HYDROLOGIC CHARACTERISTICS OF BEAR CREEK 

NEAR SILVER HILL AND BUFFALO RIVER NEAR ST. 

JOE, ARKANSAS, 1999-2000

Water-Resources Investigations Report 02-4024

U.S. Department of the Interior

U.S. Geological Survey
HYDROLOGIC CHARACTERISTICS OF BEAR CREEK 

NEAR SILVER HILL AND BUFFALO RIVER NEAR ST. 

JOE, ARKANSAS, 1999-2000

By James C. Petersen1, Brian E. Haggard2, and W. Reed Green1

U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 02-4024

Little Rock, Arkansas

2002

1

U.S. Geological Survey, Little Rock, AR 72211

2

U.S. Department of Agriculture—Agricultural Research Service, 203 Engineering Hall, University of

Arkansas, Fayetteville, AR 72701
U.S. DEPARTMENT OF THE INTERIOR

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

For additional information Copies of this report can be

write to: purchased from:

District Chief U.S. Geological Survey

U.S. Geological Survey, WRD Branch of Information Services

401 Hardin Road Box 25286

Little Rock, Arkansas 72211 Denver Federal Center

Denver, Colorado 80225
Contents III

CONTENTS

Abstract ................................................................................................................................................................1

Introduction ..........................................................................................................................................................1

Purpose and Scope ......................................................................................................................................3

Description of Study Area...........................................................................................................................3

Methods................................................................................................................................................................4

Hydrologic Characteristics...................................................................................................................................6

Streamflow ..................................................................................................................................................6

Water Quality..............................................................................................................................................8

Concentrations ................................................................................................................................. 11

Loads................................................................................................................................................ 11

Annual..................................................................................................................................... 11

Seasonal .................................................................................................................................. 19

Flow-Weighted Concentrations ....................................................................................................... 21

Yields ............................................................................................................................................... 22

Summary ............................................................................................................................................................ 23

References .......................................................................................................................................................... 23

Appendix - Water-quality data for Buffalo River near St. Joe and Bear Creek near Silver Hill, Arkansas ...... 25

ILLUSTRATIONS

Figure 1. Map showing location of Bear Creek and Buffalo River sampling sites ..........................................2

2-6. Graphs showing :

2. Daily base flow and total streamflow and associated water-quality sample times during

calendar years 1999 and 2000 for Bear Creek near Silver Hill, Arkansas...................................6

3. Flow-accumulation curve for Bear Creek near Silver Hill, Arkansas, January 1, 1999 to

December 31,2000........................................................................................................................9

4. Daily base flow and total streamflow and associated water-quality sample times during

calendar years 1999 and 2000 for Buffalo River near St. Joe, Arkansas ................................... 9

5. Flow-accumulation curve for Buffalo River near St. Joe, Arkansas, January 1, 1999 to

December 31, 2000..................................................................................................................... 10

6. Daily streamflow for Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas

in 1999 and 2000 ........................................................................................................................ 10

7-11. Boxplots showing distribution of:

7. Nitrogen concentrations for Bear Creek near Silver Hill and Buffalo River near St. Joe,

Arkansas, 1999-2000 .................................................................................................................. 12

8. Phosphorus concentrations for Bear Creek near Silver Hill and Buffalo River near St. Joe,

Arkansas, 1999-2000.................................................................................................................. 13

9. Bacteria concentrations for Bear Creek near Silver Hill and Buffalo River near St. Joe,

Arkansas, 1999 and 2000 ........................................................................................................... 14

10. Dissolved organic carbon concentrations for Bear Creek near Silver Hill and Buffalo River

near St. Joe, Arkansas, 1999-2000 ............................................................................................. 15

11. Suspended sediment concentrations for Bear Creek near Silver Hill and Buffalo River

near St. Joe, Arkansas, 1999-2000 ............................................................................................. 16
IV Contents

TABLES

Table 1. Sampling site information .................................................................................................................... 3

 2. Annual and monthly streamflow statistics for Bear Creek near Silver Hill and Buffalo River near

St. Joe, Arkansas, 1999-2000........................................................................................................... 7

3. Annual nitrogen, phosphorus, dissolved organic carbon, and suspended sediment loads and yields

for Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000 ..................17

 4. Seasonal nitrogen, phosphorus, dissolved organic carbon, and suspended sediment for Bear Creek

near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000...........................................19

 5. Comparison of Bear Creek and Buffalo River flow-weighted concentrations with flow-weighted

concentrations for undeveloped basins and the Illinois River, Arkansas .......................................21

 6. Comparison of Bear Creek and Buffalo River yields with yields for undeveloped basins and the

Illinois River, Arkansas ...................................................................................................................22

CONVERSION FACTORS AND ABBREVIATIONS

Multiply By To obtain

mile (mi) 1.609 kilometer

square mile (mi2) 2.590 square kilometer

cubic foot per second (ft3/s) 0.02832 cubic meter per second

pound per year (lb/yr) 4.536 kilogram per year

pound per year per square mile (lb/yr/mi2) 1.751 kilogram per year per square 

kilometer

degree Celsius (°C) 1.8 x °C + 32 degree Fahrenheit
Abstract 1

HYDROLOGIC CHARACTERISTICS OF BEAR CREEK 

NEAR SILVER HILL AND BUFFALO RIVER NEAR

ST. JOE, ARKANSAS, 1999-2000

By James C. Petersen, Brian E. Haggard, and W. Reed Green

ABSTRACT

The Buffalo River and its tributary Bear Creek 

are in the White River Basin in the Ozark Plateaus in 

north-central Arkansas. Analysis of streamflow measurements and water-quality samples at a site on Bear 

Creek and a site on the Buffalo River in Searcy County, 

Arkansas, quantify differences between the two sites 

during calendar years 1999 and 2000. Streamflow and 

water quality also vary seasonally at each site. Mean 

annual streamflow was substantially larger at the Buffalo River site (836 and 719 cubic feet per second in 

1999 and 2000) than at the Bear Creek site (56 and 63 

cubic feet per second). However, during times of low 

flow, discharge of Bear Creek comprises a larger proportion of the flow of the Buffalo River. Concentrations of nutrients, fecal-indicator bacteria, dissolved 

organic carbon, and suspended sediment generally 

were greater in samples from Bear Creek than in samples from the Buffalo River. Statistically significant 

differences were detected in concentrations of nitrite 

plus nitrate, total nitrogen, dissolved phosphorus, 

orthophosphorus, total phosphorus, fecal coliform bacteria, and suspended sediment. Loads varied between 

sites, hydrologic conditions, seasons, and years. Loads 

were substantially higher for the Buffalo River than for 

Bear Creek (as would be expected because of the Buffalo’s higher streamflow). Loads contributed by surface runoff usually comprised more than 85 percent of 

the annual load. Constituent yields (loads divided by 

drainage area) were much more similar between sites 

than were loads. Flow-weighted concentrations and 

dissolved constituent yields generally were greater for 

Bear Creek than yields for the Buffalo River and flowweighted concentrations yields were higher than typical flow-weighted concentrations and yields in undeveloped basins, but lower than flow-weighted 

concentrations and yields at a site in a more developed 

basin. 

INTRODUCTION

The Buffalo River and its tributary, Bear Creek, 

are in the White River Basin in the Ozark Plateaus 

physiographic province (Fenneman, 1946) in northcentral Arkansas (fig. 1). Most of the Buffalo River and 

a part of Bear Creek near its confluence with the Buffalo River lie within the boundaries of the Buffalo 

National River. A better understanding of the hydrology of this area is of interest to many, including the 

National Park Service, which administers the Buffalo 

National River. To contribute to this understanding, the 

U.S. Geological Survey (USGS) conducted a study to 

describe and compare streamflow and water-quality 

characteristics for a site on Bear Creek and a nearby 

site on the Buffalo River. This study is part of the 

National Park Service (NPS)/USGS Water-Quality 

Monitoring and Assessment Partnership. Studies conducted as part of the Water-Quality Monitoring and 

Assessment Partnership are designed to contribute 

information that would enhance the understanding of 

NPS water-quality management issues.

Because Bear Creek is one of the larger tributaries of the Buffalo River it can have a substantial effect 

on water quality and streamflow of the Buffalo River, 

and therefore on water-quality management issues. 

Immediately downstream from the confluence of Bear 

Creek and the Buffalo River, 9.8 percent of the Buffalo 

River’s drainage area is contributed by the Bear Creek 

Basin. Relative to many other tributaries of the Buffalo 

River a large part (28 percent) of the Bear Creek Basin 

is cleared land (Panfil and Jacobson, 2001). Previous 

investigations (Mott, 1997; Steele and Mott, 1998) 

have indicated that Bear Creek (and other nearby tributaries with relatively large percentages of clear land 

within their basins) may contribute to elevated concentrations of nitrate in the middle section of the Buffalo 

River (a water-quality management issue). The recent 

decision (August 2001) of the U.S. Army Corps of 

Engineers to issue a federal permit, in response to an 
2

HydrologicCharacteristicsofBearCreeknearSilverHillandBuffaloRivernearSt.Joe,Arkansas,1999-2000

Figure 1. Location of Bear Creek and Buffalo River sampling sites.
Introduction 3

application from the Searcy County Regional Water 

District, that would allow the District to build a 0.14 

mi2

 water supply reservoir in the upper reaches of Bear 

Creek is related to water-quality and other management 

issues (U.S. Army Corps of Engineers, 2001). The proposed dam site is approximately 26 miles up Bear 

Creek from its confluence with the Buffalo River. The 

area upstream from the proposed dam constitutes about 

12 percent of the total Bear Creek watershed and about 

1 percent of that part of the Buffalo River watershed 

that is upstream from the mouth of Bear Creek (U.S. 

Army Corps of Engineers, 2001).

Purpose and Scope

The purpose of this report is to describe and 

compare streamflow and water-quality characteristics 

for a site on Bear Creek (drainage area of 83.1 mi2) and 

a site on the Buffalo River (drainage area of 829 mi2) 

upstream from the confluence of Bear Creek and the 

Buffalo River (fig. 1, table 1). Comparisons of streamflow and water-quality characteristics of the two sites 

are of interest because of the influence of Bear Creek 

upon the hydrology of the Buffalo River. Both the Bear 

Creek and Buffalo River sites are in Searcy County, 

Arkansas. The study area primarily is limited to these 

two sites; however, related information for the area 

upstream from each site and downstream to the influence of Bear Creek and the Buffalo River also is presented.

Stage was measured continuously and water 

samples were collected periodically at both sites from 

January 1999 through September 2001; selected data 

for calendar years 1999 and 2000 are described in this 

report. Data for January 1999 through September 2001 

are listed in the appendix. Streamflow data for the Buffalo River site are available since October 1939; these 

data also are summarized and used to describe streamflow conditions for the Buffalo River. Water samples 

were analyzed for several properties and constituents, 

including specific conductance, dissolved oxygen, pH, 

alkalinity, fecal-indicator bacteria, nutrients, organic 

carbon, and suspended sediment. Annual and seasonal 

loads and yields were estimated for nutrients, organic 

carbon, and suspended sediment. Yields and flowweighted concentrations of selected nutrients were estimated and compared with yields and flow-weighted 

concentrations for undisturbed and developed basins 

for the purpose of evaluating the water-quality characteristics of Bear Creek and the Buffalo River relative to 

other sites.

Description of Study Area

Bear Creek and the Buffalo River are in the 

southern Ozark Plateaus physiographic province. An 

overview of the environmental and hydrologic setting 

of the Ozark Plateaus can be found in Adamski and others (1995). Data and descriptions of the geology, physiography, land use, and stream habitat of Bear Creek 

and other streams in the Buffalo River Basin can be 

found in Panfil and Jacobson (2001). 

Table 1. Sampling site information

Site name

U.S. Geological Survey

station identification number

Drainage area

(square

miles)

Distance upstream

from Bear CreekBuffalo River

confluence

(river miles)

Bear Creek near

Silver Hill, Arkansas 07056515 83.1 8

Buffalo River near

St. Joe, Arkansas 07056000 829 5
4 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000

Karst topography caused by caves, sinkholes, 

springs, and underground drainage resulting from dissolution of limestone has a major effect on the hydrology of the area. Within the study area much of the 

downstream sections of both streams lies within the 

Boone Formation, a geologic formation composed 

mainly of limestone. Enlarged fractures within the 

limestone allow rapid infiltration into the ground 

water; losing stream reaches and seasonally dry sections occur in both streams.

