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Research about Platte River

Source-linked reports with geographic coverage including Platte River.

At least 19 recordsLinked to original sources
USGS2023

An integrated hydrologic model to support the Central Platte Natural Resources District Groundwater Management Plan, central Nebraska

The groundwater and surface-water supply of the Central Platte Natural Resources District supports a large agricultural economy from the High Plains aquifer and Platte River, respectively. This study provided the Central Platte Natural Resources District with an advanced numerical modeling tool to assist with the update of their Groundwater Management Plan. An integrated hydrologic model, called the Central Platte Integrated Hydrologic Model, was constructed using the MODFLOW-One-Water Hydrologic Model code with the Newton solver. This code integrates climate, landscape, surface water, and groundwater-flow processes in a fully coupled approach. Model framework included 163 rows; 327 columns; 2,640 feet cell sides; and 3 vertical layers. A predevelopment model simulated steady-state hydrologic conditions prior to April 30, 1895, and a development period model discretized into 610 stress periods simulated transient hydrologic conditions from May 1, 1895, to December 31, 2016, using 170 biannual stress periods from 1895 to 1980, and monthly stress periods from May 1, 1980, to December 31, 2016. Calibration of the Central Platte Integrated Hydrologic Model involved two phases: a manual adjustment of parameters, followed by the automated calibration completed using BeoPEST that was facilitated by the employment of the singular value decomposition-assist features of PEST that specified 50 super parameters assembled from the 435 adjustable parameters and Tikhonov regularization. The average absolute groundwater-level residuals for model layers one, two, and three were 6.1, 12.4, and 7.4 feet, respectively. Calibrated horizontal hydraulic conductivity was about 70, 32, and 35 feet per day for layers 1, 2, and 3, respectively. The largest development period inflow to groundwater was recharge from deep percolation past the root zone, averaging 1,122,257 acre-feet per year (2.7 inches per year), and the largest outflow was to irrigation wells, averaging 693,171 acre-feet per year (10.2 inches per year for the Central Platte Natural Resources District). Other substantial groundwater outflows included evapotranspiration and base flow. For the total development period, there was a net change in storage of −122,393 acre-feet per year (−0.3 inch per year). The calibrated Central Platte Integrated Hydrologic Model was used to simulate eight different potential future climate and irrigation pumping conditions from January 1, 2017, to December 31, 2049. Simulated future groundwater levels within the Central Platte Natural Resources District varied significantly between scenarios and locally, from 13.8 feet below to 7.6 feet above baseline 1982 groundwater levels. Most areas exhibited groundwater-level declines for the drought scenarios and rises for the alternate irrigation scenarios. Changes in scenario groundwater levels correlated with the relations between farm net recharge and irrigation pumping. Linear “first order second moment” techniques indicated that the uncertainty in projected groundwater altitudes was reduced by 15.33 feet through model calibration.

Nebraska↗
USGS2022

Automating sandhill crane counts from nocturnal thermal aerial imagery using deep learning

Population monitoring is essential to management and conservation efforts for migratory birds, but traditional low-altitude aerial surveys with human observers are plagued by individual observer bias and risk to flight crews. Aerial surveys that use remote sensing can reduce bias and risk, but manual counting of wildlife in imagery is laborious and may be cost-prohibitive. Therefore, automated methods for counting are critical to cost-efficient application of remote sensing for wildlife surveys covering large areas. We conducted nocturnal surveys of sandhill cranes ( Antigone canadensis ) during spring migration in the Central Platte River Valley of Nebraska, USA, using midwave thermal infrared sensors. We developed a framework for automated counting of sandhill cranes from thermal imagery using deep learning, assessed and compared the performance of two automated counting models, and quantified the effect of spatial resolution on counting accuracy. Aerial thermal imagery data were collected in March 2018 and 2021; 40 images were analyzed. We applied two deep learning models: an object detection approach, Faster R-CNN and a recently developed pixel-density estimation approach, ASPDNet. Model performance was determined using data independent of the training imagery. The effect of spatial resolution was quantified with a beta regression on relative error. Our results showed model accuracy of 9% mean percent error for ASPDNet and 18% for Faster R-CNN. Most error was related to the undercounting of sandhill cranes. ASPDNet had < 50% of the error of Faster R-CNN as measured by mean percent error, root-mean-squared error and mean absolute error. Spatial resolution affected accuracy of both models, with error rate increasing with coarser resolution, particularly with Faster R-CNN. Deep learning models, particularly pixel-density estimators, can accurately automate counting of migratory birds in a dense, aggregate setting such as nocturnal roosting sites.

