U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2007–3098

April 2008

Prepared in cooperation with the National Park Service

Water-Quality and Fish-Community Data for the Niobrara 

National Scenic River, Nebraska, 2003–05

Printed on recycled paper

Introduction

In 1991, a 76-mile reach of the Niobrara River in northcentral Nebraska was designated as a National Scenic River 

(NSR). This reach of the river hosts a unique ecosystem that 

provides habitat for a diverse fish and wildlife population 

that include several threatened and endangered species. The 

Niobrara NSR also is a popular destination for campers, canoeists, kayakers, and tubers.

Changes in surface-water quality, related to recreation, 

industrial and municipal discharge, and agricultural activities in 

the region have the potential to affect fish and wildlife populations within the Niobrara NSR. Additionally, water users may 

be at risk if elevated concentrations of chemical or biological 

contaminants are present in the waterway. The U.S. Geological Survey (USGS) and the National Park Service (NPS) began 

a 3-year cooperative study of water-quality characteristics in 

Niobrara NSR in 2003. During the study, water samples were 

collected for analysis of a suite of physical, chemical, and 

biological indicators of water quality in the Niobrara River. 

The resulting data have been published previously (Hitch and 

others, 2004; Hitch and others, 2005) and included: major ions, 

nutrients, trace elements, pesticides, organic (wastewater) compounds, bacteria, and suspended sediment. In addition to waterquality sampling, fish communities were sampled to identify the 

presence and diversity of species at selected sites (data available 

online in Annual Water Data Reports). These water-quality and 

fish-community data are summarized in this report. The data 

were collected to provide baseline information that will help 

NPS managers determine if changes in recreational activities, 

land-use practices, and other factors are affecting the Niobrara 

River. 

Background

The Niobrara River extends 536 miles from eastern 

Wyoming to its mouth near Niobrara, Nebraska. Streamflow 

within the basin is derived primarily from snowmelt and seepage from the underlying High Plains aquifer. Flows are usually 

highest in the spring and early summer and lowest in late summer and early fall. Land use in the Niobrara River Basin primarily consists of rangeland, alfalfa, and row crops. Minnechaduza 

Creek, a small tributary to the Niobrara River, located on the 

northern edge of Valentine, Nebraska, the largest community in 

the sparsely populated region, receives runoff and treated wastewater discharge from the city. 

The Niobrara NSR designation begins near Valentine and 

extends 76 miles downstream to north of Newport, Nebraska, 

and encompasses 23,000 acres of open water, forests, hills, prairies, and canyons. The area received approximately 53,400 visitors in 2004 (National Park Service, 2005). Although recreation 

activities take place year-round, the greatest public use occurs 

from mid-May to mid-October.

The study area includes the 35-mile reach of the Niobrara 

NSR from the Borman Bridge to the Carns Bridge (fig. 1). Four 

sites were selected to monitor water-quality conditions from 

Photograph by Stuart Schneider, National Park Service
June to September 2003 and from May to December 2004. 

Filtered (0.45-micron) and unfiltered samples were collected 

to evaluate dissolved and total concentrations. Samples were 

collected twice in June 2003 and once per month from July 

through September 2003 using methods described in Meyers 

(2004) and Wilde (variously dated), and U.S. Geological Survey 

(variously dated). Samples were collected monthly from May 

2004 through December 2004. Three of the four sampling sites 

were located along the Niobrara River—upstream from Fort 

Niobrara National Wildlife Refuge at the Borman Bridge (site 

1, USGS station 06460800), at Berry Bridge near Sparks (site 

2, USGS station 06461500), and at the Norden Bridge (site 3, 

USGS station 06462000). The fourth site was located on Minnechaduza Creek downstream from Valentine (site 4, USGS 

station 06461010). A continuous streamflow recorder has been 

in operation at Berry Bridge near Sparks (site 2) since 1946. 

Fish-community sampling occurred once at each of 18 

sites of which 7 were located on the Niobrara River main stem 

and 11 were located on selected tributaries (fig. 1). Potential 

fish migration barriers occurred within the reach such as the 

Cornell Dam, a large knickpoint near the Norden bridge, and 

rock riffles. Samples were obtained using electroshocking and 

seining techniques (fig. 2) primarily during early to mid-September 2003–05.