Bear Creek is a major tributary of the Buffalo 

River in north-central Arkansas (fig. 1). Bear Creek 

originates southeast of Witts Springs, Arkansas, in the 

Boston Mountains physiographic section. It flows 

northward into the Springfield Plateau physiographic 

section and empties into the Buffalo River north of 

Marshall, Arkansas. The drainage area of Bear Creek 

at its mouth is 91.6 mi2

 (Sullavan, 1974 revised). Bear 

Creek’s drainage area comprises nearly 10 percent of 

the Buffalo River's drainage area at the location just 

below the confluence of Bear Creek and the Buffalo 

River. The 7Q10 (the minimum daily-mean streamflow 

for 7 consecutive days expected to occur an average of 

once every 10 years) for Bear Creek near Marshall at 

Highway 65 (fig. 1) (drainage area 77.9 mi2

) is estimated to be 2.0 ft3/s (Ludwig, 1992). 

Land use in the Bear Creek Basin primarily is a 

mixture of forest and pasture. Approximately 33 percent of the land in the basin is pasture (Scott and Hofer, 

1995). The town of Marshall (population approximately 1,300) lies partially within the basin and effluent from the wastewater-treatment plant (treatment 

includes sedimentation, trickling filtration, activated 

sludge, and chlorine disinfection) (D.E. Ramsey, 

Arkansas Department of Environmental Quality, written commun., 2001) is discharged into Forest Creek, a 

tributary of Bear Creek (Arkansas Department of Environmental Quality, 2000; Steele and Mott, 1998). 

Except during wet periods of the year, it is likely that 

Forest Creek discharges most or all of its flow to 

ground water before reaching Bear Creek and it has not 

been determined if this ground water later resurfaces in 

the Forest Creek Basin or in adjacent basins (D.N. 

Mott, National Park Service, oral commun., 2001; Bob 

Singleton, Arkansas Department of Environmental 

Quality, oral commun., 2002).

Previous investigations indicated that nutrient 

and fecal-indicator bacteria concentrations and loads 

generally were elevated in Bear Creek relative to concentrations and loads in streams in basins containing 

smaller percentages of pasture and less effluent from 

wastewater-treatment plants (Mott, 1997; Petersen and 

others, 1998; Steele and Mott, 1998).

The Buffalo River originates north of Fallsville, 

Arkansas, in the Boston Mountains. It flows eastward 

into the Springfield and Salem Plateaus. The drainage 

area of the Buffalo River below its confluence with 

Bear Creek is 935 mi2 (Sullavan, 1974 revised). The 

7Q10 for the Buffalo River near St. Joe, Arkansas, 

(approximately 5 river miles upstream from the confluence of the Buffalo River and Bear Creek, 829 mi2) is 

estimated to be 17 ft3/s (Ludwig, 1992). 

Land use in the Buffalo River Basin (upstream 

from Highway 65) primarily is a mixture of forest and 

pasture. Approximately 13 percent of the land is agricultural (mostly pasture) (Davis and Bell, 1998). 

Previous investigations indicated that nutrient 

and bacteria concentrations at the Buffalo River near 

St. Joe were lower than concentrations at a group of 

selected sites with larger percentages of agricultural 

land use or with major municipal wastewater streamflows in their basins (Davis and Bell, 1998). However, 

dissolved organic carbon and suspended sediment concentrations were not lower than concentrations at the 

same group of selected sites.

METHODS

Stream stage was measured continuously at a site 

on Bear Creek and a site on the Buffalo River (fig. 1, 

table 1). Stage and instantaneous surface runoff were 

measured and continuous streamflow data were computed from stage-discharge rating curves using methods described in Buchanan and Somers (1968), Carter 

and Davidian (1968), Buchanan and Somers (1969), 

and Kennedy (1984). Stage has been measured continually from January 22, 1999 to present (2002) at Bear 

Creek and from October 1939 to present (2002) at the 

Buffalo River site. Because stage was not measured on 

January 1-21, 1999, at the Bear Creek site, the mean 

daily flow for 1999 was used for estimates of load for 

this period in this study.

Water samples were collected periodically at 

both sites from January 1999 through September 2001. 

Samples were collected monthly and during six supplemental high-flow storm events per year. High-flow 

samples for Bear Creek were collected at the Highway 

74 bridge approximately 2.9 river miles upstream from 

the streamflow measurement and low-flow water-quality sampling site. Water samples were collected using 
5 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000

depth integrated, equal width increment sampling 

methods described in Edwards and Glysson (1999).

The resulting streamflow and water-quality data 

were analyzed or summarized using several graphical 

and statistical techniques. Boxplots were used to compare streamflow and concentrations of selected constituents between sites for data collected during calendar 

years 1999 and 2000. Concentrations reported as less 

than a reporting limit were converted to one-half the 

reporting limit for preparation of box plots, calculation 

of total nitrogen concentrations (the sum of nitrite plus 

nitrate and ammonia plus organic nitrogen), and statistical analyses. The Wilcoxon rank sum test (Helsel and 

Hirsch, 1992) was used to test for differences in 

selected water-quality constituents between sites. 

Streamflow was separated using a hydrograph 

separation computer program, Base Flow Index (BFI), 

to identify base-flow and surface-runoff components 

(Institute of Hydrology, 1980a, 1980b; Wahl and Wahl, 

1995). Base flow is the sustained fair weather flow of 

the stream; in most streams, base flow is composed 

largely of ground-water flow (Langbein and Iseri, 

1960). Surface runoff was defined as total flow minus 

base flow. Base flow contributions were analyzed 

using a method proposed by the Institute of Hydrology 

(1980a, 1980b). The minimum flow in 5-day increments is identified, and minimum flows less than 90 

percent of adjacent minimum flows are defined as turning points (Wahl and Wahl, 1988, Wahl and Tortorelli, 

1997). The BFI program estimates the volume of base 

flow from successive turning points; straight lines 

drawn between turning points estimate the baseflow 

hydrograph.

Water-quality samples were divided into those 

collected under base-flow or surface-runoff conditions. 

Base-flow water-quality samples were collected on 

days when the estimated base flow was greater than or 

equal to 70 percent of total flow. Surface-runoff samples were defined as water-quality samples collected on 

days when surface runoff was greater than 30 percent 

of total flow. Simple linear regression was used to 

assess relations between concentrations and total 

streamflow during base-flow or surface-runoff conditions.

Constituent load (L) is a function of volumetric 

rate of water passing a point in the stream (Q) and the 

constituent concentration within the water (C). Regression methods used to estimate constituent loads use the 

natural logarithmic (ln) transformed relation between 

Q and C to estimate daily C (or L) of the constituent 

(Cohn and others, 1989; Cohn and others, 1992; Cohn, 

1995). The regression method can account for nonnormal data distributions, seasonal and long-term 

cycles, censored data, biases associated with using logarithmic transformations, and serial correlations of the 

residuals (Cohn, 1995). The regression method uses 

discrete water-quality samples often collected over 

several years and a daily streamflow hydrograph. This 

study used the simple relation between natural logarithm-transformed L and Q:

(1)

where L represents the constituent load, βo is the 

regression constant, β1 is the regression 

coefficient, and Q represents daily streamflow. 

In this model, constituent loads are based solely 

on the relations between L and Q; the β1 coefficient 

will be significantly different from zero if a relation 

exists between L and Q. A minimum variance unbiased estimator was used to transform the results from 

logarithmic space to real space (Cohn and others, 1989; 

Cohn and others, 1992). The LOADEST2 computer 

program (Crawford, 1991; 1996) was used to estimate 

constituent loads in these streams under base-flow and 

surface-runoff conditions. LOADEST2 is functionally 

equivalent to the ESTIMATOR computer program 

(Cohn and others, 1989), except LOADEST2 gives 

estimates of constituent loads using the rating curve 

with parametric and non-parametric transformations. 

Loads were estimated for calendar year 1999 and calendar year 2000. 

In this report, base-flow loads refer to the load 

transported on days when base flow is greater than or 

equal to 70 percent of total flow. Surface-runoff loads 

refer to the load transported on days when surface runoff is greater than 30 percent of total flow.

Yields were calculated for each load. Yield was 

calculated by dividing the load by the drainage area of 

the sampling site. For selected constituents a second 

yield estimate was calculated from a second load estimate computed from a subset of the water-quality samples—those samples collected at monthly intervals. 

The loads and yields based on the monthly (or fixedinterval) samples were derived for a comparison of 

Bear Creek and the Buffalo River with a group of sites 

in undisturbed basins. The undisturbed-basin sites typically had been sampled at fixed-intervals.

() β L o β ln = + 1 ln( ) Q
6 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000

Flow-weighted concentrations also were calculated from the loads derived from the fixed-interval 

samples. Flow-weighted concentrations were calculated by dividing the annual load by total annual flow, 

and applying appropriate conversion factors for dimensional units.

HYDROLOGIC CHARACTERISTICS

This section describes the streamflow and waterquality characteristics of Bear Creek near Silver Hill 

and Buffalo River near St. Joe. Most of the description 

is based upon data collected from January 1999 

through December 2000. However, streamflow data 

for the Buffalo River near St. Joe measured prior to 

January 1999 also are described.

Streamflow

Streamflow for Bear Creek near Silver Hill varied annually and seasonally (fig. 2). The mean streamflow for calendar years 1999 and 2000 was 56 and 65 

ft3/s, respectively (table 2). Mean daily streamflow 

ranged from 2.7 to 3,650 ft3

/s. The maximum mean 

daily streamflow for 2000 (3,650 ft3

/s) was more than 

three times the maximum for 1999 (1,110 ft3

/s). 

Median and mean flows generally were greatest in January through June and lowest in August through October. Monthly median values ranged from 3.5 to 131

ft3

/s; monthly mean values ranged from 3.5 to 257

ft3/s. Additional summary statistics for January 1999 

through September 2000 are reported in Porter and others (2001). 

Figure 2. Daily base flow and total streamflow and associated water-quality sample times during calendar years 1999 and 

2000 for Bear Creek near Silver Hill, Arkansas.

DATE

1/1/99 4/1/99 7/1/99 10/1/99 1/1/00 4/1/00 7/1/00 10/1/00 1/1/01

STREAMFLOW, IN CUBIC FEET PER SECOND

1

10

100

1,000

10,000

BASE FLOW

TOTAL STREAMFLOW

SAMPLE ASSOCIATED WITH BASE FLOW

SAMPLE ASSOCIATED WITH SURFACE RUNOFF
7 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000 Table 2. Annual and monthly streamflow statistics for Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-200

[Values are in cubic feet per second] Annual January February March April May June July August September O

Bear Creek 1999 Minimum 2.7 55 26 19 54 14 8 10 4.0 2.9 

Median 14 79 67 119 131 27 10 15 5.3 3.5 Mean 56 81 86 151 172 35 42 35 5.9 3.5 Maximum 1,110 123 382 413 563 101 923 307 10 4.4 

Bear Creek 2000 Minimum 2.7 11 11 35 22 29 27 10 5.8 5.1 

Median 21 16 12 45 33 88 93 12 8.0 6.2 Mean 65 23 78 62 46 257 170 17 8.1 6.3 Maximum 3,650 85 1,090 172 199 3,650 1,150 50 11 9.4 

Buffalo River 1999 Minimum 18 532 513 396 1,000 514 165 93 32 22 

Median 357 917 1,135 1,590 1,655 1,020 320 233 58 34 Mean 836 1,203 1,472 1,699 2,409 1,624 467 737 57 34 Maximum 12,800 4,450 5,230 4,020 8,430 12,800 3,210 9,520 90 58 

Buffalo River 2000 Minimum 19 78 64 438 331 250 337 261 25 19 

Median 321 153 70 643 473 504 1,350 418 75 22 Mean 719 211 306 711 491 1,724 3,542 512 108 27 Maximum 28,700 647 2,050 1,250 786 17,900 28,700 1,350 318 50 
8 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000

Much of the total streamflow for Bear Creek during calendar years 1999 and 2000 occurred during relatively few days (fig. 3). For example, more than 10 

percent of the streamflow occurred during 2 days and 

50 percent of the streamflow occurred during 51 days 

(about 7 percent of the 2-year period).

Streamflow for Buffalo River near St. Joe also 

varied annually and seasonally (fig. 4). The mean 

streamflow for calendar years 1999 and 2000 was 836 

and 719 ft3/s, respectively (table 2). The maximum 

mean daily streamflow for 2000 (28,700 ft3

/s) was 

more than two times the maximum for 1999 (12,800 

ft3

/s). Median and mean flows generally were greatest 

in January through May and lowest in August through 

October. Monthly median values ranged from 22 to 

1,655 ft3

/s; monthly mean values ranged from 23 to 

3,542 ft3/s. Mean daily streamflow ranged from 18 to 

28,700 ft3/s. 