Nebraska↗
USGS2020

Deposition potential and flow-response dynamics of emergent sandbars in a braided river

Sandbars are ubiquitous in sandy‐braided rivers throughout the world. In the Great Plains of the United States, recovery and expansion of emergent sandbar habitat (ESH) has been a priority in lowland rivers where the natural extent of sandbars has been degraded. Recovery efforts are aimed at protection of populations of the interior least tern ( Sterna antillarum ) and piping plover ( Charadrius melodus ). But quantitative observations of deposition and erosion dynamics of populations of sandbars across long segments of rivers are rare. We present a three‐part case study which used Bayesian regression models to examine relations between hydrology, channel morphology, and ESH responses in the Platte River, eastern Nebraska. Logistic regression indicates presence of ESH is positively related to the Parker, (1976) stability criterion and a gradient in sediment transport mode, and negatively related to presence of vegetation. Hierarchical linear regression modeling shows direct coupling between sandbar top‐surface height and formative flood magnitude, but the gap between formative flood stage and sandbar top‐surface increases with increasing discharge. Finally, linear regression modeling of sandbar erosion demonstrates rates of ESH erosion are on the order of 10 −1 ha/day during high‐flow periods and 10 −2 during low‐flow periods, but sandbar persistence is largely a function of sandbar starting size. The collective observations highlight the importance of large floods (>3‐year recurrence) in creating very large sandbars that persist as high‐quality ESH over periods of years whereas lower‐magnitude, more‐frequent flood events create lower‐quality ESH that typically does not persist into the following nesting season.

Nebraska↗
USGS2020

Temporospatial shifts in Sandhill Crane staging in the Central Platte River Valley in response to climatic variation and habitat change

Over 80% of the Mid-Continent Sandhill Crane ( Antigone canadensis ) Population (MCP), estimated at over 660,000 individuals, stops in the Central Platte River Valley (CPRV) during spring migration from mid-February through mid-April. Research suggests that the MCP may be shifting its distribution spatially and temporally within the CPRV. From 2002 to 2017, we conducted weekly aerial surveys of Sandhill Cranes staging in the CPRV to examine temporal and spatial trends in their abundance and distribution. Then, we used winter temperature and drought severity measures from key wintering and early migratory stopover locations to assess the impacts of weather patterns on annual migration chronology in the CPRV. We also evaluated channel width and land cover characteristics using aerial imagery from 1938, 1998, and 2016 to assess the relationship between habitat change and the spatial distribution of the MCP in the CPRV. We used generalized linear models, cumulative link models, and Akaike’s information criterion corrected for small sample sizes (AICc) to compare temporal and spatial models. Temperatures and drought conditions at wintering and migration locations that are heavily used by Greater Sandhill Cranes ( A. c. tabida ) best predicted migration chronology of the MCP to the CPRV. The spatial distribution of roosting Sandhill Cranes from 2015 to 2017 was best predicted by the proportion of width reduction in the main channel since 1938 (rather than its width in 2016) and the proportion of land cover as prairie-meadow habitat within 800 m of the Platte River. Our data suggest that Sandhill Cranes advanced their migration by an average of just over 1 day per year from 2002 to 2017, and that they continued to shift eastward, concentrating at eastern reaches of the CPRV. Climate change, land use change, and habitat loss have all likely contributed to Sandhill Cranes coming earlier and staying longer in fewer reaches of the CPRV, increasing their site use intensity. These historically unprecedented densities may present a disease risk to Sandhill Cranes and other waterbirds, including Whooping Cranes ( Grus americana ). Our models suggest that conservation actions may be maintaining Sandhill Crane densities in areas that would otherwise be declining in use. We suggest that management actions intended to mitigate trends in the distribution of Sandhill Cranes, including wet meadow restoration, may similarly benefit prairie- and braided river–endemic species of concern.

