Long Term Resource Monitoring Program

Program Report

2002-P004

Limnological Monitoring on the

Upper Mississippi River System, 1993–1996:

 Long Term Resource Monitoring Program

 Bellevue Field Station

This PDF file may appear different from the printed report

because of slight variations incurred by electronic transmission.

The substance of the report remains unchanged.

October 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 Program

Bellevue Field Station 

by

David M. Soballe, David E. Gould, Scott A. Gritters,

Russ D. Gent, and Michael J. Steuck

October 2002

U.S. Geological Survey

Upper Midwest Environmental Sciences Center

2630 Fanta Reed Road

La Crosse, Wisconsin 54603
Suggested citation:

Soballe, D. M., D. E. Gould, S. A. Gritters, R. D. Gent, and M. J. Steuck. 2002. Limnological monitoring on the Upper

Mississippi River System, 1993–1996: Long Term Resource Monitoring Program Bellevue Field Station. U.S. Geological

Survey, Upper Midwest Environmental Sciences Center, La Crosse, Wisconsin, October 2002. LTRMP 2002-P004. 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Sample Collection and Field Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

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

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

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

Table 2. Period of operation for each of the Long Term Resource Monitoring Program field stations. . 7

Figures

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. ................................................................ 3

Figure 2. 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

Figure 3. Water elevation (meters above mean sea level) at Lock and Dam 12 tailwater 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 Bellevue 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

Bellevue Field Station

by 

David M. Soballe

U.S. Geological Survey

Upper Midwest Environmental Sciences Center

2630 Fanta Reed Road

La Crosse, Wisconsin 54603

 David E. Gould, Scott A. Gritters, Russ D. Gent, and Michael J. Steuck

Iowa Department of Natural Resources

Mississippi River Monitoring Station

206 Rose Street

Bellevue, Iowa 52031

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.

Several short-term trends were noted during 1993–96. Total nitrogen, nitrate–nitrite nitrogen, soluble reactive

phosphorus, total phosphorus, and turbidity generally decreased while ammonia increased in all study pools

(12, 13, and 14). Sediment and plant nutrient concentrations were higher in two tributaries (the Maquoketa and

Wapsipinicon Rivers, Iowa) than in the main channel of the Mississippi River.

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 Iowa Department of Natural

Resources 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

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.

<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.
4

Figure 2. 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.

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.
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).

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 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). In the nonbraided portion of the Upper

Mississippi River main stem (between Pools 14 and 26), sampling under the LTRMP is limited to the

extreme upstream and downstream ends. However, the Mississippi River main stem and its tributaries in this

reach are monitored by other state and Federal programs. Staff of the Iowa Department of Natural Resources

Mississippi River Monitoring Station office in Bellevue, Iowa, conduct LTRMP monitoring in the vicinity

of Pool 13, defined by Lock and Dam 13 at Mississippi River mile 522.5 and Lock and Dam 12 at

Mississippi River mile 556.7, as well as Pool 12, Pool 14, and selected tributaries (Figure A-1). Water quality

has been monitored since 1988 (Appendixes A and B).

The total water surface area of the pool (between Lock and Dam 12 and Lock and Dam 13) is 11,183 ha

(27,636 acres), with 9,600 ha (23,756 acres) of backwater and 1,570 ha (3,880 acres) of main channel. This

reach of river exhibits braided-channel morphometry and has a diverse mosaic of backwaters, side channels,

and other aquatic areas.
7

The floodplain in the vicinity of Pool 13 is dominated by open water habitats and aquatic vegetation and

has low agricultural use. The vast expanse of lower Pool 13 is an important resting area for migratory

waterfowl and supports one of the largest documented populations of fingernail clams (Sphaeriidae) in the

Upper Mississippi River.

In 1992, the exotic zebra mussel (Dreissena polymorpha) was first documented in Pool 13, and, during

this study period (1993–96), became well established in the region. Zebra mussels can have multiple effects

on water quality and riverine biota. Their high capacity for filtering can effectively remove plankton and

other particulate material from the water, thus reducing turbidity and competing with other particulate

feeders. By removing oxygen-producing phytoplankton from the water, by consuming oxygen in their own

respiration, and by the decay of their fecal material, zebra mussels may significantly alter the oxygen regime.

Close monitoring is needed to evaluate these effects.

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).

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 $$$$ $$$$$ $$$$$$ $$$$$$

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).

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
8

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 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. 

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

150 sites are randomly selected from six sampling strata and sampling is usually completed 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 pool- 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
9

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 for tracking or

mapping changes in stratum boundaries, and the LTRMP staff intend 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 at least 0.2 m deep or

deeper. However, samples are occasionally collected in shallower waters, particularly under ice cover, when

they can be taken 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
10

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

analyses 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

conduct of field work. Guidelines for the time of sampling and randomization of sampling order 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:
11

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 Rivers discharge

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 Lock and Dam 12 tailwater gage (Figure 3) represent the hydrologic regime in the

Pools 12–14 study area. Flood stage at this gage is 182.03 m (597.20 feet) above mean sea level. Water levels

at this site reflect the large, late-season flood of 1993 and indicate that water levels during the entire

reporting period have generally been above the 56-year average but usually below flood stage. Flood stage

was reach only three times during the study period (twice in 1993 and once in 1996). In general, the

hydrograph is dominated by a high flow period in spring with a smaller rise in fall. Summer and winter

periods are characterized by low water levels. Summer and fall water levels have been substantially elevated

above average during the reporting period, which has probably influenced the limnological data. Weekly

fluctuations of 1–2 m are not uncommon for Pool 13.

