent of the suspended-sediment load at Sioux City. The Lower Missouri River reach from Omaha, Nebraska, to Nebraska City, Nebr., had periods of concurrent sediment data for each primary budget component with which to analyze and determine a suspended-sediment budget for selected annual, monthly, and daily time increments. The temporal changes in the cumulative annual budget residuals were poorly correlated with the comparatively steady 1968–2011 annual stage trends at the Missouri River at Nebraska City, Nebr., station. An accurate total sediment budget is developed by having concurrent data available for all primary suspended and bedload components for a reach of interest throughout a period. Such a complete budget, with concurrent record for suspended-sediment load and bedload components, is unavailable for any reach and period in the Lower Missouri River. The primary data gaps are in bedload data, and also in suspended-sediment gains and losses including ungaged tributary inputs and sediment storage. Bedload data gaps in the Missouri River Basin are much more prevalent than suspended-sediment data gaps, and the first step in the development of reach bedload budgets is the establishment of a standardized bedload monitoring program at main-stem stations. The temporal changes in flow-adjusted suspended-sediment concentrations analyzed at main-stem Missouri River stations indicated an overall downward change in concentrations between 1968 and 2014. Temporary declines in flow-adjusted suspended-sediment concentrations during and following large floods were evident but generally returned to near pre-flood values within about 6 months. Data uncertainties associated with the development of a sediment budget include uncertainties associated with the collection of suspended-sediment and bedload data and the computation of suspended-sediment loads. These uncertainties vary depending on the frequency of data collection, the variability of conditions being represented by the discrete samples, and the statistical approach to suspended-sediment load computations. The coefficients of variation of suspended-sediment loads of Missouri River tributary stations for 1968–2014 were greater, 75.0 percent, than the main-stem stations, 47.1 percent. The lower coefficient of variation at main-stem stations compared to tributaries, primarily is the result of the lower variability in streamflow and sediment discharge identified at main-stem stations. To obtain similar accuracy between suspended-sediment loads at main-stem and tributary stations, a longer period of record is required of the tributary stations. During 1968–2014, however, the Missouri River main-stem station record was much more complete (87 percent) than the tributary station record (28 percent).

Missouri River Basin↗

USGS2018

Water-quality conditions with an emphasis on cyanobacteria and associated toxins and taste-and-odor compounds in the Kansas River, Kansas, July 2012 through September 2016

Cyanobacteria cause a multitude of water-quality concerns, including the potential to produce toxins and taste-and-odor compounds that may cause substantial economic and public health concerns, and are of particular interest in lakes, reservoirs, and rivers that are used for drinking-water supply. Extensive cyanobacterial blooms typically do not develop in the Kansas River; however, reservoirs in the lower Kansas River Basin occasionally develop blooms that may affect downstream water quality. During July 2012 through September 2016, continuous and (or) discrete water-quality data were collected at several sites (Wamego, De Soto, and three main reservoir-fed tributaries) on the Kansas River to characterize the sources, frequency and magnitude of occurrence, and causes of cyanobacteria, cyanobacterial toxins, and taste-and-odor compounds and to develop a real-time notification system of changing water-quality conditions that may affect drinking-water treatment. Algal biomass, as estimated by chlorophyll, was consistently higher at the downstream De Soto site than the upstream Wamego site. Higher algal biomass at the De Soto site likely was caused by algal growth during downstream transport without major losses due to grazing by aquatic organisms or other processes. Algal biomass at the Wamego and De Soto sites was negatively correlated with streamflow and total and bioavailable nutrient concentrations. The negative association between algal biomass and nutrients in the Kansas River likely reflects the relatively strong positive association between nutrient concentrations and streamflows. Cyanobacteria were relatively common in the Kansas River but rarely dominated the algal community. Like overall algal biomass, cyanobacterial abundances typically were higher at the De Soto site than the Wamego site. Cyanobacterial abundances generally peaked in late summer or early fall (July through October), with smaller peaks occasionally observed in spring (April through May). Cyanobacteria in the Kansas River rarely exceeded 20,000 cells per milliliter, the abundance at which cyanobacteria may become a concern for drinking-water treatment. Relations between cyanobacterial abundance and streamflow, turbidity, and nutrients in the Kansas River were similar to those between chlorophyll and total phytoplankton abundance, indicating the same processes that influence overall algal biomass and dynamics also are influencing cyanobacteria. The cyanotoxin microcystin was detected in about 27 percent of the samples collected from Kansas River tributary and main-stem sites. Cylindrospermopsin was detected in one sample from the De Soto site. Microcystin occurrence and concentration were similar between the Wamego and De Soto sites. Concentrations exceeded the U.S. Environmental Protection Agency health advisory guidance values for finished drinking water of 0.3 (for bottle-fed infants and pre-school children) and 1.6 micrograms per liter (μg/L; for school-age children and adults) in 6 percent or less of samples collected. These guidance values are for finished drinking water and are not directly applicable to observed environmental concentrations but do provide a benchmark for comparison. Microcystin was detected most often and had the highest concentrations during summer. Though seasonal patterns in microcystin occurrence were generally consistent, seasonal maxima varied by an order of magnitude across years. The taste-and-odor compounds geosmin and 2-methylisoborneol (MIB) were detected in about 78 and 43 percent of samples, respectively, collected across all sites (main stem and tributaries). Geosmin and MIB occurrence and concentration varied considerably between the Wamego and De Soto sites. Geosmin was detected in about 67 percent of Wamego samples and 81 percent of De Soto samples. The human detection threshold of 5 nanograms per liter (ng/L) was exceeded for geosmin in about 11 and 17 percent of the samples collected at the Wamego and De Soto sites, respectively. Geosmin was detected during all months of the year at both sites, and there were no clear seasonal patterns. MIB was detected less frequently in the Kansas River than geosmin and was observed in about 42 percent of Wamego samples and 33 percent of De Soto samples. Concentrations exceeded 5 ng/L in about 7 and 5 percent of samples from the Wamego and De Soto sites, respectively. As observed for geosmin, there were no clear seasonal patterns in MIB occurrence or concentration. There seems to be a connection between microcystin detections in the Kansas River and occurrence of microcystin in upstream reservoirs (and tributary streams). Microcystin concentrations greater than 0.3 μg/L may be likely during the summer when streamflow is less than 3,000 cubic feet per second (ft 3 /s) and contributions from Milford Lake exceed about 30 percent of total flow in the Kansas River. Observed microcystin concentrations typically were higher at the De Soto site than the Wamego or tributary sites during 2012 through 2016, indicating cyanobacteria may continue to grow and produce microcystin once introduced to the Kansas River. The spatial and temporal patterns in geosmin and MIB occurrence and concentration were more complex than microcystin. There were no clear connections between geosmin and MIB occurrence in the Kansas River and potential upstream reservoir (or tributary stream) sources. Likewise, there was not a clear relation between algal biomass, cyanobacteria, or actinomycetes bacteria and taste-and-odor events in the Kansas River. Geosmin and MIB were not strongly correlated with any measured environmental variable at either Kansas River site. Continuous water-quality data may be used independently or in combination with regression models to provide information on changing water-quality conditions that may affect drinking-water treatment processes or recreational activities on the Kansas River. For example, logistic regression model outputs and continuous water-quality data may both be indicative of the potential for microcystin events. Logistic regression models that are estimating a high probability of microcystin occurrence at concentrations above 0.1 μg/L can be used as one indicator. Streamflows less than 3,000 ft 3 /s during upstream reservoir releases during periods with low turbidity and increased chlorophyll fluorescence, specific conductance, and pH values may also be indicative of microcystin events. Advanced or near-real-time notification may inform proactive, rather than reactive, management strategies when water-quality conditions are changing rapidly or are likely to cause cyanobacteria-related events.