Nebraska↗
USGS2017

Impacts of invasive plants on Sandhill Crane ( Grus canadensis ) roosting habitat

Invasive plants continue to spread in riparian ecosystems, causing both ecological and economic damage. This research investigated the impacts of common reed, purple loosestrife, riparian shrubland, and riparian woodlands on the quality and quantity of sandhill crane roosting habitat in the central Platte River, Nebraska, using a discrete choice model. A more detailed investigation of the impacts of common reed on sandhill crane roosting habitat was performed by forecasting a spread or contraction of this invasive plant. The discrete choice model indicates that riparian woodlands had the largest negative impact on sandhill crane roosting habitat. The forecasting results predict that a contraction of common reed could increase sandhill crane habitat availability by 50%, whereas an expansion could reduce the availability by as much as 250%. This suggests that if the distribution of common reed continues to expand in the central Platte River the availability of sandhill crane roosting habitat would likely be greatly reduced.

Nebraska↗
USGS2017

Sandhill crane roost selection, human disturbance, and forage resources

Sites used for roosting represent a key habitat requirement for many species of birds because availability and quality of roost sites can influence individual fitness. Birds select roost sites based on numerous factors, requirements, and motivations, and selection of roosts can be dynamic in time and space because of various ecological and environmental influences. For sandhill cranes (Antigone canadensis) at their main spring-staging area along the Platte River in south-central Nebraska, USA, past investigations of roosting cranes focused on physical channel characteristics related to perceived security as motivating roost distribution. We used 6,310 roost sites selected by 313 sandhill cranes over 5 spring migration seasons (2003–2007) to quantify resource selection functions of roost sites on the central Platte River using a discrete choice analysis. Sandhill cranes generally showed stronger selection for wider channels with shorter bank vegetation situated farther from potential human disturbance features such as roads, bridges, and dwellings. Furthermore, selection for roost sites with preferable physical characteristics (wide channels with short bank vegetation) was more resilient to nearby disturbance features than more narrow channels with taller bank vegetation. The amount of cornfields surrounding sandhill crane roost sites positively influenced relative probability of use but only for more narrow channels < 100 m and those with shorter bank vegetation. We confirmed key resource features that sandhill cranes selected at river channels along the Platte River, and after incorporating spatial variation due to human disturbance, our understanding of roost site selection was more robust, providing insights on how disturbance may interact with physical habitat features. Managers can use information on roost-site selection when developing plans to increase probability of crane use at existing roost sites and to identify new areas for potential use if existing sites become limited.

Nebraska↗
USGS2014

Responses of predatory invertebrates to seeding density and plant species richness in experimental tallgrass prairie restorations

In recent decades, agricultural producers and non-governmental organizations have restored thousands of hectares of former cropland in the central United States with native grasses and forbs. However, the ability of these grassland restorations to attract predatory invertebrates has not been well documented, even though predators provide an important ecosystem service to agricultural producers by naturally regulating herbivores. This study assessed the effects of plant richness and seeding density on the richness and abundance of surface-dwelling (ants, ground beetles, and spiders) and aboveground (ladybird beetles) predatory invertebrates. In the spring of 2006, twenty-four 55 m × 55 m-plots were planted to six replicates in each of four treatments: high richness (97 species typically planted by The Nature Conservancy), at low and high seeding densities, and low richness (15 species representing a typical Natural Resources Conservation Service Conservation Reserve Program mix, CP25), at low and high seeding densities. Ants, ground beetles, and spiders were sampled using pitfall traps and ladybird beetles were sampled using sweep netting in 2007–2009. The abundance of ants, ground beetles, and spiders showed no response to seed mix richness or seeding density but there was a significant positive effect of richness on ladybird beetle abundance. Seeding density had a significant positive effect on ground beetle and spider species richness and Shannon–Weaver diversity. These results may be related to differences in the plant species composition and relative amount of grass basal cover among the treatments rather than richness.

