Long Term Resource Monitoring Program

Program Report

2002-P005

Limnological Monitoring on the

Upper Mississippi River System, 1993–1996:

 Long Term Resource Monitoring Program

 Havana Field Station

November 2002
The Upper Midwest Environmental Sciences Center issues LTRMP Program Reports

to provide Long Term Resource Monitoring Program partners

with programmatic documentation, procedures manuals, and annual status reports.

Cover graphic by Mi Ae Lipe-Butterbrodt

Mention of trade names or commercial products does not constitute endorsement

or recommendation for use by the U.S. Department of the Interior, U.S. Geological Survey.
Limnological Monitoring on the

Upper Mississippi River System, 1993–1996:

Long Term Resource Monitoring Havana Field Station

by

David M. Soballe, Richard H. Wright, and Steven W. Stenzel

November 2002

U.S. Geological Survey

Upper Midwest Environmental Sciences Center

2630 Fanta Reed Road

La Crosse, Wisconsin 54603
Suggested citation:

Soballe, D. M., R. H. Wright, and S. W. Stenzel. 2002. Limnological monitoring on the Upper Mississippi River System,

1993–1996: Long Term Resource Monitoring Program Havana Field Station. U.S. Geological Survey, Upper Midwest

Environmental Sciences Center, Onalaska, Wisconsin, November 2002. LTRMP 02-P005. 16 pp. + Appendixes A–F

Additional copies of this report may be obtained from the National Technical Information Service, 5285 Port Royal Road,

Springfield, VA 22161 (1-800-553-6847 or 703-487-4650). Also available to registered users from the Defense Technical

Information Center, Attn: Help Desk, 8725 Kingman Road, Suite 0944, Fort Belvoir, VA 22060-6218 (1-800-225-3842 or

703-767-9050).
iii

Contents

Page

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

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

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

The Upper Mississippi River System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Methods .......................................................................... 6

Study Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Monitoring Network and Sampling Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Sample Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Laboratory Analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Quality Assurance and Quality Control Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

River Discharge Regime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Fixed-site Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Sample Collecting and Field Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Fixed-site Sampling Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Stratified Random Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Sample Collection and Field Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Stratified Random Sampling Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Summary and Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Appendix A. Fixed-site Sampling Sites: January 1993–December 1996 . . . . . . . . . . . . . . . . . . . . . . . A-1

Appendix B. Stratified Random Sampling Sites: January 1993–December 1996 . . . . . . . . . . . . . . . . . B-1

Appendix C. Limnological Parameters Measured in the Long Term Resource Monitoring Program . C-1

Appendix D. Water Quality Sample Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1

Appendix E. Fixed-site Sampling Data: January 1993–December 1996 . . . . . . . . . . . . . . . . . . . . . . . E-1

Appendix F. Stratified Random Sampling Data: 1993–1996 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-1
iv

Tables

Page

1a. Dams on the Upper Mississippi River . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

1b. Dams on the Illinois River . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2. Period of operation for each of the Long Term Resource Monitoring Program field stations ...... 8

Figures

1. The Long Term Resource Monitoring Program (LTRMP) study area. . . . . . . . . . . . . . . . . . . . . . . . 3

2a. Water surface elevation (meters above mean sea level) of the Mississippi River from the head

of navigation near St. Paul, Minnesota, to the confluence of the Ohio River near Cairo, Illinois. . . 4

2b. Water surface elevation (meters above mean sea level) of the Illinois River from Lockport,

Illinois, to the confluence of the Mississippi River near Grafton, Illinois. ..................... 4

3. Water elevation (meters above mean sea level) of the Illinois River at Havana from 1993

through 1996 (solid line) and the 1940–1996 average annual hydrograph (dashed line) . . . . . . . . . 12
v

Preface

The Long Term Resource Monitoring Program (LTRMP) was authorized under the Water Resources

Development Act of 1986 (Public Law 99-662) as an element of the U.S. Army Corps of Engineers’

Environmental Management Program. The LTRMP is being implemented by the Upper Midwest

Environmental Sciences Center, a U.S. Geological Survey science center, in cooperation with the five Upper

Mississippi River System (UMRS) States of Illinois, Iowa, Minnesota, Missouri, and Wisconsin. The U.S.

Army Corps of Engineers provides guidance and has overall Program responsibility. The mode of operation

and respective roles of the agencies are outlined in a 1988 Memorandum of Agreement.

The UMRS encompasses the commercially navigable reaches of the Upper Mississippi River, as well as

the Illinois River and navigable portions of the Kaskaskia, Black, St. Croix, and Minnesota Rivers. Congress

has declared the UMRS to be both a nationally significant ecosystem and a nationally significant commercial

navigation system. The mission of the LTRMP is to provide decision makers with information for

maintaining the UMRS as a sustainable large river ecosystem given its multiple-use character. The long-term

goals of the Program are to understand the system, determine resource trends and effects, develop

management alternatives, manage information, and develop useful products.

In this report, limnological monitoring conducted by the Havana (Illinois) Field Station from 1993 through

1996 is summarized. Reports of this type provide a synopsis of the collected data and collection methods,

as well as a preliminary report of remarkable or unusual conditions in the system. They are intended to be

produced annually.

This report was prepared under Task 2.2.3.6, Evaluate and Summarize Current Monitoring Results of the

Operating Plan (U.S. Fish and Wildlife Service 1993). This report was developed with funding provided by

the Long Term Resource Monitoring Program.
Limnological Monitoring on the

Upper Mississippi River System, 1993–1996:

Long Term Resource Monitoring Program Havana Field Station

by

David M. Soballe

U.S. Geological Survey

Upper Midwest Environmental Sciences Center

2630 Fanta Reed Road

La Crosse, Wisconsin 54603

 Richard H. Wright and Steven W. Stenzel

Illinois Natural History Survey

Havana Field Station

704 North Schrader Avenue

Havana, Illinois 62644

Abstract. Since 1988, the Long Term Resource Monitoring Program (LTRMP) staff have performed basic

limnological field measurements in the Upper Mississippi River System. The period of this report (1993–96)

includes a major revision of the LTRMP sampling design in 1993 that added randomization, broader spatial

coverage, and increased monitoring of tributaries and locations that allow monitoring of material transport. Two

significant floods (1993 and 1995) occurred in the reporting period. In 1993, the La Grange reach of the Illinois

River was above the 1940–96 mean river stage for most of the year and was below flood stage for only three brief

periods. The flood in spring 1995 receded sooner than in 1993; however, the 137 m (450.66 feet) peak on

May 31, 1995, was the third highest river elevation recorded at Havana, Illinois. Low dissolved oxygen levels

in the main channel were also notable in 1993–96, with concentrations at or below 5 mg/L observed each year.

Key words: Annual report, limnology, LTRMP, Mississippi River, water quality

Introduction

The Upper Mississippi River is a major resource of multiple uses that include navigation, water supply,

hydroelectric generation, fish and wildlife habitat, and recreation. Effective management of this resource

requires scientific understanding of the ecosystem and of its long-term trends and conditions. To meet this

need, Congress authorized a Long Term Resource Monitoring Program (LTRMP) for the Upper Mississippi

River System (UMRS). The LTRMP, begun in 1988, is intended to provide scientifically sound and useful

information by using consistent and reliable methods to monitor and evaluate long-term changes in selected

physical, chemical, and biological characteristics. 

The LTRMP water quality staff collects basic information on selected physical and chemical features of

the UMRS to aid in the interpretation or prediction of long- and short-term patterns. The data focus on a

subset of limnological variables (i.e., physicochemical features, suspended sediment, and major plant

nutrients) known to be significant to aquatic habitat in this system. The LTRMP is designed to complement,

not replace or duplicate, the monitoring programs of other state and Federal agencies. It therefore includes

some limnological characteristics not routinely monitored in water quality programs, and it excludes others

that are of concern primarily for human consumption or regulatory purposes (e.g., chemical oxygen demand,

biochemical oxygen demand, total coliform bacteria, fecal coliform bacteria, fecal streptococcus, heavy

metals, pesticides, and polychlorinated biphenyls). 
2

The present report is one in a series summarizing limnological monitoring at each of the LTRMP field

stations. This report is intended to (1) document those aspects of sample collection (e.g., sampling times,

period of record, sample locations, and allocations among strata) needed for valid interpretation of the data,

and (2) report limnological conditions. Detailed analyses and interpretation of the limnological data are

reported separately. This report covers multiple years.

To improve readability and increase the usefulness of this document as a reference, the many graphic and

tabular summaries are included as appendixes. These appendixes are referenced extensively in the main body

of the report, and each appendix contains explanatory information that allows it to be used as a nearly

independent document.

The data presented here represent a concerted effort by personnel of the Illinois Natural History Survey

and the U.S. Geological Survey who collected, compiled, verified, and organized the data. The specific data

used in this report have been archived at the Upper Midwest Environmental Sciences Center (UMESC)

La Crosse, Wisconsin, (formerly the Environmental Management Technical Center, Onalaska, Wisconsin),

and are available on request. This archival step isolates these data from the dynamics (additions and

corrections) of the main LTRMP database and thus facilitates the reexamination, reconstruction, or

expansion of the results presented here.

The Upper Mississippi River System

The basin of the UMRS (about 490,000 km2) extends from north-central Minnesota to the Ohio River

confluence near Cairo, Illinois. The enabling authorization for the LTRMP, however, restricts monitoring

to the geological floodplain (about 2% of the total drainage). The LTRMP study areas include selected

sections of the Mississippi River (Navigation Pools 4, 8, 13, and 26), La Grange Pool of the Illinois River,

and the open river reach (Middle Mississippi River) between the Missouri River and Ohio River confluences

(Figure 1). 

Field teams of the LTRMP monitor more than 2,000 km of large river; across this expanse there exist

distinct differences in climate, geomorphology, surficial geology, and land use. Patterns that arise from the

north–south orientation of the system are overlain by upstream to downstream changes related to river size

(Vannote et al. 1980). Consequently, the areas monitored by individual field stations differ markedly in the

distribution and characteristics of aquatic habitat and aquatic biota. The LTRMP monitoring design must

contend with these differences by being flexible enough to accommodate local conditions but appropriately

uniform across all study areas to permit comparison and synthesis.

Dam construction on the Upper Mississippi and Illinois Rivers has profoundly altered these rivers,

creating a series of rapidly flushed impoundments connected by short stretches of flowing river that are

influenced by dam operations (Figure 2).

The dams on the main stem of the Upper Mississippi River are numbered from upstream to downstream

(starting near St. Paul, Minnesota), and the river reach above each dam is called a pool (Table 1a). The pool

has the same numeric designation as the downstream dam. For example, Pool 14, near Clinton, Iowa,

includes the entire reach of river upstream of Lock and Dam 14 and downstream of Lock and Dam 13. A

similar system is used on the Illinois River, but the individual dams are named rather than numbered

(Table 1b). Although the navigation dams have created significant zones of permanent inundation in

Pools 1–13 of the Upper Mississippi River, these zones are usually less than half the total water surface

within the pool (LTRMP aquatic areas database) and are semifluvial (average hydraulic residence times
3

<2 days). Between Pools 13 and 26 in the Mississippi River and in most of the Illinois River, the navigation

dams have deepened the river and widened it slightly, but have permanently inundated little terrestrial area

compared with major river impoundments and have created minimal lake-like habitat. The term pool is

therefore misleading inasmuch as it suggests that the UMRS is a stair-step series of lake-like impoundments.

Nonetheless, the term is widely used and recognized by those familiar with the UMRS, and it is used freely

in this report.

Figure 1. The Long Term Resource Monitoring Program (LTRMP) study area. Although the Missouri River is shown for

reference, only the mouth of this tributary is sampled for water quality under the LTRMP.
4

Figure 2a. Water surface elevation (meters above mean sea level) of the Mississippi River from the head of navigation

near St. Paul, Minnesota, to the confluence of the Ohio River near Cairo, Illinois.

Figure 2b. Water surface elevation (meters above mean sea level) of the Illinois River from Lockport, Illinois, to the

confluence of the Mississippi River near Grafton, Illinois.
5

Table 1a. Dams on the Upper Mississippi River.

Name of dam

Date placed

 in service City

River

mile

Drainage

area

 (km2

)

Dam

height

 (m)

Pool

elevation

(feet)

Lower St. Anthony

Falls

11/13/1958 Minneapolis, Minnesota 853.2 51,000 7.3 750.0

1 07/03/1917 St. Paul, Minnesota 847.6 51,000 11.3 725.1

2 07/01/1931 Hastings, Minnesota 815.2 96,000 3.7 687.2

3 07/21/1938 Red Wing, Minnesota 796.9 117,000 3.7 675.0

4 05/25/1935 Alma, Wisconsin 752.8 148,000 2.4 667.0

5 05/29/1935 Minneiska, Minnesota 738.1 152,000 2.1 660.0

5a 07/06/1936 Winona, Minnesota 728.5 153,000 2.7 651.0

6 06/30/1936 Trempealeau, Wisconsin 714.3 155,000 1.7 645.0

7 04/19/1937 Dresbach, Minnesota 702.5 161,000 2.0 639.0

8 04/26/1937 Genoa, Wisconsin 679.2 168,000 2.4 631.0

9 07/08/1937 Lynxville, Wisconsin 647.9 172,000 3.4 620.0

10 11/26/1937 Guttenberg, Iowa 615.1 206,000 2.7 611.0

11 09/14/1937 Dubuque, Iowa 583.0 211,000 2.4 603.0

12 05/14/1939 Bellevue, Iowa 556.7 213,000 3.4 592.0

13 05/13/1939 Clinton, Iowa 522.5 221,000 2.7 583.0

14 06/14/1939 Le Claire, Iowa 493.3 229,000 3.3 571.9

15 03/07/1934 Rock Island, Illinois 482.9 229,000 4.9 561.0

16 07/10/1937 Muscatine, Iowa 457.2 257,000 2.7 545.0

17 05/14/1939 New Boston, Illinois 437.1 258,000 2.4 536.0

18 09/08/1937 Burlington, Iowa 410.5 294,000 3.0 528.0

19 06/12/1913 Keokuk, Iowa 364.2 308,000 11.6 518.2

20 06/09/1936 Canton, Missouri 343.2 348,000 3.0 480.4

21 07/21/1938 Quincy, Illinois 324.9 348,000 3.2 470.0

22 07/22/1938 Saverton, Missouri 301.2 356,000 3.1 459.5

23a —

24 1940 Clarksville, Missouri 273.4 365,000 4.6 449.2

25 05/18/1939 Cap Au Gris, Missouri 241.4 368,000 4.6 434.9

26b 05/01/1938 Alton, Illinois 202.9 443,000 6.7 419.0

Melvin Price 1990-1994 Alton, Illinois 200.8 444,000 7.3 419.0

a

Lock and Dam 23 was never built.

b

Lock and Dam 26 was removed after the Melvin Price Dam was placed in service.
6

Table 1b. Dams on the Illinois River.

Name of dam

Date placed in

service

River

mile

Drainage

area

 (km2)

Dam

height

 (m)

Pool

elevation

(feet)

Thomas J. O'Briena 1960 326.5 0 1.2 583.5

Lockport 1933 291.1 1,900 12.3 579.5

Brandon Road 1933 286.0 3,900 10.4 539.0

Dresden Island 1933 271.5 18,800 6.7 505.0

Marseilles 1933 247.0 21,400 7.3 483.0

Starved Rock 1933 231.0 28,600 5.8 459.0

Peoria 1938 157.7 37,700 3.4 440.0

La Grange 1939 80.2 66,400 2.9 429.0

a

This structure controls diversion discharge into the Illinois waterway from outside the drainage basin (Lake Michigan)

The first major dam on the Upper Mississippi River was constructed in 1913 near Keokuk, Iowa, and was

followed by 27 additional dams on the main stem to create a 2.7-m (9-foot) navigational waterway from

Alton, Illinois, to St. Anthony Falls near St. Paul, Minnesota. Twenty-two dams were built between 1935 and

1940; the last dam was completed in 1958 at Lower St. Anthony Falls near Minneapolis (Table 1a). The

navigation system was altered significantly in 1993 when Lock and Dam 26 at Alton was replaced by a new

structure (Melvin Price Locks and Dam) with increased lock capacity about 3.2 km (2 miles) farther

downstream. The previous Lock and Dam 26 was removed after the new structure was completed.

The history of impoundment on the Illinois River is similar to that of the Upper Mississippi River, and

the Illinois River is now divided into six navigational pools (Table 1b). The first dams were completed on

the upper portions of the Illinois River (Starved Rock, Marseilles, and Dresden Island) in 1933; additional

dams at Peoria and La Grange were completed in 1938. The Melvin Price Locks and Dam on the Mississippi

River near Alton, Illinois, also impounds the lowermost portion of the Illinois River.

Methods 

Study Area

 The study area of the LTRMP includes the Mississippi River from Cairo, Illinois, to the head of

navigation near St. Paul, Minnesota; the Illinois River; and navigable portions of the Kaskaskia, Black, and

St. Croix Rivers. In recognition of the highly variable and widely differing river characteristics within this

large study area, the Comprehensive Master Plan (Jackson et al. 1981) recommended 17 pools or reaches for

detailed monitoring. Available resources, however, have limited the LTRMP to six selected areas, and the

five states bordering the Upper Mississippi River now operate six LTRMP monitoring stations that focus on

these specific reaches. These areas (Figure 1) are concentrated in the uppermost segments of the Mississippi

River. The river sections presently monitored under LTRMP for water quality include Pools 4, 8, 9, 12, 13,

14, and 26 in the impounded portion of the Upper Mississippi River; 130 km (80 miles) of the open river

above the Ohio River confluence at Cairo, Illinois; and La Grange Pool of the Illinois River. All of the major

tributaries of the Mississippi and Illinois Rivers in these river segments are monitored under the LTRMP.

The long (400 km) reach of the Upper Mississippi River between Pools 14 and 26 is not monitored under
7

the LTRMP, but other state and Federal programs collect water quality information in this reach and

adjoining tributaries (i.e., Iowa-Cedar, Rock, and Des Moines Rivers).

Personnel from the Illinois Natural History Survey, Havana Field Station, conduct LTRMP monitoring

on La Grange Pool, defined by Peoria Lock and Dam at Illinois River mile 157.7, La Grange Lock and Dam

at Illinois River mile 80.1, and adjacent portions of the Illinois River and its tributaries (Figure A-1). The

LTRMP water quality has been monitored on La Grange Pool since 1989 (Appendixes A and B).

The drainage area of the La Grange reach is the smallest of any LTRMP study area, roughly the same

(50,000 km2

) as the uppermost impoundment on the Mississippi River (St. Anthony Falls). In addition, about

20% of the flow volume (90 m3

/s) in La Grange Pool is diversion water from Lake Michigan (through the

Chicago Sanitary and Ship Canal) and a large part (15–20%) of the catchment is urbanized (by the Chicago

metropolitan area). The Illinois River valley is also notable for its unusual geomorphology and extensive

human modifications (levee construction and agriculture). The present channel of the lower Illinois River

(from Henry to Grafton, Illinois) was originally occupied by the much larger Mississippi River before this

larger river was diverted to the west by glacial action. Consequently, the large size and low slope of the

Illinois River channel and floodplain are not matched to the present drainage area and volume of flow.

Because of this, the reach has an unusually large number of backwaters and is unable to transport the high

sediment loads delivered by its tributaries from intensively farmed areas (cf. Demissie et al. 1992). Unlike

the braided-channel reaches of the Upper Mississippi River main stem, the Illinois River floodplain has been

extensively leveed and isolated from the river. 

Zebra mussels, Dreissena polymorpha, were first reported in the Illinois River in 1991 in Bath Chute

(La Grange reach) with increasing numbers through 1993. Scientists from the Illinois Natural History Survey

performed a variety of studies including population analysis, zebra mussels versus native unionid, growth

models, and veliger collections. The veliger collections are still being conducted. Another invasive species,

Daphnia lumholtzi, was discovered in 1995; its presence is being monitored by Illinois Natural History

Survey. The Illinois Nutrient and Sediment Assessment (Illinois State Water Survey 1998) is presently

attempting to assess nutrient and sediment transport by the Illinois River and its tributaries and determine

how this may be affecting the nutrient and sediment loads to the Gulf of Mexico.

Monitoring Network and Sampling Design

The LTRMP was begun in 1988; field stations were added to the network from 1988 to 1991 (Table 2).

This staggered start is significant when making comparisons among study areas or assessing overall trends

across the system. Limnological monitoring during the first years (1988–91) was limited to fixed sites and

to in situ physical and chemical measurements. The present LTRMP sampling design (implemented in

June 1993) includes both fixed-site (Appendix A) and stratified random sampling (SRS; Appendix B) and

combines in situ field measurements with laboratory analyses of chemical constituents (Appendix C).

 Fixed-site sampling in the present design monitors inflows (tributaries and dam releases) and outflows

from each of the LTRMP study areas. Secondarily, fixed sites are used to monitor locations of special

significance, either because of their long data record or some other feature that makes them notable or

especially interesting. Each LTRMP field station monitors about 15–30 fixed sites biweekly with no attempt

to capture or avoid high or low flows (Appendix A).
8

Table 2. Period of operation for each of the Long Term Resource Monitoring Program field stations.

Field station 1988 1989 1990 1991 1992–1996

Lake City Jan $$ $$$$$$ $$$$$$

Onalaska Jul $$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$

Bellevue Aug $$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$

Pool 26 Jul $$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$

Open River Mar $$ $$$$$$

Havana Sept $$$$ $$$$$$ $$$$$$ $$$$$$

From 1988 to 1993, the LTRMP used 24 aquatic habitat classes (Appendix A) to describe the permanently

fixed monitoring sites. Some of these classes included a seasonally varying attribute (aquatic vegetation) as

part of their definition, and the classes were not mutually exclusive. For example, a site in midchannel

downstream of a dam might be classified as “Main Channel” (MC), “Channel Trough” (CTR), “Open

Tailwater” (TWR-O), or “Tailwater” (TW). This classification scheme was revised in 1993 when vegetation

status was dropped from the habitat designators and those categories that were viewed as redundant or not

distinguishable by routine water quality measurements were eliminated. The revised system has seven habitat

classes (Table A-4), and all previous habitat classifications for fixed sites were converted to this system. The

original designations for all fixed sites are permanently on file at UMESC and at the individual field stations.

As with the six field stations, the period of record differs among individual fixed sites. When the emphasis

of fixed-site sampling shifted to tributaries and other transport monitoring points in 1993, sites were added

and eliminated from the sampling network in each study reach. At the same time, sampling frequency at fixed

sites was reduced from weekly to biweekly (Figure A-2) to keep the overall level of monitoring constant

despite the addition of SRS.

The habitat class associated with each fixed site provides useful ancillary information about the site and

a convenient way to retrieve data from the LTRMP database. However, LTRMP fixed-site data cannot be

used generally to make inferences about these habitat classes because fixed sites were chosen subjectively

and without randomization and represent only specific locations. Although the sampling sites can be grouped

by their habitat categories, the resultant groupings are not unbiased samples of these categories. To overcome

this limitation, the monitoring design was modified in 1993 to include SRS and thus provide unbiased

information about broad spatial areas.

The LTRMP design for both fixed-site sampling and SRS, established in September 1993, requires that

each day's sampling effort be centered on noon (1200 h), central standard time, and that the order of site

visits within each sampling day be randomized to the extent feasible within operational constraints.

The SRS complements the fixed-site design and provides a seasonal assessment of known precision and

confidence on limnological conditions in broad sampling strata in the LTRMP study areas. Limnological data

from SRS are intended to be linked to patterns in fish, vegetation, and invertebrates at the spatial scale of a

whole navigational pool or river reach and at temporal scales ranging from seasons to decades. The SRS data

can be interpreted confidently at these scales of space and time. Higher resolution questions (e.g., short-term

movements or locations of fish, growth dynamics within individual aquatic plant beds) are outside the realm

of routine monitoring as defined by the LTRMP and are not addressed by SRS or fixed-site sampling in the

LTRMP monitoring design. 
9

The SRS is performed in four quarterly episodes each year (Appendix B). In each SRS episode, about

130 sites are randomly selected from six sampling strata and sampling is completed usually within 14 days

(Appendix B). The sampling strata are condensed from the geomorphic aquatic areas of Wilcox (1993) and

are objectively defined in a geographic information system (Owens and Ruhser 1996). Specific sampling

points for each sampling episode are selected by overlaying a square grid with 200-m spacing on a map of

the sampling strata. Grid intersections are randomly selected for each sampling episode. Beginning in spring

1995, a 50-m grid was used for side channel and backwater strata. A smaller grid spacing was deemed

appropriate to the spatially diverse conditions within these strata (i.e., points 50 m apart are likely to be

different); this increases the number of potential sites available for site selection. Although the number of

sites selected was not altered by this change in grid spacing, the number of locations resampled in subsequent

episodes was greatly reduced. The allocation of samples among strata emphasizes off-channel areas and is

not proportional to the surface area of the strata (Appendix B). Data from the strata must be weighted to

obtain accurate poolwide or reachwide estimates, and this weighting must account for the areas of the strata,

the differing grid intervals among the strata, changes to the grid in 1995, and the allocation of sampling effort

(Appendix B).

The sampling strata used by the LTRMP are primarily a statistical tool that allows the spatial allocation

of sampling effort to match differences in desired precision and variability among the strata. An exact

correspondence between sampling strata and the aquatic areas of Wilcox (1993) is not attainable and is not

required by the LTRMP statistical design. The data from a sampling stratum, therefore, should not be

regarded as precisely representing a specific aquatic area type. 

Because the river is dynamic, the borders of the aquatic areas change over time, but the sampling strata

boundaries have been (with minor exceptions) static since their original designation in 1993. Thus, the

aquatic areas are expected to gradually diverge from the sampling strata because of long-term changes in

river morphology. In addition, short-term fluctuations in water level can make sites unusable or atypical of

their parent stratum. The field teams use data comments to report sites that cannot be sampled or seem to be

outside their designated sampling stratum. These comments are extremely valuable for data interpretation

and also give a rough indication of the rate or extent of divergence between the sampling strata and the

aquatic areas. However, field comments lack the spatial intensity and consistency required to track or map

changes in stratum boundaries, and the LTRMP staff intends to track changes in aquatic areas by systemwide

remapping and reclassification of areas at regular (e.g., 10-year) intervals. If future remapping results in new

sampling strata, all sampling locations will have both pre- and postrevision stratum codes assigned. This will

allow analysis for the full period of monitoring to be based on either mapping scheme.

The capacity of the LTRMP analytical laboratory has restricted the number of chemical measurements

performed on SRS samples. Consequently, from 1993 to 1996, SRS has included major plant nutrients,

suspended solids, and phytopigments, but has excluded major cations (sodium, magnesium, calcium,

potassium) and major anions (chloride and sulfate). In situ measurements are made at all SRS sites; to reduce

the laboratory sample load, samples are collected for a full complement of laboratory analyses only in a

randomly selected subset (about half) of sites.

Sample Collection

 The LTRMP limnological monitoring includes measurements at multiple depths (Soballe and Fischer

2003). About 80% of LTRMP measurements from 1993 to 1996 were taken near the water surface (0.0 to

0.20 m); laboratory analyses during this period were performed only on near-surface and near-bottom

samples. The LTRMP sampling for water quality is generally restricted to waters 0.2 m deep or deeper.
10

However, samples are occasionally collected in shallower waters, particularly under ice cover, when this can

be done without disturbing the substrate. Discrete, rather than integrated, samples are collected and analyzed.

Grabs for chemical analyses are taken with either a bucket (near surface) or a Van Dorn sampler (at depth).

When the sampling design was revised in 1993, grab-sampling techniques remained unchanged; however,

individual instruments used to monitor pH, conductivity, temperature, and dissolved oxygen were replaced

by a multiparameter monitoring device used for in situ measurement and recording. The LTRMP Procedures

Manual (Soballe and Fischer 2003) provides additional details.

Ice cover can vary widely in extent and thickness across the study area, complicating sample collection

and the recording of sample information. It is not meaningful, for example, to report limnological conditions

at 0.2 m below the water surface when the ice extends below this depth, nor to report maximum water depth

when ice extends into the substrate. Consequently, when ice is present, LTRMP crews collect near-surface

samples at 0.2 m below the bottom of the ice (where possible). The reported sampling depth in this situation

(0.2 m) must be adjusted for the vertical extent of ice below the water surface (also recorded) to determine

the actual vertical location of the sample in reference to the free water surface. Here we summarize the data

by depth sampling category rather than precise vertical location; the sampling depths have not been adjusted

for the vertical extent of ice below the water surface. In addition, sites that were frozen to the substrate have

been excluded from the summaries of water depth. 

Laboratory Analyses

The LTRMP added a limited suite of laboratory analyses to the limnological monitoring in 1991 and

expanded the list of chemical constituents in 1993 (Appendix C). From 1991 to 1993, samples for chemical

analysis were collected biweekly during the ice-free period; this frequency was reduced to monthly in winter.

Also during this period, chemical analyses were performed at the Waterways Experiment Station (WES)

laboratories at Vicksburg, Mississippi, and the U.S. Army Corps of Engineers Eau Galle laboratory near

Spring Valley, Wisconsin. In 1993, analysis of LTRMP limnological samples was gradually shifted to the

UMESC (Table C-2). 

In late summer and fall 1996, the UMESC analytical laboratory experienced contamination in its total

phosphorus analyses. The problem was eventually identified and eliminated in December 1996; those

analytical results affected by this contamination have been excluded from this report and are identified in

the LTRMP database. The laboratory also experienced ammonia contamination in May 1996, which

invalidated many of the ammonium samples collected in the spring 1996 SRS episode. Those data have also

been excluded from this report. Detailed descriptions of the methods used by the UMESC and WES

laboratories are available on request from the UMESC in La Crosse, Wisconsin.

Quality Assurance and Quality Control Procedures

The value of LTRMP data depends on their quality and reliability. The use of standard methods to assure

and control the quality of the data are thus extremely important. The original LTRMP procedures (Lubinski

and Rasmussen 1988) gave guidance on instrument calibration, record keeping, data management, and

organizational relations. Revisions to the procedures (Soballe and Fischer 2003) provided details on

assessing the accuracy and precision of field measurements and laboratory determinations and also addressed

issues (i.e., daily and seasonal sampling windows, randomization of sampling sites and times) related to the
11

conduct of field work. Guidelines for the time of sampling and randomization of sampling were implemented

in 1993, and compliance with these guidelines is reported here (Appendix D). 

The LTRMP field teams began collecting additional Quality Assurance and Quality Control (QA/QC)

measurements and samples near the end of April 1995 to assess the accuracy and precision of both laboratory

and field measurements. The QA/QC sampling data are readily available

(http://www.umesc.usgs.gov/data_library/water_quality/water_quality_page.html), but not summarized here.

Following the recommendations of APHA (1992), at least 5% of each type of chemical or physical

measurement collected by an LTRMP water quality team is accompanied by a series of QA/QC

measurements, and each sampling crew is required to perform at least one QA/QC series during each day

of field work. The daily crew requirement results in about 15% of all samples being accompanied by QA/QC

measurements, exceeding the APHA recommendation and LTRMP minimum requirement. Because of

logistic constraints, the LTRMP did not use field spikes (additions of known concentrations of chemical

constituents)in 1993–96, but did collect four types of QA/QC samples:

Routine: The regular or routine sample or measurement taken at the site.

Field split: A field sample that is as similar as possible to the routine sample at the point of collection. It is

used to evaluate laboratory precision and variability introduced by field handling or processing.

Field splits are performed for all the constituents listed in Table C-2 that are presently analyzed.

Blank: A sample used to check for contamination of the analytical water supply or sample containers,

or contamination and losses during handling and storage. It is also used to evaluate precision at

concentrations near the detection limit.

Replicate: A second, separate sample taken at the same location and in the same way as the routine, but

separated by an interval of 5–10 minutes. This provides information on natural, random

background variability in ambient conditions.

Results

River Discharge Regime

River discharge (flow) is a major factor in the ecological and limnological structure and functioning of

the UMRS. Flow strongly influences limnological conditions and, thus, the interpretation of the monitoring

data must consider the hydrologic setting (flow regime) under which the data were collected. Because river

discharge is so important, staff of the LTRMP have assembled the Mississippi and Illinois River discharges

and surface elevation data collected by the U.S. Geological Survey and the U.S. Army Corps of Engineers

into a database at the UMESC (Wlosinski et al. 1995). The discharge and water elevation data used in this

report were obtained from that database.