Kansas↗

USGS2020

Precipitation, temperature, groundwater-level elevation, streamflow, and potential flood storage trends within the Brazos, Colorado, Big Cypress, Guadalupe, Neches, Sulphur, and Trinity River basins in Texas through 2017

The U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers (USACE), analyzed streamflow trends and streamflow-related variables through 2017 in seven important water-supply basins to provide information that can help water managers with the USACE and river authorities make future water management decisions. The primary purpose of this report is to document trends in long-term streamflow data at 114 selected USGS streamflow-gaging stations and 36 simulated reservoir-inflow stations in 7 river basins primarily in Texas: Brazos, Colorado, Big Cypress, Guadalupe, Neches, Sulphur, and Trinity. In this report, trends were considered statistically significant if their p -values were less than or equal to 0.05 ( p -value ≤0.05). Streamflow data selected for temporal trend analyses included annual minimum streamflow, annual peak streamflow, and streamflow volume. Precipitation, air temperature, and groundwater-level-elevation data were analyzed for trends that may help to explain changes observed in the streamflow statistics. Basins were divided into sections along county lines for precipitation analyses. Streamflow volumes were analyzed for associations with potential flood storage. The potential flood storage, defined as the difference between maximum storage and normal storage, was computed for each dam from the National Inventory of Dams database and accumulated over time based on the completion date of the dam. Precipitation and air temperature trends were analyzed for each of the eight climate divisions (High Plains, Trans-Pecos, Low Rolling Hills, Edwards Plateau, North Central Texas, South Central Texas, East Texas, and Upper Coast). Results of precipitation trend analyses indicated moderate upward trends in the Upper Coast and East Texas Climate Divisions analyzed on an annual time step from 1900 through 2017. These two climate divisions are in the eastern and southeastern parts of the State, and they receive more mean annual precipitation (45.88 and 46.09 inches, respectively) than the other climate divisions. The results of air temperature analyses indicated upward trends in annual mean air temperature within all climate divisions, with a mean slope of 0.02 degree Fahrenheit per year, or 1 degree every 50 years. Within the Brazos River Basin, results of precipitation trend analyses on an annual time step indicated that precipitation amounts are most likely increasing in the lower and middle sections of the basin. Downward trends in annual streamflow and in the ratio of streamflow volume to precipitation volume were indicated at 7 of the 15 stations in the upper sections of the basin. The lower sections of the basin had mostly downward trends in annual minimum streamflow, whereas upward trends in annual minimum streamflow were indicated in the upper sections of the basin. Downward trends in annual peak streamflow were indicated at many of the stations in the upper sections of the basin. At the same seven stations in the upper sections of the basin where there were downward trends in annual streamflow, there were also downward trends in the ratio of streamflow volume to precipitation volume. The data from the same seven stations indicated negative associations between potential flood storage volume and annual streamflow volume and downward trends in the ratio of annual streamflow volume to potential flood storage volume. With the known addition of 13,006,394 acre-feet of potential flood storage between 1900 and 2010 in the subbasins analyzed, streamflow volumes have decreased in the upper sections of the Brazos River Basin. Within the Colorado River Basin, results of precipitation trend analyses on an annual time step indicated no trends in the basin. Downward trends in annual streamflow were indicated at 16 stations in the upper sections of the basin, whereas no trends in annual streamflow were indicated in the lower section of the basin. In the lower section of the basin, one station that was operated as a continuous streamflow-gaging station through 2017 had a downward trend in annual minimum streamflow, and another station (operated through 2007) had an upward trend in annual minimum streamflow. In the upper sections of the basin, data from seven stations indicated upward trends in annual minimum streamflow, and data from six stations indicated downward trends. Data from 18 stations in the upper sections of the basin indicated downward trends in annual peak streamflow. Thirteen of the 16 stations in the upper sections of the basin with data that indicated downward trends in annual streamflow also have data that indicated downward trends in the ratio of streamflow volume to precipitation volume. Data from the same 13 stations indicated negative associations between potential flood storage volume and annual streamflow volume and downward trends in the ratio of annual streamflow volume to potential flood storage volume. With the known addition of 7,193,147 acre-feet of potential flood storage between 1891 and 2014 in the subbasins analyzed, streamflow volumes have decreased in the upper sections of the Colorado River Basin. Within the Big Cypress Basin, results of precipitation trend analyses on annual, seasonal, and monthly time steps indicated almost no trends in the basin as defined in this report. However, the annual precipitation p -value only slightly exceeded the p -value threshold for a statistically significant trend. Given the upward trend in precipitation in the East Texas Climate Division, which includes the Big Cypress Basin, and the low p -value for annual precipitation within the basin, precipitation in the basin may be increasing over time. Two annual streamflow trends, one upward and one downward, were in the upper parts of the basin. Data from USGS streamflow-gaging station 07346000 Big Cypress Bayou near Jefferson, Texas, indicated an upward trend in annual minimum streamflow and a downward trend in annual peak streamflow. The station is immediately downstream from Lake O’ the Pines; presumably, minimums have increased because of regulated releases, and annual peaks have decreased because of storage from the lake for flood control. Despite the known addition of 2,737,154 acre-feet of potential flood storage between 1898 and 2011 in the subbasins analyzed, there have not been widespread reductions in streamflow volumes in the Big Cypress Basin, except for within the drainage area for the farthest upstream station on the main stem downstream from Mount Pleasant, Texas. Within the Guadalupe River Basin, results of precipitation trend analyses on an annual time step indicated an upward trend in the lower section of the basin, but no trends in annual streamflow were indicated in the lower section of the basin. In the upper section of the basin, data from 1 of the 13 stations indicated an upward trend in annual streamflow. Data from 6 of the 13 stations in the upper section of the basin indicated a trend in annual minimum streamflow with 4 upward and 2 downward trends. Data from 2 of the 13 stations in the upper section of the basin indicated downward trends in annual peak streamflow. Despite the known addition of 2,016,534 acre-feet of potential flood storage between 1849 and 2013 in the subbasins analyzed, streamflow volumes have not decreased in the Guadalupe River Basin. Within the Neches River Basin, results of precipitation trend analyses on an annual time step indicated upward trends in the basin. None of the data from stations analyzed in the Neches River Basin indicated annual trends in streamflow despite upward trends in annual precipitation within the basin. Data from 9 of the 19 stations analyzed in the basin indicated upward trends in annual minimum streamflow. Data from one of the simulated-inflow stations indicated a downward trend in annual minimum streamflow into Sam Rayburn Reservoir. Data from two stations indicated downward trends in annual peak streamflow, and data from one small subbasin indicated an upward trend in annual peak streamflow. Despite the known addition of 4,839,609 acre-feet of potential flood storage between 1888 and 2008 in the subbasins analyzed, there have not been widespread reductions in streamflow volumes in the Neches River Basin. Within the Sulphur River Basin, results of precipitation trend analyses on an annual time step indicated a moderate upward trend within the basin. Data from only one of the stations, the simulated inflow to Jim Chapman Lake, indicated an annual upward trend in streamflow despite an upward trend in annual precipitation throughout the basin. Data from three of the six stations in the Sulphur River Basin indicated upward trends in annual minimum streamflow, and data from one of the six stations indicated a downward trend in annual peak streamflow. Despite the known addition of 6,933,361 acre-feet of potential flood storage between 1904 and 2006 in the subbasins analyzed, streamflow volumes have not decreased in the Sulphur River Basin. Within the Trinity River Basin, results of precipitation trend analyses on an annual time step indicated upward trends in most sections of the basin. Data from 8 of the 36 stations analyzed for trends in annual streamflow indicated upward trends, and all 8 stations are in the upper sections of the basin. None of the data from stations in the lower sections of the basin indicated trends in annual streamflow. Data from 16 of the 36 stations indicated upward trends in annual minimum streamflow. Upward trends in annual minimum streamflow could be the result of managed reservoir releases in combination with wastewater treatment plant releases in the large Dallas-Fort Worth metroplex in the upper sections of the basin. All the trends in annual peak streamflow were in the sections of the basin that include the Dallas-Fort Worth metroplex. Data from two stations, one USGS streamflow-gaging station and one simulated-inflow station, indicated upward trends in annual peak streamflow, and data from one streamflow-gaging station indicated a downward trend in annual peak streamflow. Of the basins included in this study, the Trinity River Basin has the second largest amount of potential flood storage of 8,947,349 acre-feet from dams added between 1890 and 2013. Eleven stations in the Trinity River Basin had positive associations between potential flood storage volume and annual streamflow volume, indicating that annual streamflow increases as potential flood storage increases. Data from 7 of the 11 stations also indicated upward trends in annual streamflow. The positive associations may be the result of increases in minimum streamflow, which could be the result of any combination of managed reservoir releases, wastewater treatment plant releases, or increased runoff from urbanized areas, particularly in the urbanized area of the Dallas-Fort Worth metroplex.