Nebraska↗
USGS2014

Microbial water quality during the northern migration of Sandhill Cranes (Grus canadensis) at the central Platte River, Nebraska

The central Platte River is an important resource in Nebraska. Its water flows among multiple channels and supports numerous beneficial uses such as drinking water, irrigation for agriculture, groundwater recharge, and recreational activities. The central Platte River valley is an important stopover for migratory waterfowl and cranes, such as the Whooping ( Grus americana ) and Sandhill Cranes ( Grus canadensis ), in their annual northward traversal of the Central Flyway. Waterfowl, cranes, and other migratory birds moving across international and intercontinental borders may provide long-range transportation for any microbial pathogen they harbor, particularly through the spread of feces. Samples were collected weekly in the study reach from three sites (upstream, middle, and downstream from the roosting locations) during the spring of 2009 and 2010. The samples were analyzed for avian influenza, Escherichia coli, Cryptosporidium, Giardia, Campylobacter , and Legionella . Analysis indicates that several types of fecal indicator bacteria and a range of viral, protozoan, and bacterial pathogens were present in Sandhill Crane excreta. These bacteria and pathogens were present at a significantly higher frequency and densities in water and sediments when the Sandhill Cranes were present, particularly during evening roosts within the Platte River environment.

Nebraska↗
USGS2013

Cost-effectiveness analysis of sandhill crane habitat management

Invasive species often threaten native wildlife populations and strain the budgets of agencies charged with wildlife management. We demonstrate the potential of cost-effectiveness analysis to improve the efficiency and value of efforts to enhance sandhill crane ( Grus canadensis ) roosting habitat. We focus on the central Platte River in Nebraska (USA), a region of international ecological importance for migrating avian species including sandhill cranes. Cost-effectiveness analysis is a valuation process designed to compare alternative actions based on the cost of achieving a pre-determined objective. We estimated costs for removal of invasive vegetation using geographic information system simulations and calculated benefits as the increase in area of sandhill crane roosting habitat. We generated cost effectiveness values for removing invasive vegetation on 7 land parcels and for the entire central Platte River to compare the cost-effectiveness of management at specific sites and for the central Platte River landscape. Median cost effectiveness values for the 7 land parcels evaluated suggest that costs for creating 1 additional hectare of sandhill crane roosting habitat totaled US $1,595. By contrast, we found that creating an additional hectare of sandhill crane roosting habitat could cost as much as US $12,010 for some areas in the central Platte River, indicating substantial cost savings can be achieved by using a cost effectiveness analysis to target specific land parcels for management. Cost-effectiveness analysis, used in conjunction with geographic information systems, can provide decision-makers with a new tool for identifying the most economically efficient allocation of resources to achieve habitat management goals.

Nebraska↗
USGS2013

Emergent sandbar dynamics in the lower Platte River in eastern Nebraska: methods and results of pilot study, 2011

The lower Platte River corridor provides important habitats for two State- and federally listed bird species: the interior least tern (terns; Sternula antillarum athallassos) and the piping plover (plovers; Charadrius melodus). However, many of the natural morphological and hydrological characteristics of the Platte River have been altered substantially by water development, channelization, hydropower operations, and invasive vegetation encroachment, which have decreased the abundance of high-quality nesting and foraging habitat for terns and plovers. The lower Platte River (LPR), defined as 103 miles (mi) of the Platte River between its confluence with the Loup River and its confluence with the Missouri River, has narrowed since the late-19th and early-20th centuries, yet it partially retains many geomorphologic and hydrologic characteristics important to terns and plovers. These birds nest on the sandbars in the river and along shorelines at sand- and gravel-pit lakes in the adjacent valley. The need to balance continued economic, infrastructure, and resource development with the conservation of important physical and aquatic habitat resources requires increased understanding of the physical and biological dynamics of the lower Platte River. Spatially and temporally rich datasets for emergent sandbar habitats are necessary to quantify emergent sandbar dynamics relative to hypothesized controls and stressors. In cooperation with the Lower Platte South Natural Resources District, the U.S. Geological Survey initiated a pilot study of emergent sandbar dynamics along a 22-mi segment of the LPR downstream from its confluence with Salt Creek, near Ashland, Nebraska. The purposes of the study were to: (1) develop methods to rapidly assess sandbar geometries and locations in a wide, sand-bed river, and (2) apply and validate the method to assess emergent sandbar dynamics over three seasons in 2011. An examination of the height of sandbars relative to the local stage of the formative discharge event, and how subsequent river discharges, of both high and low magnitude, alter sandbar geometries and abundance within the LPR was of particular interest. A “rapid-assessment” method was developed with the goal of characterizing the spatial distribution and habitat-relevant geometries of the complete population of sandbars along the study segment. Three primary measures were used to assess emergent sandbar dynamics in the study segment: sandbar area, sandbar height, and sandbar location. Data to derive these measures were collected during three, week-long survey periods in 2011, herein named “spring survey period,” “summer survey period,” and “fall survey period.” Emergent sandbars were grouped into one of three generalized types: (1) bank-attached, (2) island-attached, and (3) mid-channel.