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.
12

Figure 3. Water elevation (meters above mean sea level) at Lock and Dam 12 tailwater 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.

In 1993–96, the Bellevue water quality team made about 1,900 site visits to fixed sampling locations.

During these visits, about 1,500 grab samples were collected for chemical processing (Appendix E).

Although the number of site visits during a week of sampling was typically about 15–16, sampling often

spanned a weekend (Figure D-1 and Table D-1). The 1993 sampling redesign reduced the number of weekly

fixed-site visits from 26 to 16 (Figure D-1).

Median sampling time (Figures D-2–D-4) showed little effect from the September 1993 change in the

fixed-site sampling protocol because the Bellevue Field Station already centered most sampling around noon.

However, the effect of the new sampling window definition decidedly narrowed the distribution of sampling

times (Figure D-2). Fixed-site sampling generally complied well with the LTRMP design, but a seasonal

pattern has emerged in the sampling times, with a tendency to sample later in late winter and early spring,

and earlier in summer. The linear trend in sampling time at the fixed sites was not statistically significant

(P = 0.10).
13

The distribution of median sampling times for sites (Figure D-4) is parallel to that for samples

(Figure D-2). In 1993, the median sampling time varied substantially among sites (Figure D-4) and most sites

were sampled consistently in the morning. After noon-centered sampling was implemented in 1993, the

median sampling times in 1994 and 1995 were tightly grouped around noon (Figure D-2).

Fixed-site Sampling Data

Fixed-site sampling by Bellevue 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.

The fixed-site data reveal important aspects of the three navigational pools and tributaries in this study

area. For example, the data suggest a long-term decline in the concentrations of total and nitrate–nitrite

nitrogen as well as total and soluble reactive phosphorus (Figure E-2). When coupled with steady-todeclining flows (Figure 3), a significant decline in the transport of these materials in this reach is suggested.

Detailed loading calculations are needed to verify this apparent trend. Ammonia appeared to increase during

this period without a readily apparent cause.

Tributaries in this study reach seem to have detrimental effects in the receiving waters of the Mississippi

River. The monitored tributaries are much higher in nitrogen, phosphorus, suspended solids, and turbidity

than the main channel of the Mississippi River. All the monitored tributaries exhibit spring turbidity maxima

coincident with increased agricultural activity, snow melt, and higher rainfall.

 The increase in turbidity and suspended solids from upstream to downstream in Pool 13 (Figure E-2)

indicates that this reach (and its adjacent watershed) overall is a significant source of sediment to the system.

The Maquoketa River enters Pool 13 near midpool and carries suspended solids and turbidity at levels more

than 10 times that in the main channel of the Mississippi River (Appendix E). The influence of the

Maquoketa River and other tributaries is evident from the higher (clearer) Secchi transparencies in upper

Pool 13 than downstream (Figure E-1).

The fixed-site data (Appendix E) show the strong seasonality of flow-related parameters (e.g., turbidity,

Secchi transparency, suspended solids, total phosphorus, nitrogen species). Nitrate, ammonium, and silicate

concentrations peaked in the tributaries in late winter and early spring, but these patterns are less distinct in

the main channel. In backwaters, ammonium nitrogen concentrations peaked in January and February when

backwater sites are generally ice covered and ammonium can accumulate from the decay of organic material

(e.g., dead fish, vegetation, and algae). Elevated ammonium concentrations may stress fish populations that

congregate in backwaters in winter. 

Dissolved oxygen saturation is a function of water temperature and thus shows strong seasonality at all

sites. Monthly means do not show the extremes in dissolved oxygen, 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.
14

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, the Bellevue Field Station participated in 14 stratified random sampling episodes. In

these 14 episodes, the field team visited about 2,100 sites (Appendix B) and about 2,000 grab samples were

collected for chemical analyses. Most samples were analyzed for chlorophyll a and suspended solids, but in

accord with the design for stratified random sampling, about half of the samples (1,100) were also analyzed

for nitrogen and phosphorus species.

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

record (Table B-2), although there have been a few exceptions resulting from hazardous weather and unsafe

ice conditions that prohibited safe field operations.

The SRS by the Bellevue field team has conformed well to the general LTRMP design, has been generally

consistent during this period, and is centered on noon (Figure D-5). However, there is a tendency to sample

the backwater and impounded strata later in the day in winter months; also, a shift toward earlier sampling

times occurred in the main channel stratum in 1996.

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).