Water levels at the Havana gage (Figure 3) represent the hydrologic regime in La Grange Pool. Flood

stage at this gage is 133.62 m (438.40 feet) above mean sea level. Water levels at this gage fluctuated

substantially above and below the 56-year average during this reporting period and, with the possible

exception of 1994, none of the annual hydrographs resemble the average closely. High discharges during the

flooding of 1993 were less pronounced than on the main stem of the Mississippi River, but the duration of

high water in 1993 was remarkable. Except for two short periods, the river was above the 56-year average
12

for all of 1993. The third highest river elevation on record for Havana, Illinois, was on May 31, 1995, at

137.36 m (450.66 feet), with the highest recorded elevation being 137.62 m (451.50 feet) in 1943. On the

other extreme, 1996 was below the 56-year average except for the two high-water periods in summer. These

patterns have undoubtedly influenced the limnological data.

Figure 3. Water elevation (meters above mean sea level) of the Illinois River at Havana from 1993 through 1996 (solid

line) and the 1940–1996 average annual hydrograph (dashed line). Vertical lines above the horizontal axis indicate dates

of stratified random sampling. Water elevation for flood stage is indicated by the horizontal line.

Fixed-site Sampling

Sample Collection and Field Measurements

The volume of field work completed by each field station is important to document for planning and

budgetary purposes. The schedule of sample collection is also important to report because many of the

limnological characteristics monitored by the LTRMP exhibit regular daily (diel) patterns. The time of

measurement can thus strongly influence the value that is observed and, because the LTRMP strives to

monitor patterns over time across the UMRS, it is important that sampling times be consistent and unbiased

over time, among sampling locations, and among field stations.

In 1993–96, the Havana water quality team made about 1,550 site visits to fixed sampling locations.

During these visits, about 1,150 grab samples were collected for chemical processing (Appendix E). The

number of site visits during each week of sampling was typically 18–22 (Figure D-1 and Table D-1); the
13

redesign in 1993 reduced the weekly number of site visits by more than 50% (Figure D-1) to 13. Although

deviations from the normal fixed-site sampling schedule were rare, they were sometimes required because

of unsafe field conditions or equipment failures (Table D-1).

The field efforts of the Havana water quality team have conformed well to the overall LTRMP sampling

design. The distribution of sampling across the hours of the day (Figures D-2–D-4 ) shows little effect of the

September 1993 change in the fixed-site sampling protocol because the sampling by the Havana water quality

team was already centered on 1200 h. The slight tendency to sample more in the morning than in the

afternoon that was evident in 1993 was corrected when the sampling window was formally defined, and

subsequent years show a symmetrical pattern of sampling times that are centered within 10 minutes of noon.

Although there is no apparent seasonal pattern in fixed-site sampling times by the Havana team, a slight

(about 5 minutes per year), but significant (P < 0.001), downward trend is evident in the time of sample

collection.

The distribution of sites by median sampling times (Figure D-4) also shows good compliance with the

design goals. The sites are distributed tightly around noon with median sampling times at most sites within

30 minutes of 1200 h (Figure D-4).

Fixed-site Sampling Data

Fixed-site sampling by the Havana Field Station staff from 1993 to 1996 has generated a large volume

of data (Appendix E). These data allow comparisons of tributary and main-stem inflows and outflows within

this study area and thus provide information on sources of material such as nutrients and suspended sediment

and the functioning of the study reach as a processor of those materials.

Oxygen solubility in water is a function of temperature and thus dissolved oxygen concentration shows

strong seasonality at all sites. The daily extremes in dissolved oxygen are not revealed by monthly mean

values (Figure E-1), and the LTRMP sampling schedule (centered on noon) does not give a good

representation of extremely low (expected near sunrise) or high (expected in mid- or late afternoon) oxygen

concentrations.

Low dissolved oxygen concentrations in the main channel of the Illinois River were observed during

1993–96, with levels at or below 5 mg/L each year. The lowest observed concentration was 4.0 mg/L

(Table E-1). In 1996, the lowest main channel dissolved oxygen level was 5.1 mg/L (Table E-1). The

dissolved oxygen data suggest little change in concentration from upstream to downstream (Figure E-1a)

within this reach.

Turbidity and suspended solids concentrations are closely linked. The main and side channel sites were

relatively high in turbidity and suspended solids, whereas backwater areas had much lower values.

Tributaries had the highest and most variable values; for example, a turbidity of five nephelometric turbidity

units was seen in the La Moine River (LM07.2M) in summer 1995, and a value of 5,500 nephelometric

turbidity units was observed under the ice in 1996 (Table E-1).

Silica concentrations at fixed sites showed an unexpected pattern; they were lower and somewhat less

variable in the main and side channels (mean = 4.2 mg/L, standard deviation = 1.9) than at backwater and

tributary sites (mean = 2.7 mg/L, standard deviation = 1.2). Also notable were the mean total phosphorus and

soluble reactive phosphorus concentrations; both constituents were higher at the main and side channel sites

(total phosphorus = 0.33 mg/L, soluble reactive phosphorus = 0.14 mg/L) than in the tributaries and
14

backwaters (total phosphorus = 0.23 mg/L, soluble reactive phosphorus = 0.05 mg/L). However, the

Sangamon River (SG16.2C) was a notable exception, with elevated mean concentrations of total phosphorus

(0.38 mg/L) and soluble reactive phosphorus (0.12 mg/L) that were about the same as in the main and side

channels.

Stratified Random Sampling

Sample Collection and Field Measurements

As in fixed-site sampling, the number and frequency of samples collected and the scheduling of sample

collection in SRS is important for planning and data interpretation. Sample collection in SRS must be

consistent and unbiased over time, within each sampling episode, across sampling strata, and among LTRMP

field stations. The partitioning of effort among strata within each SRS episode (Table B-1) reflects an

emphasis on off-channel areas and a recognition that these areas are probably more spatially variable than

the main channel.

During 1993–96, Havana Field Station personnel participated in 14 SRS episodes. In these 14 episodes,

the field team visited about 1,800 sites (Appendix B) and collected about 1,500 grab samples for chemical

analyses. All of these samples were analyzed for chlorophyll and suspended solids; however, in accord with

the design for SRS, only about two-thirds (900) were also analyzed for nitrogen and phosphorus species.

The total number of sites sampled in each episode and stratum was relatively uniform across the period

of record (Table B-2). In five SRS episodes, fewer sites than normal were sampled because of environmental

factors. Extremely low water reduced the number of sites sampled during three of the four fall SRS episodes

(1994, 1995, and 1996), with unsafe ice conditions reducing the number of sites sampled during two of the

three winter SRS episodes (1994 and 1996).

The SRS sampling by the Havana field team has conformed to the general LTRMP design, although some

minor adjustments are needed. The distribution of SRS times across the period of record (Figure D-5) shows

no consistent seasonal pattern and no significant linear trend in sampling times over the years (P > 0.20)

except in backwaters. In this stratum, the time of sample collection tends to be slightly earlier (4–5 minutes)

in each successive episode. This trend can be distinguished statistically (P < 0.001) from a constant sampling

time. A tendency to conduct SRS more in the afternoon than in the morning is also evident.

Stratified Random Sampling Data

The SRS provides an unbiased estimate of conditions within each sampling stratum during each of four

quarterly episodes per year. Seasonality, interannual variations, and long-term trends within each stratum can

be assessed with summaries of these data (Appendix F); however, some of the most valuable applications

for these data require analyses that are beyond the scope of this report. For example, the SRS provides

statistically valid estimates of the extent or frequency of limnological conditions in combination (e.g., to meet

the temperature, dissolved oxygen, and velocity requirements of overwintering fish), this information is being

used to address changing relations among limnological variables over time, differences among the sampling

strata, and habitat availability and suitability in the Upper Mississippi River ecosystem (Fischer et al. 1997;

Soballe et al. 1997).
15

The data collected by the Havana field team in SRS reveal long-term patterns in this reach of the Illinois

River and document significant differences in concentrations and year-to-year variability among the sampling

strata (aquatic areas).

Spring and summer 1993 was a period of record flooding along the main stem of the Mississippi River

and many of its tributaries. Although 1993 was a high-water year in the Illinois River, more flooding in the

La Grange reach was even more pronounced 2 years later (spring 1995). These events undoubtedly

influenced the water quality data collected during SRS, but immediate effects are not obvious in the data

summaries and analyses beyond the scope of this summary report are needed to adequately address the

influence of these events on water quality in the La Grange reach.

Compared with main and side channels, backwater areas show greater variation in almost every parameter,

especially dissolved oxygen, Secchi transparency, total nitrogen, ammonia, and chlorophyll. (Figures F-2,

F-5, F-8, F-10, and F-13). The main channel shows the least variation except for seasonal changes.

The SRS data show strong seasonal maxima in temperature and dissolved oxygen (Figure F-2). Summer

and fall oxygen levels have been markedly low. In 1994 and 1995 summer SRS episodes, dissolved oxygen

readings just above 5 mg/L were recorded. In summer and fall 1996 episodes, main channel dissolved oxygen

fell below 5 mg/L (4.6 and 4.9 mg/L, respectively; Table F-1).

The extreme peak of ammonium nitrogen in the winter episode of 1996 in the main and side channels

(Figure F-10) remains unexplained. However, high values of ammonium are common in winter, checking

of the QA/QC samples and analytical laboratory records gives no reason to doubt these values. A similar

peak is reported in the analytical data from all six LTRMP monitoring stations.

Summary and Recommendations

In this report, we document 4 years of LTRMP monitoring by the staff of the field station at Havana,

Illinois, and provide basic graphic and tabular summaries of the collected data. The Havana Field Station

staff completed about 1,550 visits to fixed sampling sites and 1,800 visits to stratified random sites from

1993 through 1996. This period was marked by several important events, including the redesign of the

monitoring network and the updating of field equipment in 1993, and record flooding in spring and summer

1993 and 1995.

Detailed analysis of the LTRMP monitoring data can reveal a wealth of information on the condition and

ecological functioning of this river reach and its tributaries over time. The general data summaries included

here demonstrate that this reach of the Illinois River is turbid, has very high concentrations of plant nutrients

and suspended solids, and may occasionally experience low dissolved oxygen (<5 mg/L).

References

American Public Health Association, American Water Works Association, and Water Environment

Federation (APHA). 1992. Standard methods for the examination of water and wastewater. 18th edition,

American Public Health Association, Washington, D.C. 981 pp. + 6 plates

Demissie, M., L. Keefer, and R. Xia. 1992. Erosion and sedimentation in the Illinois River basin. Illinois

State Water Survey Contract Report ILENR/RE-WR-92/04. 112 pp.
16

Fischer, J. R., D. M. Soballe, and J. T. Rogala. 1997. Factors affecting fish habitat during periods of ice

cover on the Upper Mississippi River. Fifty-ninth annual Midwest Fish and Wildlife Conference,

Milwaukee, Wisconsin, December 6–10, 1997.

Illinois State Water Survey. 1998. Illinois State Water Survey Annual Report, July 1, 1997–June 30, 1998

Illinois State Water Survey, Champaign, Illinois.

Jackson, G. A., C. E. Korschgen, P. A. Thiel, J. M. Besser, D. W. Steffeck, and M. H. Bockenhauer. 1981.

A long-term resource monitoring plan for the Upper Mississippi River System. Volume 1.

Upper Mississippi River Basin Commission, Bloomington, Minnesota. 384 pp. 

Lubinski, K. S., and J. L. Rasmussen. 1988. Procedures manual of the Long Term Resource Monitoring

Program for the Upper Mississippi River System. U.S. Fish and Wildlife Service, Environmental

Management Technical Center, Onalaska, Wisconsin. EMTC 88-03. 216 pp. (NTIS # 94-14885)

Owens, T., and J. J. Ruhser. 1996. Long Term Resource Monitoring Program standard operating procedures:

Aquatic areas database production. National Biological Service, Environmental Management Technical

Center, Onalaska, Wisconsin, March 1996. LTRMP 95-P008-6. 4 pp. + Appendix (NTIS #PB96-172267)

Soballe, D. M., and J. Fischer. 2003. Long Term Resource Monitoring Program procedures: Water quality

monitoring. U.S. Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse,

Wisconsin. In press.

Soballe, D. M., J. T. Rogala, and J. R. Fischer. 1997. Finding suitable winter habitat for fish in shallow

impoundments of the Upper Mississippi River. Seventeenth Annual Symposium of the North American

Lake Management Society, Houston, Texas, December 2–6, 1997.

U.S. Fish and Wildlife Service. 1993. Operating Plan for the Upper Mississippi River System Long Term

Resource Monitoring Program. Environmental Management Technical Center, Onalaska, Wisconsin,

Revised September 1993. EMTC 91-P002R. 179 pp. (NTIS #PB94-160199)

Vannote, R. L., G. W. Minshall, K. W. Cummins, J. R. Sedell, and C. E. Cushing. 1980. The river continuum

concept. Canadian Journal of Fisheries and Aquatic Sciences 37:130–137.

Wilcox, D. B. 1993. An aquatic habitat classification system for the Upper Mississippi River System.

U.S. Fish and Wildlife Service, Environmental Management Technical Center, Onalaska, Wisconsin,

May 1993. EMTC 93-T003. 9 pp. + Appendix A (NTIS #PB93-208981)

Wlosinski, J. H., D. E. Hansen, and S. R. Hagedorn. 1995. Long Term Resource Monitoring Program

procedures: Water surface elevation and discharge. National Biological Service, Environmental

Management Technical Center, Onalaska, Wisconsin, August 1995. LTRMP 95-P002-4.

9 pp. + Appendixes A–O
A-1

Appendix A. Fixed-site Sampling Sites: January 1993–December 1996

In Appendix A, we provide information on the sample collection sites used from January 1993 through

December 1996. In some instances, sites not used during this period have been included for reference. The

site description tables provide additional information on the locations and are keyed to the site map. The sites

lists are provided in three formats to allow easy cross-referencing: (1) by map identifier (north–south, then

east–west), (2) in alphabetical order, and (3) by habitat class. The period of record for each site is also

portrayed graphically (Figure A-5) so that the duration of and interruptions in the record can be easily

visualized.

Location codes (seven characters) used for routine fixed-site sampling are based on the distance upstream

from the river mouth or major confluence (river miles and tenths) and on the relative left-to-right (facing

upstream) location of the site between the horizontal limits of the geological–historical floodplain. Sites on

the Mississippi and Illinois River main stems use a single-letter prefix (M or I, respectively), whereas

tributaries and Missouri River sites use a two-letter prefix (Table A-5). The left-to-right location of a site is

indicated by a suffix between A and Z. When tributary sites are sampled in midstream, they are assigned the

suffix M without regard to position in the floodplain. Locations near the left or right bank (facing upstream)

are indicated with an A or Z, respectively.

Habitat classes (Table A-4) are assigned to all Long Term Resource Monitoring Program sampling

locations used in fixed-site monitoring. Although these classes convey significant information about the site,

the fixed sites are subjectively chosen and cannot be assumed to represent the associated habitat classes (see

stratified random sampling, Appendix B).
A-2

Table A-1. Long Term Resource Monitoring Program fixed-site water quality sampling locations keyed to map codes with

associated period of record from 1993 through 1996, habitat class, Universal Transverse Mercator (UTM) Coordinates

(zone 15, meters), and the number of sampling visits to the site.

Location

code

Map

identification Period of record

Habitat

classa

UTM

Site visits

Easting Northing 1993–1996

I157.8D 1 04/28/93–12/30/96 MC 783249 4501489 94

MK04.4M 2 04/26/93–12/30/96 TRIB 776765 4491575 97

I135.8W 3 10/19/89–04/15/93 BWI 764092 4483187 15

I135.8X 4 10/19/89–04/15/93 BWI 764206 4482995 15

I129.8W 5 07/01/91–05/25/93 BWI 757518 4475007 16

I128.8F 6 08/28/90–05/25/93 SC 755668 4474868 16

I128.8T 7 09/05/89–05/25/93 BWI 756326 4474258 16

I127.9W 8 04/25/90–05/25/93 BWI 755714 4473468 16

I124.8R 9 04/25/90–05/25/93 BWI 751508 4471935 16

I122.5X 10 09/01/89–04/13/93 BWC 750637 4468394 15

I122.6Y 11 09/01/89–12/30/96 BWC 750707 4468389 111

QV04.6M 12 04/26/93–12/30/96 TRIB 758620 4468071 97

I121.5X 13 09/01/89–04/13/93 SC 749599 4466910 15

I121.2W 14 09/01/89–12/30/96 MC 749108 4466765 112

S000.2K 15 12/05/90–12/30/96 TRIB 748649 4465581 112

I113.0T 16 09/06/89–12/30/96 SC 743376 4455335 111

I109.5D 17 09/12/89–12/31/96 BWI 738629 4453509 85

I107.2R 18 09/06/89–04/12/93 MC 738242 4448885 15

I107.0S 19 09/06/89–04/12/93 SC 738347 4448554 15

I106.8X 20 10/30/89–04/12/93 BWC 739451 4447933 15

I106.5X 21 09/06/89–04/12/93 BWC 739042 4447352 15

I106.5Y 22 09/06/89–04/12/93 BWC 739082 4447313 15

I099.4C 23 09/06/89–04/12/93 BWC 727389 4445489 15

I099.4D 24 09/06/89–04/12/93 BWC 727389 4445436 15

I098.0C 25 09/06/89–04/12/93 BWC 725466 4444200 15

I095.2C 26 09/06/89–04/12/93 MC 722628 4441535 15

I094.8D 27 09/06/89–04/12/93 SC 722694 4441126 15

SG16.2C 28 04/10/92–12/31/96 TRIB 743373 4438599 112

LM00.5M 29 09/24/93–12/31/96 TRIB 711723 4429191 82

LM07.2M 30 01/20/94–12/31/96 TRIB 707351 4428445 78

I080.2C 31 01/20/94–12/31/96 MC 710613 4423724 78

I080.2M 32 04/28/93–12/31/96 MC 710757 4423711 93

a

See Table A-4 for habitat class descriptions.
A-3

Table A-2. Long Term Resource Monitoring Program fixed-site water quality sampling sites sorted by location code with

associated period of record from 1993 through 1996, habitat class, Universal Transverse Mercator (UTM) Coordinates

(zone 15, meters), and number of sampling visits to the site.

Location

code

Map

identification Period of record

Habitat

classa

UTM

Site visits

Easting Northing 1993–1996

I080.2C 31 01/20/94–12/31/96 MC 710613 4423724 78

I080.2M 32 04/28/93–12/31/96 MC 710757 4423711 93

I094.8D 27 09/06/89–04/12/93 SC 722694 4441126 15

I095.2C 26 09/06/89–04/12/93 MC 722628 4441535 15

I098.0C 25 09/06/89–04/12/93 BWC 725466 4444200 15

I099.4C 23 09/06/89–04/12/93 BWC 727389 4445489 15

I099.4D 24 09/06/89–04/12/93 BWC 727389 4445436 15

I106.5X 21 09/06/89–04/12/93 BWC 739042 4447352 15

I106.5Y 22 09/06/89–04/12/93 BWC 739082 4447313 15

I106.8X 20 10/30/89–04/12/93 BWC 739451 4447933 15

I107.0S 19 09/06/89–04/12/93 SC 738347 4448554 15

I107.2R 18 09/06/89–04/12/93 MC 738242 4448885 15

I109.5D 17 09/12/89–12/31/96 BWI 738629 4453509 85

I113.0T 16 09/06/89–12/30/96 SC 743376 4455335 111

I121.2W 14 09/01/89–12/30/96 MC 749108 4466765 112

I121.5X 13 09/01/89–04/13/93 SC 749599 4466910 15

I122.5X 10 09/01/89–04/13/93 BWC 750637 4468394 15

I122.6Y 11 09/01/89–12/30/96 BWC 750707 4468389 111

I124.8R 9 04/25/90–05/25/93 BWI 751508 4471935 16

I127.9W 8 04/25/90–05/25/93 BWI 755714 4473468 16

I128.8F 6 08/28/90–05/25/93 SC 755668 4474868 16

I128.8T 7 09/05/89–05/25/93 BWI 756326 4474258 16

I129.8W 5 07/01/91–05/25/93 BWI 757518 4475007 16

I135.8W 3 10/19/89–04/15/93 BWI 764092 4483187 15

I135.8X 4 10/19/89–04/15/93 BWI 764206 4482995 15

I157.8D 1 04/28/93–12/30/96 MC 783249 4501489 94

LM00.5M 29 09/24/93–12/31/96 TRIB 711723 4429191 82

LM07.2M 30 01/20/94–12/31/96 TRIB 707351 4428445 78

MK04.4M 2 04/26/93–12/30/96 TRIB 776765 4491575 97

QV04.6M 12 04/26/93–12/30/96 TRIB 758620 4468071 97

S000.2K 15 12/05/90–12/30/96 TRIB 748649 4465581 112

SG16.2C 28 04/10/92–12/31/96 TRIB 743373 4438599 112

a

See Table A-4 for habitat class descriptions.
A-4

Table A-3. Long Term Resource Monitoring Program fixed-site water quality sampling locations sorted by habitat class

with associated period of record from 1993 through 1996, habitat class, Universal Transverse Mercator (UTM)

Coordinates (zone 15, meters), and number of sampling visits to the site.

Location

code

Map

identification Period of record

Habitat

classa

UTM

Site visits

Easting Northing 1993–1996

I098.0C 25 09/06/89–04/12/93 BWC 725466 4444200 15

I099.4C 23 09/06/89–04/12/93 BWC 727389 4445489 15

I099.4D 24 09/06/89–04/12/93 BWC 727389 4445436 15

I106.5X 21 09/06/89–04/12/93 BWC 739042 4447352 15

I106.5Y 22 09/06/89–04/12/93 BWC 739082 4447313 15

I106.8X 20 10/30/89–04/12/93 BWC 739451 4447933 15

I122.5X 10 09/01/89–04/13/93 BWC 750637 4468394 15

I122.6Y 11 09/01/89–12/30/96 BWC 750707 4468389 111

I109.5D 17 09/12/89–12/31/96 BWI 738629 4453509 85

I124.8R 9 04/25/90–05/25/93 BWI 751508 4471935 16

I127.9W 8 04/25/90–05/25/93 BWI 755714 4473468 16

I128.8T 7 09/05/89–05/25/93 BWI 756326 4474258 16

I129.8W 5 07/01/91–05/25/93 BWI 757518 4475007 16

I135.8W 3 10/19/89–04/15/93 BWI 764092 4483187 15

I135.8X 4 10/19/89–04/15/93 BWI 764206 4482995 15

I080.2C 31 01/20/94–12/31/96 MC 710613 4423724 78

I080.2M 32 04/28/93–12/31/96 MC 710757 4423711 93

I095.2C 26 09/06/89–04/12/93 MC 722628 4441535 15

I107.2R 18 09/06/89–04/12/93 MC 738242 4448885 15

I121.2W 14 09/01/89–12/30/96 MC 749108 4466765 112

I157.8D 1 04/28/93–12/30/96 MC 783249 4501489 94

I094.8D 27 09/06/89–04/12/93 SC 722694 4441126 15

I107.0S 19 09/06/89–04/12/93 SC 738347 4448554 15

I113.0T 16 09/06/89–12/30/96 SC 743376 4455335 111

I121.5X 13 09/01/89–04/13/93 SC 749599 4466910 15

I128.8F 6 08/28/90–05/25/93 SC 755668 4474868 16

LM00.5M 29 09/24/93–12/31/96 TRIB 711723 4429191 82

LM07.2M 30 01/20/94–12/31/96 TRIB 707351 4428445 78

MK04.4M 2 04/26/93–12/30/96 TRIB 776765 4491575 97

QV04.6M 12 04/26/93–12/30/96 TRIB 758620 4468071 97

S000.2K 15 12/05/90–12/30/96 TRIB 748649 4465581 112

SG16.2C 28 04/10/92–12/31/96 TRIB 743373 4438599 112

a

See Table A-4 for habitat class descriptions.
A-5

Table A-4. Habitat classes used in fixed-site water quality sampling. Previous habitat classes refer to categories used

from 1988 through 1993 and are now combined within each of the present habitat classes.

Present

habitat class

designator Previous habitat designators included in present class Habitat class description

BWC BWC, BWC-O, BWC-V Contiguous backwaters

BWI BWI, BWI-O, BWI-V Isolated backwaters

SC SC, SCB, SCT, SCU Side channels

IMP IMP-O, IMP-V Impounded areas

IMP-L IMP-L Lakes—Swan or Pepin

MC MC, CTR, CBU, CBW, TW, TWB, TWBU, TWR-O, TWW Main channel

TRIB TRIB, TRM Tributary

Table A-5. Abbreviations used to designate fixed-site sampling locations in the Long Term Resource Monitoring

Program. Not all streams in this list have been sampled by the Long Term Resource Monitoring Program. The Mackinaw,

Spoon, and Sangamon Rivers are all tributaries to the Illinois River. Each site identifier includes the distance (in miles)

above the tributary mouth (xx.x) and the relative location (A–Z) of the sampling site between the left and right (facing

upstream) limits of the floodplain.

Site identifier Tributary name

APxx.xM Apple River, Missouri

ALxx.xM Apple River, Illinois

BCxx.xM Bob's Creek, Missouri

BFxx.xM Buffalo River, Wisconsin

BKxx.xM Black River, Wisconsin

BMxx.xM Big Muddy River, Illinois 

BXxx.xM Bad Axe River, Wisconsin

CAxx.xM Cahokia Creek, Illinois

CCxx.xM Coon Creek, Wisconsin

CFxx.xM Catfish Creek, Iowa

CHxx.xM Chippewa River, Wisconsin

CNxx.xM Cannon River, Minnesota

CRxx.xM Cache River, Illinois

CUxx.xM Cuivre River, Missouri

DCxx.xM Dardenne Creek, Missouri

DMxx.xM Des Moines River, Iowa

ERxx.xM Elk River, Iowa

HDxx.xM Headwaters Diversion, Missouri (formerly Little River, LRxx.xM)

Ixxx.xZ Illinois River, Illinois

IWxx.xM Iowa River, Iowa

LMxx.xM LaMoines River, Illinois

LRxx.xM Little River, Missouri (now Headwaters Diversion, HDxx.xM)
Table A-5. Continued.

Site identifier Tributary name

A-6

LXxx.xM La Crosse River, Wisconsin

Mxxx.xZ Mississippi River (main stem) 

MCxx.xM Mill Creek, Iowa

MKxx.xM Mackinaw River, Illinois

MOxx.xM Missouri River, Missouri

MQxx.xM Maquoketa River, Iowa

PExx.xM Peruque Creek, Missouri 

PIxx.xM Piasa Creek, Illinois

PRxx.xM Plum River, Illinois

QVxx.xM Quiver Creek, Illinois

Rxxx.xM Root River, Minnesota

RCxx.xM Rush Creek, Illinois

Sxxx.xM Spoon River, Illinois

SGxx.xM Sangamon River, Illinois

SKxx.xM Skunk River, Iowa 

SXxx.xM St. Croix River, Minnesota/Wisconsin

UIxx.xM Upper Iowa River, Iowa

VMxx.xM Vermillion River, Minnesota

WDxx.xM Wood River, Illinois

WPxx.xM Wapsipinicon River, Iowa

WSxx.xM Wisconsin River, Wisconsin

WWxx.xM Whitewater River, Minnesota

YLxx.xM Yellow River, Iowa

ZMxx.xM Zumbro River, Minnesota
A-7

Figure A-1. Fixed-site sampling locations in the Havana study area.
A-8

Figure A-2. Sampling dates from January 1993 through December 1996 at each of the fixed sites monitored by the

Havana Field Station.
B-1

Appendix B. Stratified Random Sampling Sites: January 1993–December 1996

Randomly selected sites are used in stratified random sampling (SRS) to provide an unbiased

representation of sampling strata (and entire study areas) within each Long Term Resource Monitoring

Program study reach. Individual sites are generally not resampled in subsequent SRS episodes. Information

from an individual site is not intended to be interpreted in isolation, as it is only a single random

measurement from all the locations within a stratum during a specific episode. When pooled together,

multiple measurements (sites) from each stratum provide a statistically reliable sample of the episode and

the study reach.

Unlike the fixed-site location maps (Appendix A), the maps provided for SRS do not show the individual

sampling locations, but rather the sampling strata within the reach. This approach allows a legible portrayal

and deemphasizes the individual identities of SRS locations.

The tables in Appendix B show the allocation of sampling effort across the sampling strata and across the

14 SRS episodes within the 1993–96 period.

Table B-1a. Sampling strata and design allocation of sampling effort for water quality stratified random sampling in the

vicinity of the Havana Field Station. Total area of the study reach is greater than the total area included within the

sampling strata due to inaccessible areas that are excluded from sampling.

Sampling

stratum

Area within

the stratum

(ha)

Fraction of

study area

within the

stratum

 (%)

Number of

potential

sampling sites

in the stratumb

Number of

sites

assigned

Fraction of

stratum

sampled

(%)

Fraction

of total

effort 

(%)

Main channel 2,492 22 623 35 5.6 26

Side channel 140 1 558 20 3.6 15

Backwater 1,049 9 4,197 80 1.9 59

Lake 0 0 0 0 0.0 0

Impounded 0 0 0 0 0.0 0

Isolated 0 0 0 0 0.0 0

Totalc 11,535 32 5,378 135 2.5 100

a

Table B-1 was corrected on April 15, 2003.

b

Total potential sites reflect a 200-m grid in most strata but a 50-m grid in side channels and backwaters.

CTotal area refers to the entire pool or study reach and is greater than the sum of areas within the sampling strata.
B-2

Table B-2. Sampling dates and sampling activity of the Havana Field Station in each stratified random sampling episode

from 1993 through 1996.

Sampling period Number of samples collected/sites visited

Episode

Start

date

End

date Total

Main

channel

Side

channel

Contiguous

backwater Lake Impoundment Isolated

Summer 93 07/12/93 07/21/93 227/130 36/35 41/20 150/75 — — —

Fall 93 10/18/93 10/28/93 233/134 35/35 40/20 158/79 — — —

Winter 94 01/24/94 02/26/94 166/98 20/19 40/20 106/59 — — —

Spring 94 04/25/94 05/04/94 230/132 36/35 40/20 154/77 — — —

Summer 94 07/25/94 08/01/94 164/120 35/35 36/20 93/65 — — —

Fall 94 10/11/94 10/19/94 111/89 36/35 29/18 46/36 — — —

Winter 95 01/31/95 02/10/95 211/122 30/30 39/20 142/72 — — —

Spring 95 04/25/95 05/04/95 233/135 35/35 39/20 159/80 — — —

Summer 95 07/24/95 07/28/95 176/133 35/35 33/20 108/78 — — —

Fall 95 10/10/95 10/18/95 134/97 35/35 32/19 67/43 — — —

Winter 96 01/30/96 02/15/96 111/83 23/23 30/17 58/43 — — —

Spring 96 04/22/96 05/07/96 183/134 35/35 38/20 110/79 — — —

Summer 96 07/22/96 07/31/96 233/135 35/35 36/20 162/80 — — —
B-3

Figure B-1. Long Term Resource Monitoring Program sampling strata used in water quality stratified random sampling

in the vicinity of the Havana Field Station.
C-1

Appendix C. Limnological Parameters Measured in the

Long Term Resource Monitoring Program

Table C-1. Period of record for limnological measurements (laboratory and in situ) performed by Long Term Resource

Monitoring Program field teams from 1988 through 1996.

Parameter 1988 1989 1990 1991 1992 1993–1996

Water temperature $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$

Dissolved oxygen $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$

Conductivity $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$

pH June $ $$$$$$ $$$$$$

Turbidity $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$

Secchi depth $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$

Total suspended solids $$$$$$ $$$$$$ $$$$$$

Volatile suspended solids $$$$$$ $$$$$$ $$$$$$

Chlorophyll a June $ $$$$$$ $$$$$$

Total phosphorus June $ $$$$$$ $$$$$$

Soluble reactive phosphorus June $ $$$$$$ $$$$$$

Total soluble phosphorus June $ $$$$$$ $$ Apr 93

Total nitrogen June $ $$$$$$ $$$$$$

Total soluble nitrogen June $ $$$$$$ $$ Apr 93

NOx (nitrate–nitrite) June $ $$$$$$ $$$$$$

NHx (ammonium) June $ $$$$$$ $$$$$$

Si (silicate) June $ $$$$$$ $$$$$$

Cl (chloride) June $ $$$$$$ $$$$$$

Ca (calcium) June $ $$$$$$ $$$$$$

Mg (magnesium) June $ $$$$$$ $$$$$$

Na (sodium) June $ $$$$$$ $$$$$$

K (potassium) June $ $$$$$$ $$$$$$

Fe (iron) June $ $$$$$$ $$ Feb 93

Mn (manganese) June $ $$$$$$ $$ Feb 93

Ice and snow $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$

Water depth $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$

Water velocity $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$
C-2

Table C-2. Laboratory measurements performed on limnological samples from 1988 through 1996. Each laboratory

processed samples or parameters between the dates listed. The precision of result reporting is shown in parentheses.

Analytical techniques are described in the procedures manuals for the Waterways Experiment Station (WES)

Environmental Laboratories and by the American Public Health Association et al. (1992).