Texas↗

USGS2021

Cimarron River alluvial aquifer hydrogeologic framework, water budget, and implications for future water availability in the Pawnee Nation Tribal jurisdictional area, Payne County, Oklahoma, 2016–18

The Cimarron River is a free-flowing river and is a major source of water as it flows across Oklahoma. Increased demand for water resources within the Cimarron River alluvial aquifer in north-central Oklahoma (primarily in Payne County) has led to increases in groundwater withdrawals for agriculture, public, irrigation, industrial, and domestic supply purposes. The Pawnee Nation of Oklahoma (Pawnee Nation) is particularly concerned about the sustainability of the Cimarron River alluvial aquifer and whether the aquifer will continue to be a viable water resource for future generations of Tribal members and residents. To better understand current (2021) water resources and possible future water availability in the Pawnee Nation Tribal jurisdictional area, the U.S. Geological Survey, in cooperation with the Bureau of Indian Affairs and the Pawnee Nation of Oklahoma, compiled available hydrogeologic data and developed conceptual and numerical groundwater-flow models for the Cimarron River alluvial aquifer in Payne County, north-central Oklahoma, including a focus area in the Pawnee Nation Tribal jurisdictional area for the 2016–18 study period. A conceptual water budget was created to establish estimates of groundwater fluxes into and out of the aquifer through hydrologic boundaries and groundwater withdrawals for use in the numerical groundwater-flow model. The conceptual water budget focuses on the alluvial aquifer, meaning that inflows include sources of water to the aquifer and that outflows include sources of water out of the aquifer, such as base-flow contributions to the Cimarron River. The conceptual water budget was constructed by using data from 2017 (the most complete year of record for each data type included in the model) for the Pawnee Nation subdomain of the Cimarron River alluvial aquifer model extent (Pawnee Nation subdomain). Groundwater withdrawals were estimated from groundwater-withdrawal rate information for permanent and temporary permitted wells that was obtained from the Oklahoma Water Resources Board. One-half of each annual permitted groundwater-withdrawal rate allotted was used as the estimated annual groundwater-withdrawal amount. Halving the permitted groundwater-withdrawal rate was done because permitted withdrawal rates are the maximum permitted rate and actual groundwater withdrawals are generally appreciably lower than the maximum permitted rate. Total groundwater withdrawals were estimated as 1,300 acre-feet per year for the Pawnee Nation subdomain. Various hydrogeologic data were measured to assist with model development, including depth to bedrock and water-table altitude data. In support of the model development, analyses pertaining to groundwater flow, groundwater/surface-water interactions, base flows in the Cimarron River, and lithological interpretations in the Pawnee Nation Tribal jurisdictional area were used to compute a conceptual water budget applicable to the 2016–18 study period. A numerical groundwater-flow model was developed using the hydrogeologic framework of the Cimarron River alluvial aquifer and the conceptual water budget. The numerical model consists of a single layer representing alluvium and terrace deposits within the alluvial aquifer model area. Hydraulic conductivities were estimated and modeled for the alluvium and terrace deposits in the alluvial aquifer. Base-flow values were estimated using the base-flow index from streamflow data collected at U.S. Geological Survey streamgages. Stream seepage values were derived from the mean 2017 base-flow index between certain streamgages. Hydraulic conductivities were specified an initial (before calibration) value of 120 feet per day for the alluvium deposits and 16 feet per day for the terrace deposits. The simulated inflows in the numerical groundwater-flow model of the Pawnee Nation subdomain were higher than the inflows of conceptual water budget, and the simulated outflows were lower than the outflows of the conceptual water budget. Overall, simulated base flows matched closely to observed base flows for the 2016 and 2017 stress periods. Simulated streamflow tended to match better with the observed streamflow for 2017, which was the period with the most data for the Cimarron River alluvial aquifer model. Streamflow capture analysis was applied to the steady-state simulation to identify areas of the aquifer where base flows in the Cimarron River were most sensitive to groundwater withdrawals. The initial base-flow value was assigned the value obtained from streamflow-routing software used to simulate stream outflow for the calibrated steady-state base model. Subsequent simulations were run in each active cell in the Pawnee Nation subdomain for a specified groundwater-withdrawal rate of 180,000 cubic feet per day. The study area that includes the Pawnee Nation subdomain is in the upper Arkansas River Basin. A groundwater-withdrawal rate of 180,000 cubic feet per second per day represents a 34 percent increase compared to the highest permitted groundwater-withdrawal rate for the study area, which corresponds to the estimated 34 percent increase in groundwater withdrawals predicted by 2060 for the upper Arkansas River Basin. Simulated streamflow capture was highest in the alluvium deposits adjacent to the Cimarron River; that is, base flow in the Cimarron River decreased the most for simulated groundwater withdrawals in the alluvium deposits adjacent to the Cimarron River. Streamflow capture increased as the distance of a well from the Cimarron River decreased in the simulation. The northeastern part of the Pawnee Nation subdomain showed greater streamflow capture in a broader area; streamflow in that part of the Pawnee Nation subdomain is likely more sensitive to groundwater withdrawals compared to other parts of the Pawnee Nation subdomain.