Water-Quality Properties

During water-quality sample collection, study personnel 

measured specific conductance, pH, air and water temperatures, and dissolved oxygen concentration using calibrated 

instruments (Wilde, chapter sections variously dated). Specific 

conductance values measured at the Niobrara River sites ranged 

from 198 to 229 microsiemens per centimeter at 25 degrees 

Celsius (μS/cm) and were less than values measured in Minnechaduza Creek (site 4), which ranged from 285 to 335 μS/cm. 

Specific conductance observations at individual sites did not 

STUDY AREA

5

7

8 10

11

12

13 9 14

15

16

17

18

22

19

20

21

2

3

1

6

100°30’

43°

42°40’

50’

20’ 10’ 100° 50’ 40’ 99°30’

0 3 6 9 12 MILES

0 3 6 9 12 KILOMETERS

SOUTH DAKOTA

NEBRASKA

Tripp County

Keya Paha County

Cherry County

Brown County Rock County

Gregory County

Todd County

Valentine

Sparks

Wood Lake

Springview

Burton

Base from U.S. Geological Survey digital data, 1:100,000, 1999

Universal Transverse Mercator projection,

Zone 14

Horizontal coordinate information is referenced to the North American

 Datum of 1983 (NAD 83)

Keya Paha River

97

20

83

83

20

12

12

7

183

183

12

Niobrara

River

Fort Niobrara

National Wildlife

Refuge

Niobrara National

Scenic River

Borman bridge

Carns bridge

Norden bridge

Minnechaduza Creek

Long Pine Creek

4

Niobrara River Basin

Keya Paha River Basin

Elkhorn River Basin

Missouri River

Basin

Index map

SOUTH DAKOTA

NEBRASKA

Niobrara River Study area drainage area

Keya Paha River

drainage area

Newport

EXPLANATION

Extent of High Plains aquifer

Niobrara National Scenic River

 designation

Boundary of drainage basin

Water-quality sampling site and

 map number

Fish community sampling site and

 map number 17

3

Figure 1. Location of the study area for water-quality and fish-community data collection for the Niobrara National Scenic River, 

Nebraska, 2003–05.
vary substantially. At the Niobrara River sites, pH values varied 

from 7.8 to 8.7 standard units, and in general, the values were 

smallest at the most upstream site (Borman Bridge, site 1). In 

most cases, pH values were highest at the Minnechaduza Creek 

site (site 4), where pH ranged from 8.1 to 8.8 and the highest 

pH value (8.8) of all samples at all sites was measured in May 

2004. The highest water temperatures usually were measured 

when the highest air temperatures were measured, and the 

lowest water temperatures were measured when the lowest air 

temperatures were measured at all four water-quality sites. Dissolved oxygen concentrations were larger than 7.2 milligrams 

per liter (mg/L) in all samples and typically were larger when 

water temperatures were low. Dissolved oxygen concentrations 

usually were largest at Berry Bridge near Sparks (site 2) and 

smallest at Norden Bridge (site 3).

Major Ions

All water-quality samples were analyzed for 10 major 

ions at the USGS National Water Quality Laboratory (NWQL) 

in Lakewood, Colorado, using methods described in Fishman 

(1993). The dominant cation in water at the sampling sites 

was calcium. Sulfate and chloride were the dominant anions. 

Samples from the Niobrara River sites showed stable major ion 

concentrations throughout the sampling period and were less 

than concentrations in Minnechaduza Creek. Potassium concentrations ranged from 5 to 7 mg/L in samples from Niobrara 

River sites and from 6 to 10 mg/L in samples from the Minnechaduza site. Silica concentrations ranged from 40 to 70 mg/L 

in samples from the Niobrara River and from 42 to 47 mg/L in 

samples from Minnechaduza Creek. Iron concentrations were 

near or less than the minimum reporting level (8 micrograms 

per liter (μg/L)) in all samples. Fluoride concentrations ranged 

from 0.3 to 0.5 mg/L in all samples.