Much of the total streamflow for the Buffalo 

River during calendar years 1999 and 2000 occurred 

during relatively few days (fig. 5). For example, more 

than 10 percent of the streamflow occurred during 3 

days and 50 percent of the streamflow occurred during 

57 days (about 8 percent of the 2-year period).

Additional summary statistics for the Buffalo 

River near St. Joe for October 1939 through September 

2000 are reported in Porter and others (2001). The 

mean streamflow for this time period was 1,052 ft3

/s, 

compared to the means of 836 and 719 ft3/s for calendar years 1999 and 2000. The maximum instantaneous 

streamflow for the time period is estimated to be 

158,000 ft3/s and the minimum instantaneous streamflow was 6.6 ft3/s. 

Streamflow for the Buffalo River near St. Joe 

generally is substantially greater than for Bear Creek 

near Silver Hill; however, during times of low flow, 

streamflow in Bear Creek comprises a larger proportion of the flow of the Buffalo River. During calendar 

years 1999 and 2000, median streamflow for the Buffalo River was 357 and 321 ft3

/s, respectively (fig. 6). 

Median streamflow for Bear Creek near Silver Hill was 

14 and 21 ft3

/s in 1999 (beginning January 22) and 

2000. The minimum mean daily streamflows during 

the 2 years were 18 ft3

/s for the Buffalo River and 2.7 

ft3

/s for Bear Creek. The Bear Creek mean annual 

streamflows for 1999 and 2000 were about 7 and 9 percent of the mean annual streamflows for the Buffalo 

River. However, on 25 percent of the days in August 

through October (the 3 months of 1999 and 2000 with 

the lowest flows) Bear Creek flows comprised at least 

18 percent (range 18.6 to 95.0 percent) of the same-day 

flow of the Buffalo River near St. Joe. On 23 consecutive days in September 2000, the flows at the Bear 

Creek site were at least 25 percent (range 25.7 to 33.7 

percent) of the flows at the Buffalo River site. 

Some users of this report may be more interested 

in streamflow (and loads) at the confluence of Bear 

Creek and the Buffalo River than at the two measurement sites. The comparisons discussed in the preceding 

paragraph provide considerable information that can be 

used to estimate the expected proportion of the volumetric rate of flow from Bear Creek into the Buffalo 

River to the volumetric rate of flow in the Buffalo 

River immediately downstream from Bear Creek. 

However, the changes in streamflow between the Bear 

Creek gaging site and the mouth of Bear Creek (a distance of about 8 river miles) and between the Buffalo 

River gaging site and the confluence of the Buffalo 

River and Bear Creek (about 5 river miles) are 

unknown. Reaches of Bear Creek and the Buffalo 

River upstream from the gaging sites lose and gain substantial volumes of water to and from subsurface flow 

and so reliability of a drainage area ratio to estimate 

streamflow at the mouth of Bear Creek and at the Buffalo River upstream from Bear Creek from streamflow 

at the gaging sites is uncertain. However, if streamflow 

does increase between the gaging sites and the downstream location in proportion to increase in drainage 

area, streamflow at the mouth of Bear Creek would be 

about 10 percent greater than at the Bear Creek gaging 

site and Buffalo River streamflow just upstream from 

Bear Creek would be about 2 percent greater than at the 

Buffalo River gaging site. Ratios of streamflow in Bear 

Creek to streamflow in Buffalo River, calculated using 

estimated streamflows at Buffalo River upstream from 

the confluence with Bear Creek and at the mouth of 

Bear Creek, were similar to ratios calculated using 

streamflows measured at the gaging sites; ratios generally were within 1 percent (as an absolute difference, 

not a percentage difference) of ratios calculated at the 

gaging sites. 

Water Quality

Water quality for two sites on Bear Creek and the 

Buffalo River is described below in terms of concentration (in base flow samples and in samples from base 

flow and surface runoff), load, flow-weighted concentration (from base flow samples), and yield. Substantial 

differences between sites were indicated. Concentrations, flow-weighted concentrations, and yields generally were greater at the Bear Creek site.
Hydrologic Characteristics 9

CUMULATIVE DAYS

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800

CUMULATIVE STREAMFLOW, IN PERCENT

0

10

20

30

40

50

60

70

80

90

100

DATE

1/1/99 4/1/99 7/1/99 10/1/99 1/1/00 4/1/00 7/1/00 10/1/00 1/1/01 

STREAMFLOW, IN CUBIC FEET PER SECOND

10

100

1,000

10,000

100,000

BASE FLOW

TOTAL STREAMFLOW

SAMPLE ASSOCIATED WITH BASE FLOW

SAMPLE ASSOCIATED WITH SURFACE RUNOFF

Figure 4. Daily base flow and total streamflow and associated water-quality sample times during calendar years 1999 and 

2000 for Buffalo River near St. Joe, Arkansas.

Figure 3. Flow-accumulation curve for Bear Creek near Silver Hill, Arkansas, January 1, 1999 to December 31, 2000.
10 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000

CUMULATIVE DAYS

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800

CUMULATIVE STREAMFLOW, IN PERCENT

0

10

20

30

40

50

60

70

80

90

100

SITE AND YEAR

DAILY STREAMFLOW, IN CUBIC FEET PER SECOND

0

1000

2000

3000

Bear

1999

Buffalo

1999

Bear

2000

Buffalo

2000

75th percentile

25th percentile

90th percentile

50th percentile

10th percentile

Figure 6. Daily streamflow for Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, in 1999 and 2000.

Figure 5. Flow-accumulation curve for Buffalo River near St. Joe, Arkansas, January 1, 1999 to December 31, 2000.
Hydrologic Characteristics 11

During 1999 and 2000 a difference occurred in 

the timing of the high-flow storm-event samples from 

the two sites relative to the time of the maximum 

streamflow for storm events. Bear Creek samples typically were collected about 2 to 10 hours after the maximum streamflow. Buffalo River samples typically 

were collected about 10 hours before to 10 hours after 

the maximum streamflow. Although variable, suspended sediment concentrations of streams most commonly peak before the streamflow peak (Guy, 1970). 

Phosphorus concentration may increase rapidly and 

peak before the streamflow peak and then slowly 

decrease in concentration (for example, see Richards 

and others, 2001; Richards and Holloway, 1987; Thomas, 1988). Therefore, because the Buffalo River 

storm-event samples were more likely than the Bear 

Creek samples to be collected before the streamflow 

peak, concentrations of suspended constituents collected during storm events may be biased toward 

higher concentrations for the Buffalo River relative to 

concentrations for Bear Creek. 

Concentrations

Nutrient concentrations in samples from Bear 

Creek generally were greater than in samples from the 

Buffalo River (figs. 7 and 8). Statistically significant 

(p<0.05) differences between sites were detected in 

concentrations of ammonia plus organic nitrogen (during base flow only), nitrite plus nitrate, total nitrogen, 

dissolved phosphorus, orthophosphorus (during base 

flow only), and total phosphorus.

At each site nutrients generally increased as 

streamflow increased (see appendix). However, ammonia concentrations remained relatively constant as 

streamflow increased. Nitrate concentrations generally 

decreased as streamflow increased at the Bear Creek 

site and appeared to increase and then decrease as 

streamflow increased at the Buffalo River site.

Concentrations of fecal-indicator bacteria also 

generally were higher in Bear Creek samples than in 

samples from the Buffalo River (fig. 9). The differences were most apparent at the upper percentiles of 

the distributions for each site. For example, the concentrations that were between the 75th and 90th percentile for Escherichia coli (E. coli) and fecal coliform 

bacteria for Bear Creek were substantially higher than 

for the Buffalo River. However, statistically significant 

differences were detected only for fecal coliform bacteria. At each site bacteria concentrations generally 

increased as streamflow and suspended sediment concentrations increased (see appendix).

Dissolved organic carbon concentrations often 

were higher in samples from Bear Creek than in samples from the Buffalo River; however, median concentrations were similar (fig. 10). As with bacteria, it was 

often the higher concentrations at each site that were 

more dissimilar. Concentration differences were not 

statistically significant. At each site dissolved organic 

carbon concentrations generally increased as streamflow increased (see appendix).

Suspended sediment concentrations generally 

were higher in samples from Bear Creek than in samples from the Buffalo River (fig. 11). However, many 

of the highest concentrations were in samples from the 

Buffalo River. Statistically significant differences 

were detected. At each site suspended sediment concentrations generally increased as streamflow 

increased (see appendix).

Loads

Annual

Estimated base flow and surface runoff loads of 

nitrite plus nitrate, total nitrogen, dissolved phosphorus, orthophosphorus, total phosphorus, dissolved 

organic carbon, and suspended sediment for 1999 and 

2000 at the Buffalo River and Bear Creek sites indicate 

substantial differences between sites, hydrologic conditions, seasons, years, and constituents. Loads were 

substantially higher for the Buffalo River than for Bear 

Creek (as would be expected because of the Buffalo’s 

higher streamflow). Loads were substantially higher 

on days when flow included a substantial amount (30 

percent or more) of surface runoff ; on an annual basis, 

loads associated with days with a substantial amount of 

surface runoff always comprised 85 percent or more of 

the total annual load. For Bear Creek and the Buffalo 

River, loads generally were less in 1999 than in 2000.

Annual loads for the Buffalo River site typically 

were 5 to 10 times higher than loads for the Bear Creek 

site (table 3). However, in 1999 the dissolved phosphorus load for the Buffalo River was only 4.2 times 

greater than the Bear Creek load. In 2000, it was only 

3.2 times greater. These 2 years of data indicate that 

Bear Creek contributes a proportionately larger part of 

the dissolved phosphorus load than loads of other constituents to the Buffalo River; although some of this 

load could be attributed to the wastewater effluent, concentrations usually increased as streamflow increased 
12 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000

SITE AND NITROGEN SPECIES

CONCENTRATION, IN MILLIGRAMS PER LITER AS NITROGEN

0.0

0.5

1.0

1.5

Bear Buffalo

Ammonia

Bear Buffalo

Ammonia plus

organic

Bear Buffalo

Nitrite plus

nitrate

Bear Buffalo

Total 

nitrogen

NS

p<0.001

90th percentile

75th percentile

50th percentile

10th percentile

NS 25th percentile

p<0.001

0.0

0.2

0.4

0.6

0.8

1.0

p=0.007

p<0.001

NS

p<0.001

All samples

Base flow samples

Figure 7. Distribution of nitrogen concentrations for Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 

1999-2000. The p-value is the probability that the median concentrations at the two sites are equal. NS indicates the 

probability exceeds 0.05. Several total nitrogen values were calculated from the sum of individual nitrogen species 

concentrations that included estimated concentrations set equal to one-half the reporting limit. For example, a nitrite plus 

nitrate concentration of <0.050 mg/L was converted to 0.025 mg/L.
Hydrologic Characteristics 13

SITE AND PHOSPHORUS SPECIES

CONCENTRATION, IN MILLIGRAMS PER LITER AS PHOSPHORUS

0.00

0.01

0.02

0.03

0.04

0.05

Bear Buffalo

Dissolved

phosphorus

Bear Buffalo

Orthophosphorus

Bear Buffalo

Total

phosphorus

p<0.001

p<0.001

90th percentile

p<0.001

75th percentile

50th percentile

25th percentile

10th percentile

0.0

0.1

0.2

0.3

NS

p<0.001

p<0.001

Base flow samples

All samples

Figure 8. Distribution of phosphorus concentrations for Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 

1999-2000. The p-value is the probability that the median concentrations at the two sites are equal. NS indicates the

probability exceeds 0.05.
14 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000

SITE AND BACTERIA TYPE

1

10

100

1,000

Bear

E. coli

Buffalo

E.coli

Bear

Fecal

 coliforms

Buffalo

Fecal 

coliforms

75th percentile

25th percentile

90th percentile

50th percentile

10th percentile

NS p=0.004

Base flow samples

BACTERIA, IN COLONIES PER 100 MILLILITERS

1

10

100

1,000

10,000

75th percentile

25th percentile

90th percentile

50th percentile

10th percentile

NS p=0.04

All samples

Figure 9. Distribution of bacteria concentrations for Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999 

and 2000. The p-value is the probability that the median concentrations are equal at the two sites. NS indicates the probability 

exceeds 0.05.
Hydrologic Characteristics 15

0

2

4

6

8

10

90th percentile

50th percentile

75th percentile

25th percentile

10th percentile

NS

SITE 

DISSOLVED ORGANIC CARBON, IN MILLIGRAMS PER LITER AS CARBON

0

1

2

3

90th percentile

50th percentile

75th percentile

25th percentile

10th percentile

Bear Buffalo

NS

All samples

Base flow samples

Figure 10. Distribution of dissolved organic carbon concentrations for Bear Creek near Silver Hill and Buffalo River near

St. Joe, Arkansas, 1999-2000. The p-value is the probability that the median concentrations at the two sites are equal. NS 

indicates the probability exceeds 0.05.
16 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000

0

50

100

150

10th percentile

25th percentile

50th percentile

75th percentile

p=0.03 90th percentile

SITE

SUSPENDED SEDIMENT, IN MILLIGRAMS PER LITER

0

25

50

75

100

10th percentile

25th percentile

50th percentile

75th percentile

90th percentile

p=0.002

Bear Buffalo

All samples

Base flow samples

Figure 11. Distribution of suspended sediment concentrations for Bear Creek near Silver Hill and Buffalo River near St. Joe, 

Arkansas, 1999-2000. The p-value is the probability that the median concentrations at the two sites are equal. NS indicates the

probability exceeds 0.05.
Hydrologic Characteristics 17

suggesting primarily nonpoint sources of dissolved 

phosphorus. Relative to other constituents, Bear Creek 

appears to contribute a smaller proportion of suspended 

sediment load to the Buffalo River; the suspended sediment load for the Buffalo River site was about 18 to 24 

times greater than the load for the Bear Creek site.