Oklahoma↗

USGS2022

Evaluation of salinity and nutrient conditions in the Heart River Basin, North Dakota, 1970–2020

The Heart River Basin is predominantly an agricultural basin in western North Dakota and is approximately 3,350 square miles. The U.S. Geological Survey, in cooperation with the U.S. Department of Agriculture Natural Resources Conservation Service and the Grant County Soil Conservation District, completed a study to assess spatial and temporal patterns of water quality in the Heart River Basin. The purpose of this report is to describe the methods and results of a study to evaluate salinity and nutrients in the Heart River Basin in western North Dakota. Water-quality and streamflow data used in the study were compiled from 1970 to 2020 using the National Water Quality Monitoring Council Water Quality Portal and National Water Information System. Changes in streamflow characteristics were investigated at three sites from 1970 to 2020, and changes in water quality were investigated at four sites from 1974 to 2019. Streamflow analysis indicated decreasing streamflow from 1970 until the late 1990s followed by increasing streamflow through 2020, with the largest increase in the 7-day minimum streamflow or base flow. For the historical water-quality trend period (1974–2019), total dissolved solids, sulfate, sodium, chloride, and sodium adsorption ratio concentrations have increased since the mid-1970s through 2019. Potassium concentrations during the historical period remained mostly constant with some small fluctuations. Calcium and magnesium concentrations increased since the mid-1970s at all sites, except for a decrease at one site between 1974 and 1999. During the recent trend period (1999–2019), increasing concentrations in total dissolved solids, sulfate, sodium, chloride, calcium, magnesium, and sodium adsorption ratios were observed across the Heart River Basin. The magnitude of the increases was smaller at tributary sites compared to main-stem sites. During the recent period, potassium was mostly constant, although small (−0.9 milligram per liter or less) decreases on tributaries and minor (1.3 milligrams per liter) increases on the main-stem sites were detected. Unlike dissolved ion concentrations, significant increases in nutrient concentrations were not detected from 1999 to 2019, but nitrate plus nitrite concentrations most likely decreased upstream from Lake Tschida. Inverse modeling for period 1 (1974–99) in model zone 1 (Heart River reach from site 5 to site 6) had eight reasonable models that indicated the clay mineral-water interactions and dissolution of evaporites control the geochemistry. Results of the inverse modeling for period 2 (1999–2019) in model zone 1 also had eight reasonable models that indicated that the dissolution of evaporites was the major geochemical control. Results of the geochemical modeling for period 1 (1974–99) in model zone 2 (Heart River and Sweetbriar Creek reach from sites 20 and 21 to site 22) produced seven reasonable models, and the geochemical control of the system was the dissolution of sulfate evaporite minerals. Geochemical modeling results for period 2 (1999–2019) in model zone 2 produced 11 reasonable models and was also controlled by the dissolution of sulfate evaporite minerals. Differences between the two model zones indicated that geology controls some of the water-quality changes in the Heart River Basin. Loads were estimated for total dissolved solids, sulfate, sodium, and chloride and total phosphorus. Annual loads estimated for the Heart River from 2013 through 2020 at the Heart River site upstream from Lake Tschida (site 5) and near Mandan (site 22) were generally greatest in 2014 and least in 2016 for total dissolved solids, sulfate, sodium, and chloride. Most of the annual loads of total dissolved solids, sulfate, sodium, and chloride are delivered in March through July in the Heart River at these sites and are likely from snowmelt and spring and summer rains. The mean annual yields of total dissolved solids and sodium from 2013 to 2020 generally were largest in Big Muddy Creek (site 18), whereas yields of sulfate and chloride were largest at Sweetbriar Creek (site 21) compared to the other selected sites in the Heart River Basin. Larger yields of total dissolved solids, sulfate, sodium, and chloride at sites located on Big Muddy Creek and Sweet Briar Creek in the lower Heart River Basin were likely a result of differences in geology and soils upstream from the selected sites. A mass balance of total dissolved solids, sulfate, sodium, and chloride was estimated for the lower Heart River Basin, specifically the reach below Lake Tschida to Mandan (site 7 to site 22). Intervening flow was the largest contributor to the dissolved ion loads in the lower Heart River Basin and is an important part of understanding the transport of dissolved ions in the basin. The intervening load can include groundwater discharge, irrigation return flow, local runoff, and input from smaller ephemeral tributaries. Tributaries in the lower Heart River Basin contributed portions of the total dissolved solids, sulfate, sodium, and chloride loads at the Heart River near Mandan (site 22) that generally were proportional to the streamflow contributions. Annual loads for total phosphorus between 2013 and 2020 at the Heart River site upstream from Lake Tschida (site 5) and near Mandan (site 22) generally were largest in 2019 and smallest in 2016. Most of the total phosphorus loads for main-stem sites 5 and 22 were transported in March, April, and June, likely from snowmelt and early summer rains. The mean annual yields of total phosphorus for 2013–20 were largest on the main-stem site upstream from Lake Tschida (site 5) and Sweetbriar Creek (site 21), whereas the smallest yields were in Big Muddy Creek (site 18). Much of the phosphorus that enters Lake Tschida from the upper basin does not get transported downstream to the lower basin, and much of the phosphorus in the lower basin was attributed to intervening flow.

North Dakota↗

USGS2023

Characterization of streamflow and nutrient occurrence in the upper White River Basin, Colorado, 1980–2020