As with the fixed-site data, the SRS results (Appendix F) indicated a general decline in nitrogen and

phosphorus concentrations from 1993 to 1996, and strong seasonality was noted in many of the parameters

monitored. Winter is typified by a high Secchi transparency, high ammonium nitrogen, low total suspended

solids, low volatile suspended solids, and low chlorophyll. Spring is characterized by high turbidity, high

suspended solids, high chlorophyll levels, and relatively high plant nutrients. The summer sampling episodes

have the lowest dissolved oxygen values recorded. Dissolved oxygen concentration is driven by the decreased

solubility of oxygen in water at higher temperature. Dissolved oxygen values rarely fell below 5 mg/L (an

accepted threshold for stress to many fish species). Extremely low oxygen values were found only in

backwater areas. In fall, most of the monitored parameters were close to their annual averages.
15

As was found in the fixed-site sampling, ammonium nitrogen values peaked in winter beneath the ice.

This was especially pronounced in winter 1996. These high under-ice ammonium values may add additional

stress to fish populations, especially in backwaters. Fish are known to concentrate in certain backwaters and

constant exposure to high ammonium may be detrimental. Further investigation of this phenomenon seems

warranted.

Summary and Recommendations

In this report, we document 4 years of LTRMP sampling by the staff of the Iowa Department of Natural

Resources, Mississippi River Monitoring Station at Bellevue, Iowa. The sampling crews completed about

1,900 visits to fixed sampling sites and 2,100 visits to stratified random sites from 1993 through 1996. We

provide basic graphic and tabular summaries of the collected data.

The period of monitoring was marked by several important events: the redesign of the monitoring network

and updating of field equipment in 1993, and record flooding in spring and summer 1993 and spring 1996.

The zebra mussel, a prolific bivalve introduced from Europe that became well established in this study reach

during this period, has the potential to affect water quality and river biota. When present in large numbers,

zebra mussels can effectively filter a significant fraction of the plankton and other particulate material from

the water, thus reducing turbidity and competing with other particulate feeders. By removing oxygenproducing phytoplankton from the water, by consuming oxygen in their own respiration, and by the decay

of their fecal material, zebra mussels may significantly alter the oxygen regime. These effects can only be

shown by continued, close-interval monitoring in vulnerable areas.

The monitoring data show that the Mississippi River near Bellevue is moderately turbid, has nearsaturated dissolved oxygen concentrations at most locations throughout most of the year (near midday), and

has high concentrations of plant nutrients (particularly nitrogen) and suspended sediment. Tributaries

monitored in this study reach are especially rich in plant nutrients and suspended solids in relation to the

main channel.

Several short-term trends were noted during this reporting period (1993–96). Plant nutrients (nitrogen and

phosphorus) exhibited declining concentrations, as did turbidity, total suspended solids, volatile suspended

solids, and chlorophyll a. One notable exception was ammonium nitrogen, which tended to increase and may

have negative environmental effects if this trend continues. 

 We recommend future expansion of tributary monitoring in this reach because the watershed adjacent to

Pools 12–14 is a major contributor of suspended solids and plant nutrients to the Mississippi River. Several

tributaries in this reach remain unmonitored, including the Little Maquoketa River (Iowa), Catfish Creek

(Iowa), the Little Menominee River (Illinois), Sisinawa River (Illinois), Tetes Des Morts River (Iowa), Mill

Creek (Iowa), Apple River (Illinois), Elk River (Iowa), and Otter Creek (Illinois).

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
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.

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 site

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

M582.5B 1 05/06/93–12/31/96 MC 693483 4711424 94

M574.2D 2 05/06/93–11/28/95 SC 698355 4701302 55

M566.2R 3 01/13/94–02/20/95 BWC 708476 4695192 8

M564.5T 4 01/13/94–01/25/96 BWC 710457 4693461 12

M563.9T 5 05/06/93–12/17/96 BWC 711179 4692608 90

TM04.1M 6 11/07/97– TRIB 703023 4692249 0

M556.4A 7 10/15/90–12/17/96 MC 712792 4681148 112

M554.8F 8 08/02/88–11/17/94 MC 714669 4679382 37

M551.3N 9 08/02/88–10/21/96 BWC 719457 4676895 61

M551.3M 10 08/02/88–04/28/93 BWC 719234 4676806 17

M550.5L 11 08/02/88–04/28/93 MC 719815 4675321 16

AL02.3M 12 05/03/93–12/31/96 TRIB 728236 4674110 95

MQ02.1M 13 05/05/93–12/31/96 TRIB 720150 4671205 95

RC01.7M 14 05/03/93–12/31/96 TRIB 732728 4671124 95

M544.6F 15 01/13/89–04/27/93 BWC 727542 4670419 15

M545.5B 16 09/14/89–12/19/96 BWC 726287 4670292 109

M544.6E 17 06/19/95–10/09/95 BWC 727301 4670292 7

M543.6G 18 05/31/90–10/09/95 BWC 728972 4670128 7

M544.2D 19 08/05/88–04/27/93 BWC 728068 4669884 17

M544.2C 20 08/05/88–04/27/93 BWC 728063 4669840 17

M542.5E 21 08/09/88–04/27/93 BWC 729999 4669388 17

M542.7C 22 12/30/88–04/06/93 BWC 729830 4669270 4

M541.7L 23 06/19/95–10/09/95 BWC 731882 4668876 7

M540.2T 24 05/07/91–12/20/96 BWC 733781 4668352 110

M536.4B 25 08/10/88–04/07/93 BWI 732416 4662625 4

M535.9J 26 08/04/88–04/27/93 BWC 733189 4662145 17

M535.9K 27 08/04/88–04/27/93 BWC 733511 4662054 17

PR03.2M 28 05/03/93–12/31/96 TRIB 737936 4661849 95

M532.3T 29 05/07/91–12/20/96 BWC 737891 4656988 109

M530.3K 30 08/05/88–04/26/93 MC 736622 4653780 15

M529.7M 31 08/04/88–04/26/93 MC 737208 4652779 15

M525.5N 32 09/09/88–04/26/93 IMP 736505 4647293 16
Table A-1. Continued.