At both sites, annual loads were largely contributed by daily loads occurring on days with a substantial 

amount of surface runoff (table 3). Although only 40 

to 45 percent of the days each year included a substantial amount of surface runoff, most (usually more than 

90 percent) of the annual load occurred on these days. 

For total phosphorus about 96 to 99 percent of the 

annual load occurred on these days.

Table 3. Annual nitrogen, phosphorus, dissolved organic carbon, and suspended sediment loads and yields for Bear Creek 

near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000

[lb/yr is pounds per year; lb/yr/mi2 is pounds per year per square mile; SD is standard deviation; NA is not available (not calculated by the model). Yields 

and surface runoff load percentages were calculated before loads were rounded to two significant figures]

Total

load

(lb/yr)

Total yield

(lb/yr/mi2)

Base-flow

load

(±SD)

(lb/yr)

Baseflow

 yield

(lb/yr/mi2)

Surfacerunoff 

load

(±SD)

(lb/yr)

Surfacerunoff

yield

(lb/yr/mi2)

Load

contributed

by

surface

runoff

(percent)

Ammonia plus organic

nitrogen, as nitrogen

Bear-1999 43,000 520 2,900 ±400 35 40,000 ±8,800 480 93

Bear-2000 83,000 1,000 2,600 ±400 31 80,000 ±29,000 970 97

Buffalo-1999 660,000 800 40,000 ±3,000 48 620,000 ±140,000 750 94

Buffalo-2000 790,000 950 24,000 ±1,100 29 770,000 ±220,000 920 97

Nitrite plus nitrate, as

nitrogen

Bear-1999 56,000 670 8,400 ±1,500 100 47,000 ±7,700 570 85

Bear-2000 58,000 700 7,300 ±1,000 88 51,000 ±8,800 610 88

Buffalo-1999 420,000 500 55,000 ±10,000 66 360,000 ±10,000 440 87

Buffalo-2000 350,000 420 20,000 ±3,000 24 330,000 ±10,000 400 94

Total nitrogen

Bear-1999 91,000 1,100 10,000 ±1,100 120 80,000 ±8,800 970 89

Bear-2000 130,000 1,500 9,100 ±700 110 120,000 ±16,000 1,400 93

Buffalo-1999 NA NA NA NA 1,100,000 ±23,000 1,300 NA

Buffalo-2000 NA NA NA NA 1,100,000 ±310,000 1,400 NA

Dissolved phosphorus

Bear-1999 4,700 57 350 ±20 4.2 4,400 ±690 53 93

Bear-2000 7,200 87 280 ±15 3.4 6,900 ±2,000 83 96

Buffalo-1999 20,000 24 1,600 ±130 1.9 18,000 ±3,400 22 92

Buffalo-2000 23,000 28 910 ±51 1.1 22,00 ±5,500 26 96
18 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000

Orthophosphorus

Bear-1999 3,600 44 280 ±40 3.4 3,400 ±550 40 92

Bear-2000 5,700 69 230 ±29 2.8 5,500 ±1,000 66 96

Buffalo-1999 NA NA NA NA 20,000 ±4,000 24 NA

Buffalo-2000 NA NA NA NA 20,000 ±5,100 25 NA

Total phosphorus

Bear-1999 11,000 140 510 ±40 6.1 11,000 ±2,400 130 96

Bear-2000 25,000 300 440 ±29 5.3 25,000 ±9,500 300 98

Buffalo-1999 160,000 200 2,600 ±400 3.1 160,000 ±58,000 190 98

Buffalo-2000 270,000 320 1,500 ±110 1.8 270,000 ± 140,000 320 99

Dissolved organic

carbon

Bear-1999 430,000 5,100 25,000 ±3,000 300 400,000 ±6,200 4,800 94

Bear-2000 790,000 9,500 21,000 ±2,000 250 770,000 ±190,000 9,200 97

Buffalo-1999 4,400,000 5,300 400,000 ±31,000 480 4,000,000 ±58,000 4,800 91

Buffalo-2000 4,600,000 5,600 230,000 ±14,000 280 4,400,000 ±84,000 5,300 95

Suspended sediment

Bear-1999 6,600,000 80,000 770,000 ±91,000 9,200 5,800,00 ±120,000 70,000 88

Bear-2000 11,000,000 130,000 690,000 ±80,000 8,300 9,900,000 ± 310,000 120,000 93

Buffalo-1999 160,000,000 190,000 7,700,000 ±120,000 9,200 150,000,000 ± 44,000,000 180,000 95

Buffalo-2000 190,000,000 230,000 5,100,000 ±590,000 6,200 180,000,000 ±66,000,000 220,000 97

Table 3. Annual nitrogen, phosphorus, dissolved organic carbon, and suspended sediment loads and yields for Bear Creek 

near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000--Continued

[lb/yr is pounds per year; lb/yr/mi2 is pounds per year per square mile; SD is standard deviation; NA is not available (not calculated by the model). Yields 

and surface runoff load percentages were calculated before loads were rounded to two significant figures]

Total

load

(lb/yr)

Total yield

(lb/yr/mi2)

Base-flow

load

(±SD)

(lb/yr)

Baseflow

 yield

(lb/yr/mi2)

Surfacerunoff 

load

(±SD)

(lb/yr)

Surfacerunoff

yield

(lb/yr/mi2)

Load

contributed

by

surface

runoff

(percent)
Hydrologic Characteristics 19

Total loads generally were greater in 2000 than 

in 1999 for Bear Creek and the Buffalo River (table 3). 

Loads for 2000 generally were about 1.2 to 1.8 times 

the loads for 1999. Differences were greater between 

years for Bear Creek than for the Buffalo River; loads 

for 2000 were almost always less than 1.3 times the 

1999 loads for the Buffalo River. Mean streamflow for 

Bear Creek in 2000 was about 1.2 times the 1999 mean 

streamflow. Mean streamflow for the Buffalo River in 

2000 was about 0.9 times the 1999 streamflow.

Seasonal

Daily loads varied seasonally at both sites (table 

4). At both sites and during both years, daily base-flow 

loads generally were greatest in the spring, although 

spring and winter loads were often nearly equal at Bear 

Creek in 1999. These results are similar to those of 

Steele and Mott (1998). Daily surface-runoff loads 

were related to times of greatest streamflow and were 

greatest in the spring (March through May) or summer 

(June through August). In 1999, daily surface-runoff 

loads were greatest in the spring at both sites. In 2000, 

daily runoff loads were greatest in the spring at Bear 

Creek, but greatest in the summer at the Buffalo River. 

The higher daily runoff loads for the Buffalo River in 

the summer of 2000 were largely the result of high 

flows in mid to late June.

Table 4. Seasonal nitrogen, phosphorus, dissolved organic carbon, and suspended sediment loads for Bear Creek near Silver 

Hill and Buffalo River near St. Joe, Arkansas, 1999-2000

[Values are loads in pounds per day, plus or minus the standard deviation. Significant figures of reported values vary, depending on streamflow and constituent concentration. NA is not available (not calculated by the model). Ammonia loads for 1999 were not calculated because of the high frequency of concentrations less than the reporting limit. Spring is March through May, summer is June through August, fall is September through November, and winter is 

January, February, and December]

Constituent Site Annual Spring Summer Fall Winter

Base flow (1999)

Ammonia plus organic nitrogen

as nitrogen

Bear 8 ±1 12 ±1 6 ±0 4 ±0 12 ±1

Buffalo 110 ±7 230 ±16 42 ±2 17 ±1 160 ±9

Nitrite plus nitrate as nitrogen Bear 23 ±4 33 ±7 17 ±2 10 ±2 33 ±6

Buffalo 150 ±28 360 ±76 31 ±4 5 ±1 190 ±34

Total nitrogen Bear 28 ±3 39 ±5 21 ±2 13 ±2 40 ±5

Buffalo NA NA NA NA NA

Dissolved phosphorus Bear 0.96±0.06 1.5 ±0.12 0.59 ±0.03 0.31 ±0.02 1.5 ±0.11

Buffalo 4.4 ±35 9.4 ±.87 1.5 ±.09 .55 ±.05 6.2 ±48

Orthophosphorus Bear 0.77 ±11 1.2 ±21 .48 ±.06 .25 ±.04 1.2 ±20

Buffalo NA NA NA NA NA

Total phosphorus Bear 1.4 ±11 2.2 ±.21 .89 ±.06 .48 ±.04 2.1 ±20

Buffalo 7 ±1 13 ±2 3 ±0 1 ±0 9 ±1

Dissolved organic carbon Bear 69 ±7 100 ±13 45 ±4 25 ±3 100 ±13

Buffalo 1,100 ±86 2,200 ±210 400 ±23 160 ±15 1,500 ±120

Suspended sediment Bear 2,100 ±250 2,300 ±390 2,000 ±230 1,500 ±260 2,500 ±380

Buffalo 21,000 ±3,200 41,000 ±7,500 8,800 ±970 4,400 ±720 29,000 ±4,500

Base flow (2000)

Ammonia plus organic nitrogen

as nitrogen

Bear 7 ±1 12 ±2 7 ±0 3 ±0 7 ±0

Buffalo 67 ±3 120 ±6 81 ±4 17 ±1 45 ±2

Nitrite plus nitrate as nitrogen Bear 20 ±3 34 ±6 19 ±3 8.0 ±1 20 ±3

Buffalo 54 ±7 120 ±17 65 ±9 8.0 ±1 28 ± 3

Total nitrogen Bear 25 ±2 41 ±5 24 ±2 10 ±1 24 ±2

Buffalo NA NA NA NA NA

Dissolved phosphorus Bear 0.78 ±.04 1.5 ±.10 .71 ±.04 .26 ±.01 .71 ±.04

Buffalo 2.5 ±.14 4.7 ±.30 3.0 ±17 .58 ±.04 1.6 ±.09

Orthophosphorus Bear 0.64 ±.08 1.2 ±.19 .58 ±.07 .21 ±.03 .58 ±.07

Buffalo NA NA NA NA NA
20 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000

Total phosphorus Bear 1.2 ±.08 2.1 ±.18 1.1 ±.07 .39 ±.03 1.1 ±.07

Buffalo 4 ±.31 7.3 ±.64 4.8 ±38 1 ±.09 2.7 ±.20

Dissolved organic carbon Bear 58 ±5 100 ±12 53 ±4 20 ±2 54 ±4

Buffalo 630 ±38 1,200 ±78 770 ±45 160 ±10 430 ±24

Suspended sediment Bear 1,900 ±220 2,500 ±400 2,000 ±220 1,000 ±140 2,000 ±220

Buffalo 14,000 ±1,600 24,000 ±3,100 16,000 ±1,900 3,900 ±500 9,700 ±1,000

Surface runoff (1999)