In 2016, Colorado Parks and Wildlife identified filamentous algae collected from the main stem White River as Cladophora glomerata , a pervasive nuisance aquatic alga. Excessive levels of filamentous algae can compromise aesthetic quality, limit recreational activities, and have negative effects on aquatic life including strong fluctuations in dissolved oxygen levels and a reduction in overall biodiversity. To increase understanding of the biology of the upper White River Basin in Colorado, identify potential factors promoting or limiting nuisance algal abundance, and outline information to aid in the understanding and protection of water resources, the U.S. Geological Survey (USGS), in cooperation with the White River and Douglas Creek Conservation Districts and the White River Algae Technical Advisory Group, initiated a study to collect and analyze physical, chemical, and biological information for the upper White River Basin. The report describes long-term changes and spatial variations in streamflow and nutrient concentrations and loads in the upper White River Basin and identifies possible nutrient sources in the basin. Long-term streamflow and nutrient data indicate that conditions in the upper White River Basin have become more favorable to benthic algae over varying timescales. Upward trends in total phosphorus concentrations and loads were found at three sites across the basin from 2000 to 2020. Total phosphorus loads increased around 50 percent, ranging from 18 to 48 pounds per year. Annual estimated concentrations of total phosphorus from 2005 to 2020 were above algal-specific nutrient criteria at the North Fork White River at Buford, Colo., indicating that phosphorus concentrations at this site likely promote algal growth. Discrete concentrations of total phosphorus exceeded algal-specific nutrient criteria on the South Fork and main stem White River during the summer season, though less frequently than samples collected from the North Fork White River. Nitrogen to phosphorus molar ratios collected from July to September indicate movement from colimitation (10–22) to nitrogen limited (less than 13) conditions at the North Fork White River at Buford, Colo. and the South Fork White River at Buford, Colo. starting in 2012. The magnitude of trends in phosphorus loads were generally greater than trends in concentrations across all sites, indicating that the largest changes in concentrations occurred during greater streamflow periods. At White River above Coal Creek, near Meeker, Colo., significant downward trends in streamflow were found in August and September for mean streamflow (15 and 14 percent per decade, respectively) and 7-day minimum streamflows (23 and 22 percent per decade, respectively). Significant downward trends in annual 7-day minimum streamflows of 24 percent per decade, or 66 percent over the 40-year period of analysis, were also observed. Though not significant based on 90-percent confidence intervals, downward trends in 1-day maximum and mean streamflows in May and June and corresponding increases in April may indicate a shift toward earlier snowmelt runoff, as observed across western North America and the Colorado River Basin. Alteration of the annual hydrograph can influence factors that influence algae including nutrient input and dilution potential, water temperature, dissolved oxygen, light availability, and physical disturbance. Results from a synoptic-style sampling identified the lower North Fork White River subbasin as a large source of phosphorus to the downstream system. Large increases in phosphorus loads were observed below Marvine Creek. Synoptic samples and samples collected during spring and summer of 2019 and 2020 also show large increases in total nitrogen, orthophosphate, and total phosphorus occurring at the furthest three downstream sites on the White River. To further evaluate sources of nitrogen in the upper White River Basin, the dual isotopic composition of nitrate was compared across four sites. The isotopic compositions of nitrate were all within the expected range of typical soil-derived nitrate, though the same values can also be derived from a mixture of agricultural fertilizer and manure or septic sources.

Colorado↗

USGS2025

Assessment of channel morphology, hydraulics, and bedload transport along the Siletz River, western Oregon

Significant Findings Chinook salmon ( Oncorhynchus tshawytscha ) and Pacific lamprey ( Entosphenus tridentatus ) are native, anadromous fish species in the Siletz River Basin, western Oregon, that face many threats to their survival in freshwater and the ocean. The Confederated Tribes of Siletz Indians of Oregon seek to mitigate freshwater threats to Chinook salmon and Pacific lamprey, where possible, with habitat conservation and restoration efforts. This study was conducted to assist the Confederated Tribes of Siletz Indians of Oregon in documenting and understanding the hydrogeomorphic processes shaping present-day habitat conditions and assessing future habitat implications for Chinook salmon and Pacific lamprey along the main-stem Siletz River. As such, this study focused on understanding geomorphic processes and patterns of channel change, including lateral and vertical adjustments in channel position and changes in bed-material sediment (sands, gravels, and cobbles that mantle the channel bed), which collectively determine overall patterns of channel morphology and fluvial habitats. Objective One was to evaluate lateral changes in channel position, vertical changes in bed elevation, and longitudinal patterns in bed-material particle size along the Siletz River using detailed channel maps developed from aerial photographs collected from 1939 to 2016, long-term records of stage and discharge collected by the U.S. Geological Survey (USGS) near the City of Siletz, and sediment particle size data. Objective Two was to assess hydraulic conditions using one- and two-dimensional hydraulic models and transport capacity of bed-material sediment using bedload transport models and sediment particle size data for a range of discharge conditions. Objective Three was to identify potential burrowing habitat for lamprey larvae (PBH) along the Siletz River network and provide insights in local factors influencing PBH along the main-stem Siletz River. The overall findings are synthesized to describe habitat implications for Chinook salmon and Pacific lamprey under present-day and future conditions. Results of Objective One, an evaluation of changes in channel position and bed elevations and longitudinal patterns in bed-material particle size along the Siletz River, include the following From 1939 to 2016, channel planform and the mapped area of gravel bars did not change considerably along the 97.2-kilometers (km) of Siletz River between Elk Creek and Millport Slough, except for in short sections generally less than 1 km long. This inherent lateral channel stability results from the resistant bedrock and terraces that bound most of the channel and limit lateral changes in channel position. Intermittent sections along the study reach where the active channel widened at channel bends displayed noticeable planform changes and increases in mapped bar area. From water year (WY; a 12-month period from October 1 through September 30 and named for the year in which it ends) 1906 to 2021, changes in the stage-discharge relation interpreted as rising and lowering channel bed levels were observed at the USGS streamgage 14305500 (Siletz River at Siletz, OR) in response to floods (such as high flows in February 1996 and January 2002 that exceeded 0.1 and 0.667 annual exceedance probabilities [AEP] events, respectively). However, the rating curve representing the stage-discharge relation did not change in response to high-magnitude floods between 2007 and 2021. Along the approximately 54-km of the Siletz River between Moonshine Park and the Bulls Bag area, surficial particle distributions varied considerably between sampling sites in response to changes in channel width and gradient, sediment inputs from tributaries, and basin geology. Despite this variability, median particle sizes tended to decrease in size in the downstream direction over the 54 km. Results of Objective Two, an evaluation of hydraulic and bedload transport conditions along the Siletz River, include the following The most substantial increases in maximum and mean water velocity and bedload sediment transport capacity occurred at events between the 0.995 and 0.50 AEPs. Events of these magnitudes occur approximately every 1–2 years. Smaller events (0.995 AEP) are generally contained by the banks of the main channel, whereas larger events (0.50 AEP) generally spill over the banks and inundate high-elevation bar and low-elevation floodplain surfaces. Multiple smaller floods within a WY that exceed the 0.995 and 0.50 AEPs (such as in WY 1996) can transport as much or more bed-material sediment than a single, higher magnitude event (such as the maximum event recorded in WY 2000 with an estimated AEP of around 0.002). Bedload transport capacity generally exceeds sediment supply (greater than 2 millimeters [mm]) for most of the study area from Wildcat Creek to the City of Siletz as evidenced by substantial in-channel bedrock. Despite overall conditions of limited sediment supply, transport capacity still varies considerably within and between years with discharge magnitude and spatially in relation to local hydraulics imposed by bedrock, channel morphology, and human infrastructure (such as bridges). Results of Objective Three, an analysis of PBH for lamprey larvae, include the following About 28 percent of the Siletz River network meets the mean annual suspended sediment loads and channel slope criteria for PBH. Along the main-stem Siletz River, in-channel bedrock outcrops and high transport capacity are expected to further constrain PBH. Together, these results suggest that most of the Siletz River between Wildcat Creek and the City of Siletz has had only modest vertical and lateral change between the 1930s and 2010s because of the bedrock in and along the main channel and the river’s relatively high transport capacity relative to bed-material sediment supply. However, localized sections of the Siletz River where the active channel widens, particularly at channel bends, exhibited some change in channel planform and the locations and area of gravel bars. In the future, moderate increases in autumn-winter discharge may not result in substantial changes in coarse gravel bars along the Siletz River but may result in selective transport of finer bed-material sediment (gravel, sands, and silts) that provide spawning habitats for Chinook salmon and Pacific lamprey and burrowing habitats for lamprey larvae. Assuming no substantial changes in bed-material sediment supply, increased bedload transport capacity may cause frequent entrainment of lamprey larvae that are burrowed in coarse sand deposits, suspension and downstream transport of salmon eggs incubating in gravels, and reductions in the areas of spawning gravels for Chinook salmon and Pacific lamprey. Exact implications of current and future discharge conditions for these species along the Siletz River depends on many factors, including sediment supply, local hydraulics, and the timing of flood events relative to fish life stages.