A-3

Location

code

Map

identification Period of record

Habitat

classa

UTM

Site visits

Easting Northing 1993–1996

M525.5L 33 08/09/88–12/20/96 IMP 735860 4646700 108

RK03.7M 34 06/11/96–12/30/96 TRIB 723012 4630693 15

RK00.1M 35 06/11/96–12/30/96 TRIB 725147 4628644 15

M511.4B 36 05/05/93–12/30/96 MC 728010 4628642 95

M508.1F 37 05/05/93–12/30/96 BWC 723381 4625871 93

WP02.6M 38 05/05/93–12/30/96 TRIB 719436 4622793 95

M497.2B 39 05/19/93–12/30/96 MC 721528 4608462 94

a

See Table A-4 for habitat class descriptions.

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

AL02.3M 12 05/03/93–12/31/96 TRIB 728236 4674110 95

M497.2B 39 05/19/93–12/30/96 MC 721528 4608462 94

M508.1F 37 05/05/93–12/30/96 BWC 723381 4625871 93

M511.4B 36 05/05/93–12/30/96 MC 728010 4628642 95

M525.5L 33 08/09/88–12/20/96 IMP 735860 4646700 108

M525.5N 32 09/09/88–04/26/93 IMP 736505 4647293 16

M529.7M 31 08/04/88–04/26/93 MC 737208 4652779 15

M530.3K 30 08/05/88–04/26/93 MC 736622 4653780 15

M532.3T 29 05/07/91–12/20/96 BWC 737891 4656988 109

M535.9J 26 08/04/88–04/27/93 BWC 733189 4662145 17

M535.9K 27 08/04/88–04/27/93 BWC 733511 4662054 17

M536.4B 25 08/10/88–04/07/93 BWI 732416 4662625 4

M540.2T 24 05/07/91–12/20/96 BWC 733781 4668352 110

M541.7L 23 06/19/95–10/09/95 BWC 731882 4668876 7

M542.5E 21 08/09/88–04/27/93 BWC 729999 4669388 17

M542.7C 22 12/30/88–04/06/93 BWC 729830 4669270 4

M543.6G 18 05/31/90–10/09/95 BWC 728972 4670128 7

M544.2C 20 08/05/88–04/27/93 BWC 728063 4669840 17

M544.2D 19 08/05/88–04/27/93 BWC 728068 4669884 17

M544.6E 17 06/19/95–10/09/95 BWC 727301 4670292 7
A-4

Table A-2. Continued

Location

code

Map

identification Period of record

Habitat

classa

UTM

Site visits

Easting Northing 1993–1996

M544.6F 15 01/13/89–04/27/93 BWC 727542 4670419 15

M545.5B 16 09/14/89–12/19/96 BWC 726287 4670292 109

M550.5L 11 08/02/88–04/28/93 MC 719815 4675321 16

M551.3M 10 08/02/88–04/28/93 BWC 719234 4676806 17

M551.3N 9 08/02/88–10/21/96 BWC 719457 4676895 61

M554.8F 8 08/02/88–11/17/94 MC 714669 4679382 37

M556.4A 7 10/15/90–12/17/96 MC 712792 4681148 112

M563.9T 5 05/06/93–12/17/96 BWC 711179 4692608 90

M564.5T 4 01/13/94–01/25/96 BWC 710457 4693461 12

M566.2R 3 01/13/94–02/20/95 BWC 708476 4695192 8

M574.2D 2 05/06/93–11/28/95 SC 698355 4701302 55

M582.5B 1 05/06/93–12/31/96 MC 693483 4711424 94

MQ02.1M 13 05/05/93–12/31/96 TRIB 720150 4671205 95

PR03.2M 28 05/03/93–12/31/96 TRIB 737936 4661849 95

RC01.7M 14 05/03/93–12/31/96 TRIB 732728 4671124 95

RK00.1M 35 06/11/96–12/30/96 TRIB 725147 4628644 15

RK03.7M 34 06/11/96–12/30/96 TRIB 723012 4630693 15

TM04.1M 6 11/07/97– TRIB 703023 4692249 0

WP02.6M 38 05/05/93–12/30/96 TRIB 719436 4622793 95

a

See Table A-4 for habitat class descriptions.