Ammonia plus organic nitrogen

as nitrogen

Bear 110 ±24 240 ±48 67 ±17 0.02 ±0.01 140 ±31

Buffalo 1,700 ±380 4,100 ±930 830 ±190 1 ±0 1,900 ±400

Nitrite plus nitrate as nitrogen Bear 130 ±21 280 ±47 54 ±9 0 ±0 170 ±30

Buffalo 1,000 ±300 2,300 ±690 520 ±140 3 ±2 1,200 ±350

Total nitrogen Bear 220 ±24 500 ±54 110 ±13 0 ±0 280 ±30

Buffalo 2,900 ±640 6,800 ±1,600 1,400 ±310 3 ±1 3,400 ±710

Dissolved phosphorus Bear 12 ±1.9 26 ±4.1 6.2 ±1.2 .00 ±.00 14 ±2.4

Buffalo 50 ±9.3 120 ±23 24 ±4.6 .03 ±.01 57 ±9.9

Orthophosphorus Bear 9.2 ±1.5 20 ±3.2 5.0 ±1.0 .00 ±.00 11 ±1.9

Buffalo 55 ±11 130 ±27 27 ±5.4 .07 ±.03 65 ±13

Total phosphorus Bear 30 ±6.7 64 ±13 19 ±5.1 .00 ±.00 39 ±9.2

Buffalo 440 ±160 1,100 ±400 220 ±85 .05 ±.03 450 ±150

Dissolved organic carbon Bear 1,100 ±170 2,400 ±370 640 ±120 0 ±0 1,400 ±220

Buffalo 11,000 ±1,600 26,000 ±3,900 5,200 ±770 8.0 ±2.0 12,000 ±1,700

Suspended sediment Bear 16,000 ±3,300 36,000 ±7,200 8,800 ±2,200 5 ±3 20,000 ±4,200

Buffalo 420,000 ±120,000 990,000 ±280,000 200,000 ±57,000 210 ±99 470,000 ±120,000

Surface runoff (2000)

Ammonia plus organic nitrogen

as nitrogen

Bear 220 ±79 580 ±250 170 ±40 50 ±10 100 ±26

Buffalo 2,100 ±600 2,500 ±680 5,200 ±1,600 410 ±77 230 ±44

Nitrite plus nitrate as nitrogen Bear 140 ±24 250 ±47 150 ±25 95 ±20 82 ±14

Buffalo 900 ±290 1,100 ±360 1,800 ±700 340 ±94 270 ±81

Total nitrogen Bear 320 ±45 690 ±120 300 ±34 130 ±15 160 ±20

Buffalo 3,100 ±850 3,800 ±1,000 7,300 ±2,200 780 ±150 500 ±100

Dissolved phosphorus Bear 19 ±5 45 ±14 16 ±3 6 ±1 9 ±2

Buffalo 60 ±15 72 ±17 150 ±39 12 ±2 7 ±1

Orthophosphorus Bear 15 ±4 36 ±11 13 ±2 5 ±1 7 ±1

Buffalo 56 ±14 69 ±17 130 ±36 16 ±3 11 ±2

Total phosphorus Bear 68 ±26 180 ±83 47 ±12 13 ±3 29 ±8

Buffalo 730 ±370 830 ±390 2,000 ±1,000 76 ±23 34 ±10

Dissolved organic carbon Bear 2,100 ±520 5,100 ±1,600 1,600 ±280 520 ±86 940 ±180

Buffalo 12,000 ±2,300 15,000 ±2,700 30,000 ±6,200 2,700 ±360 1,700 ±230

Suspended sediment Bear 27,000 ±8,400 64,000 ±25,000 23,000 ±5,200 8,000 ±1,700 13,000 ±3,200

Buffalo 500,000 ±180,000 600,000 ±210,000 1,200,000 ±490,000 98,000 ±24,000 55,000 ±14,000

Table 4. Seasonal nitrogen, phosphorus, dissolved organic carbon, and suspended sediment loads for Bear Creek near Silver 

Hill and Buffalo River near St. Joe, Arkansas, 1999-2000--Continued

[Values are loads in pounds per day, plus or minus the standard deviation. Significant figures of reported values vary, depending on streamflow and constituent concentration. NA is not available (not calculated by the model). Ammonia loads for 1999 were not calculated because of the high frequency of concentrations less than the reporting limit. Spring is March through May, summer is June through August, fall is September through November, and winter is 

January, February, and December]

Constituent Site Annual Spring Summer Fall Winter
Hydrologic Characteristics 21

Flow-Weighted Concentrations

Flow-weighted concentrations (table 5) for Bear 

Creek and the Buffalo River were compared to flowweighted concentrations in 82 undeveloped basins 

identified across the nation, including two basins in the 

Ozark Plateaus (Clark and others, 2000), and to a more 

developed basin (Green and Haggard, 2001). The flowweighted concentrations for Bear Creek and the Buffalo River were calculated from loads calculated using 

water-quality data collected at fixed intervals. These 

data were a subset of the water-quality data collected 

and used to calculate the loads in tables 3 and 4; data 

from the supplemental high-flow storm events were not 

included. The data associated with the supplemental 

storm events were omitted because the data for the 

undeveloped basins generally included small amounts 

of supplemental high-flow storm event data. The flowweighted concentrations for the developed basin were 

calculated from loads computed from data that 

included some storm event data.

Flow-weighted concentrations for Bear Creek 

generally were higher than for concentrations for the 

Buffalo River; flow-weighted concentrations for both 

sites were higher than concentrations at undisturbed 

sites but lower than concentrations at a site in a more 

developed basin. Nitrite plus nitrate concentrations 

were approximately 4 times (Buffalo River) and 5 

times (Bear Creek) higher than the median concentration for undeveloped basins (Clark and others, 2000). 

Total phosphorus concentrations were approximately 3 

(Buffalo River) and 5 to 6 times (Bear Creek) higher 

than the median concentration for undeveloped basins. 

Total phosphorus concentrations for Bear Creek also 

were substantially higher than the 75th percentiles of 

concentrations for the undeveloped basins. Flowweighted concentrations of nitrite plus nitrate, total 

nitrogen, orthophosphorus, and total phosphorus were 

about 3 to 8 times higher at a site on the Illinois River 

(Green and Haggard, 2001) than at the Bear Creek and 

Buffalo River sites. The Illinois River site is downstream from several wastewater-treatment plants and 

also is affected by pasture land and poultry waste 

(Arkansas Department of Environmental Quality, 

2000).

Table 5. Comparison of Bear Creek and Buffalo River flow-weighted concentrations with flow-weighted concentrations for 

undeveloped basins and the Illinois River, Arkansas

[Values are in milligrams per liter. Bear Creek and Buffalo River concentrations are calculated from loads computed from fixed-interval sampling data. Values for undeveloped basins are from Clark and others (2000). Values for North Sylamore Creek and Paddy Creek are from data compiled and summarized by 

Clark and others (2000). Values from Clark and others (2000) primarily are derived from fixed-interval sampling data. Values for the Illinois River are based 

on data in Green and Haggard (2001) and includes some data collected during high-flow storm events. NA is not available]

Dissolved

nitrite

plus nitrate,

as nitrogen

Total

nitrogen

Dissolved

orthophosphorus,

as phosphorus

Total

phosphorus

Bear Creek-1999 0.46 0.82 0.03 0.09

Bear Creek-2000 0.46 0.88 0.04 0.13

Buffalo River-1999 0.35 0.75 NA 0.05

Buffalo River-2000 0.39 0.93 NA 0.06

Undeveloped basin median 0.09 0.26 0.01 0.02

Undeveloped basin 75th percentile 0.21 0.50 0.01 0.04

North Sylamore Creek, Arkansas (undeveloped) 0.10 0.23 <0.01 0.03

Paddy Creek, Missouri (undeveloped) 0.04 <0.20 <0.01 0.04

Illinois River, Arkansas 2.4 3.4 0.22 0.40
22 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000

Yields

Constituent yields (annual load divided by drainage area) at the two sites were much more similar than 

loads, because the effect of drainage area size is 

removed. Yields of dissolved constituents (dissolved 

nitrite plus nitrate, dissolved phosphorus, and dissolved orthophosphorus) generally were greater at the 

Bear Creek site (table 3). Yields of most other constituents (particularly total phosphorus and suspended sediment) more often were greater at the Buffalo River site 

(table 3).

Yields (table 6) for Bear Creek and the Buffalo 

River were compared to yields in 82 undeveloped 

basins identified across the nation, including two 

basins in the Ozark Plateaus (Clark and others, 2000), 

and to a more developed basin (Green and Haggard, 

2001). The yields for Bear Creek and the Buffalo River 

were calculated from loads calculated using waterquality data collected at fixed intervals. These data 

were a subset of the water-quality data collected and 

used to calculate the loads in tables 3 and 4; data from 

the supplemental high-flow storm events were not 

included. The data associated with the supplemental 

storm events were omitted because the data for the 

undeveloped basins generally did not include supplemental high-flow storm event data. The yields for the 

developed basin were calculated from loads computed 

from data that included some storm event data. Nitrite 

plus nitrate yields were approximately 4 to 5 times 

(Buffalo River and Bear Creek) higher than the median 

yield for undeveloped basins (Clark and others, 2000). 

Total phosphorus yields were approximately 2 times 

(Buffalo River) and 2 to 4 times (Bear Creek) higher 

than the median yield for undeveloped basins. Yields 

for Bear Creek and the Buffalo River also were often 

substantially higher than the 75th percentiles of yields 

for the undeveloped basins; phosphorus yields were the 

most elevated relative to the 75th percentiles. Nutrient 

yields were about 5 to 10 times higher at a site on the 

Illinois River (Haggard and Green, 2001) than at the 

Bear Creek and Buffalo River sites. The Illinois River 

site is downstream from several wastewater-treatment 

plants and also is affected by pasture land and poultry 

waste (Arkansas Department of Environmental Quality, 2000).

Table 6. Comparison of Bear Creek and Buffalo River yields with yields for undeveloped basins and the Illinois River, 

Arkansas

[Values are in pounds per year per square mile. Bear Creek and Buffalo River yields are calculated from loads computed from fixed-interval sampling data. 

Values for undeveloped basins are from Clark and others (2000). Values for North Sylamore Creek and Paddy Creek are from data compiled and summarized by Clark and others (2000). Values from Clark and others (2000) primarily are derived from fixed-interval sampling data. Values for the Illinois River 

are based on data in Green and Haggard (2001) and included some data collected during high-flow storm events. NA is not available]

Nitrite plus

nitrate, as 

nitrogen

Total

nitrogen

Dissolved

orthophosphorus,

as

phosphorus

Total

phosphorus

Bear Creek-1999 610 1,100 44 120

Bear Creek-2000 700 1,400 61 190

Buffalo River-1999 700 1,500 NA 97

Buffalo River--2000 660 1,600 NA 100

Undeveloped basin median 150 490 16 49

Undeveloped basin 75th percentile 500 1,300 27 69

North Sylamore Creek,Arkansas (undeveloped) 170 390 7.4 43

Paddy Creek,0issouri (undeveloped) 80 360 9.1 74

Illinois River, Arkansas 5,900 8,600 540 960
Summary 23

SUMMARY

Analyses of streamflow measurements and 

water-quality samples at a site on Bear Creek and a site 

on the Buffalo River in Searcy County, Arkansas, 

quantify differences between the two sites during calendar years 1999 and 2000. Streamflow and water 

quality also vary seasonally at each site.

Mean annual streamflow was substantially larger 

at the Buffalo River site (836 and 719 ft3

/s in 1999 and 

2000) than at the Bear Creek site (56 and 65 ft3/s). 

Drainage areas of the Buffalo River and Bear Creek 

sites are 2,147 and 215 km2

, respectively. However, 

during times of low flow streamflow of Bear Creek 

comprises a larger proportion of the flow of the Buffalo 

River. For example, on 23 consecutive days in September 2000 the flows at the Bear Creek site were 25 

percent or more of the flows at the Buffalo River site. 

At both sites streamflow varied seasonally. Flows generally were greatest in January through June and least 

in August through October.

Concentrations of nutrients, fecal-indicator bacteria, dissolved organic carbon, and suspended sediment generally were greater in samples from Bear 

Creek than in samples from the Buffalo River. Statistically significant (p<0.05) differences were detected in 

concentrations of nitrite plus nitrate, total nitrogen, dissolved phosphorus, orthophosphorus, total phosphorus, 

fecal coliform bacteria, and suspended sediment.

Loads varied between sites, hydrologic conditions, years, and seasons. Loads were substantially 

higher for the Buffalo River than for Bear Creek (as 

would be expected because of the Buffalo’s higher 

streamflow). Loads contributed by surface runoff 

always comprised 85 percent or more of the total 

annual load.