Nebraska↗
USGS2011

Evaluating the potential for remote bathymetric mapping of a turbid, sand-bed river: 2. application to hyperspectral image data from the Platte River

This study examined the possibility of mapping depth from optical image data in turbid, sediment-laden channels. Analysis of hyperspectral images from the Platte River indicated that depth retrieval in these environments is feasible, but might not be highly accurate. Four methods of calibrating image-derived depth estimates were evaluated. The first involved extracting image spectra at survey point locations throughout the reach. These paired observations of depth and reflectance were subjected to optimal band ratio analysis (OBRA) to relate ( R 2 = 0.596) a spectrally based quantity to flow depth. Two other methods were based on OBRA of data from individual cross sections. A fourth strategy used ground-based reflectance measurements to derive an OBRA relation ( R 2 = 0.944) that was then applied to the image. Depth retrieval accuracy was assessed by visually inspecting cross sections and calculating various error metrics. Calibration via field spectroscopy resulted in a shallow bias but provided relative accuracies similar to image-based methods. Reach-aggregated OBRA was marginally superior to calibrations based on individual cross sections, and depth retrieval accuracy varied considerably along each reach. Errors were lower and observed versus predicted regression R 2 values higher for a relatively simple, deeper site than a shallower, braided reach; errors were 1/3 and 1/2 the mean depth for the two reaches. Bathymetric maps were coherent and hydraulically reasonable, however, and might be more reliable than implied by numerical metrics. As an example application, linear discriminant analysis was used to produce a series of depth threshold maps for characterizing shallow-water habitat for roosting cranes.

Platte River↗
USGS2011

Influence of a thin veneer of low-hydraulic-conductivity sediment on modelled exchange between river water and groundwater in response to induced infiltration

A thin layer of fine‐grained sediment commonly is deposited at the sediment–water interface of streams and rivers during low‐flow conditions, and may hinder exchange at the sediment–water interface similar to that observed at many riverbank‐filtration (RBF) sites. Results from a numerical groundwater‐flow model indicate that a low‐permeability veneer reduces the contribution of river water to a pumping well in a riparian aquifer to various degrees, depending on simulated hydraulic gradients, hydrogeological properties, and pumping conditions. Seepage of river water is reduced by 5–10% when a 2‐cm thick, low‐permeability veneer is present on the bed surface. Increasing thickness of the low‐permeability layer to 0·1 m has little effect on distribution of seepage or percentage contribution from the river to the pumping well. A three‐orders‐of‐magnitude reduction in hydraulic conductivity of the veneer is required to reduce seepage from the river to the extent typically associated with clogging at RBF sites. This degree of reduction is much larger than field‐measured values that were on the order of a factor of 20–25. Over 90% of seepage occurs within 12 m of the shoreline closest to the pumping well for most simulations. Virtually no seepage occurs through the thalweg near the shoreline opposite the pumping well, although no low‐permeability sediment was simulated for the thalweg. These results are relevant to natural settings that favour formation of a substantial, low‐permeability sediment veneer, as well as central‐pivot irrigation systems, and municipal water supplies where river seepage is induced via pumping wells.