Parameter and method

Laboratory

WES–Vicksburg WES–Eau Galle UMESCa

Total suspended solids:

Gravimetric/105° C

— June 91–June 93

(1 :g/L)

June 93–Present

(1 :g/L)

Volatile suspended solids:

Gravimetric/550° C

— June 91–June 93

(1 :g/L)

June 93–Present

(1 :g/L)

Chlorophyll a: FluorometricDMSO-acetone extraction

— — June 93–Present

(1 :g/L)

Chlorophyll a:

Spectrophotometric 90% acetone

extraction

— June 91–June 93

(1 :g/L)

June 93–Present

(1 :g/L)

Total phosphorus: Automated/

persulfate/ascorbic acid

— June 91–Jan. 94

(1 :g/L)

Jan. 94–Present

(1 :g/L)

Soluble reactive phosphorus

(H): Automated/ H2SO4

preservation, ascorbic acid

June 91–Dec. 93

(1 :g/L)

— —

Soluble reactive phosphorus:

Automated /frozen/ascorbic acid

Jan. 94–Feb. 94

(1 :g/L)

— Feb. 94–Present

(1 :g/L)

Total soluble phosphorus:

Automated/persulfate/ascorbic

acid

— June 91–Apr. 93

(1 :g/L)

—

Total nitrogen:

Automated/Devarda's alloy

— June 91–Jan. 94

(0.01 mg/L)

Jan. 94–Present

(0.01 mg/L)

Total soluble nitrogen:

Automated/Devarda's alloy

— June 91–Apr. 93

(0.01 mg/L)

–

Nitrate–nitrite nitrogen:

Automated Cd reduction, ion

chromatography 

June 91–Apr. 94

Automated Cd

Reduction

(0.01 mg/L)

— Apr.–June 94: 

Cd reduction 

June 94–Present:

Ion C.

(0.01 mg/L)

NHx: Automated salicylate June 91–Feb. 94

(1 :g/L)

— Feb. 94–Present

(1 :g/L)

Dissolved silicate silica:

Automated/molybdate

June 91–Feb. 94

(0.01 mg/L)

— Mar. 94–Present

(0.01 mg/L)

SO4: Ion chromatography — — Jan. 94–Present

(0.1 mg/L)

Dissolved chloride: Automated

ferro-cyanide, ion

chromatography

June 91–June 94:

Automated FeCN

 (0.1 mg/L)

— June 94–Present: 

IC

(0.1 mg/L)

Dissolved calcium: Ion

chromatography

— — Jan. 94–Present

(0.1 mg/L)

Dissolved calcium: Atomic

absorption

June 91–Oct. 93

(0.1 mg/L)

— Oct. 93–Jan. 94

(0.1 mg/L)
Table C-2. Continued.

Parameter and method

Laboratory

WES–Vicksburg WES–Eau Galle UMESCa

C-3

Dissolved magnesium: Ion

chromatography

Jan 94–Present

(0.1 mg/L)

Dissolved sodium: Ion

chromatography

Jan. 94–Present

(0.1 mg/L)

Dissolved potassium: Atomic

absorption

June 91–Oct. 93

(0.1 mg/L)

— Oct. 93–Present

(0.1 mg/L)

Dissolved iron: Atomic

absorption

June 91–Apr. 93

(0.01 mg/L)

— —

Dissolved manganese: Atomic

absorption

June 91–Apr. 93

(0.01 mg/L)

— —

a

Upper Midwest Environmental Sciences Center
D-1

Appendix D. Water Quality Sample Collection

Details of sample collection are important to ensure that field activities comply with the monitoring design

and are producing unbiased results. The figures in Appendix D focus on site visits and sample collection

times. Consistent differences in sampling times among sites, over time, or among field stations can introduce

serious bias into measurements influenced by daily cycles (e.g., temperature and dissolved oxygen). Gaps

in the data record can also have important ramifications for data interpretation and are therefore documented

here.

Table D-1. Fixed-site sampling visit exceptions from 1993 through 1996 at the Havana Field Station. Table entries are

keyed to numbered points on Figure D-1.

Figure

code

Begin

date

Site 

visits Comment

 1 01/08/93 25 Weekly sampling of 25 sites before network redesign 

 2 01/15/93 25 Weekly sampling of 25 sites before network redesign

 3 01/22/93 25 Weekly sampling of 25 sites before network redesign

 4 01/29/93 25 Weekly sampling of 25 sites before network redesign

 5 02/05/93 25 Weekly sampling of 25 sites before network redesign

 6 02/12/93 25 Weekly sampling of 25 sites before network redesign

 7 02/19/93 25 Weekly sampling of 25 sites before network redesign

 8 02/26/93 25 Weekly sampling of 25 sites before network redesign

 9 03/05/93 25 Weekly sampling of 25 sites before network redesign

10 03/12/93 25 Weekly sampling of 25 sites before network redesign

11 03/19/93 25 Weekly sampling of 25 sites before network redesign

12 03/26/93 25 Weekly sampling of 25 sites before network redesign

13 04/02/93 25 Weekly sampling of 25 sites before network redesign

14 04/09/93 25 Weekly sampling of 25 sites before network redesign

15 04/16/93 25 Weekly sampling of 25 sites before network redesign

16 10/04/93 0 Schedule shifted to alternate week

17 02/10/95 1 Unsafe ice conditions
D-2

Figure D-1. Number of weekly fixed-site visits from January 1993 through December 1996 by the Havana Field Station.

Numbered points are weeks that differ by more than one standard deviation from the mean site visits per week and are

described in Table D-1. 
D-3

Figure D-2. Distribution of sample collection times at fixed sites from 1993 through 1996. Each bar is labeled with the

number of site visits within each hourly interval.
D-4

Figure D-3. Trend in fixed-site sample collection times by quarter, from 1993 through 1996. The midpoint (median) for

each quarter is joined by a solid line. The box extending above and below the median denotes the 90th and 10th

percentiles, respectively. The vertical line extends above and below the box to the maximum and minimum values for

the quarter.
D-5

Figure D-4. Distribution of fixed sites by median sampling time at each site from 1993 through 1996.
D-6

Figure D-5. Water quality sample collection times in each sampling stratum during each episode of stratified random

sampling from 1993 through 1996. The midpoints (median) of the episodes are joined by a solid line. The box extending

above and below the median denotes the 90th and 10th percentiles, respectively. The vertical line extends above and

below each box to the maximum and minimum values for the episode.
E-1

Appendix E. Fixed-site Sampling Data: January 1993–December 1996

In Appendix E, we summarize the fixed-site monitoring data in both tabular and graphic forms. The tables

contain annual statistics for each fixed site divided into two parameter groups: (1) physical and biological

measurements (Table E-1), and (2) chemical data (major anions, cations, and plant nutrients; Table E-2).

Within each parameter group, the data are divided by sampling depth into three groups (surface, middepth,

and bottom). Chemical measurements are typically collected only at the surface and near the bottom. The

majority of all measurement are in the near-surface category. Refer to Appendix A for descriptions and

locations of the individual sampling sites. Sites with less than five visits during the 1993–96 period are

excluded from these summaries.

The figures (E-1 and E-2) of the fixed-site data are in two formats. For sampling on the Mississippi (or

Illinois) River main stems, the figures generally include separate plots of monthly means from main channel

and impounded sites near the upstream and downstream ends of the reach or pool (where available). For

tributary sampling, only a single plot is provided. Unlike the summary tables, these figures combine data

from all sampling depths.

Data that have been flagged as questionable in the Long Term Resource Monitoring Program database

are excluded from this summary. Values that are below detection are indicated by the detection limit

preceded by a negative sign. Below-detection values are included in the determination of minima, maxima,

and medians, but in the calculation of means and standard deviations, values below detection have been

replaced by a value equal to half the detection limit. The Secchi transparency data in this report do not

include observations where Secchi transparency exceeded the water column depth. High transparency

conditions are thus underrepresented.
 E-2

Table E-1. Annual summaries (1993–1996) of physical measurements at fixed sites grouped into four categories: (1) near-surface (less th

surface), (2) middepth, (3) near bottom (less than or equal to 0.2 m above the substrate), and (4) miscellaneous depths.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1993 Near-surface measurements: 

I080.2M Mean 0.2 7.33 1.11 — — — — 17.9 7.79 79 550 8.2 30.4 59 74.4  Median 0.2 7.15 1.11 — — — — 20.2 7.45 78 563 8.2 31 40 54.2  Minimum 0.2 5.8 1.11 — — — — 4 4.3 52 422 6.1 11 21 17.9  Maximum 0.2 9.1 1.11 — — — — 27 12.6 121 649 9.5 50 225 338  Std. dev. 0 1.04 — — — — — 8.28 2.55 17 67 0.77 12.2 52.4 77.4 

N obs. 18 18 1 0 0 0 0 18 18 18 18 17 18 18 15 

I094.8D Mean 0.2 3.85 0.37 — — — — 2.96 12 89 737 8.1 26.4 55 —  Median 0.2 4.1 0.37 — — — — 1.6 12.5 89 751 8.1 22 43 —  Minimum 0.2 1.8 0.29 — — — — 0.1 8.7 79 600 7.2 15 24 —  Maximum 0.2 5 0.5 — — — — 11 14 99 952 9.1 45 145 —  Std. dev. 0 0.92 0.07 — — — — 3.4 1.41 4.89 114 0.45 9.7 36.1 — 

N obs. 15 14 14 0 0 0 0 14 14 14 14 14 14 14 0 

I095.2C Mean 0.2 4.53 0.41 — — — — 2.9 12.1 89 729 8 26.9 55 —  Median 0.2 4.6 0.41 — — — — 1.3 12.4 91 758 8.1 25.5 47 —  Minimum 0.2 1.5 0.26 — — — — 0.2 8.5 77 578 7.4 16 27 —  Maximum 0.2 7 0.72 — — — — 10.9 14 99 932 8.7 40 142 —  Std. dev. 0 1.72 0.12 — — — — 3.33 1.49 5.53 112 0.36 7.77 30.5 — 

N obs. 15 14 14 0 0 0 0 14 14 14 14 14 14 14 0 

I098.0C Mean 0.2 3.34 0.19 — — — — 3.15 11.9 88 739 8.2 28.7 47 —  Median 0.2 4 0.13 — — — — 1.3 12.2 88 726 8.1 28 43 —  Minimum 0.2 1 0.09 — — — — 0.3 8.6 78 603 7.2 19 25 —  Maximum 0.2 4.1 0.58 — — — — 11 14.4 102 932 9 40 82 —  Std. dev. 0 1 0.15 — — — — 3.48 1.47 5.85 109 0.47 7.84 17.8 — 

N obs. 14 13 13 0 0 0 0 13 13 13 13 13 13 13 0 

I099.4C Mean 0.2 2.89 0.21 — — — — 3.16 12.4 92 728 8.1 31.5 39 —  Median 0.2 3.2 0.21 — — — — 1.5 12.5 88 752 8.2 34 36 —  Minimum 0.2 0.6 0.07 — — — — 1 8.8 80 593 7.3 17 19 —  Maximum 0.2 3.9 0.34 — — — — 11 18.6 134 924 8.8 55 96 —  Std. dev. 0 0.98 0.09 — — — — 3.39 2.29 13.4 109 0.4 11.6 19.4 — 

N obs. 14 13 13 0 0 0 0 13 13 13 13 13 13 13 0 

I099.4D Mean 0.2 3.15 0.26 — — — — 3.05 12.2 90 708 8.1 30.2 41 —  Median 0.2 3.5 0.27 — — — — 1.4 12.4 89 655 8.2 27 41 —  Minimum 0.2 0.7 0.09 — — — — 0.5 8.8 80 603 7.5 17 20 —  Maximum 0.2 4 0.35 — — — — 10.9 15.2 107 912 9.3 50 88 —  Std. dev. 0 1.03 0.07 — — — — 3.42 1.61 6.43 108 0.45 9.9 17.6 — 

N obs. 14 13 13 0 0 0 0 13 13 13 13 13 13 13 0 
 E-3

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1993 Near-surface measurements: 

I106.5X Mean 0.2 3.1 0.24 100 7 — — 3.42 12.3 92 706 8.2 33.1 42 —  Median 0.2 3.55 0.29 100 8 — — 1.9 12.5 89 669 8.1 32 35 —  Minimum 0.2 0.69 0.01 100 3 — — 0.6 8.8 79 540 7.8 14 12 —  Maximum 0.2 4.5 0.46 100 10 — — 10.5 16 120 920 9 58 118 —  Std. dev. 0 1.05 0.15 0 3.61 — — 3.19 1.75 11.1 120 0.36 13.6 29.9 — 

N obs. 14 14 14 3 3 0 0 14 14 14 14 13 14 14 0 

I106.5Y Mean 0.2 2.91 0.2 60 4 — — 3.56 12.2 92 704 8.2 32.2 42 —  Median 0.2 3.4 0.21 50 3 — — 2 12.4 89 673 8.1 30 40 —  Minimum 0.2 0.58 0 30 3 — — 0.6 8.8 79 508 7.6 14 14 —  Maximum 0.2 4.2 0.42 100 5 — — 10.8 16 120 913 8.9 62 99 —  Std. dev. 0 1.07 0.13 36.1 1.15 — — 3.31 1.69 10.8 124 0.36 14.6 22.3 — 

N obs. 14 14 14 3 3 0 0 14 14 14 14 14 14 14 0 

I106.8X Mean 0.2 3.69 0.26 100 2 — — 3.16 11.7 87 702 8.2 30.7 44 —  Median 0.2 4 0.31 100 2 — — 1.45 12.2 88 653 8.1 29 39 —  Minimum 0.2 1 0 100 2 — — 0 9 81 570 7.7 15 17 —  Maximum 0.2 4.9 0.49 100 2 — — 10.9 12.6 93 913 9.1 55 107 —  Std. dev. 0 0.95 0.16 — — — — 3.38 1.16 3.4 120 0.38 11.4 23 — 

N obs. 15 14 14 1 1 0 0 14 14 14 14 14 14 14 0 

I107.0S Mean 0.2 4.95 0.36 — — — — 2.67 12.3 90 738 8.2 29.3 45 47.9  Median 0.2 5.3 0.35 — — — — 1.1 12.6 90 738 8 30 42 51.3  Minimum 0.2 2.5 0.28 — — — — 0.1 8.8 80 586 7.4 15 23 17  Maximum 0.2 7 0.46 — — — — 10.9 14.3 104 903 9 48 102 75.3  Std. dev. 0 1.35 0.06 — — — — 3.4 1.45 5.84 109 0.42 9.56 19.8 29.3 

N obs. 15 15 15 0 0 0 0 15 15 15 15 15 15 15 3 

I107.2R Mean 0.2 4.97 0.3 — — — — 2.71 12.4 91 748 8.2 29.3 46 47  Median 0.2 5 0.25 — — — — 1.2 12.8 89 731 8.1 28 42 33.4  Minimum 0.2 1.7 0.16 — — — — 0 8.6 78 595 7.3 15 27 30.5  Maximum 0.2 7.2 0.62 — — — — 10.8 15.6 110 932 9 48 108 77.1  Std. dev. 0 1.81 0.13 — — — — 3.36 1.75 7.98 107 0.43 9.93 19.9 26.1 

N obs. 15 15 14 0 0 0 0 15 15 15 15 15 15 15 3 

I109.5D Mean 0.2 2.58 0.03 96.7 10 — — 3.15 12.8 95 641 8.3 36.5 40 —  Median 0.2 2.84 0.02 100 10 — — 1.65 12.1 87 624 8.1 36.5 30 —  Minimum 0.2 1.44 0 90 6 — — 0.2 9.3 82 434 7.4 13 16 —  Maximum 0.2 3.59 0.1 100 15 — — 11.3 21 154 897 9.3 60 105 —  Std. dev. 0 0.65 0.03 5.16 2.99 — — 3.52 3.03 19.9 120 0.52 16.5 28.9 — 

N obs. 15 14 14 6 6 0 0 14 14 14 14 14 14 14 0 
 E-4

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1993 Near-surface measurements: 

I113.0T Mean 0.2 5.73 0.56 — — — — 11 10 86 655 8.3 27.8 60 94.9  Median 0.2 6 0.56 — — — — 6.2 11 87 632 8.1 28 50 59.4  Minimum 0.2 2.6 0.19 — — — — 0.1 4.6 59 456 7.2 10 25 28.9  Maximum 0.2 7.9 0.98 — — — — 27.2 14 109 900 9.7 48 200 314  Std. dev. 0 1.28 0.19 — — — — 10.1 2.95 10 114 0.64 10.7 41.4 81.8 

N obs. 33 33 32 0 0 0 0 33 33 33 33 32 33 33 15 

I121.2W Mean 0.2 5.63 0.49 60 7 — — 11 10.1 87 653 8.2 26.9 61 55.6  Median 0.2 5.7 0.51 60 7 — — 6.1 11.6 88 642 8.3 27 52 58.2  Minimum 0.2 2.8 0.33 60 3 — — 0 5 64 453 7.4 10 24 23  Maximum 0.2 8.2 0.74 60 10 — — 27.2 14.2 111 936 9.7 50 180 92.1  Std. dev. 0 1.31 0.14 0 4.95 — — 10 2.88 9.82 114 0.48 10.2 35.6 22.1 

N obs. 33 33 15 2 2 0 0 33 33 33 33 33 33 33 19 

I121.5X Mean 0.2 4.54 0.41 100 15 — — 2.76 12.3 90 737 8.2 24.3 62 —  Median 0.2 5 0.45 100 15 — — 1.5 12.5 89 729 8.1 23 58 —  Minimum 0.2 2 0.18 100 15 — — 0 9 79 585 7.3 12 26 —  Maximum 0.2 5.8 0.63 100 15 — — 10.4 14.2 99 918 9.7 45 140 —  Std. dev. 0 1 0.14 — — — — 3.31 1.5 5.63 111 0.54 8.78 31.8 — 

N obs. 15 15 15 1 1 0 0 15 15 15 14 15 15 15 0 

I122.5X Mean 0.2 3.7 0.52 70 2 — — 2.86 12.7 93 702 8.2 30.2 53 —  Median 0.2 4 0.58 70 2 — — 1.5 12.5 89 706 8.1 25 43 —  Minimum 0.2 0.9 0.08 50 1 — — 0.5 9.5 85 530 7.4 15 17 —  Maximum 0.2 5 0.83 90 3 — — 10.6 16.8 123 933 9.3 67 137 —  Std. dev. 0 1.14 0.26 28.3 1.41 — — 3.15 1.95 11.4 107 0.49 13.8 31.9 — 

N obs. 15 15 15 2 2 0 0 15 15 15 15 15 15 15 0 

I122.6Y Mean 0.2 3.71 0.44 65 2 — — 11.2 10.4 91 628 8.3 36.5 37 36.2  Median 0.2 3.7 0.43 65 2 — — 6.5 11.8 88 615 8.3 38 29 27.3  Minimum 0.2 1.65 0.02 50 1 — — 0.5 5 64 494 7.4 15 14 14.7  Maximum 0.2 5.7 0.81 80 3 — — 27.2 15.2 138 830 9.6 68 140 144  Std. dev. 0 1.05 0.23 21.2 1.41 — — 9.94 2.85 15.3 82.6 0.5 14.2 23.5 32.5 

N obs. 33 33 33 2 2 0 0 33 33 33 33 33 33 33 15 

I124.8R Mean 0.2 3.17 0.08 95 7 — — 4.75 11.8 90 701 8.3 29.3 57 65.9  Median 0.2 3.25 0.1 95 7 — — 1.9 12.4 89 708 8.2 25 45 65.9  Minimum 0.2 1.7 0 90 3 — — 0.8 8.9 82 558 7.4 10 18 65.9  Maximum 0.2 4.2 0.17 100 10 — — 20 14.6 105 965 9.5 70 120 65.9  Std. dev. 0 0.79 0.06 7.07 4.95 — — 5.65 1.64 5.8 112 0.56 17 33.6 — 

N obs. 15 13 13 2 2 0 0 13 13 13 13 13 13 13 1 
 E-5

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1993 Near-surface measurements: 

I127.9W Mean 0.2 3.04 0.12 97.5 4 — — 4.45 11.8 90 674 8.3 36.4 44 50.9  Median 0.2 3.3 0.07 100 3 — — 1.95 12.3 91 640 8.2 38 38 53  Minimum 0.2 0.87 0 90 1 — — 0.8 8.9 76 514 7.6 14 15 12.9  Maximum 0.2 4.21 0.35 100 8 — — 19.2 14.2 103 944 9.1 70 110 84.6  Std. dev. 0 0.99 0.12 5 3.4 — — 5.25 1.59 6.59 114 0.44 16.6 28.7 31.7 

N obs. 15 14 14 4 4 0 0 14 14 14 14 14 14 14 4 

I128.8F Mean 0.2 3.48 0.43 — — — — 4 12.3 92 700 8.2 31.8 49 52  Median 0.2 3.83 0.44 — — — — 1.8 12.5 89 711 8.2 26.5 40 50.1  Minimum 0.2 1 0.14 — — — — 0.5 7.5 78 546 7.4 10 11 19.9  Maximum 0.2 5.1 0.68 — — — — 20.1 17.4 126 989 8.8 65 140 87.7  Std. dev. 0 1.08 0.17 — — — — 5.31 2.34 10.9 107 0.44 16.3 34.5 28.8 

N obs. 16 16 16 0 0 0 0 16 16 16 16 16 16 16 4 

I128.8T Mean 0.2 3.06 0.06 100 5 — — 4.62 12.4 95 686 8.3 38.7 42 43  Median 0.2 3.21 0.05 100 5 — — 2 12.4 91 646 8.1 38 35 43  Minimum 0.2 0.84 0 100 1 — — 0.1 9.4 74 535 7.7 14 6 43  Maximum 0.2 4.1 0.16 100 10 — — 20.2 16.4 144 984 9.3 95 115 43  Std. dev. 0 0.94 0.05 0 4.51 — — 5.71 1.91 17.5 120 0.41 21.1 29.5 — 

N obs. 15 13 13 3 3 0 0 13 13 13 13 13 13 13 1 

I129.8W Mean 0.2 3.16 0.05 100 6 — — 4.76 12.2 94 675 8.4 34.2 45 42.1  Median 0.2 3.46 0.05 100 1 — — 2.15 12.1 90 634 8.2 34 36 41.1  Minimum 0.2 0.74 0 100 1 — — 0.1 8.9 72 539 8 15 16 11.4  Maximum 0.2 4.21 0.11 100 15 — — 20 17.5 131 982 9.5 55 110 74.7  Std. dev. 0 1.03 0.04 0 8.08 — — 5.88 2.3 17.2 124 0.44 14.5 29.2 26.1 

N obs. 15 12 12 3 3 0 0 12 12 12 12 12 12 12 4 

I135.8W Mean 0.2 1.78 0.01 100 10 — — 3.89 14.2 107 260 9 160 5 —  Median 0.2 1.79 0 100 10 — — 2.25 14.3 106 258 8.9 160 5 —  Minimum 0.2 1.69 0 100 5 — — 0 10.2 93 230 8.5 160 2 —  Maximum 0.2 1.9 0.03 100 15 — — 11 16.5 126 325 10 160 17 —  Std. dev. 0 0.08 0.01 0 2.67 — — 3.97 1.72 9.02 25.2 0.4 — 4.07 — 

N obs. 14 14 14 8 8 0 0 14 14 14 14 14 1 14 0 

I135.8X Mean 0.2 1.49 0 100 13 60 3 4.39 14.8 113 258 9.1 — 4 —  Median 0.2 1.49 0 100 13 60 3 3 15.2 110 256 9.2 — 5 —  Minimum 0.2 1.39 0 100 5 60 3 0.9 8.7 79 225 8.4 — 2 —  Maximum 0.2 1.6 0.04 100 20 60 3 12 19 141 316 9.5 — 8 —  Std. dev. 0 0.06 0.01 0 5.24 — — 4.03 2.6 17.2 24.8 0.35 — 1.74 — 

N obs. 14 14 14 6 6 1 1 14 14 14 14 14 0 14 0 
 E-6

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1993 Near-surface measurements: 

I157.8D Mean 0.2 20.3 — — — — — 17.1 8.74 88 603 8.4 24.3 74 70.8  Median 0.2 20.8 — — — — — 19.2 7.9 87 629 8.3 25.5 54 55.8  Minimum 0.2 15.3 — — — — — 4 5.8 72 450 7.5 5 30 30.4  Maximum 0.2 27.3 — — — — — 27 13.4 114 717 9.5 38 323 174  Std. dev. 0 3.07 — — — — — 8.37 2.25 10.7 86.3 0.57 9.28 68.9 43.8 

N obs. 17 16 0 0 0 0 0 17 17 17 17 17 16 17 14 

LM00.5M Mean 0.2 6.31 0.15 — — — — 8.69 9.89 83 503 8.6 56.3 27 30.9  Median 0.2 6.1 0.13 — — — — 5.2 10.7 83 510 8.6 59 20 20.6  Minimum 0.2 5.2 0.08 — — — — 3.8 7.1 73 444 8 20 8 10  Maximum 0.2 7.9 0.25 — — — — 18.1 12.4 94 585 9.3 105 57 91.8  Std. dev. 0 0.98 0.07 — — — — 5.41 2.1 8.49 49.3 0.53 32.4 18.5 31 

N obs. 7 7 4 0 0 0 0 7 7 7 7 7 7 7 6 

MK04.4M Mean 0.2 3.41 — — — — — 16.8 9.47 96 587 8.4 — 112 154  Median 0.2 3.05 — — — — — 19 9.4 93 628 8.4 — 39 71.2  Minimum 0.2 1.7 — — — — — 5 6.5 77 273 7.7 — 10 9.3  Maximum 0.2 7 — — — — — 24.9 13.4 156 686 9.2 — 600 646  Std. dev. 0 1.34 — — — — — 7.11 1.9 16.5 120 0.41 — 172 182 

N obs. 18 18 0 0 0 0 0 18 18 18 18 18 0 18 16 

QV04.6M Mean 0.2 0.86 — — — — — 15.5 8.38 84 540 8.1 70 31 50.2  Median 0.2 0.6 — — — — — 16.6 7.95 81 561 8 70 19 28.1  Minimum 0.2 0.4 — — — — — 7 7 73 150 7.5 70 10 6.9  Maximum 0.2 3.5 — — — — — 23.2 11.8 139 600 8.7 70 220 269  Std. dev. 0 0.74 — — — — — 4.88 1.32 14.5 100 0.39 — 47.9 65.7 

N obs. 18 18 0 0 0 0 0 18 18 18 18 18 1 18 16 

S000.2K Mean 0.2 5.79 0.61 100 7 — — 10.6 10.3 87 619 8.1 37.7 152 270  Median 0.2 5.5 0.46 100 8 — — 7.5 11.1 90 640 8 32 45 54.8  Minimum 0.2 3.7 0 100 2 — — 0 2.7 33 230 7.4 1 7 6.2  Maximum 0.2 8 1.61 100 12 — — 25 13.6 107 830 9.4 122 910 2171  Std. dev. 0 1.07 0.49 0 4.57 — — 9.37 2.82 12.5 155 0.52 33 224 528 

N obs. 33 33 18 4 4 0 0 32 33 32 33 33 33 33 19 

SG16.2C Mean 0.2 4.91 1.46 — — — — 12.2 9.72 88 566 8.4 — 98 145  Median 0.2 4.3 1.43 — — — — 11 10.4 89 577 8.1 — 59 87.2  Minimum 0.2 3 1.18 — — — — 1.1 3 28 312 7.4 — 17 15.9  Maximum 0.2 8 1.85 — — — — 26.5 14.4 110 746 9.6 — 387 689  Std. dev. 0 1.47 0.19 — — — — 8.64 2.56 13.7 105 0.54 — 93.4 169 

N obs. 33 32 13 0 0 0 0 32 32 32 32 31 0 32 19 
 E-7

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1993 Near-bottom measurements: 

I094.8D Mean 3.65 3.85 0.28 — — — — 2.96 12 88 739 8.1 — 64 —  Median 3.9 4.1 0.28 — — — — 1.6 12.4 89 756 8.1 — 52 —  Minimum 1.6 1.8 0.2 — — — — 0.1 8.5 77 595 7.4 — 30 —  Maximum 4.8 5 0.41 — — — — 11 14.1 100 954 8.9 — 200 —  Std. dev. 0.92 0.92 0.06 — — — — 3.39 1.44 5.35 114 0.37 — 43.6 — 

N obs. 14 14 14 — — — — 14 14 14 14 14 — 14 0 

I095.2C Mean 4.32 4.53 0.29 — — — — 2.87 12 88 731 8.1 — 59 —  Median 4.4 4.6 0.29 — — — — 1.3 12.4 89 756 8.1 — 49 —  Minimum 1.3 1.5 0.15 — — — — 0.2 8.5 77 578 7.5 — 27 —  Maximum 6.8 7 0.5 — — — — 11 14.1 99 939 8.5 — 140 —  Std. dev. 1.72 1.72 0.09 — — — — 3.36 1.47 5.5 114 0.29 — 33.6 — 

N obs. 14 14 14 — — — — 14 14 14 14 14 — 14 0 

I098.0C Mean 3.33 3.54 0.17 — — — — 3.32 11.8 88 733 8.1 — 52 —  Median 3.8 4 0.15 — — — — 1.75 12.4 88 715 8.1 — 48 —  Minimum 1.6 1.85 0.07 — — — — 0.3 8.6 78 603 7.6 — 30 —  Maximum 3.9 4.1 0.36 — — — — 11.1 13.4 93 941 8.8 — 88 —  Std. dev. 0.76 0.75 0.08 — — — — 3.58 1.37 3.75 114 0.36 — 18.8 — 

N obs. 12 12 12 — — — — 12 12 12 12 12 — 12 0 

I099.4C Mean 2.88 3.08 0.16 — — — — 3.24 11.9 88 730 8.1 — 48 —  Median 3.1 3.3 0.15 — — — — 1.4 12.3 88 729 8.1 — 41 —  Minimum 1.3 1.5 0.04 — — — — 1 8.7 79 599 7.7 — 20 —  Maximum 3.7 3.9 0.26 — — — — 11 14 98 928 8.8 — 110 —  Std. dev. 0.72 0.72 0.07 — — — — 3.53 1.42 4.67 114 0.3 — 26.3 — 

N obs. 12 12 12 — — — — 12 12 12 12 12 — 12 0 

I099.4D Mean 3.16 3.36 0.21 — — — — 3.2 11.9 88 720 8.1 — 46 —  Median 3.45 3.65 0.23 — — — — 1.4 12.3 88 705 8.1 — 44 —  Minimum 1.4 1.6 0.05 — — — — 0.5 8.8 80 600 7.5 — 21 —  Maximum 3.8 4 0.33 — — — — 10.9 13.7 95 920 8.9 — 97 —  Std. dev. 0.76 0.76 0.07 — — — — 3.53 1.39 4.11 112 0.36 — 22.1 — 

N obs. 12 12 12 — — — — 12 12 12 12 12 — 12 0 

I106.5X Mean 3.08 3.28 0.21 — — — — 3.31 12 90 721 8.2 — 46 —  Median 3.4 3.6 0.25 — — — — 1.8 12.4 87 687 8.1 — 40 —  Minimum 1.2 1.47 0 — — — — 0.6 8.8 80 595 7.8 — 13 —  Maximum 4.3 4.5 0.35 — — — — 10.9 16.2 121 920 8.9 — 105 —  Std. dev. 0.83 0.82 0.11 — — — — 3.39 1.73 10.1 114 0.34 — 29.8 — 

N obs. 13 13 13 — — — — 13 13 13 13 12 — 13 0 
 E-8

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1993 Near-bottom measurements: 

I106.5Y Mean 2.88 3.09 0.19 — — — — 3.37 11.9 89 726 8.1 — 48 —  Median 3.2 3.4 0.2 — — — — 1.9 12.4 88 697 8 — 40 —  Minimum 1.2 1.45 0 — — — — 0.5 8.8 80 582 7.8 — 14 —  Maximum 4 4.2 0.36 — — — — 10.9 15 113 922 8.8 — 110 —  Std. dev. 0.88 0.86 0.11 — — — — 3.38 1.53 8.08 112 0.31 — 28 — 

N obs. 13 13 13 — — — — 13 13 13 13 13 — 13 0 

I106.8X Mean 3.7 3.9 0.2 — — — — 3.04 11.7 87 716 8.1 — 47 —  Median 3.8 4 0.21 — — — — 1.3 12.2 87 680 8.1 — 47 —  Minimum 2.4 2.62 0 — — — — 0 8.8 80 575 7.8 — 17 —  Maximum 4.7 4.9 0.34 — — — — 10.9 12.6 93 922 8.8 — 107 —  Std. dev. 0.58 0.58 0.1 — — — — 3.51 1.2 3.55 118 0.32 — 23.8 — 