Oregon↗

USGS2000

Characterization and simulation of ground-water flow in the Kansas River Valley at Fort Riley, Kansas, 1990-98

Hydrologic data and a ground-water flow model were used to characterize ground-water flow in the Kansas River alluvial aquifer at Fort Riley in northeast Kansas. The ground-water flow model was developed as a tool to project ground-water flow and potential contaminant-transport paths in the alluvial aquifer on the basis of past hydrologic conditions. The model also was used to estimate historical and hypothetical ground-water flow paths with respect to a private- and several public-supply wells. The ground-water flow model area extends from the Smoky Hill and Republican Rivers downstream to about 2.5 miles downstream from the city of Ogden. The Kansas River Valley has low relief and, except for the area within the Fort Riley Military Reservation, is used primarily for crop production. Sedimentary deposits in the Kansas River Valley, formed after the ancestral Kansas River eroded into bedrock, primarily are alluvial sediment deposited by the river during Quaternary time. The alluvial sediment consists of as much as about 75 feet of poorly sorted, coarse-to-fine sand, silt, and clay, 55 feet of which can be saturated with ground water. The alluvial aquifer is unconfined and is bounded on the sides and bottom by Permian-age shale and limestone bedrock. Hydrologic data indicate that ground water in the Kansas River Valley generally flows in a downstream direction, but flow direction can be quite variable near the Kansas River due to changes in river stage. Ground-water-level changes caused by infiltration of precipitation are difficult to detect because they are masked by larger changes caused by fluctuation in Kansas River stage. Ratios of strontium isotopes Sr87 and Sr86 in water collected from wells in the Camp Funston Area indicate that the ground water along the northern valley wall originates, in part, from upland areas north of the river valley. Water from Threemile Creek, which flows out of the uplands north of the river valley, had Sr87:Sr86 ratios similar to those in ground water from wells in the northern Camp Funston Area. In addition, comparison of observed water levels from wells CF90-06, CF97-101, and CF97-401 in the Camp Funston Area and ground-water levels simulated for these wells using floodwave-response analysis indicates that ground-water inflow from bedrock is a hydraulic stress that, in addition to the changing stage in the Kansas River, acts on the aquifer. This hydraulic stress seems to be located near the northern valley wall because the effect of this stress is greater for well CF97-101, which is the well closest to the valley wall. Ground-water flow was simulated using a modular, three-dimensional, finite-difference ground-water flow model (MODFLOW). Particle tracking, used to visualize ground-water flow paths in the alluvial aquifer, was accomplished using MODPATH. Forward-in-time particle tracking indicated that, in general, particles released near the Kansas River followed much more variable paths than particles released near the valley wall. Although particle tracking does not simulate solute transport, this increased path variability indicates that, near the river, ground-water contaminants could follow many possible paths towards the river, whereas more distant from the river, ground-water contaminants likely would follow a narrower corridor. Particle tracks in the Camp Funston Area indicate that, for the 1990-98 simulation period, contaminants from the ground-water study sites in the Camp Funston Area would be unlikely to move into the vicinity of Ogden's supply wells. Backward-in-time particle tracking indicated that the flow-path and recharge areas for model cells corresponding to Ogden's supply wells lie near the northern valley wall and extend into the northern Camp Funston Area. The flow-path and recharge areas for model cells corresponding to Morris County Rural Water District wells lie within Clarks Creek Valley and probably extend outside the model area. Three hypothetical simulations, i

Water-Resources Investigations Report↗

USGS2002

Water quality in the Little Sac River basin near Springfield, Missouri, 1999-2001

The Little Sac River, north of Springfield, Missouri, flows through mainly agricultural and forest land. However, the quality of the river water is a concern because the river flows into Stockton Lake, which is a supplemental drinking water source for Springfield. Large bacterial densities and nutrient concentrations are primary concerns to the water quality of the river. A 29-river mile reach of the Little Sac River is on the 1998 list of waters of Missouri designated under section 303(d) of the Federal Clean Water Act because of fecal coliform densities larger than the Missouri Department of Natural Resources standard (hereinafter referred to as Missouri standard) of 200 colonies per 100 milliliters for whole-body contact recreation. During an investigation of the water quality in the Little Sac River by the U.S. Geological Survey, in cooperation with the Watershed Committee of the Ozarks, fecal coliform bacteria densities exceeded the Missouri standard (the standard applies from April 1 through October 31) in one sample from a site near Walnut Grove. At other sites on the Little Sac River, the Missouri standard was exceeded in two samples and equalled in one sample upstream from the Northwest Wastewater Treatment Plant (NW WTP) and in one sample immediately downstream from the NW WTP. Effluent from the NW WTP flows into the Little Sac River. Annually from April 1 through October 31, the effluent is disinfected to meet the Missouri standard for whole-body contact recreation. Fecal coliform bacteria densities in samples collected during this period generally were less than 100 colonies per 100 milliliters. For the rest of the year when the effluent was not disinfected, the bacteria densities in samples ranged from 50 (sample collected on November 1, 2000) to 10,100 colonies per 100 milliliters (both counts were non-ideal). When the effluent was disinfected and the fecal coliform bacteria density was small, samples from sites upstream and downstream from the NW WTP had a bacteria density larger than the density in the effluent. Other sources of bacteria are likely to be present in the study area in addition to the NW WTP. These potential sources include effluent from domestic septic systems and animal wastes. Nutrient concentrations in the Little Sac River immediately downstream from the NW WTP were affected by effluent from the NW WTP and possibly other sources. At two sites upstream from the NW WTP, median nitrite plus nitrate concentrations were 1.1 and 1.4 milligrams per liter. The median nitrite plus nitrate concentration for the effluent from the NW WTP was 6.4 milligrams per liter, and the median concentration decreased downstream in the Little Sac River to 2.2, 1.2, and 0.56 milligrams per liter. The effects of the effluent from the NW WTP on the water quality of the Little Sac River downstream from the NW WTP were reflected in an increase in discharge (effluent from the NW WTP can be as much as 50 percent of the flow at the site about 1.5 river miles downstream from the NW WTP), an increase in specific conductance values, an increase in several inorganic constituent concentrations, including calcium, magnesium, and sulfate, and a large increase in sodium and chloride concentrations. The effluent from the NW WTP seemed to have no effect on the pH value, temperature, and dissolved oxygen concentrations in the Little Sac River. Results of repetitive element polymerase chain reaction (rep-PCR) pattern analysis indicated that most Escherichia coli ( E. coli ) bacteria in water samples probably were from nonhuman sources, such as horses and cattle. The rep-PCR pattern analysis indicated that horses were an important source of E. coli downstream from the NW WTP, which was consistent with horses pastured adjacent to the sampling site. Fecal coliform bacteria loads increased upstream from the NW WTP from the most upstream site to the site immediately upstream from the NW WTP. Loads in the effluent from the NW WTP and also those in the Little Sac River downstream from the NW WTP were dependent on the treatment of the effluent. When the effluent was not disinfected, the loads in the effluent increased from those upstream. Downstream in the Little Sac River, the loads decreased, but then increased at the most downstream site. The increase may be a result of increased loads from tributaries and other sources not sampled during the study. When the effluent was disinfected, fecal coliform bacteria loads were less than loads in samples from the Little Sac River downstream from the NW WTP.