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

M508.1F 37 05/05/93–12/30/96 BWC 723381 4625871 93

M532.3T 29 05/07/91–12/20/96 BWC 737891 4656988 109

M535.9J 26 08/04/88–04/27/93 BWC 733189 4662145 17

M535.9K 27 08/04/88–04/27/93 BWC 733511 4662054 17

M540.2T 24 05/07/91–12/20/96 BWC 733781 4668352 110

M541.7L 23 06/19/95–10/09/95 BWC 731882 4668876 7

M542.5E 21 08/09/88–04/27/93 BWC 729999 4669388 17
A-5

Table A-3. Continued

Location

code

Map

identification Period of record

Habitat

classa

UTM

Site visits

Easting Northing 1993–1996

M542.7C 22 12/30/88–04/06/93 BWC 729830 4669270 4

M543.6G 18 05/31/90–10/09/95 BWC 728972 4670128 7

M544.2C 20 08/05/88–04/27/93 BWC 728063 4669840 17

M544.2D 19 08/05/88–04/27/93 BWC 728068 4669884 17

M544.6E 17 06/19/95–10/09/95 BWC 727301 4670292 7

M544.6F 15 01/13/89–04/27/93 BWC 727542 4670419 15

M545.5B 16 09/14/89–12/19/96 BWC 726287 4670292 109

M551.3M 10 08/02/88–04/28/93 BWC 719234 4676806 17

M551.3N 9 08/02/88–10/21/96 BWC 719457 4676895 61

M563.9T 5 05/06/93–12/17/96 BWC 711179 4692608 90

M564.5T 4 01/13/94–01/25/96 BWC 710457 4693461 12

M566.2R 3 01/13/94–02/20/95 BWC 708476 4695192 8

M536.4B 25 08/10/88–04/07/93 BWI 732416 4662625 4

M525.5L 33 08/09/88–12/20/96 IMP 735860 4646700 108

M525.5N 32 09/09/88–04/26/93 IMP 736505 4647293 16

M497.2B 39 05/19/93–12/30/96 MC 721528 4608462 94

M511.4B 36 05/05/93–12/30/96 MC 728010 4628642 95

M529.7M 31 08/04/88–04/26/93 MC 737208 4652779 15

M530.3K 30 08/05/88–04/26/93 MC 736622 4653780 15

M550.5L 11 08/02/88–04/28/93 MC 719815 4675321 16

M554.8F 8 08/02/88–11/17/94 MC 714669 4679382 37

M556.4A 7 10/15/90–12/17/96 MC 712792 4681148 112

M582.5B 1 05/06/93–12/31/96 MC 693483 4711424 94

M574.2D 2 05/06/93–11/28/95 SC 698355 4701302 55

AL02.3M 12 05/03/93–12/31/96 TRIB 728236 4674110 95

MQ02.1M 13 05/05/93–12/31/96 TRIB 720150 4671205 95

PR03.2M 28 05/03/93–12/31/96 TRIB 737936 4661849 95

RC01.7M 14 05/03/93–12/31/96 TRIB 732728 4671124 95

RK00.1M 35 06/11/96–12/30/96 TRIB 725147 4628644 15

RK03.7M 34 06/11/96–12/30/96 TRIB 723012 4630693 15

TM04.1M 6 11/07/97– TRIB 703023 4692249 0

WP02.6M 38 05/05/93–12/30/96 TRIB 719436 4622793 95

a

See Table A-4 for habitat class descriptions.
A-6

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

(LTRMP). Not all streams in this list have been sampled by the LTRMP. 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
Table A-5. Continued

Site identifier Tributary name

A-7

IWxx.xM Iowa River, Iowa

LMxx.xM LaMoines River, Illinois

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

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-8

Figure A-1. Fixed-site sampling locations in the Bellevue study area.
A-9

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

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

vicinity of the Bellevue 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 stratuma

Number of

sites

assigned

Fraction

of

stratum

sampled

(%)

Fraction

 of total

effort

(%)

Main channel 2,700 24 675 30 4.4 20

Side channel 805 7 3,219 30 0.9 20

Backwater 2,811 25 11,242 60 0.5 40

Lake – – – – – –

Impounded 3,560 32 890 30 3.4 20

Isolated 116 1 29 0 0.0 0

Totalb 11,183 89 16,055 150 9.3 100

a

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

b

Total 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 Bellevue Field Station in each stratified random sampling episode

from 1993 through 1996.

Sampling period Number of samples collected/sites visited

Date

Total

Main

channel

Side

channel

Contiguous

backwater Lake Impoundment Isolated Episode Start End

Summer 93 08/02/93 08/05/93 151/151 30/30 30/30 61/61 NA 30/30 NA 

Fall 93 10/11/93 10/18/93 155/154 30/30 30/30 63/62 NA 32/32 NA 

Winter 94 01/31/94 02/10/94 121/121 16/16 30/30 59/59 NA 16/16 NA 

Spring 94 04/25/94 05/02/94 150/150 30/30 30/30 60/60 NA 30/30 NA 

Summer 94 07/25/94 08/05/94 153/153 30/30 30/30 62/62 NA 31/31 NA 

Fall 94 10/03/94 10/14/94 156/156 30/30 32/32 64/64 NA 30/30 NA 

Winter 95 01/30/95 02/06/95 150/150 30/30 30/30 60/60 NA 30/30 NA 

Spring 95 04/24/95 05/02/95 153/153 30/30 30/30 62/62 NA 31/31 NA 

Summer 95 07/26/95 08/04/95 154/154 30/30 30/30 63/63 NA 31/31 NA 

Fall 95 10/18/95 10/26/95 152/152 30/30 30/30 62/62 NA 30/30 NA 

Winter 96 01/30/96 02/12/96 136/136 16/16 30/30 60/60 NA 30/30 NA 

Spring 96 04/22/96 05/02/96 150/150 30/30 30/30 60/60 NA 30/30 NA 

Summer 96 07/24/96 07/31/96 154/154 30/30 30/30 64/64 NA 30/30 NA 

Fall 96 10/07/96 10/15/96 164/164 30/30 32/32 70/70 NA 32/32 NA 
B-3

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

in the vicinity of the Bellevue 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)
Table C-2. Continued