N obs. 13 13 13 — — — — 13 13 13 13 13 — 13 0 

I107.0S Mean 4.75 4.95 0.3 — — — — 2.6 12.3 90 744 8.1 — 50 —  Median 5.1 5.3 0.28 — — — — 1 12.4 88 744 8 — 40 —  Minimum 2.3 2.5 0.23 — — — — 0.1 8.8 80 580 7.4 — 27 —  Maximum 6.8 7 0.42 — — — — 10.9 14.4 105 913 9 — 135 —  Std. dev. 1.36 1.35 0.07 — — — — 3.43 1.51 6.37 112 0.39 — 27 — 

N obs. 15 15 15 — — — — 15 15 15 15 15 — 15 0 

I107.2R Mean 4.77 4.97 0.32 — — — — 3.09 12.4 91 739 8.2 — 50 —  Median 4.8 5 0.34 — — — — 1.1 12.5 91 732 8.1 — 45 —  Minimum 1.5 1.7 0.16 — — — — 1 8.5 77 595 7.5 — 28 —  Maximum 7 7.2 0.46 — — — — 10.9 15.7 111 916 8.9 — 130 —  Std. dev. 1.81 1.81 0.1 — — — — 3.45 1.9 8.74 114 0.41 — 27.8 — 

N obs. 15 15 13 — — — — 13 13 13 13 13 — 13 0 

I109.5D Mean 2.34 2.58 0.01 — — — — 3.12 12.4 92 652 8.2 — 41 —  Median 2.6 2.84 0.01 — — — — 1.95 12 86 631 8.1 — 33 —  Minimum 1.1 1.44 0 — — — — 0.8 9 79 484 7.5 — 16 —  Maximum 3.3 3.59 0.05 — — — — 11.2 17.7 124 909 8.9 — 93 —  Std. dev. 0.67 0.65 0.01 — — — — 3.19 2.25 13.2 111 0.38 — 24.6 — 

N obs. 14 14 14 — — — — 14 14 14 14 14 — 14 0 

I113.0T Mean 5.53 5.73 0.37 — — — — 11 9.93 85 665 8.3 — 68 —  Median 5.8 6 0.35 — — — — 6.2 11.2 87 632 8.1 — 51 —  Minimum 2.4 2.6 0.12 — — — — 0 5.2 65 460 7.4 — 25 —  Maximum 7.7 7.9 0.68 — — — — 27.1 14 101 928 9.4 — 270 —  Std. dev. 1.28 1.28 0.15 — — — — 10.1 3.01 9.13 126 0.53 — 54.9 — 

N obs. 33 33 28 — — — — 31 31 31 31 30 — 30 0 
 E-9

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1993 Near-bottom measurements: 

I121.2W Mean 5.4 5.61 0.37 — — — — 7.14 11.1 89 692 8.2 — 77 —  Median 5.5 5.7 0.37 — — — — 2.8 12.2 88 681 8.2 — 57 —  Minimum 2.6 2.8 0.22 — — — — 0.1 5.6 69 550 7.4 — 31 —  Maximum 8 8.2 0.52 — — — — 25.3 13.8 111 941 8.9 — 160 —  Std. dev. 1.34 1.33 0.1 — — — — 8.33 2.29 8.58 122 0.45 — 43.3 — 

N obs. 19 19 13 — — — — 17 17 17 17 17 — 17 0 

I121.5X Mean 4.33 4.54 0.33 — — — — 2.73 12.3 90 740 8.2 — 73 —  Median 4.8 5 0.33 — — — — 1.5 12.4 88 732 8.1 — 64 —  Minimum 1.8 2 0.15 — — — — 0 8.8 77 597 7.4 — 32 —  Maximum 5.6 5.8 0.52 — — — — 10.4 14.2 98 930 8.9 — 140 —  Std. dev. 1.01 1 0.09 — — — — 3.26 1.52 5.96 111 0.39 — 33.4 — 

N obs. 15 15 15 — — — — 15 15 15 14 15 — 15 0 

I122.5X Mean 3.7 3.9 0.43 — — — — 2.82 12.3 90 703 8.1 — 56 —  Median 3.8 4 0.46 — — — — 1.35 12.5 88 700 8.1 — 47 —  Minimum 1.7 1.91 0.06 — — — — 0.4 9.4 84 523 7.4 — 14 —  Maximum 4.8 5 0.69 — — — — 10.6 16.7 118 935 8.9 — 140 —  Std. dev. 0.87 0.87 0.2 — — — — 3.27 1.68 8.5 115 0.44 — 33.8 — 

N obs. 14 14 13 — — — — 14 14 14 14 14 — 14 0 

I122.6Y Mean 3.51 3.71 0.31 — — — — 11.1 10.4 91 633 8.3 — 43 —  Median 3.5 3.7 0.27 — — — — 6.4 11.8 87 622 8.3 — 36 —  Minimum 1.4 1.65 0.02 — — — — 0.5 6 67 498 7.5 — 15 —  Maximum 5.5 5.7 0.67 — — — — 27.1 16 133 837 9.6 — 140 —  Std. dev. 1.06 1.05 0.2 — — — — 9.9 2.87 14.2 86.4 0.46 — 25.1 — 

N obs. 33 33 27 — — — — 33 33 33 33 33 — 32 0 

I124.8R Mean 2.95 3.17 0.05 — — — — 4.72 11.7 90 702 8.3 — 59 —  Median 3 3.25 0.06 — — — — 1.9 12.2 88 707 8.1 — 47 —  Minimum 1.4 1.7 0 — — — — 0.8 8.7 81 559 7.4 — 17 —  Maximum 4 4.2 0.11 — — — — 19.9 14.6 104 969 9.1 — 123 —  Std. dev. 0.81 0.79 0.04 — — — — 5.63 1.66 5.72 113 0.49 — 34 — 

N obs. 13 13 13 — — — — 13 13 13 13 13 — 13 0 

I127.9W Mean 3 3.21 0.09 — — — — 4.6 11.7 89 693 8.2 — 43 —  Median 3.1 3.3 0.06 — — — — 2.5 12.2 90 659 8.1 — 40 —  Minimum 1.5 1.7 0.01 — — — — 0.7 8.7 75 552 7.6 — 17 —  Maximum 4 4.21 0.28 — — — — 19.1 14.1 102 947 8.9 — 89 —  Std. dev. 0.81 0.81 0.09 — — — — 5.38 1.65 6.38 109 0.39 — 22.1 — 

N obs. 13 13 12 — — — — 13 13 13 13 12 — 12 0 
 E-10

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1993 Near-bottom measurements: 

I128.8F Mean 3.43 3.64 0.34 — — — — 4.09 11.9 89 716 8.1 — 56 —  Median 3.6 3.85 0.34 — — — — 1.6 12.4 88 711 8.2 — 53 —  Minimum 1.6 1.8 0.11 — — — — 0.5 7.3 77 580 7.4 — 11 —  Maximum 4.9 5.1 0.49 — — — — 20 14.3 101 995 8.8 — 145 —  Std. dev. 0.89 0.89 0.12 — — — — 5.44 2.01 6.9 108 0.42 — 34.7 — 

N obs. 15 15 15 — — — — 15 15 15 14 15 — 15 0 

I128.8T Mean 3.03 3.24 0.04 — — — — 5.02 11.9 93 689 8.3 — 44 —  Median 3.05 3.26 0.03 — — — — 2.45 12.3 90 665 8.1 — 41 —  Minimum 1.4 1.6 0 — — — — 0.5 9.3 74 541 7.7 — 12 —  Maximum 3.9 4.1 0.12 — — — — 20.1 14.2 137 975 9.1 — 88 —  Std. dev. 0.7 0.7 0.04 — — — — 5.73 1.56 16.2 121 0.38 — 21 — 

N obs. 12 12 12 — — — — 12 12 12 12 11 — 11 0 

I129.8W Mean 3.17 3.37 0.03 — — — — 5.1 11.6 90 686 8.3 — 43 —  Median 3.4 3.6 0.02 — — — — 2.3 12 90 642 8.2 — 40 —  Minimum 1.5 1.7 0 — — — — 0.3 8.9 72 541 8 — 19 —  Maximum 4 4.21 0.09 — — — — 19.9 14.5 123 982 9 — 87 —  Std. dev. 0.73 0.73 0.03 — — — — 5.97 1.63 13.8 125 0.36 — 20.8 — 

N obs. 11 11 11 — — — — 11 11 11 11 10 — 10 0 

I135.8W Mean 1.51 1.78 0 — — — — 4.14 14.3 108 261 9 — 3 —  Median 1.5 1.79 0 — — — — 2.9 14.4 108 267 9 — 3 —  Minimum 1.4 1.69 0 — — — — 0 9.9 90 220 8.4 — 2 —  Maximum 1.7 1.9 0.02 — — — — 11 17 127 311 9.6 — 8 —  Std. dev. 0.11 0.08 0.01 — — — — 3.81 1.9 10.8 25.7 0.33 — 1.6 — 

N obs. 14 14 14 — — — — 14 14 14 14 14 — 14 0 

I135.8X Mean 1.27 1.5 0 — — — — 4.91 14.1 109 253 9 — 4 —  Median 1.3 1.5 0 — — — — 3.2 14.7 111 257 9 — 3 —  Minimum 1.2 1.4 0 — — — — 0.9 8.5 77 224 8.3 — 2 —  Maximum 1.4 1.6 0 — — — — 11.4 16.6 132 278 9.5 — 6 —  Std. dev. 0.08 0.06 0 — — — — 4.19 2.22 14.6 18.4 0.33 — 1.51 — 

N obs. 11 11 11 — — — — 11 11 11 11 11 — 11 0 

LM00.5M Mean 6.11 6.31 0.08 — — — — 8.59 9.91 83 511 8.4 — 34 —  Median 5.9 6.1 0.08 — — — — 5.1 10.8 84 517 8.4 — 23 —  Minimum 5 5.2 0.06 — — — — 3.7 7 73 441 7.8 — 9 —  Maximum 7.7 7.9 0.09 — — — — 18.1 12.4 94 595 9.2 — 62 —  Std. dev. 0.98 0.98 0.02 — — — — 5.48 2.18 9.02 54.9 0.54 — 23.5 — 

N obs. 7 7 2 — — — — 7 7 7 7 7 — 7 0 
 E-11

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1993 Near-bottom measurements: 

MK04.4M Mean 2.89 3.09 — — — — — 16 9.4 94 625 8.4 — 71 —  Median 2.8 3 — — — — — 18 9.3 93 633 8.5 — 42 —  Minimum 1.5 1.7 — — — — — 4.8 7.4 84 424 7.8 — 9 —  Maximum 4.8 5 — — — — — 25.1 12.4 109 691 9.1 — 395 —  Std. dev. 0.95 0.95 — — — — — 7.2 1.62 6.42 61.4 0.36 — 96.4 — 

N obs. 16 16 0 — — — — 16 16 16 16 16 — 15 0 

S000.2K Mean 5.59 5.8 0.19 — — — — 10.2 10.5 88 690 8.2 — 99 —  Median 5.3 5.5 0.19 — — — — 7.55 11.1 92 698 8.2 — 54 —  Minimum 3.4 3.7 0 — — — — 0 1.7 21 296 7.3 — 7 —  Maximum 7.8 8 0.35 — — — — 24.5 13.6 106 843 9.2 — 435 —  Std. dev. 1.12 1.11 0.11 — — — — 8.78 2.9 15 114 0.45 — 123 — 

N obs. 29 29 12 — — — — 26 27 26 27 27 — 26 0 

SG16.2C Mean 4.51 4.71 — — — — — 12.8 9.78 89 577 8.3 — 92 —  Median 4 4.2 — — — — — 11 10.6 91 572 8.2 — 61 —  Minimum 2.8 3 — — — — — 1.2 2.9 27 330 7.6 — 14 —  Maximum 7.8 8 — — — — — 26.3 14 110 695 9.2 — 380 —  Std. dev. 1.48 1.48 — — — — — 8.92 2.69 15.5 86.7 0.43 — 94.5 — 

N obs. 25 25 0 — — — — 22 22 22 22 21 — 22 0 

1994 Near-surface measurements: 

I080.2C Mean 0.2 5.49 — 80 15 60 2 15.3 8.74 82 692 8.1 20.5 90 112  Median 0.2 5.2 — 80 15 60 2 16.4 8.3 82 699 8.1 20 74 82.4  Minimum 0.2 3.7 — 80 15 60 2 0 4 54 456 7.7 6 35 43.2  Maximum 0.2 10.1 — 80 15 60 2 30.5 13.7 107 895 9.1 40 280 389  Std. dev. 0 1.46 — — — — — 9.89 3.07 14.7 99 0.34 7.18 54.3 83.3 

N obs. 25 23 0 1 1 1 1 25 25 25 25 25 23 25 25 

I080.2M Mean 0.2 6.49 — — — — — 16 9.12 88 676 8.2 20.4 83 101  Median 0.2 6.4 — — — — — 16.4 8.4 90 701 8.2 20 59 69.5  Minimum 0.2 5.1 — — — — — 1.2 4.6 62 410 7.7 5 32 33.2  Maximum 0.2 8.2 — — — — — 30.3 14.1 105 850 9.3 30 280 344  Std. dev. 0 0.84 — — — — — 9.68 2.79 13.4 98.9 0.45 6.27 67.4 85.7 

N obs. 23 23 0 0 0 0 0 23 23 23 23 23 23 23 23 
 E-12

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1994 Near-surface measurements: 

I109.5D Mean 0.2 1.28 0.02 100 6 — — 19.2 11.9 130 520 8.8 26.2 55 45.5  Median 0.2 1.2 0 100 6 — — 21.8 11.4 112 520 8.7 21 65 44.7  Minimum 0.2 0.9 0 100 6 — — 2.8 7.6 77 414 8.1 13 6 6  Maximum 0.2 1.8 0.11 100 6 — — 31.1 17.2 208 594 9.7 85 94 90.9  Std. dev. 0 0.23 0.03 — — — — 8.7 2.91 41.7 59.3 0.48 17.4 24.5 23.4 

N obs. 17 17 17 1 1 0 0 17 17 17 17 17 17 17 17 

I113.0T Mean 0.2 3.06 0.32 75 1 — — 15.5 9 85 731 8.1 21.8 72 89.5  Median 0.2 2.8 0.26 75 1 — — 15.8 8.6 87 711 8 21 73 81.9  Minimum 0.2 1.55 0.1 75 1 — — 0.5 4.8 62 571 7.7 11 28 34.1  Maximum 0.2 5.5 0.73 75 1 — — 30.1 14.6 122 968 8.9 41 135 208  Std. dev. 0 1.11 0.18 — — — — 9.99 3.18 14.9 90.1 0.33 6.22 24.8 38.2 

N obs. 25 25 24 1 1 0 0 25 25 25 25 25 25 25 25 

I121.2W Mean 0.2 2.88 0.37 41.7 8 100 3 14.9 9.67 91 754 8.2 20.6 74 96.6  Median 0.2 3.05 0.37 15 10 100 3 15.6 9.75 91 732 8.1 19 74 91.4  Minimum 0.2 1.15 0.37 10 1 100 3 0 5.2 64 589 7.7 10 27 30.6  Maximum 0.2 4.3 0.37 100 14 100 3 30.3 14.1 134 1109 9.3 33 155 213  Std. dev. 0 0.86 — 50.6 6.66 — — 10.3 2.82 15.9 111 0.38 6.09 29.9 45.9 

N obs. 26 26 1 3 3 1 1 26 26 26 26 26 26 26 26 

I122.6Y Mean 0.2 1.96 0.19 100 2 — — 14.6 10.3 99 586 8.3 28.7 51 49.7  Median 0.2 1.8 0.12 100 2 — — 12.8 9.6 91 569 8.1 27 44 42.8  Minimum 0.2 0.9 0 100 2 — — 0.8 7.5 73 467 7.8 10 8 5.2  Maximum 0.2 4 0.8 100 2 — — 30 17.8 192 795 9.4 95 110 148  Std. dev. 0 0.95 0.2 — — — — 9.36 2.5 24.7 76.3 0.39 16.4 27.5 31 

N obs. 25 25 25 1 1 0 0 25 25 25 25 25 25 25 25 

I157.8D Mean 0.2 20.7 — 52.5 18 — — 14.9 9.99 95 748 8.3 22.2 62 67.8  Median 0.2 21 — 52.5 18 — — 15.1 9.8 94 723 8.2 21 60 61.1  Minimum 0.2 16.8 — 10 5 — — 0.2 5.1 68 615 7.8 13 28 20.1  Maximum 0.2 25 — 95 30 — — 29.3 14.6 125 1085 9.8 40 98 139  Std. dev. 0 2.37 — 60.1 17.7 — — 10.2 2.52 12.6 104 0.51 6.65 18.6 28.2 

N obs. 25 23 0 2 2 0 0 25 25 25 25 25 25 25 25 

LM00.5M Mean 0.2 5.15 0.32 75 6 — — 16.2 10.3 107 524 8.2 35.2 170 234  Median 0.2 5.2 0.32 75 6 — — 17 10.6 90 529 8 30 41 38.3  Minimum 0.2 3.1 0.32 50 2 — — 0.1 4.2 47 347 7.5 1 6 3.7  Maximum 0.2 7.6 0.32 100 10 — — 30.6 16.3 222 745 9.2 144 2450 3667  Std. dev. 0 1.17 — 35.4 5.66 — — 9.75 3.26 46.8 97.3 0.5 35.2 501 754 

N obs. 23 23 1 2 2 0 0 23 23 23 23 23 23 23 23 
 E-13

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1994 Near-surface measurements: 

LM07.2M Mean 0.2 2.35 — 100 16 98 2 14 10 95 541 8.1 70.5 185 236  Median 0.2 2 — 100 17 98 2 12.7 9.9 92 568 8.1 65.5 59 61.4  Minimum 0.2 1.1 — 100 10 95 1 0 5.2 57 330 7.3 21 5 5  Maximum 0.2 4.5 — 100 22 100 3 28.8 17.9 145 744 9.1 130 1720 2076  Std. dev. 0 0.96 — 0 6.03 3.54 1.4 9.45 2.77 21.2 112 0.43 53 372 474 

N obs. 25 24 0 3 3 2 2 25 25 25 25 25 4 25 25 

MK04.4M Mean 0.2 1.28 — 100 18 100 3 13.7 11.6 113 635 8.3 51.3 55 87.1  Median 0.2 0.95 — 100 18 100 3 14.2 11.7 103 620 8.1 50 23 35.6  Minimum 0.2 0.35 — 100 18 100 3 0 6.7 55 483 7.8 35 5 3.8  Maximum 0.2 5 — 100 18 100 3 27.9 16.2 209 754 9.4 78 580 1075  Std. dev. 0 1.05 — — — — — 9.22 2.24 34.5 68.5 0.47 14.3 113 207 

N obs. 26 26 0 1 1 1 1 26 26 26 26 26 6 26 26 

QV04.6M Mean 0.2 0.44 — — — — — 13.1 9.21 87 563 8.1 40.3 24 33.5  Median 0.2 0.4 — — — — — 12.6 9.2 85 564 8 40 18 20.6  Minimum 0.2 0.25 — — — — — 5.5 6.4 71 352 7.8 30 6 2.8  Maximum 0.2 0.8 — — — — — 23.8 12.3 101 635 9.2 60 105 154  Std. dev. 0 0.14 — — — — — 5.22 1.24 6.08 52.7 0.35 9.72 23.9 38.4 

N obs. 26 26 0 0 0 0 0 26 26 26 26 26 15 26 26 

S000.2K Mean 0.2 3.42 0.43 100 13 65 3 13.8 10.5 99 721 8.2 42.1 63 79.3  Median 0.2 3.2 0.43 100 12 75 2 12 10.3 98 719 8.1 25.5 47 62  Minimum 0.2 1.2 0.43 100 4 10 1 0 7.3 76 545 7.7 8 5 3.1  Maximum 0.2 6.1 0.43 100 21 100 8 30.1 14.5 133 905 9.4 150 330 316  Std. dev. 0 1.37 — 0 7.6 43.6 3.4 10.4 2.3 13.4 98.6 0.36 39.3 69 75.9 

N obs. 26 26 1 5 5 4 4 26 26 26 26 26 26 26 26 

SG16.2C Mean 0.2 3.16 — — — — — 13.9 11.6 111 661 8.3 18 122 184  Median 0.2 3.1 — — — — — 13.7 11.8 97 655 8.2 18 32 85.8  Minimum 0.2 1.2 — — — — — 0 6.3 70 285 7.4 18 7 11.1  Maximum 0.2 9.5 — — — — — 29.3 21 252 884 9.7 18 750 1241  Std. dev. 0 1.92 — — — — — 8.96 3.26 39.9 152 0.49 — 200 285 

N obs. 26 25 0 0 0 0 0 26 26 26 26 26 1 25 25 
 E-14

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1994 Middepth measurements: 

I109.5D Mean 0.65 1.33 — — — — — 24.5 10.8 130 455 9.6 — 44 —  Median 0.65 1.3 — — — — — 24 11.1 136 462 9.7 — 33 —  Minimum 0.4 0.9 — — — — — 19.5 8 100 424 9.4 — 31 —  Maximum 0.9 1.8 — — — — — 31.1 13.4 157 473 9.7 — 69 —  Std. dev. 0.16 0.31 — — — — — 4.13 2.38 24.6 21.7 0.14 — 21.4 — 

N obs. 6 6 0 — — — — 6 6 6 4 4 — 3 0 

1994 Near-bottom measurements: 

I109.5D Mean 1.1 1.31 0.01 — — — — 18.1 8.78 90 527 8.8 — 58 —  Median 1 1.2 0 — — — — 19.8 9.95 89 537 8.7 — 62 —  Minimum 0.7 0.9 0 — — — — 4.3 2.1 26 426 8.1 — 18 —  Maximum 1.6 1.8 0.04 — — — — 30.1 15.4 125 593 9.5 — 94 —  Std. dev. 0.2 0.21 0.01 — — — — 8.13 3.31 27.7 56.3 0.43 — 21.8 — 

N obs. 16 16 14 — — — — 16 16 16 16 16 — 15 0 

I113.0T Mean 2.84 3.06 0.21 — — — — 15.9 8.78 83 735 8.1 — 77 —  Median 2.6 2.8 0.17 — — — — 17 8.25 84 714 8 — 79 —  Minimum 1.3 1.55 0.08 — — — — 0.5 4.6 62 560 7.7 — 33 —  Maximum 5.3 5.5 0.61 — — — — 30.1 14.4 120 1025 8.6 — 120 —  Std. dev. 1.11 1.11 0.15 — — — — 10 3.16 14.6 97.7 0.28 — 21.8 — 

N obs. 25 25 18 — — — — 24 24 24 25 25 — 24 0 

I122.6Y Mean 1.89 2.1 0.13 — — — — 14.1 9.82 92 602 8.2 — 60 —  Median 1.6 1.8 0.07 — — — — 14.4 9.3 90 589 8.1 — 48 —  Minimum 0.7 0.9 0 — — — — 0.8 4.6 60 501 7.8 — 12 —  Maximum 3.8 4 0.4 — — — — 28.5 14.2 118 760 9 — 114 —  Std. dev. 0.92 0.93 0.14 — — — — 9.2 2.41 13.8 78.5 0.38 — 33.4 — 

N obs. 22 22 21 — — — — 22 22 22 22 22 — 22 0 

LM00.5M Mean 4.98 5.18 — — — — — 13.2 8.36 76 532 8.2 — 108 —  Median 5.05 5.25 — — — — — 13.5 7.95 82 529 7.9 — 67 —  Minimum 2.9 3.1 — — — — — 0.1 2.5 30 376 7.6 — 7 —  Maximum 7.4 7.6 — — — — — 27.8 13.2 114 750 9.6 — 380 —  Std. dev. 1.3 1.29 — — — — — 7.97 3.34 22.7 106 0.64 — 108 — 

N obs. 16 16 0 — — — — 16 16 16 15 15 — 13 0 
 E-15

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1994 Near-bottom measurements: 

LM07.2M Mean 2.84 3.05 — — — — — 9.17 11.7 98 598 8.4 — 30 —  Median 3.3 3.5 — — — — — 6.9 11.6 95 594 8.4 — 14 —  Minimum 1.3 1.55 — — — — — 0.1 7.6 71 501 7.6 — 7 —  Maximum 3.8 4 — — — — — 28.6 17 117 724 9.2 — 110 —  Std. dev. 1.05 1.04 — — — — — 10.6 3.16 17.7 76.1 0.66 — 39.9 — 

N obs. 7 7 0 — — — — 7 7 7 6 6 — 6 0 

MK04.4M Mean 1.79 1.99 — — — — — 8.39 11 91 630 8.3 — 178 —  Median 1.7 1.9 — — — — — 4.25 11.2 94 612 8.3 — 26 —  Minimum 1.2 1.4 — — — — — 0 8.3 76 488 7.9 — 7 —  Maximum 2.8 3 — — — — — 23.5 14.1 98 770 8.8 — 1108 —  Std. dev. 0.6 0.6 — — — — — 9.17 2.04 7.94 91.2 0.33 — 381 — 

N obs. 8 8 0 — — — — 8 8 8 8 8 — 8 0 

S000.2K Mean 3.72 3.93 — — — — — 11.5 10.6 93 736 8.3 — 75 —  Median 3.5 3.7 — — — — — 10.2 11 95 724 8.2 — 61 —  Minimum 1.6 1.8 — — — — — 0 7.1 74 546 7.5 — 5 —  Maximum 5.9 6.1 — — — — — 28.9 13.8 107 888 9.3 — 420 —  Std. dev. 1.45 1.44 — — — — — 10.5 2.59 8.15 105 0.45 — 102 — 

N obs. 15 15 0 — — — — 15 15 15 15 15 — 15 0 

1995 Near-surface measurements: 

I080.2C Mean 0.2 5.47 — — — — — 14.4 9.52 87 674 7.8 20.6 114 93.7  Median 0.2 5.15 — — — — — 14.3 10 86 694 7.8 20 65 71.4  Minimum 0.2 3.5 — — — — — 0.6 4.3 56 436 7.4 8 36 36.7  Maximum 0.2 10.7 — — — — — 31 15.1 109 843 8.1 35 950 254  Std. dev. 0 1.48 — — — — — 10.7 3.35 13.3 111 0.19 7.08 176 61 

N obs. 26 20 0 0 0 0 0 26 26 26 25 25 25 26 26 

I080.2M Mean 0.2 6.9 0.81 — — — — 13.1 10.3 92 697 7.8 22.5 72 93.3  Median 0.2 6.7 0.81 — — — — 9.3 11.2 93 706 7.9 21 55 54  Minimum 0.2 5.05 0.55 — — — — 1.1 4.4 59 458 7.4 9 36 27.5  Maximum 0.2 11.3 1.06 — — — — 31.7 17 120 836 8.1 36 142 270  Std. dev. 0 1.4 0.36 — — — — 10.6 3.41 14.7 92.7 0.19 7.21 35.7 70.4 

N obs. 19 16 2 0 0 0 0 19 19 19 18 18 19 19 19 
 E-16

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1995 Near-surface measurements: 

I109.5D Mean 0.2 1.56 0.01 98 12 — — 14.5 12.7 124 547 8.4 33.8 39 36.6  Median 0.2 1.3 0 100 10 — — 14.1 11.9 112 547 8.5 30.5 34 31.8  Minimum 0.2 0.9 0 90 6 — — 0 7.6 85 491 7.6 15 10 8.1  Maximum 0.2 4.6 0.11 100 20 — — 32.9 25 344 613 8.9 70 130 80.6  Std. dev. 0 0.87 0.03 4.47 6.02 — — 10.5 4.01 50.8 32.5 0.34 16.4 25.5 20.7 

N obs. 26 26 25 5 5 0 0 26 26 26 25 25 26 26 26 

I113.0T Mean 0.2 3.92 0.38 — — — — 13.9 9.89 89 710 7.9 22.2 101 84.5  Median 0.2 3.25 0.28 — — — — 12.4 9.5 90 713 7.8 20 68 83.6  Minimum 0.2 1.4 0.11 — — — — 0.8 3.9 52 568 7.6 5 27 18.6  Maximum 0.2 9.45 1 — — — — 30.7 15.4 109 892 8.1 49 730 273  Std. dev. 0 1.94 0.25 — — — — 10.4 3.56 14.6 85.9 0.15 9.1 138 48.2 

N obs. 26 26 20 0 0 0 0 26 26 26 25 25 26 26 26 

I121.2W Mean 0.2 3.41 0.32 95 6 — — 14 10 91 730 7.9 22.1 74 85  Median 0.2 3.2 0.36 95 6 — — 12.5 10.4 93 718 7.8 20 75 80  Minimum 0.2 1.15 0.07 95 6 — — 0.1 4.1 56 577 7.4 12 22 17.7  Maximum 0.2 9.15 0.52 95 6 — — 31 15.3 111 943 8.2 45 230 290  Std. dev. 0 1.69 0.15 — — — — 10.7 3.23 12.4 87.6 0.2 8.23 39.1 53.1 

N obs. 26 26 7 1 1 0 0 26 26 26 25 25 26 26 26 

I122.6Y Mean 0.2 2.44 0.2 90 2 — — 13.3 10.7 99 607 7.9 31.3 49 55.4  Median 0.2 1.78 0.13 90 2 — — 10.8 11 95 608 7.9 27.5 40 38.8  Minimum 0.2 0.8 0 90 2 — — 0.8 7.3 82 505 7.5 10 12 7.6  Maximum 0.2 6.7 1 90 2 — — 30.2 14.5 137 786 8.6 90 135 333  Std. dev. 0 1.71 0.23 — — — — 9.8 2.35 13.2 74.5 0.27 17.2 31.4 62.3 

N obs. 26 26 20 1 1 0 0 26 26 26 25 25 26 25 26 

I157.8D Mean 0.2 20 — 95 7 — — 14.6 10.4 98 730 7.9 22.4 78 86.6  Median 0.2 19.2 — 95 7 — — 14.6 10.1 98 726 7.9 19 67 57.5  Minimum 0.2 17.3 — 95 7 — — 0.2 6.3 80 528 7.5 11 24 21.7  Maximum 0.2 23.2 — 95 7 — — 30.7 14.7 123 986 8.7 48 146 255  Std. dev. 0 2.71 — — — — — 10.4 2.69 9.8 95.8 0.29 9.26 34 63.5 

N obs. 24 7 0 1 1 0 0 24 24 24 24 24 23 24 24 

LM00.5M Mean 0.2 5.96 — 100 7 — — 12.2 11.8 111 496 7.7 41.6 104 150  Median 0.2 5.4 — 100 7 — — 10.2 11.8 92 527 7.8 28 39 39.8  Minimum 0.2 3.6 — 100 3 — — 0.1 6 63 280 7.1 3 5 2.4  Maximum 0.2 12.4 — 100 11 — — 29.7 25 333 647 8.7 165 1000 1775  Std. dev. 0 2.54 — 0 4 — — 10.4 5.42 68.6 111 0.38 43.1 222 400 

N obs. 19 18 0 3 3 0 0 19 19 19 18 18 19 19 19 
 E-17

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1995 Near-surface measurements: 

LM07.2M Mean 0.2 3.98 0.96 100 10 — — 12.4 9.98 90 461 7.5 78 177 189  Median 0.2 3.8 0.96 100 10 — — 10.9 10.7 89 492 7.5 30 51 65.3  Minimum 0.2 1.3 0.96 100 10 — — -0.1 5.6 65 110 7 4 5 3.3  Maximum 0.2 9.45 0.96 100 10 — — 29.2 14.5 145 640 8.2 200 1240 1803  Std. dev. 0 1.9 — — — — — 9.78 2.85 16.5 146 0.25 106 302 376 

N obs. 26 20 1 1 1 0 0 26 26 26 26 26 3 26 26 

MK04.4M Mean 0.2 1.96 — — — — — 13 11.9 112 620 7.9 83.3 111 110  Median 0.2 1.3 — — — — — 11.3 12.1 103 649 7.9 100 30 43.7  Minimum 0.2 0.6 — — — — — 0 7.4 84 370 7.5 40 4 3.2  Maximum 0.2 4.7 — — — — — 30.7 15.9 175 765 8.7 110 1300 1050  Std. dev. 0 1.37 — — — — — 9.82 2.05 25.6 87.6 0.29 37.9 262 210 

N obs. 26 23 0 0 0 0 0 26 26 26 26 26 3 26 26 

QV04.6M Mean 0.2 0.48 — — — — — 12.6 9.68 90 576 7.7 40.3 23 33.9  Median 0.2 0.4 — — — — — 12.1 9.5 90 577 7.7 40 13 15.4  Minimum 0.2 0.2 — — — — — 2.4 7.2 77 535 7.2 20 6 2.7  Maximum 0.2 1 — — — — — 23.8 12.8 112 617 8.3 50 135 143  Std. dev. 0 0.22 — — — — — 6.13 1.58 6.83 23 0.28 8.65 25.9 38 