Nutrients

Nutrients, such as nitrogen and phosphorus compounds, 

occur naturally in surface water, but elevated concentrations 

often are associated with agricultural runoff and with detergents 

and chemicals found in municipal wastewater discharges and 

septic systems (Mueller and Helsel, 1996). Excessive nutrient 

concentrations can trigger algal blooms (U.S. Environmental 

Protection Agency, 1986) that may cause decreases in dissolved 

oxygen and increases in suspended materials. All samples were 

analyzed for eight nutrient compounds at the NWQL (Fishman, 

1993). Nitrite plus nitrate was less than 1 mg/L as nitrogen in 

all of the samples. In most months, water from the Minnechaduza Creek site showed the largest concentrations of unfiltered 

ammonia plus organic nitrogen, filtered ammonia plus organic 

nitrogen, nitrite, nitrate, filtered phosphorus, and organophosphates. Of the 51 unfiltered samples collected in the Niobrara 

NSR that were analyzed for total phosphorus, 45 exceeded the 

U.S. Environmental Protection Agency (USEPA) recommendation of 0.1 mg/L for avoiding algal blooms (U.S. Environmental 

Protection Agency, 1986). In general, phosphorus concentrations in samples from the Minnechaduza Creek site were higher 

than the phosphorus concentrations at other sites for the corresponding sampling event. 

Trace Elements

Naturally occurring arsenic can be found in deposits of the 

Cretaceous-aged Niobrara Formation and Carlile Shale of the 

Colorado Group that underlie the study area (Bradley, 1956). 

Uranium is known to occur in water-bearing units of the Brule 

Formation and Chadron Formation in Nebraska west of the 

study area (Dickinson, 1991). These compounds can be carried 

to streams from ground water and on sediment during surface 

runoff events. For the protection of aquatic life, the Nebraska 

Department of Environmental Quality criteria (Nebraska 

Department of Environmental Quality, 2006) require longterm average arsenic concentrations to be less than 16.7 μg/L. 

Although there is no State standard for dissolved uranium for 

the protection of aquatic life, uranium concentrations in publicdrinking water must be less than 30 μg/L (Nebraska Department 

of Environmental Quality, 2006). All samples were analyzed for 

trace elements arsenic, lead and uranium at the NWQL (Faires, 

1993). Concentrations for trace elements including arsenic, lead, 

and uranium were determined in samples from Minnechaduza 

Creek (site 4) and on the Niobrara River at the Borman Bridge 

(site 1). Arsenic concentrations were similar at the two sites and 

ranged from 4.9 to 7.2 μg/L. Lead concentrations were near or 

less than the minimum reporting level of the laboratory method 

(0.08 μg/L). Uranium concentrations ranged from 0.81 to 1.62 

μg/L, with slightly higher concentrations detected in samples 

from the Minnechaduza Creek site. 

Pesticides

Pesticides are commonly detected at surface-water sites in 

Nebraska because of widespread use in agriculture and urban 

settings (Larson and others, 1999). Water samples collected 

near the Norden Bridge (site 3) were analyzed for 65 pesticide compounds at the NWQL (Zaugg and others, 1995). Four 

compounds were detected in trace concentrations [atrazine, 

2-chloro-4-isopropylamino-6-amino-s-triazine (an atrazine degradate), metolachlor, and trifluralin]. Atrazine, metolachlor, and 

trifluran are herbicides used to control weeds in corn, soybeans, 

and other crops. One compound, Deet, was detected at concenFigure 2. Collecting fish by electroshocking technique, Niobrara 

River Nebraska. Photograph by Stuart Schneider, National Park 

Service.
trations greater than 1 μg/L. Deet, which is commonly found in 

insect repellents, was detected in the August 2004 samples from 

Minnechaduza Creek (site 4), and from the Niobrara River (sites 

2 and 3) and in three September 2004 samples (sites 1, 2, and 

4). No other pesticides were detected.

Organic Wastewater Compounds

Organic wastewater compounds (OWCs) are chemicals 

such as household, industrial, and agricultural-use compounds, 

pharmaceuticals, antibiotics, and sterols and hormones that can 

enter streams and ground water through discharge from municipal and industrial wastewater-treatment plants, domestic septic 

systems, animal feedlots, and other sources (Lee and others, 

2004). Samples at all 4 sites were analyzed for the presence 

of 62 OWCs at the NWQL using methods developed by the 

USGS (Zaugg and others, 2002). Tris(2-butoxyethyl) phosphate, 

a flame retardant, was detected at a low concentration in one 

sample from Minnechaduza Creek (site 4) on August 23, 2003. 