Parameter and method

Laboratory

WES–Vicksburg WES–Eau Galle UMESCa

C-3

Dissolved calcium: Atomic

absorption

June 91–Oct. 93

(0.1 mg/L)

— Oct. 93–Jan. 94

(0.1 mg/L)

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 Bellevue Field Station. Table entries are

keyed to numbered points on Figure D-1.

Figure

code Date

Site

visits Comment

1 05/10/93 1 One fixed site from previous week sampled on 5/14/93

2 06/07/93 1 Zebra mussel (Dreissena polymorpha) monitoring site

sampled 6/9/93

3 06/21/93 1 Zebra mussel monitoring site sampled 6/22/93

4 04/11/94 1 Zebra mussel monitoring site sampled 4/14/94

5 05/23/94 1 Zebra mussel monitoring site sampled 5/27/94

6 08/15/94 2 Zebra mussel monitoring site sampled 8/15/94

7 09/12/94 1 Zebra mussel monitoring site sampled 9/13/94

8 10/10/94 1 Zebra mussel monitoring site sampled 10/14/94

9 06/19/95 3 Zebra mussel monitoring site sampled 6/19/95

10 08/14/95 1 Zebra mussel monitoring site sampled 08/15/95

11 10/09/95 4 Zebra mussel monitoring sites sampled this week

12 11/06/95 1 Zebra mussel monitoring site sampled 11/6/95

13 02/19/96 0 Hovercraft breakdown 

14 03/11/96 0 Unsafe ice and delay to return to schedule

15 04/08/96 1 Zebra mussel monitoring site sampled 4/11/96

16 05/20/96 1 Zebra mussel monitoring site sampled 5/21/96

17 06/17/96 1 Zebra mussel monitoring site sampled 6/20/96

18 07/15/96 1 Zebra mussel monitoring site sampled 7/15/96

19 07/29/96 1 Zebra mussel monitoring site sampled 7/30/96

20 09/09/96 1 Zebra mussel monitoring site sampled 9/13/96

21 10/21/96 1 Zebra mussel monitoring site sampled 10/21/96

22 12/09/96 0 Two weeks between samples
D-2

Figure D-1. Number of weekly fixed-site visits from January 1993 through December 1996 by the Bellevue 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: near-surface (less than or eqmiddepth, near bottom (less than or equal to 0.2 m above the substrate), and 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: 

AL02.3M Mean 0.2 4.02 — 100 8 20 0 14 9.16 86 613 8 32 122 35.2  Median 0.2 3.93 — 100 8 20 0 15.3 8.55 86 634 8 32 31 33.3  Minimum 0.2 2.8 — 100 8 20 0 0.1 6 73 402 7.3 32 6 5.8  Maximum 0.2 6.5 — 100 8 20 0 25 13.2 100 767 8.8 32 1700 104  Std. dev. 0 1.17 — — — — — 7.69 2.31 7.13 91.7 0.38 — 394 27.7 

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

M497.2B Mean 0.2 1.78 — 90 10 100 6 15.1 9.51 90 434 8 34.9 35 42.9  Median 0.2 1.64 — 90 10 100 6 17.1 8.3 89 445 8 38 29 38.7  Minimum 0.2 0.6 — 90 10 100 6 0 5.8 67 362 6.8 16 7 7.7  Maximum 0.2 4.1 — 90 10 100 6 26.3 15.2 126 493 9.1 52 105 93.4  Std. dev. 0 0.92 — — — — — 8.65 3.22 16.5 41.7 0.57 11.5 25.5 26 

N obs. 17 15 0 1 1 1 1 17 17 17 17 17 13 17 14 

M508.1F Mean 0.2 1.74 0.06 100 12 95 2 14.7 11.8 110 488 8.3 42.1 23 30.2  Median 0.2 1.85 0 100 12 95 2 16.4 9.85 116 496 8.3 46 19 22.4  Minimum 0.2 0.5 0 100 12 95 2 0 5.6 64 312 6.9 28 10 11.1  Maximum 0.2 3.4 0.48 100 12 95 2 28.8 20 152 660 9.2 50 42 75.7  Std. dev. 0 0.85 0.13 — — — — 8.82 4.87 27.9 79.2 0.56 8.74 9.87 18.1 