N obs. 26 26 0 0 0 0 0 26 26 26 26 26 16 26 26 

S000.2K Mean 0.2 3.86 0.82 100 9 0 0 12.9 10.3 94 677 7.8 40.3 134 139  Median 0.2 3.3 0.96 100 10 0 0 11.2 10.6 93 710 7.8 30 40 43.9  Minimum 0.2 1.35 0 100 4 0 0 -0.1 6.9 79 420 7.5 3 7 4.5  Maximum 0.2 8.55 1.5 100 12 0 0 29.8 14.1 110 846 8.1 145 1400 1443  Std. dev. 0 2.02 0.76 0 3.4 — — 10.4 2.25 7.7 106 0.19 37.1 297 292 

N obs. 26 25 3 4 4 1 1 26 26 26 25 25 25 26 26 

SG16.2C Mean 0.2 2.12 — — — — — 13.8 12 116 629 7.9 — 100 156  Median 0.2 1.7 — — — — — 12.7 11.9 102 595 7.9 — 34 68.4  Minimum 0.2 0.9 — — — — — 0.9 6.8 77 362 7.3 — 5 2.7  Maximum 0.2 5 — — — — — 30.9 25 328 890 8.7 — 625 1170  Std. dev. 0 1.29 — — — — — 9.1 3.78 49.2 148 0.33 — 163 263 

N obs. 25 11 0 0 0 0 0 25 25 25 24 25 0 25 25 
 E-18

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1995 Near-bottom measurements: 

I109.5D Mean 1.4 1.61 0.01 — — — — 14.3 10.7 99 550 8.3 — 56 66.7  Median 1.1 1.33 0 — — — — 11.8 11.2 100 547 8.3 — 41 60.5  Minimum 0.8 1.05 0 — — — — 0 4 55 491 7.7 — 15 40.4  Maximum 4.4 4.6 0.08 — — — — 31 20 155 663 8.8 — 230 99.1  Std. dev. 0.9 0.89 0.02 — — — — 10.2 3.6 22.5 36.4 0.32 — 50.8 29.8 

N obs. 24 24 21 — — — — 24 24 24 23 23 — 22 3 

I113.0T Mean 3.38 3.6 0.17 — — — — 14.7 9.56 87 723 7.8 — 82 —  Median 2.85 3.08 0.15 — — — — 14.9 8.9 90 715 7.8 — 73 —  Minimum 1.2 1.4 0.06 — — — — 0.8 3.8 51 569 7.5 — 34 —  Maximum 9.2 9.45 0.4 — — — — 30.7 15.4 108 892 8.1 — 300 —  Std. dev. 1.9 1.91 0.11 — — — — 10.9 3.66 15.3 86.1 0.19 — 54.4 — 

N obs. 22 22 12 — — — — 22 22 22 21 21 — 21 0 

I122.6Y Mean 2.5 2.72 0.13 — — — — 11.7 10.6 93 621 7.9 — 70 61.7  Median 1.95 2.15 0.09 — — — — 7.9 11.8 94 637 7.9 — 46 61.7  Minimum 0.7 0.9 0 — — — — 0.8 5.1 66 505 7.5 — 10 61.7  Maximum 6.5 6.7 0.44 — — — — 28.3 14.6 129 799 8.6 — 280 61.7  Std. dev. 1.72 1.72 0.12 — — — — 9.54 2.94 13.5 76.8 0.25 — 70.2 — 

N obs. 22 22 15 — — — — 21 21 21 21 21 — 18 1 

1996 Near-surface measurements: 

I080.2C Mean 0.2 5.43 1.16 — — — — 12 9.96 87 768 7.8 21.5 129 149  Median 0.2 5.2 1.16 — — — — 10.5 10.1 91 776 7.8 20.5 68 67.6  Minimum 0.2 3.85 1.1 — — — — 0.2 5.1 55 510 7.3 5 27 34  Maximum 0.2 9.75 1.22 — — — — 28.3 14.2 104 955 8.4 35 1500 1774  Std. dev. 0 1.42 0.08 — — — — 9.93 3.17 12.9 124 0.28 6.39 287 341 

N obs. 26 13 2 0 0 0 0 25 25 25 25 25 22 25 25 

I080.2M Mean 0.19 6.75 1.17 — — — — 12.9 9.85 89 757 7.9 23.4 64 74.6  Median 0.2 6.55 1.17 — — — — 12.3 9.35 92 770 7.8 22 63 66.4  Minimum 0 5.2 1.03 — — — — 0.5 5.9 59 509 7.6 18 30 27.1  Maximum 0.2 11 1.3 — — — — 27.2 14 105 963 8.4 38 120 156  Std. dev. 0.04 1.49 0.19 — — — — 9.52 3.03 11.6 121 0.26 4.92 20.9 37.9 

N obs. 22 15 2 0 0 0 0 20 20 20 20 20 20 20 20 
 E-19

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1996 Near-surface measurements: 

I109.5D Mean 0.2 1.45 0.02 100 7 — — 12.9 13 122 554 8.3 30.5 43 36.2  Median 0.2 1.2 0 100 7 — — 11.1 13.1 108 556 8.4 30 38 28.9  Minimum 0.2 0.7 0 100 4 — — 0.7 5.7 71 456 7.4 15 14 11.9  Maximum 0.2 4 0.14 100 10 — — 29.5 25 334 614 9 70 125 110  Std. dev. 0 0.65 0.04 0 2.75 — — 10.1 3.94 49.9 38.3 0.37 13.2 25.8 22.9 

N obs. 27 27 20 4 4 0 0 27 27 27 27 27 26 27 27 

I113.0T Mean 0.2 3.22 0.59 — — — — 13.7 10.2 92 769 7.9 23.8 66 72.2  Median 0.2 2.85 0.39 — — — — 13 9.65 93 749 7.9 23 67 64.5  Minimum 0.2 1.3 0.06 — — — — 0.6 5.8 70 461 7.2 17 42 47.1  Maximum 0.2 6 3 — — — — 28 14.9 109 1011 8.4 30 125 160  Std. dev. 0 1.21 0.82 — — — — 9.41 3.09 12.3 140 0.3 4.55 17.5 25 

N obs. 26 25 15 0 0 0 0 25 24 24 25 25 24 25 25 

I121.2W Mean 0.2 2.68 — 95 8 — — 13.3 10.3 94 795 7.9 23.7 60 70.6  Median 0.2 2.48 — 95 8 — — 14.2 9.6 94 785 7.9 23.5 61 68.7  Minimum 0.2 0.5 — 95 8 — — 0.1 5.3 67 465 7.4 17 30 36  Maximum 0.2 7 — 95 8 — — 27.8 15.6 111 1073 8.5 36 110 148  Std. dev. 0 1.39 — — — — — 10 2.94 10.5 154 0.29 5.03 18 27.5 

N obs. 27 26 0 1 1 0 0 27 27 27 27 27 26 26 27 

I122.6Y Mean 0.2 1.94 0.17 — — — — 13.8 10.7 101 583 7.9 32.8 44 40.6  Median 0.2 1.3 0.12 — — — — 15.3 10.3 95 542 7.9 30.5 41 35.8  Minimum 0.2 0.6 0 — — — — 0.3 6.6 79 380 7.4 12 12 9.5  Maximum 0.2 6 0.59 — — — — 28.1 14.7 191 852 8.8 70 83 89.7  Std. dev. 0 1.42 0.2 — — — — 9.73 2.63 23.5 126 0.35 13.7 19.9 18.7 

N obs. 26 26 16 0 0 0 0 25 25 25 26 26 26 26 26 

I157.8D Mean 0.2 22 — 90 10 — — 12.4 10.9 97 816 7.9 24.5 56 63.4  Median 0.2 22.4 — 90 10 — — 13.1 10 99 777 7.9 23 55 50.6  Minimum 0.2 17 — 90 10 — — 0.1 6.5 61 509 7.2 12 29 22.6  Maximum 0.2 27.5 — 90 10 — — 28 16.2 127 1092 8.5 41 140 163  Std. dev. 0 2.87 — — — — — 9.86 3.1 13.2 150 0.28 7.82 22.3 35.3 

N obs. 25 16 0 1 1 0 0 25 25 25 25 25 25 24 25 

LM00.5M Mean 0.2 5.65 — 100 5 — — 12.3 10.5 96 543 7.8 36.5 47 37.8  Median 0.2 5.2 — 100 7 — — 11.9 11 95 552 7.9 34 28 31.3  Minimum 0.2 4 — 100 2 — — 0.1 5 54 314 7 10 12 2.4  Maximum 0.2 11 — 100 7 — — 25.7 14.1 140 721 8.3 90 192 156  Std. dev. 0 1.83 — 0 2.89 — — 9.61 2.67 22.1 96.2 0.32 21.6 50.9 35.4 

N obs. 21 17 0 3 3 0 0 20 20 20 20 20 19 20 20 
 E-20

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1996 Near-surface measurements: 

LM07.2M Mean 0.2 3.81 — 100 15 — — 12 10.4 94 551 7.7 6.5 510 480  Median 0.2 3.6 — 100 15 — — 12.5 10.9 94 550 7.8 6.5 46 52.6  Minimum 0.2 2.8 — 100 10 — — 0 5.7 54 157 7.1 3 13 3.1  Maximum 0.2 5.8 — 100 20 — — 27 13.9 143 952 8.3 10 5550 7347  Std. dev. 0 0.82 — 0 7.07 — — 9.34 2.5 18.6 141 0.29 4.95 1379 1502 

N obs. 26 19 0 2 2 0 0 26 26 26 26 26 2 25 26 

MK04.4M Mean 0.2 1.06 — 100 4 100 1 12.6 11.4 106 654 7.9 — 58 86.1  Median 0.2 0.9 — 100 4 100 1 12.6 12 102 659 7.9 — 20 30.7  Minimum 0.2 0.4 — 100 4 100 1 0.2 6.7 58 513 7.3 — 4 1.1  Maximum 0.2 2 — 100 4 100 1 27.6 15.1 176 707 8.3 — 370 987  Std. dev. 0 0.49 — — — — — 8.85 2.32 21.1 43.5 0.25 — 96.6 190 

N obs. 27 23 0 1 1 1 1 27 27 27 27 27 0 26 27 

QV04.6M Mean 0.2 0.36 — — — — — 12.1 9.54 88 558 7.7 33 35 42.5  Median 0.2 0.35 — — — — — 13.1 9.2 89 555 7.7 35 14 7.8  Minimum 0.2 0.3 — — — — — 2.3 5.2 46 519 7.4 25 4 1.4  Maximum 0.2 0.5 — — — — — 21.1 12.5 100 609 8.2 40 300 489  Std. dev. 0 0.05 — — — — — 5.58 1.64 9.66 24.7 0.22 5.7 59.7 95.8 

N obs. 27 27 0 0 0 0 0 27 27 27 27 27 5 26 27 

S000.2K Mean 0.2 3.13 — 100 9 100 2 12.3 10.5 94 676 7.8 43.1 104 101  Median 0.2 2.63 — 100 9 100 2 11.4 10.9 93 698 7.8 28 49 44.6  Minimum 0.2 1.55 — 100 6 100 2 0 5.6 69 363 7.1 5 6 3.2  Maximum 0.2 6.9 — 100 12 100 2 28.1 15.9 124 903 8.5 150 1100 1055  Std. dev. 0 1.46 — 0 2.58 — — 10.2 2.94 13.8 132 0.33 38.5 212 202 

N obs. 27 26 0 4 4 1 1 27 27 27 27 27 27 27 27 

SG16.2C Mean 0.2 1.46 — — — — — 12.2 12.6 119 773 7.9 — 103 199  Median 0.2 1 — — — — — 11.1 12.4 101 760 7.9 — 35 37.1  Minimum 0.2 0.5 — — — — — 0.1 7.3 80 419 7.5 — 4 2.3  Maximum 0.2 4.4 — — — — — 26.8 25 316 1107 8.8 — 1400 3492  Std. dev. 0 1.06 — — — — — 9.07 4.33 60.3 183 0.34 — 270 676 

N obs. 26 17 0 0 0 0 0 26 26 26 26 26 0 26 26 
 E-21

Table E-1. Continued.

Samplinglocation Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Total

suspend

solids

(mg/L)

1996 Near-bottom measurements: 

I109.5D Mean 1.28 1.5 0 — — — — 13.1 11.1 101 556 8.3 — 50 —  Median 1 1.2 0 — — — — 11.5 12.5 98 552 8.4 — 49 —  Minimum 0.7 0.95 0 — — — — 1.4 5.6 67 465 7.5 — 21 —  Maximum 3.8 4 0.04 — — — — 29.1 18.1 172 628 9 — 87 —  Std. dev. 0.67 0.67 0.01 — — — — 9.55 3.71 23.9 41.6 0.36 — 21.6 — 

N obs. 24 24 18 — — — — 24 24 24 24 24 — 22 0 

I113.0T Mean 2.87 3.09 0.19 — — — — 12.3 10.7 93 796 7.9 — 75 —  Median 2.6 2.8 0.16 — — — — 11.9 10.4 96 783 8 — 71 —  Minimum 1.1 1.3 0.06 — — — — 0.6 5.7 72 541 7.1 — 45 —  Maximum 5.8 6 0.42 — — — — 28 14.8 109 1013 8.4 — 131 —  Std. dev. 1.17 1.17 0.12 — — — — 9.44 2.99 11.6 130 0.3 — 22.6 — 

N obs. 21 21 11 — — — — 21 20 20 21 21 — 21 0 

I122.6Y Mean 2.21 2.43 0.18 — — — — 13.7 10.1 94 606 7.9 — 47 —  Median 1.6 1.85 0.12 — — — — 15.3 9.1 92 548 7.8 — 46 —  Minimum 0.8 1 0 — — — — 0.3 6.1 69 394 7.4 — 17 —  Maximum 5.8 6 0.48 — — — — 27.6 13.9 114 850 8.3 — 86 —  Std. dev. 1.45 1.45 0.17 — — — — 10 2.63 12.3 147 0.28 — 19 — 

N obs. 18 18 9 — — — — 18 18 18 18 18 — 17 0 
 E-22

Table E-2. Annual summaries (1993–1996) of chemical measurements at fixed sites grouped into near-surface (less than or equal to 0.2 m belo

(less than or equal to 0.2 m above the substrate) categories. Below-surface chemical samples are infrequently collected.

Samplinglocation Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sodi

 (mg

1993 Near-surface measurements: 

I080.2M Mean 5.21 0.07 4.22 0.26 0.14 3.97 69.1 3.28 — —  Median 4.66 0.07 3.98 0.24 0.15 4.21 70 3.24 — —  Minimum 2.31 -0.02 2.03 0.2 0.065 1.5 59.1 2.5 — —  Maximum 7.79 0.1 6.94 0.47 0.21 5.09 82.4 4.14 — —  Std. dev. 1.466 0.04 1.372 0.071 0.035 0.898 9.191 0.54 — — 

N obs. 16 17 17 16 17 17 5 11 0 0 

I113.0T Mean 5.35 0.1 4.02 0.3 0.17 3.58 67.6 3.58 — —  Median 5.26 0.1 3.72 0.28 0.16 3.95 69.5 3.74 — —  Minimum 3.34 -0.02 2.07 0.18 0.085 0.85 54.7 2.8 — —  Maximum 8.24 0.2 6.39 0.51 0.24 4.68 82.2 4.5 — —  Std. dev. 1.286 0.04 1.227 0.089 0.036 1.1 10.2 0.563 — — 

N obs. 17 18 18 17 18 17 5 11 0 0 

I121.2W Mean 5.31 0.1 4.14 0.27 0.17 3.41 65 3.64 — —  Median 5.26 0.1 3.97 0.25 0.16 3.66 65.2 3.5 — —  Minimum 3.4 0.02 2.06 0.14 0.087 0.73 39 2.9 — —  Maximum 7.15 0.4 6.09 0.4 0.3 4.59 84.1 4.76 — —  Std. dev. 0.934 0.079 1.151 0.062 0.047 0.97 13.76 0.595 — — 

N obs. 20 22 22 20 22 22 9 15 0 0 

I122.6Y Mean 4.96 0.1 3.9 0.21 0.13 3.64 64.5 3.2 — —  Median 4.31 0.09 3.72 0.22 0.13 3.6 65.6 3.1 — —  Minimum 3.06 -0.02 2.05 0.13 0.059 0.89 48 2.6 — —  Maximum 7.93 0.4 6.14 0.29 0.25 5.57 88.8 4.1 — —  Std. dev. 1.339 0.087 1.256 0.038 0.049 1.094 12.7 0.449 — — 

N obs. 19 22 22 20 22 22 9 15 0 0 

I157.8D Mean 5.34 0.1 4.28 0.32 0.19 3.6 70 3.52 — —  Median 5.09 0.1 3.79 0.32 0.19 3.76 70.8 3.43 — —  Minimum 3.19 -0.02 2.36 0.2 0.084 1.39 56 2.1 — —  Maximum 7.99 0.2 6.69 0.51 0.39 5.49 79.8 4.68 — —  Std. dev. 1.291 0.053 1.268 0.078 0.066 0.946 9.784 0.789 — — 

N obs. 15 17 17 15 17 17 5 11 0 0 

LM00.5M Mean 4.46 0.1 3.64 0.15 0.063 6.11 63.5 3.14 — —  Median 4.57 0.08 3.34 0.13 0.062 6.29 65.4 2.72 — —  Minimum 3.16 0.04 3.08 0.076 0.026 5.19 44 2.2 — —  Maximum 5.7 0.2 4.39 0.31 0.1 7.07 76.1 4.48 — —  Std. dev. 0.79 0.069 0.505 0.081 0.031 0.666 12.19 0.925 — — 

N obs. 7 7 7 7 7 7 5 6 0 0 
 E-23

Table E-2. Continued.

Samplinglocation Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sodi

 (mg

1993 Near-surface measurements: 

MK04.4M Mean 7.83 0.06 7.76 0.26 0.088 4.33 85.8 1.76 — —  Median 7.55 0.06 8.3 0.15 0.062 4.45 80 1.5 — —  Minimum 1.83 -0.02 2.28 0.044 0.013 1.04 75 1.2 — —  Maximum 13.9 0.1 12.5 0.92 0.25 5.73 103 3.5 — —  Std. dev. 3.048 0.033 2.894 0.248 0.066 1.191 12.44 0.675 — — 

N obs. 17 18 18 17 18 18 5 11 0 0 

QV04.6M Mean 2.95 0.06 2.08 0.12 0.05 6.92 78.7 1.57 — —  Median 3.08 0.06 1.99 0.085 0.036 7.1 78.7 1.26 — —  Minimum 1.91 -0.02 0.87 0.043 -0.01 3.21 71.8 1 — —  Maximum 4.38 0.2 3.17 0.48 0.2 7.82 91.5 3 — —  Std. dev. 0.668 0.041 0.605 0.103 0.045 1.009 7.87 0.717 — — 

N obs. 17 18 18 17 18 18 5 11 0 0 

S000.2K Mean 6.94 0.09 5.56 0.42 0.094 4.57 72.8 2.44 — —  Median 6.94 0.07 6.13 0.18 0.097 4.6 78.2 2.22 — —  Minimum 4.65 -0.02 1.96 0.042 0.023 2.4 28.6 1.7 — —  Maximum 9.22 0.5 8.81 2 0.16 5.98 94.3 3.7 — —  Std. dev. 1.392 0.096 1.961 0.542 0.041 0.89 20.21 0.656 — — 

N obs. 20 22 22 20 22 22 9 15 0 0 

SG16.2C Mean 6.38 0.1 5.67 0.37 0.15 4.46 67.3 2.66 — —  Median 6.34 0.07 6.12 0.27 0.14 4.7 69 2.48 — —  Minimum 4.42 -0.02 1.94 0.13 0.061 2.5 36 1.7 — —  Maximum 8.78 0.6 8.31 1.97 0.32 5.81 87 5.1 — —  Std. dev. 1.232 0.139 1.725 0.393 0.054 0.886 14.75 0.981 — — 

N obs. 20 21 21 20 21 21 9 15 0 0 

1994 Near-surface measurements: 

I080.2C Mean 4.21 0.2 3.17 0.31 0.11 2.56 61.9 4.35 26.5 39. Median 4.25 0.1 3.44 0.3 0.084 2.31 59.8 4.17 26.3 41. Minimum 2.65 -0.02 0.5 0.13 -0.01 0.54 46.2 2.43 20.7 13. Maximum 6.2 0.7 5.96 0.47 0.26 4.77 95.1 7.29 39.6 80. Std. dev. 1.132 0.161 1.467 0.091 0.073 1.268 12 1.167 4.549 15.6

N obs. 25 25 25 25 24 24 25 25 25 2
 E-24

Table E-2. Continued.

Samplinglocation Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sodi

 (mg

1994 Near-surface measurements: 

I080.2M Mean 4.16 0.2 3.43 0.27 0.1 2.63 63.2 4.45 26.7 40. Median 3.89 0.1 3.63 0.26 0.089 2.48 59.5 3.87 25.5 42. Minimum 2.8 0.03 0.62 0.13 0.019 0.54 49.8 2.55 21.3 15. Maximum 6.37 0.7 6.2 0.53 0.22 4.68 97.2 14.5 41.1 75. Std. dev. 1.037 0.147 1.497 0.089 0.053 1.207 12.37 2.375 4.37 13.9

N obs. 21 23 23 22 22 22 23 23 22 2

I109.5D Mean 2.42 0.01 0.15 0.68 0.31 2.96 42 3.24 23.6 30. Median 2.18 -0.02 -0.01 0.62 0.22 2.57 40.3 3.45 23.6 29. Minimum 0.93 -0.02 -0.01 0.032 0.019 0.22 30.7 2.22 20.2 16. Maximum 4.17 0.05 1.61 1.51 0.96 7.69 63.8 3.78 27.1 37. Std. dev. 1.017 0.01 0.385 0.44 0.295 2.257 7.714 0.497 1.697 5.27

N obs. 17 17 17 17 16 16 17 17 17 1

I113.0T Mean 4.01 0.2 3.3 0.35 0.13 2.64 63.8 4.28 27.1 48. Median 3.85 0.2 3.26 0.3 0.11 2.11 60.2 4.32 25.5 45. Minimum 2.62 0.04 0.66 0.17 -0.01 0.2 49.1 2.64 20.7 23. Maximum 6.85 0.9 6.29 0.89 0.37 6.8 98.6 6.54 42.7 10 Std. dev. 1.038 0.216 1.508 0.161 0.096 1.577 14.29 0.901 5.704 16.5

N obs. 24 25 25 24 24 24 25 25 24 2

I121.2W Mean 4.23 0.2 3.42 0.36 0.15 2.47 64.6 4.37 27.4 47. Median 4.21 0.1 3.45 0.32 0.11 2.16 61.3 4.35 25.9 46. Minimum 2.84 -0.02 0.13 0.13 0.027 0.086 40.6 2.31 16.3 11. Maximum 6.39 0.8 6.02 0.8 0.38 4.43 95.7 6.36 41.9 10 Std. dev. 1.106 0.2 1.583 0.161 0.099 1.311 15.46 0.852 6.683 19.3

N obs. 25 26 26 25 25 25 26 26 25 2

I122.6Y Mean 2.84 0.2 2.13 0.2 0.06 4.66 66.7 2.64 26.5 20. Median 2.54 0.06 1.52 0.19 0.039 4.62 65.6 2.37 25.3 9.1 Minimum 1.02 -0.02 0.43 0.041 -0.01 0.92 43.9 0.81 20.5 3.3 Maximum 4.94 0.9 4.58 0.4 0.31 7.69 94.8 6.48 38.2 58. Std. dev. 1.118 0.256 1.284 0.098 0.073 1.901 11.08 1.388 4.286 17.7

N obs. 24 24 24 24 24 24 25 25 24 2

I157.8D Mean 4.09 0.2 3.29 0.36 0.16 2.34 64.5 4.53 27 50. Median 3.89 0.1 3.52 0.32 0.16 1.89 61.9 4.41 24.6 47. Minimum 1.83 -0.02 0.61 0.12 0.045 0.089 43.7 2.07 17.7 18. Maximum 6.32 0.9 5.68 0.89 0.39 4.37 101 6.96 42.7 94. Std. dev. 1.102 0.216 1.418 0.171 0.09 1.219 15.38 1.037 6.328 15.3

N obs. 24 25 25 24 24 24 25 25 24 2
 E-25

Table E-2. Continued.

Samplinglocation Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sodi

 (mg

1994 Near-surface measurements: 

LM00.5M Mean 2.97 0.1 2.33 0.24 0.027 3.43 64.2 3.83 25.4 15. Median 2.12 0.1 2.18 0.16 0.023 3.14 58.7 3.45 23.7 12. Minimum 0.99 -0.02 -0.01 0.054 -0.01 0.14 34.2 2 12.8 7. Maximum 6.52 0.4 5.69 1.38 0.072 6.02 122 9.3 46.9 4 Std. dev. 1.71 0.1 2.029 0.285 0.021 1.793 19.57 1.813 7.732 7.94

N obs. 22 23 23 22 22 22 23 23 22 2

LM07.2M Mean 3.22 0.1 2.41 0.24 0.025 3.6 62.8 3.73 25.1 14. Median 3.45 0.05 2.52 0.16 0.021 3.6 64.2 3.45 25.2 13. Minimum 1.09 -0.02 -0.01 0.042 -0.01 0.15 30.8 1.65 11.3 6.6 Maximum 6.62 0.3 5.55 1.17 0.068 6.17 95.1 9.45 43.1 20. Std. dev. 1.636 0.098 1.981 0.265 0.019 1.839 15.7 1.761 6.991 3.78

N obs. 25 25 25 25 24 24 25 25 25 2

MK04.4M Mean 4.25 0.1 3.89 0.16 0.055 4.11 74.3 2.28 33.5 13. Median 2.98 0.05 2.47 0.088 0.012 4.62 72.9 2.04 34.3 11. Minimum 1.47 -0.02 -0.01 0.011 -0.01 0.99 48.6 1.17 19.7 5.0 Maximum 9.9 1.3 8.18 1.05 0.76 5.75 102 5.85 46.2 28. Std. dev. 2.544 0.258 2.886 0.238 0.152 1.331 14.66 1.184 5.222 5.79

N obs. 25 26 26 25 25 25 26 26 25 2

QV04.6M Mean 2.14 0.04 1.54 0.088 0.015 6.39 75.3 1.45 28.1 5.9 Median 1.46 0.03 1.08 0.051 -0.01 7.23 76.8 1.17 28.8 5.1 Minimum 0.98 -0.02 0.71 0.016 -0.01 0.59 39.1 0.75 13.1 3.2 Maximum 8.99 0.2 6.95 0.32 0.046 8.29 99.1 5.28 37.5 28. Std. dev. 1.704 0.049 1.296 0.076 0.015 1.969 10.83 0.945 4.505 4.73

N obs. 25 26 26 25 25 25 26 26 25 2

S000.2K Mean 4.36 0.05 3.96 0.15 0.022 3.5 78.8 2.64 38.9 20. Median 4.84 0.05 4.71 0.13 0.026 3.43 81 2.52 37.2 17. Minimum 0.97 -0.02 -0.01 0.063 -0.01 0.14 36.8 1.38 24.6 9.9 Maximum 7.08 0.1 8.18 0.43 0.057 6.2 115 6.78 53.9 41. Std. dev. 2.052 0.039 2.755 0.087 0.016 2.033 19.8 1.139 6.228 8.24

N obs. 25 26 26 25 25 25 26 26 25 2

SG16.2C Mean 4.22 0.07 3.35 0.31 0.089 3.46 62.1 4 28.5 3 Median 4.33 0.05 3.57 0.3 0.066 3.4 61.2 3.48 27.5 23. Minimum 1.58 -0.02 -0.01 0.043 -0.01 0.68 40.2 1.8 16.9 6.2 Maximum 6.65 0.4 7.12 0.81 0.32 5.74 99.3 9.15 45.6 75. Std. dev. 1.684 0.089 2.24 0.155 0.084 1.492 15.74 1.866 5.972 23.8

N obs. 23 25 25 23 24 24 25 25 24 2
 E-26

Table E-2. Continued.

Samplinglocation Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sodi

(mg/

1995 Near-surface measurements: 

I080.2C Mean 4.85 0.1 3.68 0.37 0.12 2.96 64.8 4.5 28 35. Median 5.04 0.1 4.07 0.3 0.086 3.04 61.7 4.02 27.3 34. Minimum 2.87 0.02 1.18 0.12 0.033 0.24 40.4 2.13 14.4 10. Maximum 6.99 0.3 5.66 1.32 0.36 4.54 109 16.8 57.5 70. Std. dev. 1.111 0.08 1.399 0.266 0.072 1.008 16.42 2.599 8.432 15.1

N obs. 26 26 26 26 26 25 26 26 26 2

I080.2M Mean 5.05 0.1 4.09 0.28 0.11 3.12 68.4 4.15 30 36. Median 5.29 0.1 4.56 0.28 0.092 3.36 67.6 3.72 29.9 34. Minimum 2.57 0.03 1.22 0.14 0.02 0.22 49.5 2.28 20.2 10. Maximum 6.78 0.3 5.69 0.46 0.34 4.45 94.5 8.79 45.8 56. Std. dev. 1.082 0.079 1.407 0.095 0.074 1.05 13.71 1.603 6.744 12.4

N obs. 19 19 19 19 19 19 19 19 19 1

I109.5D Mean 2.37 0.05 0.66 0.29 0.079 0.93 52.3 4.04 28.7 27. Median 1.94 0.05 -0.01 0.18 0.017 0.12 52.2 3.42 28.4 25. Minimum 0.6 -0.02 -0.01 0.041 -0.01 -0.05 38.1 2.37 22.9 14. Maximum 6.99 0.2 5.92 0.77 0.4 4.21 83.7 17.1 54.6 60. Std. dev. 1.456 0.046 1.562 0.239 0.125 1.372 8.669 3.018 5.942 10.2

N obs. 25 26 26 25 26 26 25 25 25 2

I113.0T Mean 5.19 0.2 3.96 0.33 0.14 2.79 68.7 3.67 29.4 41. Median 5.29 0.2 4.35 0.35 0.13 2.8 65.4 3.78 28.6 43. Minimum 2.9 0.04 1.2 0.14 0.03 0.097 49.8 0.15 21.6 17. Maximum 7.39 0.4 6.77 0.8 0.33 4.36 109 4.98 57 70. Std. dev. 1.209 0.118 1.573 0.134 0.069 1.029 13.65 0.891 7.09 13.5

N obs. 26 26 26 26 26 26 26 26 26 2

I121.2W Mean 5.15 0.2 3.94 0.32 0.15 2.7 70.1 4.09 29.7 43. Median 5.49 0.2 4.35 0.32 0.15 2.77 64.9 3.96 28.6 45. Minimum 2.87 0.04 -0.01 0.14 0.019 1.09 50 1.86 21.7 15. Maximum 6.72 0.6 6.12 0.77 0.35 3.96 101 7.05 43.3 77. Std. dev. 1.071 0.124 1.667 0.136 0.072 0.95 13.76 0.927 5.529 13.1

N obs. 26 26 26 26 26 26 26 26 26 2

I122.6Y Mean 4.12 0.1 2.83 0.19 0.054 4.47 72.5 2.69 29.7 22. Median 3.5 0.08 2.03 0.18 0.037 3.95 72.5 2.85 29.6 20. Minimum 1.51 -0.02 0.68 0.029 -0.01 1.31 54.4 0.96 23.6 3.8 Maximum 11.1 0.7 6.28 0.42 0.27 7.9 99.7 7.65 50.4 51. Std. dev. 2.16 0.141 1.911 0.105 0.055 1.984 10.2 1.477 5.297 15.3

N obs. 24 25 25 24 26 26 25 25 25 2
 E-27

Table E-2. Continued.