Water-Resources Investigations Report↗

USGS2002

Ground-water flow simulation and chemical and isotopic mixing equation analysis to determine source contributions to the Missouri River alluvial aquifer in the vicinity of the Independence, Missouri, well field

The city of Independence, Missouri, operates a well field in the Missouri River alluvial aquifer. Steady-state ground-water flow simulation, particle tracking, and the use of chemical and isotopic composition of river water, ground water, and well-field pumpage in a two-component mixing equation were used to determine the source contributions of induced inflow from the Missouri River and recharge to ground water from precipitation in well-field pumpage. Steady-state flow-budget analysis for the simulation-defined zone of contribution to the Independence well field indicates that 86.7 percent of well-field pumpage is from induced inflow from the river, and 6.7 percent is from ground-water recharge from precipitation. The 6.6 percent of flow from outside the simulation-defined zone of contribution is a measure of the uncertainty of the estimation, and occurs because model cells are too large to uniquely define the actual zone of contribution. Flow-budget calculations indicate that the largest source of water to most wells is the Missouri River. Particle-tracking techniques indicate that the Missouri River supplies 82.3 percent of the water to the Independence well field, ground-water recharge from precipitation supplies 9.7 percent, and flow from outside defined zones of contribution supplies 8.0 percent. Particle tracking was used to determine the relative amounts of source water to total well-field pumpage as a function of traveltime from the source. Well-field pumpage that traveled 1 year or less from the source was 8.8 percent, with 0.6 percent from the Missouri River, none from precipitation, and 8.2 percent between starting cells. Well-field pumpage that traveled 2 years or less from the source was 10.3 percent, with 1.8 percent from the Missouri River, 0.2 percent from precipitation, and 8.3 percent between starting cells. Well-field pumpage that traveled 5 years or less from the source was 36.5 percent, with 27.1 percent from the Missouri River, 1.1 percent from precipitation, and 8.3 percent between starting cells. Well-field pumpage that traveled 10 years or less from the source was 42.7 percent, with 32.6 percent from the Missouri River, 1.8 percent from precipitation, and 8.3 percent between starting cells. Well-field pumpage that traveled 25 years or less from the source was 71.9 percent, with 58.9 percent from the Missouri River, 4.7 percent from precipitation, and 8.3 percent between starting cells. Results of chemical (calcium, sodium, iron, and fluoride) and isotopic (oxygen and hydrogen) analyses of water samples collected from the Missouri River, selected monitoring wells around the Independence well field, and combined well-field pumpage were used in a two component mixing equation to estimate the relative amount of Missouri River water in total well-field pumpage. The relative amounts of induced inflow from the Missouri River in well-field pumpage ranged from 49 percent for sodium to 80 percent for calcium, and sensitivities ranged from 0 percent for iron to plus or minus 35 percent for naturally occurring stable isotope ( 18 O). The average of all mixing equation results indicated that 61 percent of well-field pumpage was from induced inflow from the Missouri River. All methods used in the study indicate that more than one-half of the water in well-field pumpage was inflow from the Missouri River. River inflow estimates from ground-water simulation methods are larger and error values are smaller than those using chemical and isotopic data in the mixing equation, although substantial uncertainties exist for both estimation methods. Because of the complex hydrology of the aquifer near the Independence well field, the source estimates using particle tracking probably are the most reliable of the ground-water simulation methods. Mixing equation results are less reliable than those of the ground-water simulation for this study. However, more reliable results can be obtained from the mixing equation by increasing the number of samples and collecting samples for a longer period of time, and during different flow conditions. In the absence of a calibrated ground-water flow simulation, the mixing equation can provide a reasonable estimate of the sources of water to a well field at relatively low cost, if sources of error are clearly understood.

Water-Resources Investigations Report↗

USGS2003

Simulations of floodflows on the White River in the vicinity of U.S. Highway 79 near Clarendon, Arkansas

A two-dimensional finite-element surface-water model was used to study the effects of the proposed modification to the U.S. Highway 79 corridor on flooding on the White River near Clarendon, Arkansas. The effects of floodflows were simulated for the following scenarios: existing, natural, and four proposed bridging alternatives. All of the scenarios were modeled with floods having the 5- and 100-year recurrence intervals (115,100 and 216,000 cubic feet per second). The simulated existing conditions included a 3,200-foot White River bridge located on the east side of the study area near Clarendon, Arkansas; a 3,700-foot First Old River bridge located 0.5 mile west of the White River bridge opening; and a 1,430-foot Roc Roe Bayou bridge located 1.6 mile west of the First Old River bridge. The simulated hypothetical natural conditions involved removing the U.S. Highway 79 and the Union Pacific Railroad embankments along the entire length of the flood plain. The primary purpose of model simulations for natural conditions was to calculate backwater data for the existing and proposed conditions. The four simulated hypothetical proposed alternatives involved a 1.8-mile White River bridge located on the east side of the study area near Clarendon, Arkansas, either a 1,400-foot relief bridge (Alternative 1) or a 1,545 relief bridge (Alternatives 2-4) located 0.25 mile west of the White River bridge opening, and three different Roc Roe Bayou bridge openings ranging from 1,540-3,475 feet in length located 0.9 mile west of the relief bridge (Alternatives 1-4). Simulation of the 5-year floodflow for the existing bridge openings indicates that about 57 percent (65,600 cubic feet per second) of flow was conveyed by the White River bridge, about 26 percent (29,900 cubic feet per second) by the First Old River bridge, and about 17 percent (19,600 cubic feet per second) by the Roc Roe Bayou bridge. Maximum depth-averaged point velocities for the White River, First Old River, and Roc Roe Bayou bridges were 3.6, 1.6, and 3.3 feet per second, respectively. For the 100-year floodflow, the simulation indicates that about 56 percent (123,100 cubic feet per second) of flow was conveyed by the White River bridge, about 26 percent (56,200 cubic feet per second) by the First Old River bridge, and about 19 percent (41,000 cubic feet per second) by the Roc Roe Bayou bridge. The maximum depth-averaged point velocities for the White River, First Old River, and Roc Roe Bayou bridges were 4.2, 2.2, and 4.1 feet per second, respectively. Simulation of the 5-year floodflow for the proposed U.S. Highway 79 alignment alternatives indicates that 76-78 percent (87,100-89,900 cubic feet per second) of the flow was conveyed by the proposed White River bridge, 6-7 percent (7,000-7,500 cubic feet per second) by the proposed relief bridge, and 13-16 percent (14,600-18,600 cubic feet per second) by the proposed Roc Roe Bayou bridge. For the 100-year floodflow, simulations predicted that 70-72 percent (151,200-155,600 cubic feet per second) of the flow was conveyed by the proposed White River bridge, 9-10 percent (19,800-20,700 cubic feet per second) by the proposed relief bridge, and 14-20 percent (30,700-43,000 cubic feet per second) by the proposed Roc Roe Bayou bridge.