N obs. 16 16 15 1 1 1 1 16 16 16 16 16 15 16 13 

M511.4B Mean 0.2 1.85 — 75 10 25 0 15.4 9.43 90 433 8.1 35.1 37 49.9  Median 0.2 1.9 — 75 10 25 0 17 8.4 87 432 8.1 32 31 42.3  Minimum 0.2 0.6 — 75 10 25 0 0 5.3 62 290 7.3 16 6 7.1  Maximum 0.2 4 — 75 10 25 0 27.8 15 138 521 9.2 80 110 141  Std. dev. 0 1.06 — — — — — 8.39 3.31 18.7 48.5 0.51 15 26.8 41 

N obs. 18 16 0 1 1 1 1 18 18 18 17 17 15 18 14 

M525.5L Mean 0.2 1.51 0.26 98.8 24 48 2 9.15 11.3 94 409 8.2 40.9 36 41.2  Median 0.2 1.3 0.26 100 26 45 0 6.1 11.5 93 400 8.1 38.5 27 37.3  Minimum 0.2 0.88 0.1 95 18 0 0 0 5.7 66 255 7 12 4 3.2  Maximum 0.2 3.7 0.5 100 30 100 7 25 15.8 148 553 9.2 90 164 93.9  Std. dev. 0 0.63 0.12 2.31 4.07 45.7 2.7 9.38 3.12 15.4 61.9 0.57 21.9 34.4 28.1 

N obs. 33 33 22 8 8 8 8 33 32 32 33 32 28 33 18 

M525.5N Mean 0.2 1.07 0.15 98.8 24 48 2 2.24 13.1 95 412 8.4 31.4 36 37.5  Median 0.2 0.97 0.1 100 24 45 0 0.15 13.4 98 404 8.3 27 24 15.2  Minimum 0.2 0.74 0.06 95 21 0 0 0 10.3 73 324 7.5 16 4 2.3  Maximum 0.2 1.98 0.36 100 28 100 6 11.2 15.8 108 542 9.1 58 85 117  Std. dev. 0 0.37 0.11 2.31 2.83 45.7 2.4 3.43 1.71 7.88 72.2 0.5 14.5 31.7 54 

N obs. 16 16 16 8 8 8 8 16 15 15 16 16 10 16 4 
 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: 

M529.7M Mean 0.2 1.62 0.22 99.3 23 53 2 2.31 12.8 93 408 8.3 53.5 40 57.5  Median 0.2 1.63 0.16 100 23 50 1 0.1 13.1 93 418 8.2 40 32 39.6  Minimum 0.2 1.5 0.07 95 14 0 0 0 9.8 68 308 7.3 15 4 3.7  Maximum 0.2 1.8 0.45 100 29 100 6 11.3 15.8 108 535 9.2 120 112 147  Std. dev. 0 0.12 0.12 1.89 5.34 47.2 2.8 3.56 1.83 9.56 75.5 0.5 38.7 37.6 67.3 

N obs. 15 15 15 7 7 7 7 15 14 14 15 15 15 15 4 

M530.3K Mean 0.2 2.72 0.77 97.1 16 50 1 2.19 12.7 92 416 8.3 54.6 49 —  Median 0.2 2.57 0.67 100 18 50 0 0.1 12.9 93 410 8.4 38 33 —  Minimum 0.2 2.14 0.31 90 10 0 0 0 9.4 66 319 7.4 13 4 —  Maximum 0.2 3.98 1.49 100 28 100 6 11 15.8 108 550 9 160 160 —  Std. dev. 0 0.49 0.41 3.93 6.78 44.3 2.5 3.45 1.9 10.1 76.6 0.41 45.2 46.7 — 

N obs. 15 15 15 7 7 7 7 15 14 14 15 15 15 15 0 

M532.3T Mean 0.2 1.5 0.05 97.5 17 31 1 9.89 12.7 107 400 8.5 48.6 23 24.2  Median 0.2 1.3 0 100 20 5 0 6.8 13 102 394 8.5 46 16 22.5  Minimum 0.2 0.96 0 80 1 0 0 0 5.3 63 256 7.2 15 4 2.7  Maximum 0.2 3.7 0.3 100 26 100 3 27 20 195 563 9.8 92 166 52.3  Std. dev. 0 0.64 0.08 6.22 7.3 41.9 1.2 8.99 4.32 26.6 77.4 0.72 19 29 13 

N obs. 35 35 35 12 12 12 12 35 32 32 35 34 30 35 19 

M535.9J Mean 0.2 1.49 0.09 97.5 21 35 1 2.41 12.1 88 439 8.2 47.3 26 16.3  Median 0.2 1.21 0.02 100 24 3 0 0.4 12.3 89 454 8.1 42 16 14.6  Minimum 0.2 0.94 0 80 7 0 0 0 9.7 67 303 7.8 16 5 5  Maximum 0.2 3.2 0.42 100 28 100 7 11.1 14.6 100 571 9 98 84 31  Std. dev. 0 0.67 0.14 6.22 7.12 48 2.1 3.57 1.45 7.83 84 0.32 26 25.2 13.1 