Samplinglocation Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sodi

(mg/

1995 Near-surface measurements: 

I157.8D Mean 5.25 0.2 3.75 0.38 0.16 2.6 69 4.32 29.5 45. Median 5.32 0.2 4.2 0.35 0.15 2.55 66.6 3.78 27.6 44. Minimum 2.84 0.07 0.92 0.039 0.012 0.71 52.9 1.98 21.2 15. Maximum 7.36 0.6 6.47 1.14 0.31 4.2 110 11.2 56.5 8 Std. dev. 1.204 0.138 1.752 0.235 0.074 1.047 13.37 1.663 6.952 15.7

N obs. 23 24 24 23 24 24 24 24 24 2

LM00.5M Mean 3.91 0.09 2.98 0.25 0.047 4.75 58.6 3.73 23.2 1 Median 3.45 0.06 2.92 0.15 0.032 4.99 59.2 3.24 22.4 12. Minimum 1.86 -0.02 -0.01 0.037 -0.01 1 32.4 2.34 10.6 4.4 Maximum 7.42 0.2 5.75 1.55 0.14 6.57 86.1 6.51 35 72. Std. dev. 1.49 0.065 1.675 0.331 0.04 1.369 15.17 1.296 7.054 14.5

N obs. 19 19 19 19 19 19 19 19 19 1

LM07.2M Mean 3.96 0.1 2.61 0.28 0.042 4.49 58.5 3.92 23.3 14. Median 3.8 0.1 2.38 0.15 0.027 4.45 60 3.39 24.5 11. Minimum 1.72 0.02 0.3 0.053 -0.01 1.31 23.4 1.95 7.56 3. Maximum 7.64 0.2 5.67 1.81 0.13 6.67 101 13.5 54.4 53. Std. dev. 1.421 0.057 1.563 0.386 0.037 1.391 19.73 2.225 9.997 12.2

N obs. 26 26 26 26 26 26 26 26 26 2

MK04.4M Mean 6.4 0.07 5.48 0.17 0.02 3.87 78.1 1.87 35.5 13. Median 5.89 0.05 6.05 0.07 -0.01 4 77.9 1.65 34.6 12. Minimum 2.17 -0.02 0.92 0.03 -0.01 1.23 41.4 -0.01 18.4 6.2 Maximum 13.6 0.2 10.8 1.87 0.16 5.89 111 3.6 61.6 48. Std. dev. 3.4 0.051 3.425 0.359 0.034 1.209 14.39 0.839 7.831 8.02

N obs. 26 26 26 26 26 26 26 26 26 2

QV04.6M Mean 2.37 0.05 1.73 0.07 0.007 6.94 80.7 1.85 30.6 5.4 Median 1.58 0.04 1 0.041 -0.01 7.22 78.8 1.11 29.7 5.3 Minimum 1.13 -0.02 0.61 0.013 -0.01 1.75 66.8 0.66 25.1 2.8 Maximum 6.77 0.2 6.35 0.33 0.015 8.67 108 17.8 42.7 8.4 Std. dev. 1.552 0.04 1.486 0.075 0.003 1.681 7.448 3.276 3.294 1.40

N obs. 26 26 26 26 26 26 26 26 26 2

S000.2K Mean 5.45 0.08 4.45 0.27 0.023 3.58 79.1 3.13 37.6 17. Median 5.89 0.06 4.93 0.12 0.016 3.77 81.6 2.37 38.7 16. Minimum 1.74 -0.02 0.021 0.04 -0.01 0.17 45.4 1.56 19.5 8. Maximum 8.55 0.2 8.29 1.85 0.08 6.17 116 16.8 52.8 29. Std. dev. 1.966 0.062 2.278 0.405 0.02 1.626 18.41 2.9 9.1 5.30

N obs. 26 26 26 26 26 26 26 26 26 2
 E-28

Table E-2. Continued.

Samplinglocation Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sodi

(mg/

1995 Near-surface measurements: 

SG16.2C Mean 4.47 0.05 3.25 0.38 0.088 3.66 66 4 31.1 34. Median 4.14 0.04 1.99 0.24 0.06 3.73 64.7 3.39 30.9 27. Minimum 1.94 -0.02 0.041 0.11 -0.01 0.85 8.68 1.83 2.75 2.4 Maximum 8.99 0.2 6.72 1.41 0.4 6 101 17.6 57.4 81. Std. dev. 1.882 0.048 2.264 0.359 0.09 1.148 16.38 3.107 9.18 23.8

N obs. 24 24 24 24 25 25 24 24 24 2

1996 Near-surface measurements: 

I080.2C Mean 4.93 0.2 3.28 0.41 0.13 2.18 65.7 5.15 27.3 47. Median 5.08 0.1 3.05 0.31 0.14 2.24 65 5.1 27.4 52. Minimum 2.19 -0.02 -0.01 0.07 0.02 0.52 33.7 3.51 12.9 16. Maximum 8.19 0.8 6.59 2.29 0.33 3.6 112 7.14 58.7 76. Std. dev. 1.6 0.236 1.451 0.498 0.083 0.837 16.02 1.045 8.346 19.0

N obs. 24 21 25 17 25 23 25 25 25 2

I080.2M Mean 4.49 0.2 3.42 0.29 0.14 2.05 65.5 5.34 26.4 47. Median 4.33 0.1 3.04 0.3 0.13 2.13 64.3 5.07 26.5 52. Minimum -0.1 -0.02 1.53 0.084 0.035 0.38 33.3 3.96 13.2 17. Maximum 8.17 0.9 6.62 0.53 0.29 3.62 87.8 7.71 40.2 72. Std. dev. 1.964 0.242 1.334 0.117 0.076 0.838 13.92 1.012 6.182 19.2

N obs. 20 17 20 13 20 17 20 20 20 2

I109.5D Mean 2.39 0.05 0.9 0.2 0.045 1.01 46.9 4.03 25 2 Median 1.9 0.02 -0.01 0.19 0.025 0.38 47.9 4.17 25.8 2 Minimum 0.58 -0.02 -0.01 0.078 -0.01 -0.05 5.24 0.15 3.01 2.7 Maximum 7.28 0.5 6.66 0.36 0.21 3.76 76.2 5.94 33.9 3 Std. dev. 1.518 0.101 1.984 0.092 0.053 1.235 13.3 1.07 6.259 7.03

N obs. 26 22 27 19 27 24 27 27 27 2

I113.0T Mean 4.85 0.2 3.83 0.45 0.14 1.99 69.1 5.36 27.6 4 Median 4.53 0.1 3.53 0.29 0.13 2.14 71.2 5.28 29.4 4 Minimum 0.38 -0.02 1.48 0.087 0.03 0.12 33.7 3.72 12.8 16. Maximum 8.99 0.9 6.8 2.71 0.33 3.29 104 7.14 42.1 77. Std. dev. 1.973 0.258 1.622 0.582 0.08 0.832 16.53 1.089 6.844 19.6

N obs. 25 20 25 18 25 23 25 25 25 2
 E-29

Table E-2. Continued.

Samplinglocation Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sodi

 (mg

1996 Near-surface measurements: 

I121.2W Mean 4.88 0.3 3.67 0.32 0.16 1.98 71.2 5.2 28.6 52. Median 4.89 0.1 3.48 0.29 0.17 1.92 73.9 5.4 29 53. Minimum 1.29 -0.02 0.83 0.12 0.037 -0.05 34 1.5 12.8 15. Maximum 8.66 0.9 6.9 0.56 0.45 3.49 111 7.47 57.8 88. Std. dev. 1.828 0.306 1.611 0.118 0.103 0.923 16.06 1.193 8.381 21.6

N obs. 27 22 27 19 27 24 27 27 27 2

I122.6Y Mean 3.63 0.07 2.78 0.16 0.042 3.85 65.5 3.29 25.2 18. Median 2.83 0.06 1.58 0.16 0.012 3.8 68.4 3.75 25 7.8 Minimum 1.46 -0.02 0.33 0.027 -0.01 1.35 31 0.84 12.3 2.4 Maximum 8.78 0.2 7.01 0.29 0.15 6.21 86.8 5.7 33.5 59. Std. dev. 2.172 0.05 2.101 0.082 0.047 1.462 13.63 1.492 5.146 18.4

N obs. 26 21 26 18 26 23 26 26 26 2

I157.8D Mean 4.67 0.2 3.65 0.31 0.19 1.94 70.1 5.5 27.3 53. Median 4.39 0.1 3.21 0.27 0.18 1.98 73.8 5.31 29 52. Minimum 0.19 -0.02 0.95 0.17 0.056 -0.05 34.8 2.91 13.2 15. Maximum 8.87 0.7 6.96 0.57 0.41 3.73 86.1 7.95 35.1 91. Std. dev. 1.875 0.191 1.63 0.123 0.093 1.02 13.42 1.132 5.961 22.2

N obs. 24 21 25 16 25 23 25 25 25 2

LM00.5M Mean 3.32 0.1 2.1 0.16 0.043 3.13 60.3 4.68 22.5 13. Median 2.88 0.03 1.62 0.11 -0.01 3.07 64.9 4.35 24.5 1 Minimum 0.8 -0.02 -0.01 0.07 -0.01 1.13 32 2.94 10.8 5.3 Maximum 6.58 0.9 5.85 0.39 0.43 4.98 86.2 9.69 31.7 28. Std. dev. 1.957 0.219 1.912 0.106 0.094 1.063 15.11 1.482 5.947 6.60

N obs. 19 17 20 13 20 17 20 20 20 2

LM07.2M Mean 3.49 0.09 2.25 0.59 0.021 3.31 62.6 4.17 23.9 14. Median 3.38 0.02 1.79 0.14 -0.01 3.13 64.2 4.08 24.1 11. Minimum 0.7 -0.02 -0.01 0.053 -0.01 1.13 17.9 2.01 4.75 1.6 Maximum 9.68 0.6 6.32 3.64 0.091 5.72 101 6.15 53.9 49. Std. dev. 2.396 0.151 1.988 1.104 0.027 1.112 18.4 0.983 8.859 9.51

N obs. 26 21 26 18 26 24 26 26 26 2

MK04.4M Mean 5.32 0.05 4.16 0.13 0.01 3.03 77 2.62 33.9 14. Median 4.72 0.03 3.18 0.066 -0.01 2.94 79.2 2.55 34.8 14. Minimum 0.77 -0.02 0.61 0.028 -0.01 1.22 37.1 1.29 19.6 7.0 Maximum 16.8 0.2 13.2 0.7 0.036 5.19 94.6 5.64 42.2 28. Std. dev. 4.135 0.06 3.435 0.158 0.008 0.974 11.86 0.938 4.767 4.99

N obs. 26 22 26 19 27 25 27 27 27 2
 E-30

Table E-2. Continued.

Samplinglocation Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sodi

 (mg

1996 Near-surface measurements: 

QV04.6M Mean 2.15 0.03 1.5 0.12 0.008 5.96 73.9 1.63 26.7 5.0 Median 1.39 0.03 0.84 0.049 -0.01 6.32 74.7 1.53 26.5 4.3 Minimum 0.9 -0.02 0.59 0.011 -0.01 2.78 7.61 0.63 2.76 0.4 Maximum 9.09 0.09 6.91 0.9 0.03 7.6 106 4.59 51.3 38. Std. dev. 1.979 0.023 1.587 0.199 0.006 1.386 18.38 0.878 8.448 6.74

N obs. 26 22 27 19 27 25 27 27 27 2

S000.2K Mean 3.99 0.1 2.88 0.22 0.029 1.98 74.3 3.81 36.3 21. Median 3.97 0.04 2.65 0.13 0.011 1.73 75 3.72 37 20. Minimum 0.19 -0.02 -0.01 0.017 -0.01 -0.05 23.1 1.74 16.3 4.5 Maximum 9.08 1.1 7.67 1.17 0.36 4.84 122 7.86 70.1 57. Std. dev. 2.639 0.246 2.58 0.266 0.068 1.599 21.62 1.329 11.54 12.0

N obs. 27 22 27 19 27 26 27 27 27 2

SG16.2C Mean 4.09 0.06 3.16 0.48 0.16 2.64 65.1 5.18 29.3 53. Median 3.29 0.03 2.58 0.3 0.09 3.03 66.6 4.14 29.6 46. Minimum 1.26 -0.02 -0.01 0.14 -0.01 0.52 30.3 2.19 15 7.6 Maximum 10.1 0.3 6.87 2.59 0.62 4.11 79.9 10.8 39.5 12 Std. dev. 2.407 0.089 2.155 0.566 0.174 1.073 12.28 2.464 5.035 35.3

N obs. 26 21 26 18 26 23 26 26 26 2
E-31

Figure E-1a. Monthly means of temperature (°C), dissolved oxygen (mg/L), oxygen saturation (%), pH, specific

conductivity (:S), and turbidity (NTU) at sites in upper and lower La Grange Pool from 1993 through 1996.
E-32

Figure E-1b. Monthly means of temperature (°C), dissolved oxygen (mg/L), oxygen saturation (%), pH, specific

conductivity (:S), and turbidity (NTU) in the Mackinaw River from 1993 through 1996.
E-33

Figure E-1c. Monthly means of temperature (°C), dissolved oxygen (mg/L), oxygen saturation (%), pH, specific

conductivity (:S), and turbidity (NTU) in the Spoon River from 1993 through 1996.
E-34

Figure E-1d. Monthly means of temperature (°C), dissolved oxygen (mg/L), oxygen saturation (%), pH, specific

conductivity (:S), and turbidity (NTU) in the Sangamon River from 1993 through 1996.
E-35

Figure E-2a. Monthly means of total nitrogen (mg/L), nitrate–nitrite nitrogen (mg/L), ammonium nitrogen (mg/L), silicate

silicon (mg/L), total phosphorus (mg/L), soluble reactive phosphorus (mg/L), total suspended solids (mg/L), and

chlorophyll a (:g/L) at sites in upper and lower La Grange Pool from 1993 through 1996.
E-36

Figure E-2b. Monthly means of total nitrogen (mg/L), nitrate–nitrite nitrogen(mg/L), ammonium nitrogen (mg/L), silicate

silicon (mg/L), total phosphorus (mg/L), soluble reactive phosphorus (mg/L), and total suspended solids (mg/L) in the

Mackinaw River from 1993 through 1996.
E-37

Figure E-2c. Monthly means of total nitrogen (mg/L), nitrate–nitrite nitrogen(mg/L), ammonium nitrogen (mg/L), silicate

silicon (mg/L), total phosphorus (mg/L), soluble reactive phosphorus (mg/L), and total suspended solids (mg/L) in the

Spoon River from 1993 through 1996.
E-38

Figure E-2d. Monthly means of total nitrogen (mg/L), nitrate–nitrite nitrogen(mg/L), ammonium nitrogen (mg/L), silicate

silicon (mg/L), total phosphorus (mg/L), soluble reactive phosphorus (mg/L), and total suspended solids (mg/L) in the

Sangamon River from 1993 through 1996.
F-1

Appendix F. Stratified Random Sampling Data: 1993–1996

In Appendix F, we summarize data from stratified random sampling (SRS) in both tabular and graphic

forms. The tables contain summary statistics for each SRS episode and stratum divided into two parameter

groups: (1) physical and biological measurements (Table F-1), and (2) chemical data (major plant nutrients;

Table F-2). Within each parameter group, the data are divided by sampling depth into three groups (surface,

middepth, and bottom). Chemical measurements are typically collected only at the surface and near the

bottom. The majority of all measurement are in the near-surface category and most episodes do not have

chemical data from other depths. Refer to Appendix A for maps and descriptions of the individual sampling

strata and episodes.

The figures (F-1–F-13) are box-whisker diagrams that connect the medians for each sampling episode

from spring 1993 through fall 1996. The 10th and 90th percentiles for each episode are indicated by the

lower and upper limits of the box. Vertical lines extend above and below each box to the minimum and

maximum observed value or to the limits of the plotting axis.

Data that have been flagged as questionable in the Long Term Resource Monitoring Program database

because of recorder error, instrument malfunction, sample damage, contamination, improper handling,

analytical error, or other difficulties are excluded from this summary. Values that are below detection are

indicated by the detection limit preceded by a negative sign. Below-detection values are included in the

determination of minima, maxima, and medians, but in the calculation of means and standard deviations,

values below detection have been replaced by a value equal to half the detection limit. The Secchi

transparency data in this report do not include observations where Secchi transparency exceeded the water

column depth. High transparency conditions are thus underrepresented.
 F-2

Table F-1. Summaries of physical-biological measurements during each stratified random sampling episode from 1993 through 1996. Data adepth categories: near surface (less than 0.2 m from surface), middepth, and near bottom (0.2 m above the substrate).

Samplingstratum Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Tota

suspen

solid

(mg/

1993 Near-surface measurements: summer

1. Main channel Mean 0.2 7.17 0.68 — — — — 26.7 5.75 73 511 8.2 35.1 31 31.4  Median 0.2 7.3 0.72 — — — — 26.8 5.8 72 511 8.1 32 31 31.3  Minimum 0.2 3.1 0.35 — — — — 26 4.3 54 500 7.8 29 14 17.2  Maximum 0.2 10 0.98 — — — — 27.6 7.4 94 523 8.9 68 50 63.6  Std. dev. 0 1.58 0.32 — — — — 0.45 0.5 6.44 6.59 0.35 7.92 7.44 10.5 

N obs. 35 35 3 0 0 0 0 35 35 35 35 35 35 35 19 

2. Side channel Mean 0.2 5.12 0.26 — — — — 26.8 5.79 73 502 8.2 33.2 32 28.6  Median 0.2 4.9 0.22 — — — — 26.5 5.8 73 503 8.1 30.5 34 27.8  Minimum 0.2 2.1 0 — — — — 25.8 5 62 489 7.8 28 18 15.2  Maximum 0.2 7.6 0.61 — — — — 28 6.5 83 515 8.9 42 43 53.2  Std. dev. 0 1.58 0.22 — — — — 0.6 0.39 5.62 6.31 0.35 4.56 7.77 12.4 

N obs. 20 20 20 0 0 0 0 20 20 20 20 20 20 20 11 

3. Backwater Mean 0.2 4.35 0.19 — — — — 26.9 5.86 74 511 8.1 42.9 23 18.9  Median 0.2 4.3 0.15 — — — — 26.9 5.7 73 509 8 40 23 17.5  Minimum 0.2 2 0.04 — — — — 25.8 4.7 60 488 7.8 23 11 7.4  Maximum 0.2 6.5 0.65 — — — — 28.8 7.6 100 564 8.9 82 38 41.9  Std. dev. 0 0.67 0.13 — — — — 0.7 0.66 8.95 15.8 0.26 13.4 6.84 8.5 

N obs. 75 75 75 0 0 0 0 75 75 75 75 75 75 75 43 

1993 Middepth measurements: summer

2. Side channel Mean 2.3 4.6 — — — — — 26.5 5.1 64 — — — — —  Median 2.3 4.6 — — — — — 26.5 5.1 64 — — — — —  Minimum 2.3 4.6 — — — — — 26.5 5.1 64 — — — — —  Maximum 2.3 4.6 — — — — — 26.5 5.1 64 — — — — —  Std. dev. — — — — — — — — — — — — — — — 

N obs. 1 1 0 — — — — 1 1 1 0 0 — 0 0 

1993 Near-bottom measurements: summer

1. Main channel Mean 6.2 6.4 0.5 — — — — 26.5 6 75 510 7.9 — 39 —  Median 6.2 6.4 0.5 — — — — 26.5 6 75 510 7.9 — 39 —  Minimum 6.2 6.4 0.5 — — — — 26.5 6 75 510 7.9 — 39 —  Maximum 6.2 6.4 0.5 — — — — 26.5 6 75 510 7.9 — 39 —  Std. dev. — — — — — — — — — — — — — — — 

N obs. 1 1 1 — — — — 1 1 1 1 1 — 1 0 
 F-3

Table F-1. Continued.

Samplingstratum Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Tota

suspen

solid

(mg/

1993 Near-bottom measurements: summer

2. Side channel Mean 4.92 5.12 0.16 — — — — 26.4 5.16 65 509 8.2 — 42 —  Median 4.7 4.9 0.14 — — — — 26.3 5.5 69 509 8.1 — 42 —  Minimum 1.9 2.1 0 — — — — 25.2 0.4 5 495 7.8 — 24 —  Maximum 7.4 7.6 0.48 — — — — 27 5.9 75 540 8.7 — 75 —  Std. dev. 1.58 1.58 0.15 — — — — 0.46 1.23 15.5 8.89 0.3 — 10.9 — 

N obs. 20 20 20 — — — — 20 20 20 20 20 — 20 0 

3. Backwater Mean 4.15 4.35 0.1 — — — — 26.3 5.19 65 515 8 — 34 —  Median 4.1 4.3 0.08 — — — — 26.3 5.2 65 510 7.9 — 33 —  Minimum 1.8 2 0 — — — — 25 4.1 52 502 7.7 — 14 —  Maximum 6.3 6.5 0.34 — — — — 27.6 6.4 82 566 8.7 — 69 —  Std. dev. 0.67 0.67 0.08 — — — — 0.55 0.46 5.91 14.1 0.2 — 10.9 — 

N obs. 75 75 75 — — — — 75 75 75 75 75 — 75 0 

1993 Near-surface measurements: fall

1. Main channel Mean 0.2 5 — — — — — 14 8.27 80 589 8.4 22.1 69 80.5  Median 0.2 5.5 — — — — — 14.6 8.2 80 619 8.4 20 68 77.1  Minimum 0.2 1.2 — — — — — 11.7 7.5 69 467 8 12 33 42.4  Maximum 0.2 7.6 — — — — — 14.9 10.4 96 688 8.7 35 148 138  Std. dev. 0 1.85 — — — — — 1.13 0.47 4.75 77.9 0.21 5.75 23.9 24.5 

N obs. 35 35 0 0 0 0 0 35 35 35 35 35 35 35 19 

2. Side channel Mean 0.2 3.4 0.35 — — — — 14.2 8.05 78 601 8.3 26.6 50 66.6  Median 0.2 3.25 0.32 — — — — 14.5 8 78 627 8.3 22 46 62.3  Minimum 0.2 1.8 0.05 — — — — 11.8 7.3 72 478 8 12 23 29.3  Maximum 0.2 5.8 0.78 — — — — 14.7 8.8 86 660 8.6 48 134 155  Std. dev. 0 1.24 0.2 — — — — 0.85 0.34 3.13 53.7 0.17 9.19 24.4 38.4 

N obs. 20 20 20 0 0 0 0 20 20 20 20 20 20 20 11 

3. Backwater Mean 0.2 2.86 0.15 — — — — 13.6 7.79 75 560 8.1 42 26 22.1  Median 0.2 2.7 0.11 — — — — 13.7 7.8 74 556 8.1 41 25 20  Minimum 0.2 1.5 0 — — — — 11.3 4.9 48 420 7.6 23 13 7.3  Maximum 0.2 5.5 0.58 — — — — 14.8 9.1 89 675 8.7 61 48 44.3  Std. dev. 0 0.64 0.15 — — — — 0.89 0.72 6.63 49.2 0.19 9.76 7.4 9.24 

N obs. 79 79 68 0 0 0 0 79 79 79 79 79 79 79 42 
 F-4

Table F-1. Continued.

Samplingstratum Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Tota

suspen

solid

(mg/

1993 Near-bottom measurements: fall

2. Side channel Mean 3.2 3.4 0.24 — — — — 14.2 7.94 77 600 8.2 — 57 —  Median 3.05 3.25 0.25 — — — — 14.5 8 78 628 8.3 — 52 —  Minimum 1.6 1.8 0.07 — — — — 11.8 7.2 71 489 8 — 23 —  Maximum 5.6 5.8 0.42 — — — — 14.7 8.4 83 664 8.4 — 150 —  Std. dev. 1.24 1.24 0.11 — — — — 0.85 0.31 2.73 52.9 0.12 — 28.7 — 

N obs. 20 20 10 — — — — 20 20 20 20 20 — 20 0 

3. Backwater Mean 2.66 2.86 0.07 — — — — 13.6 7.57 73 560 8.1 — 29 —  Median 2.5 2.7 0.05 — — — — 13.7 7.6 72 556 8 — 27 —  Minimum 1.3 1.5 0 — — — — 11.3 4.4 43 418 7.5 — 15 —  Maximum 5.3 5.5 0.25 — — — — 14.8 8.9 86 672 8.5 — 52 —  Std. dev. 0.64 0.64 0.07 — — — — 0.87 0.82 7.54 50.8 0.16 — 8.03 — 

N obs. 79 79 68 — — — — 79 79 79 79 79 — 79 0 

1994 Near-surface measurements: winter

1. Main channel Mean 0.2 4.16 — 10 20 — — 1.12 12.3 87 850 8.1 29.2 50 70  Median 0.2 4.9 — 10 20 — — 1.2 12.2 86 852 7.8 29 43 61.1  Minimum 0.2 0.6 — 10 20 — — 0.5 11 78 728 7.7 18 26 28.4  Maximum 0.2 6.4 — 10 20 — — 1.9 15.5 108 994 9.4 41 84 134  Std. dev. 0 1.9 — — — — — 0.34 1.09 7.19 66.1 0.54 6.39 18.7 31.7 

N obs. 19 19 0 1 1 0 0 19 19 19 19 19 19 19 19 

2. Side channel Mean 0.19 2.67 0.29 30 9 — — 1.07 11.8 83 762 8.4 33 45 57.6  Median 0.2 2.1 0.27 30 10 — — 1.2 12 84 765 8.3 30 44 54.7  Minimum 0.1 0.9 0 10 5 — — 0.3 10.1 71 530 7.3 18 14 12.4  Maximum 0.2 5.5 0.55 80 12 — — 2 12.9 91 972 9.3 60 130 180  Std. dev. 0.03 1.56 0.13 21.8 2.42 — — 0.44 0.65 4.64 91.5 0.61 10.9 24.5 36.7 

N obs. 20 20 20 9 9 0 0 20 20 20 20 20 20 20 20 

3. Backwater Mean 0.2 1.1 0.04 100 22 90 3 1.33 13.2 94 629 8.2 57.5 16 14.3  Median 0.2 0.9 0 100 21 100 2 1 13.2 92 640 8.1 52 14 11.5  Minimum 0.2 0.4 0 100 5 30 1 0 7.4 54 368 7 20 5 3  Maximum 0.2 6.4 0.56 100 38 100 5 5 19.8 143 838 9.2 136 55 74.3  Std. dev. 0 0.87 0.1 0 7.35 22.5 1.3 0.92 2.72 19.6 122 0.31 24 9.9 11.4 

N obs. 59 59 59 56 56 44 44 59 59 59 59 59 46 59 59 
 F-5

Table F-1. Continued.

Samplingstratum Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Tota

suspen

solid

(mg/

1994 Near-bottom measurements: winter

2. Side channel Mean 2.47 2.67 0.23 — — — — 1.04 12 84 787 8.4 — 46 —  Median 1.9 2.1 0.2 — — — — 1.2 11.9 84 775 8.2 — 49 —  Minimum 0.7 0.9 0.12 — — — — 0 10.3 72 693 7.4 — 11 —  Maximum 5.3 5.5 0.45 — — — — 2 13.6 93 960 9.6 — 68 —  Std. dev. 1.56 1.56 0.1 — — — — 0.52 0.79 5.18 70 0.67 — 15.2 — 

N obs. 20 20 15 — — — — 20 20 20 14 14 — 14 0 

3. Backwater Mean 1.02 1.22 0.03 — — — — 1.58 14.3 103 662 8.2 — 17 —  Median 0.7 0.9 0.01 — — — — 1.45 13.2 92 662 8.1 — 15 —  Minimum 0.4 0.6 0 — — — — 0.2 8.4 61 433 7.3 — 6 —  Maximum 6.2 6.4 0.48 — — — — 3.2 21 156 835 8.9 — 87 —  Std. dev. 0.93 0.93 0.09 — — — — 0.87 3.63 27.4 100 0.23 — 13.4 — 

N obs. 47 47 46 — — — — 46 46 46 47 47 — 47 0 

1994 Near-surface measurements: spring

1. Main channel Mean 0.2 5.91 0.52 — — — — 17.6 9.5 99 604 8.2 26.5 50 61.2  Median 0.2 6.4 0.52 — — — — 17.7 9.8 103 578 8.2 21 45 53.1  Minimum 0.2 2.1 0.41 — — — — 16.1 7.5 81 471 7.9 10 16 22.8  Maximum 0.2 10.1 0.64 — — — — 19.2 11.6 118 727 8.5 58 91 195  Std. dev. 0 1.88 0.12 — — — — 1.07 1.34 12.3 86.3 0.14 11.7 23.7 38.5 

N obs. 35 35 3 0 0 0 0 35 35 35 35 35 35 35 35 

2. Side channel Mean 0.2 4.1 0.34 — — — — 17.9 9.43 100 587 8.2 28 51 61  Median 0.2 4 0.32 — — — — 18 8.9 96 574 8.3 29.5 42 49.7  Minimum 0.2 2.1 0.12 — — — — 16.2 7.9 84 446 7.7 15 23 22.1  Maximum 0.2 6.4 0.63 — — — — 19.2 11.4 124 716 8.4 39 110 149  Std. dev. 0 1.27 0.14 — — — — 0.99 1.2 12.6 72.9 0.22 7.57 24.5 33.2 

N obs. 20 20 20 0 0 0 0 20 20 20 20 20 20 20 20 

3. Backwater Mean 0.2 2.83 0.13 — — — — 18 10.6 113 573 8.2 31.5 38 35.9  Median 0.2 2.8 0.09 — — — — 18.8 10.7 109 592 8.2 30 33 36.9  Minimum 0.2 1.5 0 — — — — 14.9 7.2 79 446 7.5 15 13 13  Maximum 0.2 4.3 0.43 — — — — 20 15.6 169 617 8.7 60 80 66.9  Std. dev. 0 0.48 0.09 — — — — 1.5 1.9 20.6 47.5 0.37 11.6 17.4 13.9 

N obs. 77 77 75 0 0 0 0 77 77 77 77 77 76 77 77 
 F-6

Table F-1. Continued.

Samplingstratum Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Tota

suspen

solid

(mg/

1994 Near-bottom measurements: spring

1. Main channel Mean 5 5.2 — — — — — 17.5 7.9 83 465 7.8 — 73 —  Median 5 5.2 — — — — — 17.5 7.9 83 465 7.8 — 73 —  Minimum 5 5.2 — — — — — 17.5 7.9 83 465 7.8 — 73 —  Maximum 5 5.2 — — — — — 17.5 7.9 83 465 7.8 — 73 —  Std. dev. — — — — — — — — — — — — — — — 

N obs. 1 1 0 — — — — 1 1 1 1 1 — 1 0 

2. Side channel Mean 3.9 4.1 0.22 — — — — 17.8 9.15 96 585 8.2 — 70 —  Median 3.8 4 0.19 — — — — 17.9 8.75 93 568 8.3 — 57 —  Minimum 1.9 2.1 0.15 — — — — 16.1 7.9 83 445 7.7 — 33 —  Maximum 6.2 6.4 0.33 — — — — 19 10.9 111 723 8.4 — 160 —  Std. dev. 1.27 1.27 0.07 — — — — 0.98 1.08 10.6 76.1 0.24 — 36 — 

N obs. 20 20 6 — — — — 20 20 20 20 20 — 20 0 

3. Backwater Mean 2.63 2.83 0.09 — — — — 17.7 10.2 107 576 8.2 — 46 —  Median 2.6 2.8 0.07 — — — — 18.1 10.1 102 596 8.3 — 42 —  Minimum 1.3 1.5 0 — — — — 14.2 6.6 72 450 7.4 — 16 —  Maximum 4.1 4.3 0.3 — — — — 19.7 15.6 169 633 8.9 — 88 —  Std. dev. 0.48 0.48 0.07 — — — — 1.57 1.8 20.2 47.5 0.4 — 16.6 — 

N obs. 77 77 73 — — — — 77 77 77 77 77 — 77 0 

1994 Near-surface measurements: summer

1. Main channel Mean 0.2 3.58 — — — — — 27.6 6.5 84 626 8.1 22.9 61 74.5  Median 0.2 4 — — — — — 27.9 6.6 85 623 8.2 22 62 75.6  Minimum 0.2 0.8 — — — — — 26 5.3 67 608 7.7 15 24 18.8  Maximum 0.2 5.5 — — — — — 28.4 7.4 97 662 8.4 30 92 125  Std. dev. 0 1.43 — — — — — 0.59 0.51 7.13 11.8 0.22 3.58 16.9 23 

N obs. 35 35 0 0 0 0 0 35 35 35 35 35 35 35 35 

2. Side channel Mean 0.2 1.83 0.25 — — — — 27.2 6.96 89 626 7.9 21.7 70 89.9  Median 0.2 1.55 0.24 — — — — 27.2 6.3 80 639 7.8 21 70 76.5  Minimum 0.2 0.35 0.02 — — — — 24.2 5.4 69 492 7.6 17 35 50.1  Maximum 0.2 4.5 0.51 — — — — 28.3 13.3 160 667 8.4 28 140 169  Std. dev. 0 1.18 0.12 — — — — 0.85 2.16 26.5 40.5 0.24 3.13 23.6 33.5 

N obs. 20 20 20 0 0 0 0 20 20 20 20 20 20 20 20 
 F-7

Table F-1. Continued.