Loads generally were greater in 2000 than in 

1999 for Bear Creek and the Buffalo River. Loads for 

2000 generally were about 1.2 to 1.8 times the loads for 

1999. Differences were greater between years for Bear 

Creek than for the Buffalo River; loads for 2000 were 

always less than 1.3 times the 1999 loads for the Buffalo River. 

Daily loads varied seasonally at both sites. At 

both sites and during both years, daily baseflow loads 

generally were greatest in the spring. Daily surfacerunoff loads were greatest in the spring or summer. In 

1999, daily surface-runoff loads were greatest in the 

spring at both sites. In 2000, daily runoff loads were 

greatest in the spring at Bear Creek, but greatest in the 

summer at the Buffalo River.

Flow-weighted concentrations generally were 

higher for Bear Creek than the Buffalo River. Concentrations for both streams were higher than typical flowweighted concentrations for undeveloped basins, but 

lower than concentrations at a site in a more developed 

basin.

Yields for the two sites were much more similar 

because the effect of drainage area size is removed. 

Yields of dissolved constituents generally were greater 

at Bear Creek; yields of other constituents generally 

were greater at the Buffalo River. Yields of nutrients 

were higher than typical yields in undeveloped basins, 

but lower than yields at a site in a more developed 

basin.

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J.V., 1995, Environmental and hydrologic setting of the 

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chap. A7, 28 p.

——— 1969, Discharge measurements at gaging stations: 

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for gaging streams: U.S. Geological Survey Techniques 

of Water-Resources Investigations, book 3, chap. A6, 

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concentrations and yields in undeveloped stream basins 

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Cohn, T.A., Caulder, D.L., Gilroy, E.J., Zynjuk, L.D., and 

Summers, R.M., 1992, The validity of a simple log-linear model for estimating fluvial constituent loads: An 

empirical study involving nutrient loads entering Chesapeake Bay: Water Resources Research, v. 28, no. 9, p. 

2353-2363.

Cohn, T.A., DeLong, L.L., Gilroy, E.J., Hirsch, R.M. and 

Wells, D.K., 1989, Estimating constituent loads: Water 

Resources Research, v. 25, no. 5, p. 937-942.
24 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000

Crawford, C.G., 1991, Estimation of suspended-sediment 

rating curves and mean suspended-sediment loads: 

Journal of Hydrology, v. 129, p. 331-348.

———1996, Estimating mean constituent loads in rivers by 

the rating-curve and flow-duration, rating-curve methods: Bloomington, Indiana, Indiana University, Ph.D. 

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Davis, J.V., and Bell, R.W., 1998, Water-quality assessment 

of the Ozark Plateaus study unit, Arkansas, Kansas, 

Missouri, and Oklahoma—Nutrients, bacteria, organic 

carbon, and suspended sediment in surface water, 1993-

95: U.S. Geological Survey Water-Resources Investigations Report 98-4164, 56 p.

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measurement of fluvial sediment, U.S. Geological Survey Techniques of Water Resources Investigations, 

book 3, chap. C2, 89 p. 

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States: New York, McGraw-Hill Book Co., Inc., 714 p.

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nitrogen loading at Illinois River south of Siloam 

Springs, Arkansas, 1997-1999: U.S. Geological Survey 

Water-Resources Investigations Report 01-4217, 12 p.

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Survey Techniques of Water-Resources Investigations, 

book 3, chap. C1, 55 p.

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water resources: Amsterdam, Netherlands, Elsevier, 

522 p.

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——— 1980b, Low flow studies: Wallingford, Oxon, 

United Kingdom, Report No. 3, p. 12-19.

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p.

——— 1984, Discharge ratings at gaging stations: U.S. 

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and hydrologic definitions: U.S. Geological Survey 

Water-Supply Paper 1541-A, 29 p.

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4026, 57 p.

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years of water quality monitoring: Department of the 

Interior, National Park Service, Harrison, Arkansas, 35 

p.

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geology, physiography, land use, and stream habitat 

conditions in the Buffalo and Current River systems, 

Missouri and Arkansas: USGS/BRD/BSR-2001-0005, 

111 p. (This report also can be accessed via the internet 

at: http://www.cerc.usgs.gov/pubs/center/pdf docs/

BSR2001-0005.pdf).

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Water quality in the Ozark Plateaus, Arkansas, Kansas, 

Missouri, and Oklahoma, 1992-95: U.S. Geological 

Survey Circular 1158, 33 p.

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resources data, Arkansas, water year 2000: U.S. Geological Survey Water-Data Report AR-00-1, 403 p.

Richards, R.P., and Holloway, J., 1987, Monte Carlo studies 

of sampling strategies for estimating tributary loads: 

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Merryfield, E.J., and Miller, N.L., 2001, Storm discharge, loads, and average concentrations in northwest 

Ohio rivers, 1975-1995: Journal of the American Water 

Resources Associations, v. 37, p. 423-438.

Scott, H.D., and Hofer, K.R., 1995, Spatial and temporal 

analysis of the morphological and land use characteristics of the Buffalo River watershed: University of 

Arkansas Water Resources Center Publication No. 170, 

61 p.

Steele, K.F., and Mott, D.N., 1998, Storm and base flow 

water quality for Bear, Calf, and Tomahawk Creeks: 

University of Arkansas Water Resources Center Publication No. 255, unpaginated.

Sullavan, J.N., 1974, Drainage areas of streams in Arkansas, 

White River Basin: U.S. Geological Survey Open-File 

Report, 123 p.

Thomas, R.B., 1988, Monitoring baseline suspended sediment in forested basins: The effects of sampling on suspended sediment rating curves: Hydrologic Science, v. 

33, p. 499-514.

U.S. Army Corps of Engineers, 2001, Searcy County 

Regional Water District: accessed August 15, 2001 at 

URL http://www.swl.usace.army.mil/regulatory/

searcyco.html.

Wahl, K.L., and Tortorelli, R.L., 1997, Changes in flow in 

the Beaver - North Canadian River Basin upstream 

from Canton Lake, western Oklahoma: U.S. Geological 

Survey Water-Resources Investigations Report 96-

4304, 58 p.

Wahl, K.L., and Wahl, T.L., 1988, Effects of regional 

ground-water level declines on streamflow in the Oklahoma Panhandle: Proceedings of Water-Use Data for 

Water Resources Management, American Water 

Resources Association, August 1988, p. 239-249.

——— 1995, Determining the flow of Comal Springs at 

New Braunfels, Texas, in Texas Water ‘95: American 

Society of Civil Engineers, San Antonio, Texas, August 

6-17, 1995, p. 77-86.
A

ppendix25

Appendix - Water-quality data for Buffalo River near St. Joe and Bear Creek near Silver Hill, Arkansas[Five digit numbers in parentheses are U.S. Environmental Protection Agency STORET data management system parameter codes. ft3/s, cubic feet per second; mg/Lmens per centimeter at 25 degrees Celsius; °C, degrees Celsius; CaCO3, calcium carbonate; N, nitrogen; P, phosphorus; C, carbon; mm, millimeter; --, no data; E, estimideal range, >, greater than]

Date

(yyyymmdd) Time

Discharge,

instantaneous

(ft3/s)

(00061)

Oxygen,

dissolved

(percent

saturation)

(00301)

Oxygen,

dissolved

(mg/L)

(00300)

pH,

field

standard

units

(00400)

Specific

conductance

(μS/cm)

(00095)

Temperature

(°C)

(00010)

Acid

neutralizing

capacity,

field

(mg/L as

CaCO3)

(00410)

Ammonia,

dissolved

(mg/L

as N)

(00608)

Ammonia

plus

organic

nitrogen

dissolved

(mg/L

as N)

(00623)

Ammonia

plus

organic

nitrogen,

total

(mg/L

as N)

(00625)

Nitrogen,

dissolved

(mg/L

as N)

(00602)

Buffalo River near St. Joe, Arkansas

19990120 1045 673 98 12.2 7.4 181 5.5 78 <0.020 E0.07 E0.07 -- 19990209 1030 2,910 104 11.5 7.3 141 10 57 .020 E.05 .15 -- 19990309 1205 2,940 91 10.2 7.8 145 9.9 66 <.020 .11 .32 .29 19990325 845 1,290 90 9.8 8.3 168 11.2 159 <.020 E.05 <.10 -- 19990412 1350 1,890 104 10 8 163 17.3 68 <.020 E.07 E.09 -- 19990415 830 2,740 90 9.3 7.3 185 12.8 81 <.020 E.06 .13 -- 19990505 1045 17,600 96 9.2 6.5 114 15.5 52 .045 .31 2.1 .48 19990603 940 422 88 7.2 6.8 225 24 102 .032 E.09 0.12 -- 19990624 1215 159 113 9.3 8 239 24.3 108 .020 <.20 <.20 -- 19990701 830 12,100 89 8 7.4 121 19.8 61 <.020 .25 1.4 .39 19990722 900 122 83 6.4 7.5 232 28.5 105 <.020 .20 .13 -- 19990811 835 53 74 5.7 7.8 231 28.6 103 <.020 .19 .12 -- 19990907 1200 35 107 8.5 7.5 250 26.5 112 <.020 E.05 E.05 -- 19991006 830 20 -- -- 8.2 262 14 100 <.020 E.06 E.10 -- 19991123 830 37 89 8.8 7.7 266 14.7 119 <.020 <.10 E.10 -- 19991208 1215 467 87 9.8 7.9 277 9.1 132 <0.020 <0.10 .10 -- 
26 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000 19991213 1130 6,360 86 9.5 6.9 113 10.2 42 <.020 .25 0.43 0.72 

20000120 810 152 92 10.8 7.4 210 8.0 94 <.020 E.05 E.09 -- 20000201 945 88 95 12.4 8.1 214 4.6 99 <.020 <.10 <.10 -- 20000227 945 2,050 88 9.8 7.6 109 11.1 44 <.020 .12 .23 .28 20000313 1225 650 93 10.1 7.7 164 11.7 92 <.020 E.07 .13 -- 20000419 1145 550 111 9.7 7.8 170 20.6 76 <.020 E.06 .10 -- 20000506 1715 1,170 100 8.8 7.6 166 19.6 76 <.020 E.08 .24 -- 20000517 1125 273 103 9.0 7.9 168 20.9 76 <.020 .11 .16 -- 20000613 900 356 89 7.5 7.9 216 23.6 86 <.020 .14 E.08 .24 20000615 830 2,640 91 8.2 7.3 104 19.9 45 <.020 .14 .44 .25 20000617 1830 27,300 95 8.8 7.7 88 18.5 40 <.020 .29 2.5 .42 20000622 900 15,000 90 8.3 7.2 110 18.3 46 <.020 .17 .45 .32 20000726 1010 294 93 7.7 7.7 244 23.8 113 <.020 E.06 .14 -- 20000816 905 120 76 5.9 8.1 234 27.4 117 <.020 .11 .11 -- 20000907 1020 20 88 7.1 7.4 241 24.4 128 .02 E.10 .12 -- 20001003 740 40 78 6.9 7.9 251 20.8 117 .024 E.07 .11 -- 20001115 1220 492 140 15.5 8.2 215 10.1 98 <.041 <.10 <.08 -- 20001219 940 403 65 8.9 8.0 222 1.9 102 <.041 E.08 <.08 -- 20010116 1400 1,240 77 9.4 8.4 152 6.4 68 <.041 <.10 <.08 -- 

Appendix - Water-quality data for Buffalo River near St. Joe and Bear Creek near Silver Hill, Arkansas--Continued[Five digit numbers in parentheses are U.S. Environmental Protection Agency STORET data management system parameter codes. ft3/s, cubic feet per second; mg/L

mens per centimeter at 25 degrees Celsius; °C, degrees Celsius; CaCO3, calcium carbonate; N, nitrogen; P, phosphorus; C, carbon; mm, millimeter; --, no data; E, estim

ideal range, >, greater than]

Date

(yyyymmdd) Time

Discharge,

instantaneous

(ft3/s)

(00061)

Oxygen,

dissolved

(percent

saturation)

(00301)

Oxygen,

dissolved

(mg/L)

(00300)

pH,

field

standard

units

(00400)

Specific

conductance

(μS/cm)

(00095)

Temperature

(°C)

(00010)

Acid

neutralizing

capacity,

field

(mg/L as

CaCO3)

(00410)

Ammonia,

dissolved

(mg/L

as N)

(00608)

Ammonia

plus

organic

nitrogen

dissolved

(mg/L

as N)