Water-Resources Investigations Report↗

USGS2003

Nitrogen and phosphorus in streams of the Great Miami River Basin, Ohio, 1998–2000

Sources and loads of nitrogen and phosphorus in streams of the Great Miami River Basin were evaluated as part of the National Water-Quality Assessment program. Water samples were collected by the U.S. Geological Survey from October 1998 through September 2000 (water years 1999 and 2000) at five locations in Ohio on a routine schedule and additionally during selected high streamflows. Stillwater River near Union, Great Miami River near Vandalia, and Mad River near Eagle City were selected to represent predominantly agricultural areas upstream from the Dayton metropolitan area. Holes Creek near Kettering is in the Dayton metropolitan area and was selected to represent an urban area in the Great Miami River Basin. Great Miami River at Hamilton is downstream from the Dayton and Hamilton-Middletown metropolitan areas and was selected to represent mixed agricultural and urban land uses of the Great Miami River Basin. Inputs of nitrogen and phosphorus to streams from point and nonpoint sources were estimated for the three agricultural basins and for the Great Miami River Basin as a whole. Nutrient inputs from point sources were computed from the facilities that discharge one-half million gallons or more per day into streams of the Great Miami River Basin. Nonpoint-source inputs estimated in this report are atmospheric deposition and commercial-fertilizer and manure applications. Loads of ammonia, nitrate, total nitrogen, orthophosphate, and total phosphorus from the five sites were computed with the ESTIMATOR program. The computations show nitrate to be the primary component of instream nitrogen loads, and particulate phosphorus to be the primary component of instream phosphorus loads. The Mad River contributed the smallest loads of total nitrogen and total phosphorus to the study area upstream from Dayton, whereas the Upper Great Miami River (upstream from Vandalia) contributed the largest loads of total nitrogen and total phosphorus to the Great Miami River Basin upstream from Dayton. An evaluation of monthly mean loads shows that nutrient loads were highest during winter 1999 and lowest during the drought of summer and autumn 1999. During the 1999 drought, point sources were the primary contributors of nitrogen and phosphorus loads to most of the study area. Nonpoint sources, however, were the primary contributors of nitrogen and phosphorus loads during months of high streamflow. Nonpoint sources were also the primary contributors of nitrogen loads to the Mad River during the 1999 drought, owing to unusually large amounts of ground-water discharge to the stream. The Stillwater River Basin had the highest nutrient yields in the study area during months of high streamflow; however, the Mad River Basin had the highest yields of all nutrients except ammonia during the months of the 1999 drought. The high wet-weather yields in the Stillwater River Basin were caused by agricultural runoff, whereas high yields in the Mad River Basin during drought resulted from the large, sustained contribution of ground water to streamflow throughout the year. In the basins upstream from Dayton, an estimated 19 to 25 percent of the nonpoint source of nitrogen and 4 to 5 percent of the nonpoint source of phosphorus that was deposited or applied to the land was transported into streams.

Ohio↗

USGS2003

Water quality of selected rivers in the New England Coastal Basins in Maine, Massachusetts, New Hampshire, and Rhode Island, 1998-2000

Nine rivers were monitored routinely for a variety of field conditions, dissolved ions, and nutrients during 1998-2000 as part of the New England Coastal Basins (NECB) study of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program. The nine rivers, located primarily in the Boston metropolitan area, represented a gradient of increasing urbanization from 1 to 68 percent urban land use. Additional water samples were collected and analyzed for pesticides and volatile organic compounds at two of the nine rivers. Specific conductance data from all rivers were correlated with urban land use; specific conductance values increased during winter at some sites indicating the effect of road de-icing applications. In the more intensely urbanized basins, concentrations of sodium and chloride were high during winter and likely are attributed to road de-icing applications. Concentrations of total nitrogen and the various inorganic and organic nitrogen species were correlated with the percentage of urban land in the drainage basin. Total phosphorus concentrations also were correlated with urbanization in the drainage basin, but only for rivers draining less than 50 square miles. Preliminary U.S. Environmental Protection Agency total nitrogen and total phosphorus criteria for the rivers in the area were frequently exceeded at many of the rivers sampled. At the two sites monitored for pesticides and volatile organic compounds, the Aberjona and Charles Rivers near Boston, greater detection frequencies of pesticides were in samples from the spring and summer when pesticide usage was greatest. At both sites, herbicides were detected more commonly than insecticides. The herbicides prometon and atrazine and the insecticide diazinon were detected in over 50 percent of all samples collected from both rivers. No water samples contained pesticide concentrations exceeding any U.S. Environmental Protection Agency drinking-water standard or criteria for protecting freshwater aquatic life. The volatile organic compounds trichloroethylene, tetrachloroethylene, and cis-1,2- dichloroethylene--all solvents and de-greasers--were detected in all water samples from both rivers. The gasoline oxygenate methyl tert-butyl ether (MTBE) and the disinfection by-product chloroform were detected in all but one water sample from the two rivers. Two water samples from the Charles River had trichloroethylene concentrations that exceeded the U.S. Environmental Protection Agency Maximum Contaminant Level of 5 micrograms per liter for drinking water. Selected water-quality data from two NCEB rivers in the Boston metropolitan area were compared to two similarly sized intensely urban rivers in another NAWQA study area in the New York City metropolitan area and to other urban rivers sampled as part of the NAWQA Program nationally. Nutrient total nitrogen and total phosphorus concentrations and yields were less in the NECB study area than in the other study areas. In addition, the pesticides atrazine, carbaryl, diazinon, and prometon were detected less frequently and at lower concentrations in the two NECB rivers than in the New York City area streams or in the other urban NAWQA streams. Concentrations of the insecticides diazinon and carbaryl were detected more frequently and at higher concentrations in the NECB study area than in the other urban rivers sampled by NAWQA nationally. Detection frequency and concentrations of volatile organic compounds generally were higher in the two NECB streams than in the New York City area streams or in other urban NAWQA streams.

Water-Resources Investigations Report↗