Samplingstratum Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Tota

suspen

solid

(mg/

1994 Near-surface measurements: summer

3. Backwater Mean 0.2 0.67 0.03 — — — — 27.3 10.5 135 568 8.4 14.7 161 126  Median 0.2 0.44 0.02 — — — — 27 9.6 121 606 8.4 14 150 114  Minimum 0.2 0.16 0 — — — — 24.9 5.5 68 372 7.9 5 30 31.5  Maximum 0.2 2.15 0.23 — — — — 32.2 18.6 259 716 8.9 32 540 374  Std. dev. 0 0.5 0.04 — — — — 1.5 3.13 43.1 95.5 0.25 6.4 104 69.7 

N obs. 65 65 65 0 0 0 0 65 65 65 65 63 64 65 64 

1994 Middepth measurements: summer

3. Backwater Mean 0.65 1.4 — — — — — 26.6 9.19 117 495 8.4 — 85 —  Median 0.6 1.28 — — — — — 26.9 7.1 90 509 8.4 — 75 —  Minimum 0.4 0.85 — — — — — 25.3 1.8 22 395 8.1 — 36 —  Maximum 1 2.1 — — — — — 28 18 233 612 8.7 — 160 —  Std. dev. 0.21 0.44 — — — — — 1.11 5.52 72.2 84.8 0.25 — 51.1 — 

N obs. 8 8 0 — — — — 8 8 8 6 6 — 6 0 

1994 Near-bottom measurements: summer

2. Side channel Mean 1.93 2.15 0.17 — — — — 26.9 6.56 83 621 7.9 — 97 —  Median 1.75 1.98 0.18 — — — — 27 5.85 74 630 7.8 — 92 —  Minimum 0.5 0.7 0.06 — — — — 24.2 5.4 69 458 7.7 — 53 —  Maximum 4.3 4.5 0.33 — — — — 28.2 13.3 160 659 8.3 — 190 —  Std. dev. 1.1 1.09 0.07 — — — — 0.85 2.09 24.3 48.2 0.22 — 37.9 — 

N obs. 16 16 16 — — — — 16 16 16 16 16 — 15 0 

3. Backwater Mean 1.08 1.31 0.03 — — — — 25.6 7.17 89 502 8.3 — 112 —  Median 0.95 1.17 0.01 — — — — 25.7 7.6 92 529 8.3 — 93 —  Minimum 0.6 0.85 0 — — — — 23.5 1.5 18 376 7.8 — 33 —  Maximum 1.9 2.15 0.22 — — — — 28.1 12.4 159 626 8.7 — 240 —  Std. dev. 0.39 0.4 0.05 — — — — 1.23 3.03 38.7 98.4 0.24 — 53.1 — 

N obs. 20 20 20 — — — — 20 20 20 20 20 — 20 0 
 F-8

Table F-1. Continued.

Samplingstratum Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Tota

suspen

solid

(mg/

1994 Near-surface measurements: fall

1. Main channel Mean 0.2 3.03 0.1 — — — — 17.1 8.92 93 711 8.1 20.5 64 74.8  Median 0.2 3.35 0.1 — — — — 17.1 8.9 93 704 8.1 20 61 71.3  Minimum 0.2 0.3 0.1 — — — — 15.2 8 84 692 7.9 14 42 38.2  Maximum 0.2 6.1 0.1 — — — — 19.9 9.8 103 756 8.3 26 135 140  Std. dev. 0 1.65 — — — — — 1.08 0.55 5.26 18.1 0.1 3.44 17.3 23.6 

N obs. 35 35 1 0 0 0 0 35 35 35 35 35 35 35 35 

2. Side channel Mean 0.2 1.6 0.16 — — — — 16.4 8.96 92 712 8.1 19.6 73 80.7  Median 0.2 1.4 0.18 — — — — 16.3 8.4 85 693 8 19.5 72 81.3  Minimum 0.2 0.3 0 — — — — 15.3 7.6 78 672 7.9 15 35 50.4  Maximum 0.2 3.35 0.44 — — — — 18.3 14.8 158 876 8.7 26 118 124  Std. dev. 0 0.97 0.11 — — — — 0.88 1.8 20.2 59.9 0.22 2.73 20 17.7 

N obs. 18 18 17 0 0 0 0 18 18 18 18 18 18 18 18 

3. Backwater Mean 0.2 0.76 0.02 — — — — 16.4 10.9 111 546 8.6 16.1 99 110  Median 0.2 0.6 0.02 — — — — 15.8 10.3 111 598 8.6 17 75 83.6  Minimum 0.2 0.2 0 — — — — 12.3 4.3 43 357 7.9 5 39 37.2  Maximum 0.2 2 0.06 — — — — 20.3 14.8 154 846 9.1 31 480 519  Std. dev. 0 0.48 0.02 — — — — 2.07 2.82 28.8 159 0.42 5.54 82.8 95.5 

N obs. 36 36 35 0 0 0 0 36 36 36 36 36 36 36 36 

1994 Near-bottom measurements: fall

1. Main channel Mean 2.8 3.05 0.04 — — — — 17.7 8.3 87 760 8.1 — 56 —  Median 2.8 3.05 0.04 — — — — 17.7 8.3 87 760 8.1 — 56 —  Minimum 2.8 3.05 0.04 — — — — 17.7 8.3 87 760 8.1 — 56 —  Maximum 2.8 3.05 0.04 — — — — 17.7 8.3 87 760 8.1 — 56 —  Std. dev. — — — — — — — — — — — — — — — 

N obs. 1 1 1 — — — — 1 1 1 1 1 — 1 0 

2. Side channel Mean 1.95 2.19 0.12 — — — — 16 8.19 83 694 8 — 100 —  Median 1.9 2.15 0.12 — — — — 15.7 8.1 83 693 8 — 90 —  Minimum 1 1.2 0 — — — — 15 7.4 75 669 7.9 — 77 —  Maximum 3.1 3.35 0.26 — — — — 17.8 9.6 99 728 8.2 — 170 —  Std. dev. 0.74 0.76 0.07 — — — — 0.73 0.57 6.33 13.7 0.09 — 26.2 — 

N obs. 11 11 9 — — — — 11 11 11 11 11 — 11 0 
 F-9

Table F-1. Continued.

Samplingstratum Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Tota

suspen

solid

(mg/

1994 Near-bottom measurements: fall

3. Backwater Mean 1.2 1.41 0 — — — — 16.3 10.4 105 475 8.7 — 87 —  Median 1.15 1.38 0 — — — — 15.7 11.4 112 364 8.9 — 69 —  Minimum 0.9 1.1 0 — — — — 13.7 6.3 65 359 8.1 — 61 —  Maximum 1.8 2 0 — — — — 18.7 13.9 140 676 9.1 — 170 —  Std. dev. 0.32 0.32 0 — — — — 1.68 3.1 29.3 148 0.36 — 35.1 — 

N obs. 10 10 7 — — — — 10 10 10 10 10 — 10 0 

1995 Near-surface measurements: winter

1. Main channel Mean 0.2 4.29 — — — — — 0.89 11.5 80 813 7.9 28.6 46 51.4  Median 0.2 4.75 — — — — — 0.85 12.9 88 829 7.9 29 36 38  Minimum 0.2 0.65 — — — — — 0.2 5 34 712 7.8 11 23 24.9  Maximum 0.2 8.55 — — — — — 2.1 14.6 103 884 8.3 42 132 204  Std. dev. 0 2.1 — — — — — 0.54 3.26 23.1 51.6 0.11 7.14 22.3 36 

N obs. 30 30 0 0 0 0 0 30 30 30 30 30 30 30 30 

2. Side channel Mean 0.2 3.82 0.34 80 6 — — 1.01 13 91 722 7.8 34.7 32 27.1  Median 0.2 2.9 0.32 80 6 — — 0.9 13.5 95 713 7.8 35.5 32 26.3  Minimum 0.2 0.95 0 60 4 — — 0.2 5.1 35 658 7.7 26 24 15.5  Maximum 0.2 7.3 0.7 100 7 — — 3.6 15 105 888 8 44 46 55.2  Std. dev. 0 1.94 0.2 28.3 2.12 — — 0.68 2.56 18.1 56.5 0.09 4.09 4.68 9.72 

N obs. 20 20 19 2 2 0 0 20 20 20 20 20 20 20 20 

3. Backwater Mean 0.2 2.11 0.04 98.3 12 69 2 1.81 13.2 95 648 7.8 50 21 13.6  Median 0.2 2.15 0.02 100 8 60 2 1.4 13 93 663 7.8 48 22 13  Minimum 0.2 0.8 0 50 2 30 1 1 9.2 65 507 7.5 20 9 0.5  Maximum 0.2 4.3 0.21 100 24 100 4 4.3 18.2 136 734 8.6 77 55 65.1  Std. dev. 0 0.59 0.06 9.13 8.32 25.7 .72 0.8 1.63 12.9 45.8 0.28 10.2 6.17 7.07 

N obs. 72 72 67 30 30 17 17 72 72 72 72 72 72 72 72 

1995 Near-bottom measurements: winter

2. Side channel Mean 3.75 3.97 0.23 — — — — 1.04 13.3 94 716 7.8 — 31 —  Median 2.8 3.05 0.25 — — — — 0.9 13.4 95 712 7.8 — 31 —  Minimum 1.1 1.35 0 — — — — 0.2 7.6 52 658 7.7 — 24 —  Maximum 7.1 7.3 0.4 — — — — 3.6 14.6 102 890 8 — 42 —  Std. dev. 1.88 1.87 0.12 — — — — 0.69 1.69 11.7 46.3 0.06 — 4.29 — 

N obs. 19 19 18 — — — — 19 19 19 19 18 — 19 0 
 F-10

Table F-1. Continued.

Samplingstratum Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Tota

suspen

solid

(mg/

1995 Near-bottom measurements: winter

3. Backwater Mean 1.94 2.15 0.03 — — — — 1.86 13.1 95 652 7.8 — 20 —  Median 1.9 2.15 0.02 — — — — 1.4 13 92 666 7.7 — 20 —  Minimum 0.8 1 0 — — — — 1 10.2 75 559 7.6 — 6 —  Maximum 4.1 4.3 0.14 — — — — 3.6 17.7 133 739 8.6 — 57 —  Std. dev. 0.56 0.56 0.04 — — — — 0.84 1.32 11.2 41.7 0.29 — 7.79 — 

N obs. 70 70 66 — — — — 70 70 70 70 66 — 69 0 

1995 Near-surface measurements: spring

1. Main channel Mean 0.2 6 — — — — — 12.6 10.4 98 695 7.9 42.7 29 34  Median 0.2 6.4 — — — — — 12.5 10.5 99 690 8 45 28 33.3  Minimum 0.2 1.2 — — — — — 12.3 9.5 89 661 7.8 30 19 -0.1  Maximum 0.2 9.5 — — — — — 13.1 11.6 109 723 8.1 55 43 67.5  Std. dev. 0 2.46 — — — — — 0.21 0.75 6.67 21 0.1 7.36 6.02 10.6 

N obs. 35 34 0 0 0 0 0 35 35 35 35 35 35 35 35 

2. Side channel Mean 0.2 3.98 0.39 — — — — 12.8 10.1 95 671 7.9 38.3 33 35.6  Median 0.2 3.85 0.42 — — — — 12.7 10.1 96 672 7.9 40 31 32.5  Minimum 0.2 2 0.01 — — — — 12.2 9.5 89 627 7.6 31 19 22.2  Maximum 0.2 6.7 0.69 — — — — 13.6 10.6 101 711 8.1 45 44 59.3  Std. dev. 0 1.41 0.16 — — — — 0.39 0.38 3.76 20.2 0.12 3.78 6.71 11.3 

N obs. 20 20 20 0 0 0 0 20 20 20 20 20 20 20 20 

3. Backwater Mean 0.2 2.64 0.16 — — — — 12.8 11.4 107 673 8.1 44.5 22 21.7  Median 0.2 2.5 0.1 — — — — 12.8 11.3 107 685 8.1 45 21 20.8  Minimum 0.2 1.4 0 — — — — 12.1 9.3 88 600 7.7 30 8 9.8  Maximum 0.2 4.8 0.78 — — — — 13.4 13.4 127 714 8.4 70 37 52.2  Std. dev. 0 0.61 0.15 — — — — 0.31 0.77 7.5 30 0.11 8.51 6.04 7.31 

N obs. 80 80 80 0 0 0 0 80 80 80 80 80 80 80 80 

1995 Near-bottom measurements: spring

2. Side channel Mean 3.66 3.87 0.26 — — — — 12.8 10 95 673 8 — 34 —  Median 3.5 3.7 0.31 — — — — 12.7 10.1 96 671 8 — 32 —  Minimum 1.8 2 0 — — — — 12.2 9.4 88 632 7.7 — 26 —  Maximum 6.5 6.7 0.49 — — — — 13.2 10.5 100 712 8.1 — 47 —  Std. dev. 1.37 1.37 0.14 — — — — 0.35 0.37 3.48 18.4 0.1 — 6.55 — 

N obs. 19 19 19 — — — — 19 19 19 19 19 — 19 0 
 F-11

Table F-1. Continued.

Samplingstratum Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Tota

suspen

solid

(mg/

1995 Near-bottom measurements: spring

3. Backwater Mean 2.41 2.63 0.1 — — — — 12.6 11 103 675 8 — 26 —  Median 2.3 2.5 0.05 — — — — 12.7 11.1 104 686 8 — 28 —  Minimum 1.2 1.4 0 — — — — 11.7 9.2 87 612 7.7 — 8 —  Maximum 4.6 4.8 0.58 — — — — 13.4 13.4 127 715 8.4 — 47 —  Std. dev. 0.6 0.6 0.11 — — — — 0.39 0.68 6.7 28.7 0.1 — 8.12 — 

N obs. 79 79 79 — — — — 79 79 79 79 79 — 79 0 

1995 Near-surface measurements: summer

1. Main channel Mean 0.2 3.48 — — — — — 28.4 6.16 80 687 8 20.3 67 73  Median 0.2 4 — — — — — 28.3 5.9 78 689 8 19 64 61.6  Minimum 0.2 0.4 — — — — — 27.5 5.3 68 628 7.8 14 40 30.5  Maximum 0.2 5.5 — — — — — 30.2 8.3 108 734 8.5 29 138 199  Std. dev. 0 1.69 — — — — — 0.73 0.78 10.3 19.6 0.16 4.12 21.5 36.7 

N obs. 35 28 0 0 0 0 0 35 35 35 35 35 35 35 35 

2. Side channel Mean 0.2 1.73 0 — — — — 28 5.22 68 671 8 17.4 99 96.3  Median 0.2 1.38 0 — — — — 27.8 5 65 676 7.9 17.5 94 81.3  Minimum 0.2 0.3 0 — — — — 27.2 4.3 55 583 7.8 11 58 42.5  Maximum 0.2 4 0 — — — — 30.7 7.4 97 718 8.7 25 158 170  Std. dev. 0 1.16 — — — — — 0.81 0.73 9.89 26 0.26 3.9 30 37 

N obs. 20 20 1 0 0 0 0 20 20 20 20 20 20 20 19 

3. Backwater Mean 0.2 0.75 0 — — — — 30.1 9.21 125 553 8.4 16.2 137 148  Median 0.2 0.53 0 — — — — 30 9.1 126 589 8.4 12 110 99.4  Minimum 0.2 0.2 0 — — — — 25.2 4.1 55 381 7.9 1 25 17.7  Maximum 0.2 3 0 — — — — 33.8 14.1 187 724 9 41 400 511  Std. dev. 0 0.62 0 — — — — 1.99 2.12 28.6 83.4 0.23 9.89 105 131 

N obs. 78 78 2 0 0 0 0 78 76 76 78 78 78 78 77 

1995 Middepth measurements: summer

3. Backwater Mean 0.91 1.91 — — — — — 29.5 6.94 92 525 8 — — —  Median 0.9 1.8 — — — — — 30.7 8.4 107 580 7.9 — — —  Minimum 0.3 0.75 — — — — — 26.9 2.5 34 412 7.8 — — —  Maximum 1.5 3 — — — — — 31.8 12.1 157 607 8.5 — — —  Std. dev. 0.38 0.71 — — — — — 2.05 3.56 47 100 0.29 — — — 

N obs. 7 7 0 — — — — 7 7 7 5 5 — 0 0 
 F-12

Table F-1. Continued.

Samplingstratum Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Tota

suspen

solid

(mg/

1995 Near-bottom measurements: summer

2. Side channel Mean 2.13 2.34 — — — — — 27.4 4.87 62 675 7.9 — 144 —  Median 2.4 2.6 — — — — — 27.2 4.5 57 676 7.8 — 154 —  Minimum 0.6 0.75 — — — — — 27 4.2 54 660 7.8 — 97 —  Maximum 3.8 4 — — — — — 28.2 7.5 96 689 8.4 — 170 —  Std. dev. 0.96 0.97 — — — — — 0.41 0.87 11.2 8.54 0.18 — 28.6 — 

N obs. 13 13 0 — — — — 13 13 13 11 11 — 10 0 

3. Backwater Mean 1.24 1.46 — — — — — 27.5 5.99 76 485 8.2 — 73 —  Median 1 1.2 — — — — — 27.1 5.4 71 417 8.2 — 72 —  Minimum 0.5 0.7 — — — — — 24.9 0.6 8 301 7.7 — 31 —  Maximum 2.8 3 — — — — — 30.2 11.1 141 772 8.6 — 136 —  Std. dev. 0.65 0.65 — — — — — 1.7 2.87 36.2 114 0.26 — 29.4 — 

N obs. 23 23 0 — — — — 23 23 23 22 22 — 19 0 

1995 Near-surface measurements: fall

1. Main channel Mean 0.2 3.15 — — — — — 17 8.74 91 743 7.7 20 73 75.2  Median 0.2 3.65 — — — — — 16.6 8.8 90 745 7.7 20 67 65.1  Minimum 0.2 0.4 — — — — — 15.9 8 82 716 7.4 10 34 21.1  Maximum 0.2 5.8 — — — — — 20.4 9.8 106 762 7.9 26 138 212  Std. dev. 0 1.41 — — — — — 0.99 0.52 6.19 14.4 0.1 3.25 22.1 35.2 

N obs. 35 35 0 0 0 0 0 35 35 35 35 35 34 35 35 

2. Side channel Mean 0.2 1.53 0.11 — — — — 16.8 8.34 86 721 7.6 18.8 79 90.8  Median 0.2 1.45 0.09 — — — — 16.8 8.2 86 745 7.6 19 70 70.5  Minimum 0.2 0.35 0 — — — — 15.6 7.8 80 513 7.5 7 58 53.6  Maximum 0.2 3.35 0.26 — — — — 19.6 9.5 99 756 7.8 22 200 266  Std. dev. 0 0.88 0.08 — — — — 0.95 0.44 5.41 55 0.09 3.3 32.1 51.9 

N obs. 19 19 19 0 0 0 0 19 19 19 19 19 18 18 19 

3. Backwater Mean 0.2 1.15 0.01 — — — — 16.7 10.6 109 538 8.1 21.3 71 69.2  Median 0.2 1.15 0 — — — — 16 10.9 110 536 8.1 22 51 53.9  Minimum 0.2 0.2 0 — — — — 14.4 6.3 66 334 7.5 9 29 19.9  Maximum 0.2 2.6 0.06 — — — — 21.6 15.6 156 709 8.6 31 250 311  Std. dev. 0 0.64 0.02 — — — — 2.02 2.22 21.5 136 0.27 5.49 50.7 57 

N obs. 43 43 42 0 0 0 0 43 43 43 43 43 43 43 43 
 F-13

Table F-1. Continued.

Samplingstratum Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Tota

suspen

solid

(mg/

1995 Middepth measurements: fall

3. Backwater Mean 0.8 1.9 0 — — — — 14.8 10.3 102 403 8.1 — — —  Median 0.8 1.9 0 — — — — 14.8 10.3 102 403 8.1 — — —  Minimum 0.8 1.9 0 — — — — 14.8 10.3 102 403 8.1 — — —  Maximum 0.8 1.9 0 — — — — 14.8 10.3 102 403 8.1 — — —  Std. dev. — — — — — — — — — — — — — — — 

N obs. 1 1 1 — — — — 1 1 1 1 1 — 0 0 

1995 Near-bottom measurements: fall

2. Side channel Mean 1.75 1.98 0.09 — — — — 16.6 8.06 83 728 7.6 — 99 —  Median 1.7 1.9 0.08 — — — — 16.6 7.9 82 741 7.6 — 95 —  Minimum 0.8 1.05 0.01 — — — — 15.6 7.6 77 681 7.6 — 73 —  Maximum 3.1 3.35 0.2 — — — — 17.5 8.7 89 756 7.8 — 140 —  Std. dev. 0.68 0.68 0.05 — — — — 0.63 0.35 4.05 26 0.06 — 22.3 — 

N obs. 13 13 13 — — — — 13 13 13 13 13 — 11 0 

3. Backwater Mean 1.37 1.58 0 — — — — 15.1 8.88 88 491 8 — 57 —  Median 1.3 1.5 0 — — — — 14.4 9.2 90 405 8 — 50 —  Minimum 0.9 1.1 0 — — — — 14.1 4.3 44 402 7.8 — 39 —  Maximum 2.2 2.45 0.02 — — — — 19.4 14.1 139 696 8.5 — 99 —  Std. dev. 0.37 0.38 0.01 — — — — 1.44 2.05 19.2 134 0.17 — 18.2 — 

N obs. 23 23 22 — — — — 23 23 23 23 23 — 22 0 

1996 Near-surface measurements: winter

1. Main channel Mean 0.2 3.42 — 95 10 100 — 1.36 14.2 101 1016 7.7 27.8 47 51.1  Median 0.2 4.25 — 95 10 100 — 1.5 14.1 101 1030 7.7 28 47 53  Minimum 0.2 0.4 — 95 10 100 — 0 13.1 90 918 7.6 19 25 15.3  Maximum 0.2 5.8 — 95 10 100 — 2.2 15.3 109 1078 7.7 35 70 83.1  Std. dev. 0 1.89 — — — — — 0.63 0.63 5.5 44.4 0.05 4.57 12.1 17.6 

N obs. 23 23 0 1 1 1 0 23 23 23 23 23 23 23 23 

2. Side channel Mean 0.2 2.08 0 100 17 90 1 0.12 13 89 1087 7.5 39.4 31 28  Median 0.2 2 0 100 18 90 1 0.1 12.8 88 1109 7.5 40 31 27.2  Minimum 0.2 0.7 0 100 7 80 1 0 12.4 85 810 7.4 30 15 11.9  Maximum 0.2 3.6 0 100 23 100 2 0.6 15.7 109 1150 7.6 60 40 40.6  Std. dev. 0 0.99 — 0 5.09 11 .41 0.13 0.77 5.62 81.7 0.05 7.05 5.68 6.54 

N obs. 17 16 1 16 16 6 6 17 17 17 17 17 17 17 17 
 F-14

Table F-1. Continued.

Samplingstratum Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Tota

suspen

solid

(mg/

1996 Near-surface measurements: winter

3. Backwater Mean 0.2 0.97 0 100 23 96 2 1.34 17.6 125 632 7.7 65.8 10 7.2  Median 0.2 0.8 0 100 25 100 1 1.3 16.2 114 547 7.6 65 8 6.3  Minimum 0.1 0.35 0 100 1 80 1 0 13.1 90 362 7.3 39 2 -0.1  Maximum 0.2 2.1 0 100 31 100 5 2.8 24.5 177 1102 8.7 82 23 24.4  Std. dev. 0.02 0.43 0 0 6.05 7.88 1.1 0.9 3.74 29 251 0.33 13.7 6.66 5.43 

N obs. 41 41 37 39 39 21 21 41 38 38 41 41 18 41 41 

1996 Near-bottom measurements: winter

2. Side channel Mean 2.18 2.38 0 — — — — 0.15 13 89 1103 7.5 — 33 —  Median 2.1 2.3 0 — — — — 0.1 12.7 87 1118 7.5 — 33 —  Minimum 0.9 1.1 0 — — — — 0.1 12.5 86 919 7.4 — 17 —  Maximum 3.4 3.6 0 — — — — 0.5 15.3 106 1150 7.5 — 44 —  Std. dev. 0.85 0.85 — — — — — 0.11 0.75 5.43 61.9 0.04 — 6.73 — 

N obs. 13 13 1 — — — — 13 13 13 13 13 — 13 0 

3. Backwater Mean 1.19 1.4 0 — — — — 2.03 19 138 540 7.7 — 6 —  Median 1 1.2 0 — — — — 1.4 19.4 137 543 7.5 — 6 —  Minimum 0.6 0.8 0 — — — — 0.2 14.2 98 367 7.3 — 3 —  Maximum 1.9 2.1 0 — — — — 3.6 23.8 178 1161 8.1 — 15 —  Std. dev. 0.43 0.43 0 — — — — 1.06 3.12 26.2 194 0.28 — 3.82 — 

N obs. 15 15 14 — — — — 15 15 15 15 15 — 14 0 

1996 Near-surface measurements: spring

1. Main channel Mean 0.2 4.16 — — — — — 14.2 9.49 92 872 7.8 17.5 108 166  Median 0.2 4.6 — — — — — 14.5 9.3 91 888 7.8 17 103 162  Minimum 0.2 0.65 — — — — — 12.1 8.2 80 774 7 11 59 51.5  Maximum 0.2 6.7 — — — — — 15.4 12.1 116 930 8.5 23 240 463  Std. dev. 0 1.75 — — — — — 0.87 0.91 8.51 45.5 0.27 2.42 40.4 89.2 

N obs. 35 35 0 0 0 0 0 35 35 35 35 35 35 35 35 

2. Side channel Mean 0.2 2.37 0.37 — — — — 14.6 9.95 98 887 7.8 18.9 95 140  Median 0.2 2.25 0.4 — — — — 14.5 10 98 891 7.8 19 92 141  Minimum 0.2 0.45 0 — — — — 14.3 8.6 85 733 7.4 16 63 77.7  Maximum 0.2 3.9 0.52 — — — — 15.3 11.7 115 915 8.2 23 162 199  Std. dev. 0 1.02 0.15 — — — — 0.25 0.92 8.74 38.5 0.18 1.92 26.5 37.8 

N obs. 20 20 13 0 0 0 0 20 20 20 20 20 20 20 20 
 F-15

Table F-1. Continued.

Samplingstratum Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Tota

suspen

solid

(mg/

1996 Near-surface measurements: spring

3. Backwater Mean 0.2 1.19 0.04 — — — — 13.4 10.1 97 661 7.8 18.8 95 99.2  Median 0.2 0.95 0.03 — — — — 13.9 9.8 94 698 7.8 18 87 79.2  Minimum 0.2 0.4 0 — — — — 10.2 7.7 75 367 7.3 9 27 22.9  Maximum 0.2 4.25 0.24 — — — — 16.1 15.6 151 901 8.6 40 222 291  Std. dev. 0 0.67 0.04 — — — — 1.62 1.39 13.1 169 0.25 6.48 54.4 66.1 

N obs. 79 79 48 0 0 0 0 79 79 79 79 79 79 79 79 

1996 Near-bottom measurements: spring

2. Side channel Mean 2.41 2.61 0.28 — — — — 14.6 9.92 98 897 7.9 — 99 —  Median 2.3 2.5 0.27 — — — — 14.6 10 98 896 7.9 — 99 —  Minimum 0.9 1.1 0.17 — — — — 14.4 8.6 85 875 7.6 — 78 —  Maximum 3.7 3.9 0.36 — — — — 15 11.4 112 913 8.4 — 120 —  Std. dev. 0.84 0.85 0.06 — — — — 0.16 0.93 8.93 11.2 0.22 — 17.2 — 

N obs. 17 17 12 — — — — 17 17 17 17 17 — 7 0 

3. Backwater Mean 1.51 1.73 0.04 — — — — 14 9.25 90 581 7.7 — 83 —  Median 1.3 1.55 0.02 — — — — 14 9.2 89 570 7.8 — 65 —  Minimum 0.8 1.05 0 — — — — 12.3 8.3 79 368 7.3 — 29 —  Maximum 4 4.25 0.13 — — — — 16.1 11 105 901 8 — 231 —  Std. dev. 0.78 0.78 0.04 — — — — 1.14 0.63 7.06 164 0.23 — 49.8 — 

N obs. 31 31 17 — — — — 30 30 30 30 30 — 31 0 

1996 Near-surface measurements: summer

1. Main channel Mean 0.2 5.64 — — — — — 23.9 5.82 70 472 7.6 18.8 246 303  Median 0.2 6.1 — — — — — 24.4 6.3 76 494 7.6 21 63 88.8  Minimum 0.2 2.15 — — — — — 22.6 4.6 54 414 7.2 4 41 34.8  Maximum 0.2 9.15 — — — — — 24.8 7.1 86 514 8 37 750 912  Std. dev. 0 2.06 — — — — — 0.86 0.77 10.2 35.8 0.17 12.6 235 316 

N obs. 35 35 0 0 0 0 0 35 35 35 35 35 35 35 35 

2. Side channel Mean 0.2 3.46 — — — — — 23.5 5.66 67 469 7.5 13 335 424  Median 0.2 3.2 — — — — — 23 5.05 59 456 7.4 8 413 573  Minimum 0.2 1.25 — — — — — 22.8 4.9 57 448 7.4 5 33 36.1  Maximum 0.2 7 — — — — — 25.4 9.4 116 567 8.1 32 640 684  Std. dev. 0 1.46 — — — — — 0.92 1.31 17.1 35.6 0.19 8.65 207 263 

N obs. 20 20 0 0 0 0 0 20 20 20 20 20 20 20 20 
 F-16

Table F-1. Continued.

Samplingstratum Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Tota

suspen

solid

(mg/

1996 Near-surface measurements: summer

3. Backwater Mean 0.2 1.74 0.22 — — — — 25.2 7.37 91 537 7.8 20.7 84 59.7  Median 0.2 1.55 0 — — — — 25.2 6.45 79 542 7.7 18 81 54.3  Minimum 0.2 1.2 0 — — — — 22.9 4.4 51 411 7.3 6 22 14.1  Maximum 0.2 3.65 2 — — — — 27.2 13.6 173 688 8.5 55 260 183  Std. dev. 0 0.56 0.65 — — — — 0.94 2.26 29.3 81.6 0.32 10 50.1 32.2 

N obs. 80 80 18 0 0 0 0 80 80 80 80 80 80 80 80 

1996 Middepth measurements: summer

3. Backwater Mean 1.42 2.89 — — — — — 24.6 6.12 74 522 7.7 — 40 —  Median 1.5 3.05 — — — — — 24.6 5.75 70 494 7.7 — 38 —  Minimum 0.9 1.8 — — — — — 24.2 5.2 62 474 7.5 — 24 —  Maximum 1.8 3.65 — — — — — 25 7.8 94 604 7.9 — 58 —  Std. dev. 0.35 0.67 — — — — — 0.32 0.97 11.7 61 0.13 — 14.7 — 

N obs. 6 6 0 — — — — 6 6 6 6 6 — 6 0 

1996 Near-bottom measurements: summer

2. Side channel Mean 2.97 3.19 — — — — — 23.5 5.52 66 473 7.5 — 341 —  Median 2.8 3.05 — — — — — 23 5 58 458 7.4 — 430 —  Minimum 1 1.25 — — — — — 22.8 4.8 56 448 7.4 — 55 —  Maximum 6.8 7 — — — — — 24.7 7.3 89 568 8 — 650 —  Std. dev. 1.53 1.52 — — — — — 0.84 0.91 12 39.3 0.19 — 236 — 

N obs. 16 16 0 — — — — 16 16 16 16 16 — 16 0 

3. Backwater Mean 1.55 1.76 — — — — — 24.4 5.75 69 529 7.6 — 101 —  Median 1.3 1.55 — — — — — 24.5 5.6 68 504 7.6 — 89 —  Minimum 1 1.2 — — — — — 22.8 2.5 30 412 7.3 — 35 —  Maximum 3.4 3.65 — — — — — 26 9.8 121 706 8.3 — 266 —  Std. dev. 0.56 0.57 — — — — — 0.77 1.45 18.4 83.8 0.23 — 49.6 — 

N obs. 76 76 0 — — — — 76 76 76 76 76 — 76 0 
 F-17

Table F-1. Continued.

Samplingstratum Statistic

Sample

depth

(m)

Water

depth

(m)

Water

velocity

(m/s)

Ice

cover

(%)

Thickness

of ice

 (cm)

Snow

cover

(%)

Snow

depth

(cm)

Water

temp.

(oC)

Dissolved

oxygen

(mg/L)

Oxygen

saturation

(%)

Specific

cond.