(00623)

Ammonia

plus

organic

nitrogen,

total

(mg/L

as N)

(00625)

Nitrogen,

dissolved

(mg/L

as N)

(00602)
Appendix 27

20010129 1815 774 99 11.8 8.0 183 7.1 -- <.041 .20 .56 .56 20010214 645 1,590 91 10.6 7.9 146 8.7 64 <.041 <.10 -- -- 20010221 815 2,240 92 10.6 7.6 156 9.4 68 <.041 E.06 -- -- 20010320 1300 750 107 11.9 8.3 172 11.0 74 <.041 <.10 -- -- 20010425 815 477 71 7.0 6.9 176 16.2 79 <.041 E.09 -- -- 20010509 1100 244 94 8.5 8.1 210 20.7 95 <.041 E.09 .12 -- 20010607 740 176 99 8.2 7.5 202 24.0 94 <.040 E.07 E.07 -- 20010710 1145 94 84 6.4 8.0 219 28.6 99 <.040 E.09 .14 -- 20010817 710 94 64 5.2 7.5 236 24.8 145 <.040 E.09 .09 -- 20010906 945 21 81 6.6 8.1 241 25.8 109 <.040 E.08 .11 -- 

Appendix - Water-quality data for Buffalo River near St. Joe and Bear Creek near Silver Hill, Arkansas--Continued[Five digit numbers in parentheses are U.S. Environmental Protection Agency STORET data management system parameter codes. ft3/s, cubic feet per second; mg/L

mens per centimeter at 25 degrees Celsius; °C, degrees Celsius; CaCO3, calcium carbonate; N, nitrogen; P, phosphorus; C, carbon; mm, millimeter; --, no data; E, estim

ideal range, >, greater than]

Date

(yyyymmdd) Time

Discharge,

instantaneous

(ft3/s)

(00061)

Oxygen,

dissolved

(percent

saturation)

(00301)

Oxygen,

dissolved

(mg/L)

(00300)

pH,

field

standard

units

(00400)

Specific

conductance

(μS/cm)

(00095)

Temperature

(°C)

(00010)

Acid

neutralizing

capacity,

field

(mg/L as

CaCO3)

(00410)

Ammonia,

dissolved

(mg/L

as N)

(00608)

Ammonia

plus

organic

nitrogen

dissolved

(mg/L

as N)

(00623)

Ammonia

plus

organic

nitrogen,

total

(mg/L

as N)

(00625)

Nitrogen,

dissolved

(mg/L

as N)

(00602)
28 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000 Appendix - Water-quality data for Buffalo River near St. Joe and Bear Creek near Silver Hill, Arkansas--Continued [Five digit numbers in parentheses are U.S. Environmental Protection Agency STORET data management system parameter codes. ft3/s, cubic feet per second; mg/L

mens per centimeter at 25 degrees Celsius; °C, degrees Celsius; CaCO3, calcium carbonate; N, nitrogen; P, phosphorus; C, carbon; mm, millimeter; --, no data; E, estim

ideal range, >, greater than] Date Time Phos- phorus dis- solved (mg/L as P) (00666) Ortho- phosphorus, dissolved (mg/L as P) (00671) Phosphorus, total (mg/L as P) (00665) Solids, residue at 180 °C, dissolved (mg/L) (70300) E. coli (colonies per 100 mL) (31633) Fecal coliforms (colonies per 100 mL) (31625) Fecal strep- tococci (colonies per 100 mL) (31673) Organic carbon, dissolved (mg/L as C) (00681) Sediment, suspended (mg/L) (80154) 

Buffalo River near St. Joe, Arkansas 19990120 1045 <0.004 <0.010 <0.004 99 <1 K1 K1 1.3 15 

19990209 1030 .007 .016 .024 85 54 73 56 -- 27 19990309 1205 .004 .017 .049 90 220 140 190 2.1 52 19990325 845 .005 <.010 .006 -- K13 K8 K12 .8 16 19990412 1350 .006 <.010 .010 -- K10 K5 K9 .9 15 19990415 830 .007 <.010 .024 -- 200 210 150 1.0 28 19990505 1045 .033 .035 .537 76 800 500 540 6.6 565 19990603 940 <.004 .010 .007 142 K2 K7 21 1.2 21 19990624 1215 <.020 <.010 <.020 142 38 58 79 .6 23 19990701 830 .023 .019 .376 106 2,300 K22,000 K2,500 6.8 463 19990722 900 <.004 <.010 .008 133 K11 8 15 1.4 17 19990811 835 <.004 <.010 .008 129 K12 K9 83 1.1 16 19990907 1200 <.004 <.010 .006 146 K4 K14 K7 1.3 22 19991006 830 E.004 <.010 .008 149 K5 K10 120 1.0 41 19991123 830 <.006 <.010 E.007 142 K18 K19 24 .83 18 19991208 1215 E.003 .016 E.004 152 K6 K5 41 .81 34 19991213 1130 .020 .014 .088 61 1,100 1,100 4,800 4.1 49 20000120 810 E.003 <.010 .021 113 35 31 20 -- 16 
Appendix 29

20000201 945 <.006 <.010 E.004 118 K8 K7 K7 .82 16 20000227 945 0.008 <0.010 0.051 61 250 130 350 2.8 39 20000313 1225 <.006 <.010 E.005 89 K9 31 K2 1.1 12 20000419 1145 E.003 <.010 <.008 96 23 32 K8 1.1 21 20000506 1715 .013 <.010 .04 99 150 77 450 .94 51 20000517 1125 E.004 <.010 E.006 93 K2 K2 K20 1.1 14 20000613 900 E.004 <.010 E.005 118 K8 21 81 1.4 19 20000615 830 .018 <.010 .109 67 5,800 >2,000 K26,000 5.3 102 20000617 1830 .047 .033 .791 71 4,600 11,000 K25,000 7.1 852 20000622 900 .016 .01 .121 73 K1,000 K1,200 5,800 4.1 104 20000726 1010 <.006 <.010 .009 134 K7 K16 23 .93 57 20000816 905 <.006 <.010 E.007 131 K14 40 30 1.2 45 20000907 1020 E.004 <.010 .008 140 K2 K5 20 1.1 28 20001003 740 E.003 <.010 E.004 136 K10 K6 K14 .94 45 20001115 1220 E.003 <.018 .006 121 -- 51 70 1.3 26 20001219 940 E.003 <.018 E.002 123 K17 K11 K8 .74 22 20010116 1400 E.005 <.018 .008 83 K6 K4 K17 1.3 21 20010129 1815 .042 .036 .284 102 1,700 2,000 7,300 3.3 172 20010214 645 E.004 <.018 .019 86 240 210 260 1.4 28 20010221 815 .006 <.018 .020 84 120 52 58 .96 33 20010320 1300 <.006 <.018 .005 100 <1 K2 K2 .97 20 

Appendix - Water-quality data for Buffalo River near St. Joe and Bear Creek near Silver Hill, Arkansas--Continued[Five digit numbers in parentheses are U.S. Environmental Protection Agency STORET data management system parameter codes. ft3/s, cubic feet per second; mg/L

mens per centimeter at 25 degrees Celsius; °C, degrees Celsius; CaCO3, calcium carbonate; N, nitrogen; P, phosphorus; C, carbon; mm, millimeter; --, no data; E, estim

ideal range, >, greater than]

Date Time

Phosphorus

dissolved

(mg/L

as P)

(00666)

Orthophosphorus,

dissolved

(mg/L as P)

(00671)

Phosphorus,

total

(mg/L as P)

(00665)

Solids,

residue at

180 °C,

dissolved

(mg/L)

(70300)

E. coli

(colonies

per

100 mL)

(31633)

Fecal

coliforms

(colonies

per

100 mL)

(31625)

Fecal

streptococci

(colonies

per

100 mL)

(31673)

Organic

carbon,

dissolved

(mg/L

as C)

(00681)

Sediment,

suspended

(mg/L)

(80154)
30 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000 20010425 815 E.003 <.018 .007 -- 78 110 27 .92 16 

20010509 1100 E.003 <.018 .008 130 K4 K10 21 .97 19 20010607 740 <.006 <.020 .009 10,000 K14 K12 38 1.1 22 20010710 1145 <.006 <.020 .008 -- K11 K13 21 1.2 23 20010817 710 <.006 <.020 .007 69 K9 K5 35 1.9 29 20010906 945 E.003 <.020 .007 144 27 29 E18 1.4 23 

Appendix - Water-quality data for Buffalo River near St. Joe and Bear Creek near Silver Hill, Arkansas--Continued [Five digit numbers in parentheses are U.S. Environmental Protection Agency STORET data management system parameter codes. ft3/s, cubic feet per second; mg/L

mens per centimeter at 25 degrees Celsius; °C, degrees Celsius; CaCO3, calcium carbonate; N, nitrogen; P, phosphorus; C, carbon; mm, millimeter; --, no data; E, estim

ideal range, >, greater than] Date Time Phos- phorus dis- solved (mg/L as P) (00666) Ortho- phosphorus, dissolved (mg/L as P) (00671) Phosphorus, total (mg/L as P) (00665) Solids, residue at 180 °C, dissolved (mg/L) (70300) E. coli (colonies per 100 mL) (31633) Fecal coliforms (colonies per 100 mL) (31625) Fecal strep- tococci (colonies per 100 mL) (31673) Organic carbon, dissolved (mg/L as C) (00681) Sediment, suspended (mg/L) (80154) 
Appendix 31

Appendix - Water-quality data for Buffalo River near St. Joe and Bear Creek near Silver Hill, Arkansas--Continued[Five digit numbers in parentheses are U.S. Environmental Protection Agency STORET data management system parameter codes. ft3/s, cubic feet per second; mg/L

mens per centimeter at 25 degrees Celsius; °C, degrees Celsius; CaCO3, calcium carbonate; N, nitrogen; P, phosphorus; C, carbon; mm, millimeter; --, no data; E, estim

ideal range, >, greater than]

Date Time

Discharge,

instantaneous

(ft3/s)

(00061)

Oxygen,

dissolved

(percent

saturation)

(00301)

Oxygen,

dissolved

(mg/L)

(00300)

pH,

field

standard

units

(00400)

Specific

conductance

(μS/cm)

(00095)

Temperature

(°C)

(00010)

Acid

neutralizing

capacity,

field

(mg/L as

CaCO3)

(00410)

Ammonia,

dissolved

(mg/L

as N)

(00608)

Ammonia

plus

organic

nitrogen

dissolved

(mg/L

as N)

(00623)

Ammonia

plus

organic

nitrogen,

total

(mg/L

as N)

(00625)

Nitrogen,

dissolved

(mg/L

as N)

(00602)

Bear Creek near Silver Hill, Arkansas

19990120 1000 4.4 105 12.9 7.3 206 6.0 78 <0.020 0.11 0.11 0.66 19990209 1318 150 107 11.2 7.1 145 12.5 53 <.020 E.08 .13 -- 19990309 1045 254 92 10.6 7.3 99 8.9 56 <.020 .17 .27 .50 19990325 935 74 93 9.9 8.0 184 12.3 95 <.020 E.06 E.07 -- 19990412 1245 95 118 11.3 7.9 175 17.2 66 .02 .12 .13 .46 19990415 730 390 91 9.3 7.2 131 13.0 49 <.020 .18 .36 .41 19990504 2345 175 99 9.2 6.9 180 17.0 80 .044 .33 .92 .71 19990603 1035 12 102 8.8 8.1 299 21.6 126 .075 .20 .22 .67 19990624 1130 8.5 98 8.4 7.9 316 22.0 137 .040 <.20 <.20 -- 19990630 1700 1,360 92 8.1 7.1 88 20.8 33 .020 .36 1.0 .58 19990722 945 12 107 9.4 7.6 313 21.5 138 .031 .23 .17 .70 19990810 1400 6.3 98 7.4 7.6 321 28.9 132 .043 .17 .23 .56 19990907 1045 3.7 90 7.6 7.2 344 22.8 139 .020 E.08 .15 -- 19991005 1130 2.7 72 7.5 8.3 355 13.0 169 <.020 .11 .12 .51 19991122 1350 4.5 108 10.5 7.7 353 16.0 154 <.020 E.07 .25 -- 19991208 1120 8.6 75 8.2 7.6 374 9.9 166 <.020 <.10 .12 -- 
32 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000 19991212 1700 2,560 96 10.7 7.3 76 9.7 23 <.020 .29 1.1 .95 