Colorado↗
USGS2011

Geographic distribution of the mid-continent population of sandhill cranes and related management applications

The Mid-continent Population (MCP) of sandhill cranes ( Grus canadensis ) is widely hunted in North America and is separated into the Gulf Coast Subpopulation and Western Subpopulation for management purposes. Effective harvest management of the MCP requires detailed knowledge of breeding distribution of subspecies and subpopulations, chronology of their use of fall staging areas and wintering grounds, and exposure to and harvest from hunting. To address these information needs, we tagged 153 sandhill cranes with Platform Transmitting Terminals (PTTs) during 22 February–12 April 1998–2003 in the Central and North Platte River valleys of south-central Nebraska. We monitored PTT-tagged sandhill cranes, hereafter tagged cranes, from their arrival to departure from breeding grounds, during their fall migration, and throughout winter using the Argos satellite tracking system. The tracking effort yielded 74,041 useable locations over 49,350 tag days; median duration of tracking of individual cranes was 352 days and 73 cranes were tracked >12 months. Genetic sequencing of mitochondrial DNA (mtDNA) from blood samples taken from each of our random sample of tagged cranes indicated 64% were G. c. canadensis and 34% were Grus canadensis tabida . Tagged cranes during the breeding season settled in northern temperate, subarctic, and arctic North America (U.S. [23%, n = 35], Canada [57%, n = 87]) and arctic regions of northeast Asia (Russia [20%, n = 31]). Distribution of tagged cranes by breeding affiliation was as follows: Western Alaska–Siberia (WA–S, 42 ± 4% [SE]), northern Canada–Nunavut (NC–N, 21 ± 4%), west-central Canada–Alaska (WC–A, 23 ± 4%) and East-central Canada–Minnesota (EC–M, 14 ± 3%). All tagged cranes returned to the same breeding affiliation used during the previous year with a median distance of 1.60 km (range: 0.08–7.7 km, n = 53) separating sites used in year 1 and year 2. Fall staging occurred primarily in central and western Saskatchewan (69%), North Dakota (16%), southwestern Manitoba (10%), and northwestern Minnesota (3%). Space-use sharing indices showed that except for NC–N and WC–A birds, probability of finding a crane from one breeding affiliation within the home range of another breeding affiliation was low during fall staging. Tagged cranes from WC–A and EC–M breeding affiliations, on average, spent 25 and 20 days, respectively, longer on fall staging areas in the northern plains than did WA–S and NC–N birds. Cranes in the NC–N, WA–S, and WC–A affiliations spent 99%, 74%, and 64%, respectively, of winter in western Texas in Hunting Zone A; EC–M cranes spent 83% of winter along the Texas Gulf Coast in Hunting Zone C. Tagged cranes that settled within the breeding range of the Gulf Coast Subpopulation spent 28% and 42% of fall staging and winter within the range of the Western Subpopulation, indicating sufficient exchange of birds to potentially limit effectiveness of MCP harvest management. Harvests of EC–M and WC–A cranes during 1998–2003 were disproportionately high to their estimated numbers in the MCP, suggesting more conservative harvest strategies may be required for these subpopulations in the future, and for sandhill cranes to occupy major parts of their historical breeding range in the Prairie Pothole Region. Exceptionally high philopatry of MCP cranes of all 4 subpopulations to breeding sites coupled with strong linkages between crane breeding distribution, and fall staging areas and wintering grounds, provide managers guidance for targeting MCP crane harvest to meet management goals. Sufficient temporal or spatial separation exists among the 4 subpopulations on fall staging areas and wintering grounds to allow harvest to be targeted at the subpopulation level in all states and provinces (and most hunting zones within states and provinces) when conditions warrant. Knowledge gained from our study provides decision-makers in the United States, Canada, Mexico, and Russia with improved guidance for developing sound harvest regulations, focusing conservation efforts, and generating collaborative efforts among these nations on sandhill crane research and management to meet mutually important goals.

Nebraska↗
USGS2011

Diet composition and feeding patterns of adult shovelnose sturgeon (Scaphirhynchus platorynchus) in the lower Platte River, Nebraska, USA