This detection and the detection of Deet coincide with the peak 

period of recreational activity and with locations downstream 

from municipal and recreational uses and sites where fire-fighting activities may have occurred. Five other organic wastewater 

compounds (isophorone, napthalene, phenanthrene, 1,4-dichlorobenzene, and caffeine) were present at detectable concentrations, but the concentrations of these compounds were too small 

to be quantified. 

Bacteria

Surface water commonly contains Escherichia coli

(E. coli) bacteria originating from humans, livestock, and 

wildlife (Hyer and Moyer, 2003). Exposure to elevated densities of E. coli can pose health risks to humans recreating in or 

around the affected water body. Nebraska water-quality standards require that the geometric mean of E. coli densities (based 

on a minimum of 5 samples collected within a 30-day period) 

in streams designated as moderately used recreational water 

must not exceed 298 colonies per 100 milliliter (col/100 mL) 

(Nebraska Department of Environmental Quality, 2006). Grab 

samples for E. coli were collected at all four sites using methods described in Meyers (2004) and processed in sterilized 

equipment for each sample collection, except the first sample collection in June 2003 did not include bacteria samples. 

Samples were cultured using the modified mTEC method 

(U.S. Environmental Protection Agency, 2002). E. coli were 

detected in all samples, and the density of 298 col/100 mL 

was exceeded during two sample collections. The largest 

E. coli observed density during the study was 1,000 col/

100 mL was detected at the Minnechaduza Creek (site 4) in 

early November 2004. The largest density measured on the 

Niobrara River was 450 col/100 mL at site 1 in a late June 

2003 sample following several days of intense rain. Because 

these were individual sample collections rather than sets of 

five per month, they do not necessarily indicate that E. coli

criteria exceeded the water-quality standards for Nebraska.

Suspended Sediment

Large suspended-sediment concentrations can have 

negative effects on the habitat, health, and behavior of aquatic 

life (Waters, 1995). Suspended-sediment samples were collected concurrently with each water-quality sample. In general, 

suspended-sediment concentrations increased downstream on the 

Niobrara River and ranged from 22 to 1,170 mg/L for sites on the 

Niobrara River. Suspended-sediment concentrations in Minnechaduza Creek were less than 30 mg/L for all samples. Samples 

collected in late June 2003 did not have substantially higher sediment concentrations than samples collected in other months.

Fish-Community Data

At 18 sites on the Niobrara River and its tributaries (table 

1), fish were collected using electroshocking and seining 

techniques (Meador and others, 1993). Twenty-seven different species were identified within the study area, and the 

greatest number of unique species was found at a site on the 

Niobrara River upstream from Smith Falls (17 unique species collected). However, the overall number of unique species 

was greater at sites downstream from the Norden Bridge. The 

Norden Bridge location marks a distinct change from a swift, 

narrow channel upstream to a broad, shallow channel downstream with fewer riffles and pebble beds than upstream from 

the bridge. Additionally, the Norden Bridge is located near a 

steep drop in streambed elevation, which may be an obstacle to 

upstream migration. Some species, such as red shiner (Notropis 

lutrensis), sand shiner (Notropis stramineus), and bigmouth 

shiner (Notropis dorsalis) were numerous and widespread 

and, in general, appeared to lack abnormalities. Longnose dace 

(Rhinichthys cataractae) were present at most sites but were 

recorded in fewer numbers at sites downstream from the Norden 

Bridge. The presence of river carpsuckers (Carpiodes carpio) 

and quillback carpsuckers (Carpiodes cyprinus) was confined 

to reaches downstream from the Norden Bridge. Other species, such as brown trout (Salmo trutta), rainbow trout (Oncorhynchus mykiss), brook stickleback (Culaea inconstans), plains 

topminnow (Fundulus sciadicus), and western silvery minnow (Hybothnathus argyritis), were limited to just a few sites. 

Gamefish such as largemouth bass (Micropterus salmoides), 

green sunfish (Lepomis cyanellus), bluegill (Lepomis macrochirus), and channel catfish (Ictalurus punctatus) were found 

Photograph by Robert Swanson, U.S. Geological Survey
Table 1. Fish species collected using electroshocking and seining techniques at selected sites on the Niobrara River.