20000120 840 16 85 10.2 7.2 261 7.4 108 <.020 <.10 E.07 -- 20000201 1030 11 101 12.3 8.2 273 7.2 117 <0.020 <0.10 E0.06 -- 20000227 845 480 87 10 7.1 103 9.5 34 <.020 .16 .29 .69 20000313 1135 50 95 9.8 7.5 188 13.5 99 <.020 E.07 .14 -- 20000419 1030 27 111 10 7.7 208 19.1 88 .025 E.09 .14 -- 20000506 1615 577 94 8.7 7.0 99 17.2 36 <.020 .25 .47 .38 20000517 1000 31 80 7.1 7.6 209 20.1 88 <.020 .10 .11 .30 20000613 815 27 82 7.4 8.0 265 19.9 102 <.020 .15 .11 .53 20000614 2230 607 91 8.1 7.4 140 20.1 56 .024 .34 .80 .72 20000617 1730 880 94 8.4 7.8 114 20.1 45 <.020 .32 .58 .53 20000621 1430 2,380 90 8.1 7.2 98 19.6 48 <.020 .41 .70 .58 20000726 920 11 99 8.8 7.4 327 19.7 141 <.020 E.08 .14 -- 20000816 1030 7.2 102 8.5 8.2 327 23.9 151 .022 .15 .16 .62 20000907 940 6.7 106 9.1 7.3 348 21.6 169 .028 .12 .15 .55 20001003 1000 5.6 81 7.4 7.9 360 19.7 160 <0.020 0.11 0.20 0.64 20001115 1115 85 130 14.3 8.0 243 10.2 96 <.041 E.06 <.08 -- 20001219 830 30 64 8.4 8.1 259 3.7 103 <.041 E.08 E.07 -- 20010116 1315 108 109 13.3 8.7 167 7.3 65 <.041 E.07 <.08 -- 

Appendix - Water-quality data for Buffalo River near St. Joe and Bear Creek near Silver Hill, Arkansas--Continued[Five digit numbers in parentheses are U.S. Environmental Protection Agency STORET data management system parameter codes. ft3/s, cubic feet per second; mg/L

mens per centimeter at 25 degrees Celsius; °C, degrees Celsius; CaCO3, calcium carbonate; N, nitrogen; P, phosphorus; C, carbon; mm, millimeter; --, no data; E, estim

ideal range, >, greater than]

Date Time

Discharge,

instantaneous

(ft3/s)

(00061)

Oxygen,

dissolved

(percent

saturation)

(00301)

Oxygen,

dissolved

(mg/L)

(00300)

pH,

field

standard

units

(00400)

Specific

conductance

(μS/cm)

(00095)

Temperature

(°C)

(00010)

Acid

neutralizing

capacity,

field

(mg/L as

CaCO3)

(00410)

Ammonia,

dissolved

(mg/L

as N)

(00608)

Ammonia

plus

organic

nitrogen

dissolved

(mg/L

as N)

(00623)

Ammonia

plus

organic

nitrogen,

total

(mg/L

as N)

(00625)

Nitrogen,

dissolved

(mg/L

as N)

(00602)
Appendix 33

20010129 1520 943 99 11.2 7.7 126 8.8 -- .061 .51 1.2 1.2 20010214 845 607 91 10.4 7.5 130 9.5 46 .105 .26 .62 .99 20010221 1030 186 93 10.6 7.7 178 9.9 66 <.041 E.08 .13 -- 20010320 1000 43 112 12.3 8.2 210 11.1 84 <.041 <.10 .12 -- 20010425 1035 36 73 7.3 6.9 193 15 81 <.041 .10 .13 .35 20010509 900 35 93 9.2 7.8 236 16 100 <.041 .10 .12 .46 20010607 845 17 89 7.9 7.5 276 20.3 117 <.040 .11 .13 .48 20010710 855 8.6 74 6.2 7.9 331 23.4 145 E.034 .10 .18 .58 20010817 830 9.6 76 6.8 7.5 313 20.3 155 E.024 .14 .13 .69 20010906 1045 5.2 97 8.0 7.9 340 25.3 170 <.040 .13 .13 .65 

Appendix - Water-quality data for Buffalo River near St. Joe and Bear Creek near Silver Hill, Arkansas--Continued[Five digit numbers in parentheses are U.S. Environmental Protection Agency STORET data management system parameter codes. ft3/s, cubic feet per second; mg/L

mens per centimeter at 25 degrees Celsius; °C, degrees Celsius; CaCO3, calcium carbonate; N, nitrogen; P, phosphorus; C, carbon; mm, millimeter; --, no data; E, estim

ideal range, >, greater than]

Date Time

Discharge,

instantaneous

(ft3/s)

(00061)

Oxygen,

dissolved

(percent

saturation)

(00301)

Oxygen,

dissolved

(mg/L)

(00300)

pH,

field

standard

units

(00400)

Specific

conductance

(μS/cm)

(00095)

Temperature

(°C)

(00010)

Acid

neutralizing

capacity,

field

(mg/L as

CaCO3)

(00410)

Ammonia,

dissolved

(mg/L

as N)

(00608)

Ammonia

plus

organic

nitrogen

dissolved

(mg/L

as N)

(00623)

Ammonia

plus

organic

nitrogen,

total

(mg/L

as N)

(00625)

Nitrogen,

dissolved

(mg/L

as N)

(00602)
34 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000 Appendix - Water-quality data for Buffalo River near St. Joe and Bear Creek near Silver Hill, Arkansas--Continued [Five digit numbers in parentheses are U.S. Environmental Protection Agency STORET data management system parameter codes. ft3/s, cubic feet per second; mg/L

mens per centimeter at 25 degrees Celsius; °C, degrees Celsius; CaCO3, calcium carbonate; N, nitrogen; P, phosphorus; C, carbon; mm, millimeter; --, no data; E, estim

ideal range, >, greater than] Date Time Phos- phorus dis- solved (mg/L as P) (00666) Ortho- phosphorus, dissolved (mg/L as P) (00671) Phosphorus, total (mg/L as P) (00665) Solids, residue at 180 °C, dissolved (mg/L) (70300) E. coli (colonies per 100 mL) (31633) Fecal coliforms (colonies per 100 mL) (31625) Fecal strep- tococci (colonies per 100 mL) (31673) Organic carbon, dissolved (mg/L as C) (00681) Sediment, suspended (mg/L) (80154) Sedime

suspend

(perce

finer than 0.062 m

(7033

Bear Creek near Silver Hill, Arkansas 19990120 1000 0.020 0.018 0.026 117 K5 K18 23 2.4 17 98 19990209 1318 .018 .020 .031 87 36 66 28 -- 19 94 19990309 1045 .017 .026 .055 70 860 700 700 4.4 26 99 19990325 935 .017 <.010 .020 -- 34 43 26 .9 18 100 19990412 1245 .020 .018 .027 -- K5 K30 K12 1.1 17 100 19990415 730 .031 .023 .082 -- K3,000 K17 1,500 3.3 28 92 19990504 2345 .099 .082 .281 112 400 500 460 6.5 123 98 19990603 1035 .019 .026 .031 194 K11 31 58 .9 51 71 19990624 1130 <.020 .020 <.020 188 K2 K3 K6 .5 46 85 19990630 1700 .079 .047 .292 102 4,400 K23,000 K2,700 11 156 90 19990722 945 .017 .013 .027 183 29 52 130 1.1 52 88 19990810 1400 .017 <.010 .027 175 110 94 150 1.2 54 83 19990907 1045 .013 <.010 .019 194 K7 K17 200 1.4 84 82 19991005 1130 .015 .016 .022 206 K9 K21 53 1.2 90 96 19991122 1350 .010 <.010 .018 -- K10 K5 52 .87 55 79

19991208 1120 .017 <.010 .019 211 K5 K13 170 .8 89 7219991212 1700 .094 .074 .355 52 6,500 10,000 2,300 6.4 198 8320000120 840 0.015 0.019 0.049 147 K15 30 38 0.74 20 99
Appendix 35

20000201 1030 .015 <.010 .019 150 K15 K18 K9 .75 25 9620000227 845 .027 .024 .067 61 1,200 K640 390 3.2 28 9720000313 1135 .010 <.010 .016 102 21 61 K2 2.7 17 9420000419 1030 .015 .011 .023 116 K21 28 29 1.1 27 9520000506 1615 .029 .017 .105 72 540 1,100 1,000 6.2 54 9120000517 1000 .020 .013 .030 116 33 97 39 1.1 19 9720000613 815 .018 .016 .025 148 51 97 100 1.1 27 9320000614 2230 .121 .101 .232 93 K700 >2,000 7,400 8.2 99 9420000617 1730 .065 .046 .173 83 6,600 8,600 9,800 7.2 95 9120000621 1430 .085 .061 .224 81 4,200 K12,000 13,000 8.9 134 7920000726 920 .017 .013 .023 181 23 34 55 1.1 95 8620000816 1030 .011 <.010 .017 181 32 K57 26 1.3 85 8320000907 940 .013 <.010 .020 202 47 91 56 1.0 79 9320001003 1000 .011 .010 .018 202 150 160 110 1.2 51 9220001115 1115 0.025 E.015 0.031 138 -- 52 72 1.6 31 9920001219 830 .018 E.014 .022 150 110 80 51 1.1 35 9920010116 1315 .017 E.014 .024 97 K6 K6 K16 1.6 17 9820010129 1520 .087 .071 .354 85 2,900 K3,100 4,800 8.7 196 9020010214 845 .081 .073 .155 84 820 570 1,300 4.3 48 8620010221 1030 .026 .023 .035 112 130 94 60 1.2 21 10020010320 1000 .012 <.018 .016 120 25 K9 K8 1.0 24 97

Appendix - Water-quality data for Buffalo River near St. Joe and Bear Creek near Silver Hill, Arkansas--Continued[Five digit numbers in parentheses are U.S. Environmental Protection Agency STORET data management system parameter codes. ft3/s, cubic feet per second; mg/L

mens per centimeter at 25 degrees Celsius; °C, degrees Celsius; CaCO3, calcium carbonate; N, nitrogen; P, phosphorus; C, carbon; mm, millimeter; --, no data; E, estim

ideal range, >, greater than]

Date Time

Phosphorus

dissolved

(mg/L

as P)

(00666)

Orthophosphorus,

dissolved

(mg/L as P)

(00671)

Phosphorus,

total

(mg/L as P)

(00665)

Solids,

residue at

180 °C,

dissolved

(mg/L)

(70300)

E. coli

(colonies

per

100 mL)

(31633)

Fecal

coliforms

(colonies

per

100 mL)

(31625)

Fecal

streptococci

(colonies

per

100 mL)

(31673)

Organic

carbon,

dissolved

(mg/L

as C)

(00681)

Sediment,

suspended

(mg/L)

(80154)

Sedime

suspend

(perce

finer

than

0.062 m

(70331
36 Hydrologic Characteristics of Bear Creek near Silver Hill and Buffalo River near St. Joe, Arkansas, 1999-2000 20010425 1035 .013 <.018 .021 -- 55 49 31 1.1 18 98 20010509 900 .016 E.009 .017 144 32 47 63 1.2 19 98 20010607 845 .021 <.020 .03 156 -- 41 110 .96 39 48 20010710 855 .014 E.010 .022 -- 23 36 180 1.0 76 90 20010817 830 .026 E.013 .033 91 49 61 110 3.9 78 78 20010906 1045 .018 <.020 .024 202 E28 60 110 .96 84 89 Appendix - Water-quality data for Buffalo River near St. Joe and Bear Creek near Silver Hill, Arkansas--Continued [Five digit numbers in parentheses are U.S. Environmental Protection Agency STORET data management system parameter codes. ft3/s, cubic feet per second; mg/L

mens per centimeter at 25 degrees Celsius; °C, degrees Celsius; CaCO3, calcium carbonate; N, nitrogen; P, phosphorus; C, carbon; mm, millimeter; --, no data; E, estim

ideal range, >, greater than] Date Time Phos- phorus dis- solved (mg/L as P) (00666) Ortho- phosphorus, dissolved (mg/L as P) (00671) Phosphorus, total (mg/L as P) (00665) Solids, residue at 180 °C, dissolved (mg/L) (70300) E. coli (colonies per 100 mL) (31633) Fecal coliforms (colonies per 100 mL) (31625) Fecal strep- tococci (colonies per 100 mL) (31673) Organic carbon, dissolved (mg/L as C) (00681) Sediment, suspended (mg/L) (80154) Sedime

suspend

(perce

finer than 0.062 m

(7033