Two-hundred and seven adult shovelnose sturgeon ranging from 450 to 718 mm in length were sampled from June to October 2001 and May to July 2002 to determine diet composition and feeding patterns in the lower Platte River. Shovelnose sturgeon fed primarily upon aquatic insect larvae and nymphs (>99% composition by number). Diptera of the family Chironomidae were the dominant prey items in both years and composed 98.1% of the shovelnose sturgeon diet in 2001 and 96.8% in 2002. Chironomidae were primarily represented by the four genera Paracladopelma , Chernovskiia , Saetheria and Robackia accounting for 90.2% of the ingested prey items in 2001 and 83.6% in 2002. In addition, shovelnose sturgeon showed in both years a generalized feeding pattern towards Ephemeroptera of the families Isonychiidae and Caenidae, as well as Trichoptera of the family Hydropsychidae. Other aquatic insects, terrestrial invertebrates and fishes were found infrequently and in low numbers in shovelnose sturgeon diets. The four most abundant Chironomidae genera are often found on sand and the high abundance of these taxa in the diet suggests that shovelnose sturgeon feed primarily near or on this substrate type. This highlights the importance of habitats that provide sand substrate for shovelnose sturgeon foraging in the lower Platte River.

Nebraska↗
USGS2010

Use of geochemical, isotopic, and age tracer data to develop models of groundwater flow for the purpose of water management, northern High Plains aquifer, USA

A prolonged drought in the High Plains of Nebraska prompted the use of groundwater for cooling at the largest coal-fired power plant in the State. Prior to the drought, groundwater was used primarily for irrigation and the power plant relied exclusively on surface water stored in a nearby reservoir for cooling. Seepage from the reservoir system during the past ∼75 a has resulted in the buildup of a large mound of water in the underlying unconfined aquifer. A well field was installed during the drought for the purpose of tapping the groundwater mound as a supplemental source of water for cooling. Concentrations of dissolved Cl − and SO 4 2 - "> SO 4 2- indicate 65–100% of shallow groundwater and 0–100% of deep groundwater (saturated thickness ∼115 m) in the immediate vicinity of the reservoir was from seepage out of the reservoir system. Hydrogen and O isotopic data indicate most surface-water seepage occurred in the late spring and early summer when reservoir stage was at its highest level. Tritium/ 3 He apparent groundwater ages imply horizontal flow velocities from the reservoir were on the order of 60–600 m/a. These diverse data provided information regarding the spatial distribution, timing, and rate of seepage from the reservoir that could not have been obtained from the available geologic, hydraulic head, and conductivity data. In particular, mixing fractions of surface water and regional groundwater in the aquifer could not have been determined using hydraulic information. Mixing fractions were of special interest in this study because of the management objective to maximize the capture of surface-water seepage in the cooling water wells. Groundwater-flow models developed as well-field management tools were calibrated using inverse modeling techniques and observations of groundwater age, surface-water flow, reservoir stage, and groundwater levels. The age data only accounted for 6 of the 2574 field observations used to calibrate the groundwater-flow models, yet they were among the most influential for refining estimates of hydraulic conductivity, recharge, and seepage from the reservoir. Results from this study demonstrate the benefits of using geochemical, isotopic, and age tracer data to develop conceptual and numerical models of groundwater flow for the purpose of water management.

Nebraska↗
USGS2005

Occurrence of selected pharmaceutical and non-pharmaceutical compounds, and stable hydrogen and oxygen isotope ratios, in a riverbank filtration study, Platte River, Nebraska, 2001 to 2003, Volume 1