(:S) pH

Secchi

depth

(cm)

Turbidity

(NTU)

Tota

suspen

solid

(mg/

1996 Near-surface measurements: fall

1. Main channel Mean 0.2 3 — — — — — 16.6 8.68 89 724 8.1 24.3 52 53.7  Median 0.2 3.6 — — — — — 16.6 9.1 94 720 8.1 24 48 50.5  Minimum 0.2 0.35 — — — — — 14.9 4.9 49 680 7.7 17 29 26.7  Maximum 0.2 7 — — — — — 21.7 10.9 124 764 8.4 31 85 102  Std. dev. 0 1.96 — — — — — 1.29 1.37 15.8 28.8 0.13 3.71 13.7 18.6 

N obs. 35 22 0 0 0 0 0 35 35 35 35 35 35 35 35 

2. Side channel Mean 0.2 1.58 — — — — — 16.6 8.98 92 738 8 23.9 61 66.2  Median 0.2 1.2 — — — — — 17.1 8.6 89 743 8 24 56 65.1  Minimum 0.2 0.3 — — — — — 15.2 7.6 76 691 7.9 17 27 30.3  Maximum 0.2 4.5 — — — — — 19.2 13 141 903 8.5 30 86 112  Std. dev. 0 1.15 — — — — — 1.15 1.22 15 46.1 0.15 3.73 15.4 22.6 

N obs. 19 19 0 0 0 0 0 19 19 19 19 19 19 19 19 

3. Backwater Mean 0.2 1.08 0 — — — — 16.6 8.54 88 538 8.2 17 112 90.6  Median 0.2 0.83 0 — — — — 15.6 8.35 85 426 8.2 17.5 88 71.6  Minimum 0.2 0.25 0 — — — — 13.5 3.4 35 414 7.7 9 33 22.7  Maximum 0.2 2.4 0 — — — — 20.8 14.3 159 775 8.6 23 377 389  Std. dev. 0 0.67 0 — — — — 2.13 2.06 22.8 129 0.19 3.61 73.1 67.2 

N obs. 54 54 2 0 0 0 0 54 54 54 54 54 54 54 54 

1996 Near-bottom measurements: fall

2. Side channel Mean 1.99 2.19 — — — — — 16.4 8.99 92 738 8.1 — 73 —  Median 2.2 2.4 — — — — — 16.5 8.8 91 742 8 — 68 —  Minimum 1 1.2 — — — — — 15 7.6 76 692 7.9 — 30 —  Maximum 4.3 4.5 — — — — — 18.7 12.6 135 902 8.5 — 150 —  Std. dev. 1.01 1.01 — — — — — 1.11 1.34 15.9 57.3 0.17 — 30.6 — 

N obs. 12 12 0 — — — — 12 12 12 12 12 — 12 0 

3. Backwater Mean 1.52 1.73 — — — — — 15.8 8.06 81 484 8.1 — 103 —  Median 1.6 1.8 — — — — — 15.2 8.3 83 422 8.2 — 99 —  Minimum 0.8 1 — — — — — 14.3 3.6 37 417 7.6 — 40 —  Maximum 2.2 2.4 — — — — — 19.8 10 98 716 8.3 — 149 —  Std. dev. 0.38 0.38 — — — — — 1.48 1.51 14.5 107 0.17 — 25.5 — 

N obs. 25 25 0 — — — — 25 25 25 25 25 — 22 0 
 F-18

Table F-2. Summaries of chemical measurements during each stratified random sampling episode from 1993 through 1996. Data are gro

categories: near surface (less than 0.2 m below the surface), middepth, and near bottom (less than 0.2 m above the substrate).

Sampling stratum Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sod

(mg

1993 Near-surface measurements: summer

1. Main channel Mean 5.497 0.06 5.034 0.235 0.173 — — — —  Median 5.721 0.056 5.329 0.242 0.174 — — — —  Minimum 2.833 0.036 3.85 0.129 0.142 — — — —  Maximum 7.023 0.102 5.851 0.261 0.206 — — — —  Std. dev. 0.859 0.017 0.678 0.029 0.016 — — — — 

N obs. 19 19 19 19 19 0 0 0 0 

2. Side channel Mean 5.681 0.072 5.254 0.236 0.17 — — — —  Median 5.698 0.064 5.334 0.237 0.171 — — — —  Minimum 4.647 0.033 4.168 0.206 0.156 — — — —  Maximum 6.609 0.156 5.521 0.263 0.184 — — — —  Std. dev. 0.544 0.035 0.382 0.016 0.007 — — — — 

N obs. 11 11 11 11 11 0 0 0 0 

3. Backwater Mean 5.498 0.077 4.623 0.221 0.166 — — — —  Median 5.467 0.077 4.494 0.219 0.162 — — — —  Minimum 4.283 0.032 3.677 0.185 0.153 — — — —  Maximum 7.313 0.131 5.68 0.268 0.207 — — — —  Std. dev. 0.594 0.026 0.641 0.018 0.013 — — — — 

N obs. 42 43 43 42 43 0 0 0 0 

1993 Near-surface measurements: fall

1. Main channel Mean 5.34 0.079 3.412 0.32 0.154 — — — —  Median 5.199 0.075 3.243 0.322 0.146 — — — —  Minimum 3.896 0.075 3.243 0.152 0.146 — — — —  Maximum 7.173 0.083 3.58 0.435 0.161 — — — —  Std. dev. 0.707 0.006 0.238 0.058 0.011 — — — — 

N obs. 19 2 2 19 2 0 0 0 0 

2. Side channel Mean 5.437 — — 0.291 — — — — —  Median 5.535 — — 0.302 — — — — —  Minimum 4.697 — — 0.204 — — — — —  Maximum 6.029 — — 0.424 — — — — —  Std. dev. 0.491 — — 0.061 — — — — — 

N obs. 11 0 0 11 0 0 0 0 0 
 F-19

Table F-2. Continued.

Sampling stratum Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sod

(mg

1993 Near-surface measurements: fall

3. Backwater Mean 4.938 — — 0.216 — — — — —  Median 4.942 — — 0.212 — — — — —  Minimum 2.868 — — 0.115 — — — — —  Maximum 6.359 — — 0.277 — — — — —  Std. dev. 0.672 — — 0.037 — — — — — 

N obs. 42 0 0 42 0 0 0 0 0 

1994 Near-surface measurements: winter

1. Main channel Mean 3.949 0.462 5.637 0.3 0.286 4.129 76.06 4.07 34.1 69 Median 3.994 0.456 5.755 0.298 0.294 4.164 83.6 4.2 35.05 63 Minimum 3.451 0.395 4.298 0.256 0.209 3.774 11.5 3.2 25.99 49 Maximum 4.487 0.81 6.15 0.377 0.347 4.408 93.75 5.51 36.74 10 Std. dev. 0.254 0.089 0.472 0.031 0.043 0.192 19.14 0.685 2.773 18

N obs. 19 19 19 19 19 19 19 19 19 

2. Side channel Mean 4.006 0.381 5.492 0.273 0.229 4.493 82.77 3.751 34.02 52 Median 4.105 0.405 5.618 0.278 0.243 4.427 84.82 3.55 33.94 52 Minimum 3 0.198 3.915 0.097 0.069 4.089 62.53 3.28 31.19 24 Maximum 4.64 0.449 6.059 0.369 0.311 5.919 89.95 4.35 35.85 70 Std. dev. 0.435 0.073 0.583 0.067 0.063 0.491 7.424 0.4 1.388 12

N obs. 11 11 11 11 11 11 11 11 11 

3. Backwater Mean 2.844 0.219 3.717 0.133 0.103 4.352 72.07 3.229 28.55 32 Median 3.41 0.181 4.546 0.125 0.091 4.112 77.4 3.34 31.09 35 Minimum 0.804 -0.02 0.892 0.053 -0.01 1.962 42.66 1.35 17.9 5. Maximum 4.063 0.551 5.444 0.321 0.271 6.259 87.45 4.32 36.15 58 Std. dev. 1.11 0.163 1.605 0.066 0.082 0.997 12.31 0.616 6.056 16

N obs. 41 41 41 41 41 41 41 41 41 

1994 Near-surface measurements: spring

1. Main channel Mean 5.011 0.053 4.544 0.217 0.028 2.18 64.99 3.531 26.86 28 Median 5.054 0.044 4.71 0.219 0.025 2.216 63.29 3.51 25.7 25 Minimum 4.125 0.029 3.698 0.155 -0.01 1.33 54.95 2.73 22.82 10 Maximum 5.813 0.101 5.41 0.268 0.059 3.072 72.66 4.41 29.79 40 Std. dev. 0.461 0.024 0.511 0.025 0.015 0.553 6.293 0.482 2.62 8.

N obs. 19 18 18 19 19 19 19 19 19 
 F-20

Table F-2. Continued.

Sampling stratum Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sod

(mg

1994 Near-surface measurements: spring

2. Side channel Mean 4.975 0.031 4.632 0.217 0.039 2.579 61.91 3.532 25.19 25 Median 5.012 -0.02 4.656 0.219 0.038 2.441 61.07 3.39 24.64 25 Minimum 4.329 -0.02 3.851 0.176 0.015 1.599 51.4 3.12 21.08 8. Maximum 6.065 0.092 5.533 0.261 0.07 3.808 71.36 4.26 29.43 38 Std. dev. 0.432 0.028 0.452 0.025 0.017 0.648 5.365 0.317 2.313 7.8

N obs. 11 11 11 11 11 11 11 11 11 

3. Backwater Mean 5.205 0.04 4.602 0.196 0.022 2.239 59.65 3.564 24.37 22 Median 5.184 0.03 4.589 0.186 0.02 2.301 60.6 3.63 24.6 24 Minimum 4.138 -0.02 3.861 0.125 -0.01 1.078 51.62 3.03 21.29 8. Maximum 6.116 0.111 5.954 0.266 0.057 3.923 63.15 3.9 25.78 29 Std. dev. 0.502 0.029 0.487 0.037 0.011 0.557 2.916 0.257 1.13 5.4

N obs. 40 40 40 40 40 40 39 39 39 

1994 Near-surface measurements: summer

1. Main channel Mean 3.35 0.101 1.392 0.241 0.118 1.558 — — —  Median 2.872 0.089 1.694 0.238 0.127 1.609 — — —  Minimum 2.606 -0.02 0.591 0.176 0.042 1.003 — — —  Maximum 11.18 0.192 1.856 0.312 0.149 2.276 — — —  Std. dev. 1.912 0.045 0.436 0.029 0.029 0.381 — — — 

N obs. 19 19 19 19 19 18 0 0 0 

2. Side channel Mean 2.898 0.108 1.199 0.237 0.082 2.339 — — —  Median 3.135 0.125 1.577 0.259 0.102 2.026 — — —  Minimum 1.222 -0.02 -0.01 0.11 -0.01 -0.05 — — —  Maximum 3.579 0.189 1.697 0.326 0.119 6.637 — — —  Std. dev. 0.641 0.053 0.584 0.065 0.04 1.904 — — — 

N obs. 11 11 11 11 11 11 0 0 0 

3. Backwater Mean 1.675 0.042 0.464 0.219 0.045 2.253 — — —  Median 1.557 0.032 0.364 0.229 0.04 2.053 — — —  Minimum 0.88 -0.02 -0.01 0.068 -0.01 -0.05 — — —  Maximum 2.54 0.161 1.524 0.423 0.162 6.637 — — —  Std. dev. 0.468 0.041 0.453 0.084 0.036 2.058 — — — 

N obs. 35 37 37 35 37 37 0 0 0 
 F-21

Table F-2. Continued.

Sampling stratum Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sod

(mg

1994 Near-surface measurements: fall

1. Main channel Mean 3.483 0.073 2.118 0.353 0.162 1.759 — — —  Median 3.515 0.066 2.103 0.327 0.156 1.922 — — —  Minimum 3.063 -0.02 1.894 0.236 0.094 -0.05 — — —  Maximum 4.226 0.191 2.246 0.499 0.209 2.068 — — —  Std. dev. 0.274 0.039 0.084 0.081 0.028 0.471 — — — 

N obs. 19 19 19 19 19 19 0 0 0 

2. Side channel Mean 3.345 0.072 1.895 0.329 0.115 1.96 — — —  Median 3.503 0.072 2.014 0.331 0.119 1.943 — — —  Minimum 2.03 -0.02 0.376 0.284 0.02 1.765 — — —  Maximum 3.767 0.119 2.303 0.372 0.157 2.183 — — —  Std. dev. 0.47 0.028 0.513 0.028 0.036 0.11 — — — 

N obs. 11 11 11 11 11 11 0 0 0 

3. Backwater Mean 2.112 0.071 0.364 0.318 0.031 1.462 — — —  Median 2.004 -0.02 0.13 0.264 0.02 0.073 — — —  Minimum 1.513 -0.02 -0.01 0.137 -0.01 -0.05 — — —  Maximum 3.106 1.018 2.412 0.977 0.125 6.73 — — —  Std. dev. 0.489 0.188 0.615 0.172 0.027 2.315 — — — 

N obs. 31 31 31 31 31 31 0 0 0 

1995 Near-surface measurements: winter

1. Main channel Mean 6.059 0.21 5.271 0.191 0.087 3.796 — — —  Median 6.074 0.21 5.283 0.189 0.088 3.831 — — —  Minimum 5.514 0.107 4.964 0.147 0.042 3.607 — — —  Maximum 6.524 0.294 5.569 0.249 0.128 3.94 — — —  Std. dev. 0.33 0.044 0.185 0.022 0.024 0.102 — — — 

N obs. 15 15 15 15 15 15 0 0 0 

2. Side channel Mean 5.45 0.242 5.65 0.206 0.114 3.965 — — —  Median 6.455 0.261 5.818 0.203 0.128 3.968 — — —  Minimum -0.1 0.064 5.205 0.169 0.071 3.751 — — —  Maximum 7.927 0.282 5.964 0.28 0.139 4.19 — — —  Std. dev. 2.78 0.061 0.294 0.037 0.025 0.118 — — — 

N obs. 11 11 11 11 11 11 0 0 0 
 F-22

Table F-2. Continued.

Sampling stratum Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sod

(mg

1995 Near-surface measurements: winter

3. Backwater Mean 3.079 0.14 4.331 0.168 0.092 3.695 — — —  Median 3.37 0.13 5.1 0.18 0.099 3.73 — — —  Minimum -0.1 -0.02 -0.01 0.094 0.016 1.865 — — —  Maximum 8.133 0.305 5.771 0.214 0.2 4.58 — — —  Std. dev. 2.892 0.088 1.558 0.031 0.045 0.495 — — — 

N obs. 39 36 24 39 39 39 0 0 0 

1995 Near-surface measurements: spring

1. Main channel Mean 6.378 0.052 6.169 0.211 0.045 3.109 — — —  Median 6.325 0.047 6.012 0.208 0.044 3.286 — — —  Minimum 5.866 -0.02 5.567 0.177 0.024 2.532 — — —  Maximum 7.381 0.108 7.113 0.277 0.08 3.559 — — —  Std. dev. 0.458 0.027 0.491 0.023 0.014 0.416 — — — 

N obs. 19 19 19 19 19 16 0 0 0 

2. Side channel Mean 6.598 0.041 6.514 0.207 0.046 3.327 — — —  Median 6.491 0.036 6.374 0.202 0.05 3.249 — — —  Minimum 6.147 -0.02 6.028 0.125 0.017 3.093 — — —  Maximum 7.517 0.093 7.564 0.312 0.075 3.628 — — —  Std. dev. 0.444 0.028 0.486 0.05 0.019 0.19 — — — 

N obs. 11 11 11 11 11 10 0 0 0 

3. Backwater Mean 6.045 0.032 5.597 0.182 0.028 2.852 — — —  Median 6.013 0.026 5.649 0.17 0.026 2.844 — — —  Minimum 5.616 -0.02 3.987 0.125 -0.01 2.2 — — —  Maximum 6.725 0.216 6.449 0.331 0.09 3.436 — — —  Std. dev. 0.24 0.037 0.431 0.04 0.014 0.253 — — — 

N obs. 43 43 43 43 43 26 0 0 0 

1995 Near-surface measurements: summer

1. Main channel Mean 4.055 0.236 2.411 0.328 0.116 — — — —  Median 3.894 0.215 2.438 0.33 0.12 — — — —  Minimum 3.382 0.126 1.2 0.082 0.071 — — — —  Maximum 6.996 0.404 2.798 0.62 0.152 — — — —  Std. dev. 0.746 0.084 0.335 0.1 0.023 — — — — 

N obs. 19 19 19 19 19 0 0 0 0 
 F-23

Table F-2. Continued.

Sampling stratum Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sod

(mg

1995 Near-surface measurements: summer

2. Side channel Mean 3.862 0.236 2.355 0.382 0.106 — — — —  Median 3.841 0.218 2.343 0.37 0.109 — — — —  Minimum 3.592 0.2 2.123 0.298 0.072 — — — —  Maximum 4.133 0.287 2.632 0.55 0.145 — — — —  Std. dev. 0.183 0.032 0.166 0.075 0.022 — — — — 

N obs. 11 10 10 11 11 0 0 0 0 

3. Backwater Mean 2.498 0.243 0.33 0.623 0.072 — — — —  Median 2.397 0.138 0.039 0.382 0.042 — — — —  Minimum 1.544 -0.02 -0.01 0.157 -0.01 — — — —  Maximum 4.804 2.951 2.995 5.926 0.37 — — — —  Std. dev. 0.69 0.466 0.608 0.906 0.081 — — — — 

N obs. 40 40 40 40 40 0 0 0 0 

1995 Near-surface measurements: fall

1. Main channel Mean 4.59 0.203 2.724 0.484 0.203 1.386 — — —  Median 4.616 0.183 2.684 0.468 0.205 1.311 — — —  Minimum 4.331 0.156 2.528 0.343 0.139 1.186 — — —  Maximum 4.897 0.294 2.989 0.654 0.26 1.583 — — —  Std. dev. 0.151 0.044 0.146 0.076 0.039 0.157 — — — 

N obs. 19 19 19 19 19 10 0 0 0 

2. Side channel Mean 4.331 0.217 2.506 0.431 0.154 1.784 — — —  Median 4.374 0.201 2.726 0.45 0.162 1.584 — — —  Minimum 4.03 0.157 2.177 0.343 0.098 1.358 — — —  Maximum 4.681 0.288 2.776 0.495 0.185 2.589 — — —  Std. dev. 0.25 0.047 0.28 0.051 0.03 0.457 — — — 

N obs. 11 11 11 11 11 8 0 0 0 

3. Backwater Mean 2.247 0.102 0.179 0.271 0.023 2.054 — — —  Median 2.213 0.058 0.02 0.203 0.018 0.528 — — —  Minimum 1.236 0.029 -0.01 0.084 -0.01 0.287 — — —  Maximum 3.834 0.462 1.762 0.625 0.053 7.197 — — —  Std. dev. 0.761 0.112 0.421 0.178 0.015 2.731 — — — 

N obs. 26 26 26 26 26 6 0 0 0 
 F-24

Table F-2. Continued.

Sampling stratum Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sod

(mg

1996 Near-surface measurements: winter

1. Main channel Mean 6.068 0.734 3.972 0.332 0.27 2.428 — — —  Median 5.928 0.82 3.976 0.299 0.221 2.462 — — —  Minimum 5.319 0.412 3.529 0.233 0.195 2.319 — — —  Maximum 7.944 0.95 4.468 0.508 0.43 2.502 — — —  Std. dev. 0.68 0.174 0.284 0.09 0.101 0.096 — — — 

N obs. 11 11 11 11 11 3 0 0 0 

2. Side channel Mean 5.705 0.95 3.306 0.271 0.211 — — — —  Median 5.731 0.94 3.304 0.27 0.213 — — — —  Minimum 5.353 0.87 3.166 0.223 0.17 — — — —  Maximum 6.101 1.12 3.433 0.32 0.249 — — — —  Std. dev. 0.241 0.071 0.086 0.031 0.024 — — — — 

N obs. 9 9 9 9 9 0 0 0 0 

3. Backwater Mean 2.424 0.131 1.246 0.081 0.046 — — — —  Median 1.928 0.04 0.923 0.049 0.017 — — — —  Minimum 1.249 0.024 0.02 0.021 -0.01 — — — —  Maximum 5.255 0.71 3 0.257 0.29 — — — —  Std. dev. 1.259 0.203 0.928 0.073 0.079 — — — — 

N obs. 20 20 20 20 20 0 0 0 0 

1996 Near-surface measurements: spring

1. Main channel Mean 5.784 — 4.287 0.566 0.179 — — — —  Median 5.859 — 4.233 0.495 0.174 — — — —  Minimum 4.771 — 0.036 0.323 0.131 — — — —  Maximum 6.584 — 7.609 0.999 0.261 — — — —  Std. dev. 0.549 — 1.87 0.214 0.039 — — — — 

N obs. 19 0 19 19 19 0 0 0 0 

2. Side channel Mean 5.764 — 4.21 0.475 0.177 — — — —  Median 5.738 — 4.308 0.461 0.176 — — — —  Minimum 4.664 — 3.607 0.263 0.081 — — — —  Maximum 6.622 — 4.527 0.738 0.274 — — — —  Std. dev. 0.5 — 0.307 0.112 0.049 — — — — 

N obs. 11 0 11 11 11 0 0 0 0 
 F-25

Table F-2. Continued.

Sampling stratum Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sod

(mg

1996 Near-surface measurements: spring

3. Backwater Mean 4.578 — 3.606 0.315 0.078 — — — —  Median 5.168 — 4.087 0.26 0.065 — — — —  Minimum 1.606 — 0.044 0.127 0.016 — — — —  Maximum 7.295 — 7.488 1.014 0.197 — — — —  Std. dev. 1.579 — 2.049 0.234 0.051 — — — — 

N obs. 43 0 43 35 43 0 0 0 0 

1996 Near-surface measurements: summer

1. Main channel Mean 4.666 0.126 3.908 0.387 0.088 3.302 — — —  Median 4.929 0.064 4.47 0.261 0.09 3.537 — — —  Minimum 3.55 0.041 2.319 0.226 0.043 1.887 — — —  Maximum 5.729 0.265 5.245 0.77 0.14 3.87 — — —  Std. dev. 0.713 0.092 1.168 0.193 0.025 0.64 — — — 

N obs. 19 19 19 19 19 9 0 0 0 

2. Side channel Mean 4.073 0.216 2.763 0.657 0.066 2.044 — — —  Median 3.924 0.245 2.396 0.68 0.066 2.044 — — —  Minimum 3.581 0.068 2.313 0.239 0.042 2.044 — — —  Maximum 5.463 0.255 4.962 1.03 0.104 2.044 — — —  Std. dev. 0.559 0.065 0.888 0.233 0.02 — — — — 

N obs. 11 11 11 11 11 1 0 0 0 

3. Backwater Mean 3.186 0.136 2.353 0.297 0.081 1.896 — — —  Median 3.27 0.152 2.417 0.308 0.083 1.873 — — —  Minimum 2.398 -0.02 1.318 0.138 -0.01 1.138 — — —  Maximum 4.065 0.277 3.335 0.49 0.158 2.453 — — —  Std. dev. 0.321 0.091 0.392 0.068 0.037 0.348 — — — 

N obs. 43 43 43 43 43 10 0 0 0 

1996 Near-surface measurements: fall

1. Main channel Mean 3.374 0.07 2.438 — 0.145 1.247 — — —  Median 3.212 0.079 2.491 — 0.145 1.239 — — —  Minimum 2.805 -0.02 2.023 — 0.093 0.986 — — —  Maximum 5.854 0.125 2.835 — 0.225 1.42 — — —  Std. dev. 0.628 0.039 0.197 — 0.032 0.189 — — — 

N obs. 19 19 19 0 19 4 0 0 0 
 F-26

Table F-2. Continued.

Sampling stratum Statistic

Total nitrogen

(N mg/L)

Ammonium

 (N mg/L)

Nitrate–nitrite

 (N mg/L)

Total

phosphorus

(P mg/L)

Soluble

reactive P

 (P mg/L)

Silica

 (Si mg/L)

Calcium

(mg/L)

Magnesium

(mg/L)

Potassium

(mg/L)

Sod

(mg

1996 Near-surface measurements: fall

2. Side channel Mean 3.121 0.083 2.261 — 0.139 1.378 — — —  Median 3.233 0.074 2.432 — 0.128 1.181 — — —  Minimum 1.849 0.029 0.692 — 0.077 1.181 — — —  Maximum 3.434 0.139 2.569 — 0.22 1.574 — — —  Std. dev. 0.454 0.042 0.563 — 0.044 0.278 — — — 

N obs. 10 10 10 0 10 2 0 0 0 

3. Backwater Mean 1.826 0.069 0.277 — 0.022 1.179 — — —  Median 1.491 0.048 -0.01 — -0.01 1.122 — — —  Minimum 1.089 -0.02 -0.01 — -0.01 0.915 — — —  Maximum 4.298 0.3 2.966 — 0.172 1.645 — — —  Std. dev. 0.748 0.062 0.629 — 0.039 0.284 — — — 

N obs. 30 30 30 0 30 5 0 0 0 
F-27

Figure F-1. Water temperature (°C) in stratified random sampling episodes from spring 1993 (Sp93) through fall 1996.

Each sampling stratum is plotted separately. A solid line connects the medians of each episode, the 90th and 10th

percentiles of the data are shown by the upper and lower extent of the box, and vertical lines extend to the maximum

and minimum values (or to the limits of the plotting axis).
F-28

Figure F-2. Dissolved oxygen (mg/L) in stratified random sampling episodes from spring 1993 (Sp93) through fall 1996.

Each sampling stratum is plotted separately. A solid line connects the medians of each episode, the 90th and 10th

percentiles of the data are shown by the upper and lower extent of the box, and vertical lines extend to the maximum

and minimum values (or to the limits of the plotting axis).
F-29

Figure F-3. Dissolved oxygen saturation (%) in stratified random sampling episodes from spring 1993 (Sp93) through

fall 1996. Each sampling stratum is plotted separately. A solid line connects the medians of each episode, the 90th and

10th percentiles of the data are shown by the upper and lower extent of the box, and vertical lines extend to the maximum

and minimum values (or to the limits of the plotting axis).
F-30

Figure F-4. Specfic conductivity (:S) in stratified random sampling episodes from spring 1993 (Sp93) through fall 1996.

Each sampling stratum is plotted separately. A solid line connects the medians of each episode, the 90th and 10th

percentiles of the data are shown by the upper and lower extent of the box, and vertical lines extend to the maximum

and minimum values (or to the limits of the plotting axis).
F-31

Figure F-5. Secchi disk transparency (cm) in stratified random sampling episodes from spring 1993 (Sp93) through fall

1996. Each sampling stratum is plotted separately. A solid line connects the medians of each episode, the 90th and 10th

percentiles of the data are shown by the upper and lower extent of the box, and vertical lines extend to the maximum

and minimum values (or to the limits of the plotting axis).
F-32

Figure F-6. Turbidity (NTU) in stratified random sampling episodes from spring 1993 (Sp93) through fall 1996. Each

sampling stratum is plotted separately. A solid line connects the medians of each episode, the 90th and 10th percentiles

of the data are shown by the upper and lower extent of the box, and vertical lines extend to the maximum and minimum

values (or to the limits of the plotting axis).
F-33

Figure F-7. Total suspended solids (mg/L) in stratified random sampling episodes from spring 1993 (Sp93) through fall

1996. Each sampling stratum is plotted separately. A solid line connects the medians of each episode, the 90th and 10th

percentiles of the data are shown by the upper and lower extent of the box, and vertical lines extend to the maximum

and minimum values (or to the limits of the plotting axis).
F-34

Figure F-8. Total nitrogen (mg/L) in stratified random sampling episodes from spring 1993 (Sp93) through fall 1996. Each

sampling stratum is plotted separately. A solid line connects the medians of each episode, the 90th and 10th percentiles

of the data are shown by the upper and lower extent of the box, and vertical lines extend to the maximum and minimum

values (or to the limits of the plotting axis).
F-35

Figure F-9. Nitrate–nitrite nitrogen (mg/L) in stratified random sampling episodes from spring 1993 (Sp93) through fall

1996. Each sampling stratum is plotted separately. A solid line connects the medians of each episode, the 90th and 10th

percentiles of the data are shown by the upper and lower extent of the box, and vertical lines extend to the maximum

and minimum values (or to the limits of the plotting axis).
F-36

Figure F-10. Ammonium nitrogen (mg/L) in stratified random sampling episodes from spring 1993 (Sp93) through fall

1996. Each sampling stratum is plotted separately. A solid line connects the medians of each episode, the 90th and 10th

percentiles of the data are shown by the upper and lower extent of the box, and vertical lines extend to the maximum

and minimum values (or to the limits of the plotting axis).
F-37

Figure F-11. Total phosphorus (mg/L) in stratified random sampling episodes from spring 1993 (Sp93) through fall 1996.

Each sampling stratum is plotted separately. A solid line connects the medians of each episode, the 90th and 10th

percentiles of the data are shown by the upper and lower extent of the box, and vertical lines extend to the maximum

and minimum values (or to the limits of the plotting axis).
F-38

Figure F-12. Soluble reactive phosphorus (mg/L) in stratified random sampling episodes from spring 1993 (Sp93)

through fall 1996. Each sampling stratum is plotted separately. A solid line connects the medians of each episode, the

90th and 10th percentiles of the data are shown by the upper and lower extent of the box, and vertical lines extend to

the maximum and minimum values (or to the limits of the plotting axis).
F-39

Figure F-13. Fluorometric chlorophyll a (:g/L) in stratified random sampling episodes from spring 1993 (Sp93) through

fall 1996. Each sampling stratum is plotted separately. A solid line connects the medians of each episode, the 90th and

10th percentiles of the data are shown by the upper and lower extent of the box, and vertical lines extend to the maximum

and minimum values (or to the limits of the plotting axis).
REPORT DOCUMENTATION PAGE Form Approved

OMB No. 0704-0188

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data

sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other

aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and

Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188),

Washington, D.C. 20503

1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE

November 2002

3. REPORT TYPE AND DATES COVERED

4. TITLE AND SUBTITLE

 Limnological monitoring on the Upper Mississippi River System, 1993–1996: Long Term Resource Monitoring Program

Havana Field Station

5. FUNDING NUMBERS

6. AUTHOR(S)

David M. Soballe,1

 Richard H. Wright,2 and Steven W. Stenzel 2

7. PERFORMING ORGANIZATION NAME AND ADDRESS

1

U.S. Geological Survey, Upper Midwest Enviromental Sciences Center, 2630 Fanta Reed Road, La Crosse, Wisconsin 54603.

2

Illinois Natural History Survey, Havana Field Station 704 North Schrader Avenue, Havana, Illinois 62644

8. PERFORMING ORGANIZATION

 REPORT NUMBER

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

U.S. Geological Survey

Upper Midwest Environmental Sciences Center

2630 Fanta Reed Road

La Crosse, Wisconsin 54603

10. SPONSORING/MONITORING

 AGENCY REPORT NUMBER

2002-P005

11. SUPPLEMENTARY NOTES

12a. DISTRIBUTION/AVAILABILITY STATEMENT

Release unlimited. Available from National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22161

(1-800-553-6847 or 703-487-4650. Available to registered users from the Defense Technical Information Center, Attn: Help

Desk, 8725 Kingman Road, Suite 0944, Fort Belvoir, VA 22060-6218 (1-800-225-3842 or 703-767-9050).

12b. DISTRIBUTION CODE

13. ABSTRACT (Maximum 200 words)

Since 1988, the Long Term Resource Monitoring Program (LTRMP) staff has performed basic limnological field measurements in the Upper Mississippi River System. The

period of this report (1993–96) includes a major revision of the LTRMP sampling design in 1993 that added randomization, broader spatial coverage, and increased

monitoring of tributaries and locations that allow monitoring of material transport. Two significant floods (1993 and 1995) occurred in the reporting period. In 1993, the La

Grange reach of the Illinois River was above the 1940–96 mean river stage for most of the year and was below flood stage for only three brief periods. The flood in spring

1995 receded sooner than in 1993; however, the 137 m (450.66 feet) peak on May 31, 1995 was the third highest river elevation recorded at Havana, Illinois. Low dissolved

oxygen levels in the main channel were also notable in 1993–96, with concentrations at or below 5 mg/L observed each year.

14. SUBJECT TERMS

Annual report, limnology, LTRMP, Mississippi River, water quality 

15. NUMBER OF PAGES

 16 pp. + Appendixes A–F

16. PRICE CODE

17. SECURITY CLASSIFICATION

 OF REPORT

Unclassified

18. SECURITY CLASSIFICATION

 OF THIS PAGE

Unclassified

19. SECURITY CLASSIFICATION

 OF ABSTRACT

Unclassified

20. LIMITATION OF ABSTRACT
The Long Term Resource Monitoring Program (LTRMP) for the Upper Mississippi

River System was authorized under the Water Resources Development Act of 1986 as 

an element of the Environmental Management Program. The mission of the LTRMP

is to provide river managers with information for maintaining the Upper Mississippi 

River System as a sustainable large river ecosystem given its multiple-use character.

The LTRMP is a cooperative effort by the U.S. Geological Survey, the U.S. Army Corps

of Engineers, and the States of Illinois, Iowa, Minnesota, Missouri, and Wisconsin.