[BLG, bluegill; BMS, bigmouth shiner; BM, brassy minnow; BKS, brook stickleback; BKT, brown trout ; CCF, channel catfish; CCA, common carp; CCH, creek 

chub; FHC, flathead chub; FHM, fathead minnow; GP, grass pickerel; GSF, green sunfish; LMB, largemouth bass; LND, longnose dace; MC, mirror carp; NP, northern 

pike; PTM, plains top minnow; QCS, quillback carpsucker: RBT, rainbow trout; RCS, river carpsucker; RSH, red shiner; SSH, sand shiner; SRH, shorthead redhorse; 

STC, stone cat; WSV, western silvery minnow; WSK, white sucker; YWP, yellow perch]

Site Latitude Longitude Site Date Species Identified

5 42.851 -100.508 Niobrara R below Borman Bridge near 

Valentine, Nebr.

9/15/2003 BMS, BKT, CCF, CCA, GP, LND, NP, RSH, SSH, 

SRH, STC, WSK

6 42.871 -100.500 Trib Below Borman Bridge 9/16/2003 BKS, PTM

7 42.877 -100.490 Niobrara Mainstem above Cornell Dam 9/16/2003 BMS, BKT, FHM, GP, LND, NP, RSH, SSH, SRH, 

WSK

8 42.898 -100.485 Minnechaduza Creek 9/16/2003 CCH, LMB, LND, SRH, STC, WSK

9 42.901 -100.482 Trib Downstream from Refuge BridgeTrib 29/17/2003 None

10 42.902 -100.466 Niobrara Mainstem just upstream from 

Fort Falls

9/17/2003 BMS, CCA, CCH, GSF, LND, RSH, SSH, SRH, 

STC, WSK

11 42.905 -100.421 Big Beaver Creek 9/17/2003 BM, CCH, FHM, LND

12 42.908 -100.394 Crooked Creek 9/17/2003 CCH, LND

13 42.904 -100.369 Kewanee Creek 9/17/2003 None

14 42.900 -100.323 Niobrara Mainstem 1 1/2 miles upstream 

from Smith Falls

9/18/2003 BMS, BM, CCA, CCH, FHM, GP, LMB, LND, MC, 

NP, RSH, SSH, SRH, STC, WSV, WSK, YWP

15 42.890 -100.315 Smith Falls 9/18/2003 RBT

16 42.908 -100.455 Unnamed Trib 3 9/17/2003 None

17 42.721 -99.631 Long Pine Creek 9/9/2004 BMS, BM, BKT, CCH, FHM, LMB, LND, RSH, 

SSH, SRH, STC, WSK, FHC, BLG, RCS

18 42.728 -99.486 Laughing Water Creek 9/10/2004 BKT, LND, RSH

19 42.753 -99.844 Niobrara Mainstem below Meadville 

Bridge

9/8/2004 BMS, BM, CCF, CCH, FHM, LMB, LND, PTM, 

RSH, SSH, SRH, STC, WSK, FHC, BLG, RCS, 

QCS

20 42.751 -99.855 Plum Creek 9/7/2004 BMS, BM, CCH, FHM, GSF, LMB, LND, PTM, 

RSH, SSH, SRH, WSK, BLG, RCS

21 42.730 -99.497 Niobrara River Upstream from Carns 

Bridge

9/13/2005 BMS, BM, CCF, CCA, CCH, FHM, LMB, RSH, 

SSH, SRH, STC, WSK, FHC, RCS, QCS

22 42.805 -100.122 Niobrara River Downstream of Eglehoff 

Rapids

9/14/2005 BMS, CCH, FHM, GSF, LMB, LND, RSH, SSH, 

SRH, STC, WSK

throughout the Niobrara NSR, but more commonly downstream 

from the Norden Bridge. Grass pickerel (Esox americanus 

vermiculatus) and northern pike (Esox lucius) were collected in 

reaches upstream from Cornell Dam. 

Acknowledgements

The author thanks the staff of the National Park Service for 

their cooperation and contribution to this study. Appreciation is 

extended to the landowners for providing access to sampling sites.

―By B.J. Dietsch

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For further information contact:

Robert Swanson, Director

U.S. Geological Survey 

Nebraska Water Science Center

Lincoln, NE 68512

(402) 328-4100

Photograph by Robert Swanson, U.S. Geological Survey