Although studied extensively in recent years in Europe, the occurrence of endocrine disrupters and other organic wastewater compounds in the environment in the United States is not well documented. To better understand the efficiency of riverbank filtration with respect to endocrine disrupting compounds and to evaluate the use of riverbank filtration as an effective means of drinking-water treatment, a study was conducted during 2001-2003 by the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency and the City of Lincoln, at an established riverbank-filtration well field with horizontal collector wells and vertical wells. This study provides information that will be useful for (1) increased understanding of the processes and factors important in controlling the transport of endocrine disrupters, such as pesticides and pharmaceuticals during riverbank filtration, (2) better understanding of the physical and chemical processes that affect riverbank-filtration efficiency, and (3) managing the water resources of the eastern Platte River Basin. This report presents analytical methods and data collected during the study. Data are presented as generalized statistics and in figures showing temporal variations. Sites from which water-quality samples were collected for this study included wastewater sites (a cattle feedlot lagoon, a hog confinement lagoon, and wastewater-treatment plant effluent), surface-water sites (Platte River, Salt Creek, and Loup Power Canal), ground-water sites (one collector well and three vertical wells), and drinking-water sites (raw and finished). Field water-quality properties were measured in samples from these sites. Pharmaceutical compounds were detected often in the wastewater-treatment plant effluent. Surface and ground water showed low-level concentrations of pharmaceuticals. Finished drinking-water samples did not contain detectable concentrations of pharmaceuticals except for low levels of cotinine and caffeine. Antibiotics were found in some of the wastewater samples and twice in Salt Creek. Antibiotics were not detected in any samples from the Platte River or the well field. Surface-water samples were analyzed for total organic carbon and ground-water samples were analyzed for dissolved organic carbon. Samples from all sites were analyzed for major ions. Herbicides commonly detected in surface, ground, and drinking water included acetachlor, alachlor, atrazine, and metolachlor as well as degradates of these compounds. Most of the samples from wastewater sites were found to contain predominantly acetamide degradates. High concentrations of several organic wastewater indicator compounds were detected at the wastewater sites and in Salt Creek. Several organic wastewater indicator compounds were detected multiple times in samples from the Platte River. Bromoform, a by-product of disinfection in the treatment plant, was found in samples from the finished drinking water. Stable hydrogen isotope ratios show a range in seasonal variation of -73.6 per mill to -38.1 per mill relative to Vienna Standard Mean Ocean Water (VSMOW) reference water and -69.2 per mill to -46.5 per mill for surface water and ground water, respectively. Oxygen isotope ratios for surface-water samples varied between -9.86 per mill and -5.05 per mill. Stable oxygen isotope ratios of ground waters varied between -9.62 per mill and -5.81 per mill.

Nebraska↗
USGS2005

Occurrence of selected pharmaceutical and non-pharmaceutical compounds, and stable hydrogen and oxygen isotope ratios in a riverbank filtration study, Platte River, Nebraska, 2002 to 2005, Volume 2

This document is the second volume of a data series report that describes the data collected during a study conducted during 2001 through 2005 by the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency and the City of Lincoln, at an established riverbank-filtration well field with horizontal collector wells and vertical wells. The data were collected as part of a study designed to help researchers better understand the efficiency of riverbank filtration with respect to endocrine disrupting compounds and to evaluate the use of riverbank filtration as an effective means of drinking-water treatment. This study provides information that will be useful for (1) increased understanding of the processes and factors controlling the transport of endocrine disrupters, such as pesticides and pharmaceuticals during riverbank filtration, (2) better understanding of the physical and chemical processes that affect riverbank-filtration efficiency, and (3) managing the water resources of the eastern Platte River Basin. This report presents analytical methods and additional data for pharmaceuticals, dissolved organic carbon (DOC), ultraviolet absorbance at 254 nanometer (nm) wavelength (UV254), specific ultraviolet absorbance (SUVA), nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), nonylphenol ethoxycarboxylates (NPECs), and stable hydrogen and oxygen isotope ratios that were not available at the time of publication of Volume 1 in the data series. Data are presented as generalized statistics and in figures showing temporal variations. Sites from which water-quality samples were collected for this study included wastewater sites (a cattle feedlot lagoon, a hog confinement lagoon, and wastewater-treatment plant effluent), surface-water sites (Platte River, Salt Creek, and Loup Power Canal), ground-water sites (one collector well and five vertical wells), and drinking-water sites (raw and finished). Field water-quality properties also were measured in samples from these sites. Pharmaceuticals detected at least once in samples collected from the Platte River included 1,7-dimethylxanthine, acetaminophen, caffeine, carbamazapine, and cotinine. Among the ground-water samples, pharmaceutical compounds detected at low concentrations in at least one sample included 1,7-dimethylxanthine, acetaminophen, carbamazapine, and trimethoprim. When analyzing for non-pharmaceutical compounds in samples from the wastewater sites, the wastewater-treatment plant effluent samples had the highest concentrations of each of NTA, EDTA, and NPECs compounds. Surface-water samples from Salt Creek had higher concentrations of EDTA and NPECs than samples from the Platte River. NTA was not detected in any samples from the ground-water sites. EDTA was detected in all samples from all wells. Detectable concentrations of EDTA were also observed in all samples from the raw water and finished water.

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