N obs. 17 17 17 12 12 12 12 17 16 16 17 17 12 17 4 

M535.9K Mean 0.2 1.9 0.09 100 31 42 1 2.49 12.4 91 427 8.3 60.5 20 —  Median 0.2 1.56 0 100 31 0 0 0.7 12.8 90 427 8.2 52 10 —  Minimum 0.2 1.44 0 100 14 0 0 0 8.9 61 236 7.5 18 6 —  Maximum 0.2 3.56 0.52 100 38 100 9 11.1 15.6 107 550 9.2 100 72 —  Std. dev. 0 0.64 0.19 0 6.41 48.5 2.7 3.43 1.79 10.5 83 0.44 27.8 18.6 — 

N obs. 17 17 17 13 13 13 13 17 15 15 17 17 17 17 0 

M540.2T Mean 0.2 1.86 0.17 99.2 25 26 1 9.39 11.4 96 425 8.1 40.8 26 31.6  Median 0.2 1.33 0.04 100 28 0 0 6.2 11.8 92 426 8.1 34 24 36  Minimum 0.2 1 0 90 3 0 0 0 5.4 64 217 7.3 10 5 4.4  Maximum 0.2 4.3 0.76 100 33 100 9 26.8 20 156 615 9.4 110 79 65.3  Std. dev. 0 0.9 0.22 2.77 8.4 37.5 2.6 9.5 3.5 19.5 90.3 0.49 21.5 17.4 19.6 

N obs. 34 34 34 13 13 13 13 34 33 33 34 33 29 33 19 
 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: 

M542.5E Mean 0.2 1.92 0.07 98.5 30 41 2 2.56 12.5 91 439 8 53.4 25 14.4  Median 0.2 1.49 0 100 32 10 0 0.9 12.4 90 396 8.1 52 13 14.1  Minimum 0.2 1.29 0 80 16 0 0 0 10.4 81 288 5.6 16 4 3.8  Maximum 0.2 3.8 0.59 100 37 100 9 11.5 17.2 119 584 8.9 100 86 25.7  Std. dev. 0 0.83 0.18 5.55 5.93 46.3 3.3 3.48 1.68 8.49 99.1 0.74 27.3 24.6 11.5 

N obs. 17 17 17 13 13 13 13 17 17 17 17 17 17 17 4 

M544.2C Mean 0.2 3.14 0.04 100 17 41 1 3.14 11.1 83 449 8.2 58.8 21 23.2  Median 0.2 2.67 0 100 18 60 0 1.2 12.2 91 490 8 67 11 13.3  Minimum 0.2 2.4 0 100 12 0 0 0 2.3 16 300 7.5 16 6 6.9  Maximum 0.2 5.3 0.21 100 20 100 6 12 16.4 116 565 9.5 92 82 59.2  Std. dev. 0 0.98 0.07 0 2.78 38.9 2 3.64 3.74 28.7 84.9 0.54 26 21.6 24.4 

N obs. 17 17 17 9 9 9 9 17 16 16 17 17 17 17 4 

M544.2D Mean 0.2 1.35 0.03 92 21 38 2 3.24 11 84 449 8.1 39.2 21 —  Median 0.2 0.88 0 100 22 35 0 1.3 11.9 91 460 8.1 32 12 —  Minimum 0.2 0.6 0 20 2 0 0 0 2.8 19 312 7.5 18 5 —  Maximum 0.2 3.2 0.26 100 28 100 8 12 18 156 568 9.2 68 64 —  Std. dev. 0 0.87 0.07 25.3 6.94 39.2 2.8 3.78 3.89 32.6 86.4 0.44 19.8 18.9 — 

N obs. 17 17 17 10 10 10 10 17 16 16 17 17 9 17 0 

M544.6F Mean 0.2 3.74 0.02 100 18 41 0 3.93 9.02 69 454 8 61.4 20 —  Median 0.2 3.24 0 100 18 50 0 2.9 10.3 81 434 7.8 57 12 —  Minimum 0.2 2.99 0 100 10 0 0 0.4 2.8 20 310 7.4 18 6 —  Maximum 0.2 5.58 0.15 100 24 90 2 11.8 16.4 122 556 9.5 124 75 —  Std. dev. 0 0.94 0.05 0 4.16 40 .63 3.59 4.23 32.8 82 0.58 31 17.9 — 

N obs. 15 15 15 10 10 9 10 15 13 13 15 15 15 15 0 

M545.5B Mean 0.2 3.6 0.01 100 22 39 2 10.7 11.6 104 435 8.2 55.3 18 60.4  Median 0.2 3.25 0 100 22 20 0 8.5 10.7 94 433 8.2 50 15 22.7  Minimum 0.2 2.5 0 100 12 0 0 0 2.5 18 297 6.7 18 5 6.4  Maximum 0.2 6.3 0.14 100 30 100 7 27.8 19.1 221 569 9.8 119 54 573  Std. dev. 0 1.05 0.03 0 5.16 44.4 2.5 9.37 4.02 42 75 0.67 22.5 11.7 148 

N obs. 33 32 32 11 11 11 11 32 29 29 32 31 32 32 14 

M550.5L Mean 0.2 2.49 0.59 85 18 40 1 2.11 13 94 425 8.3 59.8 21 —  Median 0.2 2.08 0.5 85 19 35 1 0 13.5 94 443 8.3 50 11 —  Minimum 0.2 1.3 0.34 80 10 0 0 0 10.3 82 330 7.5 18 4 —  Maximum 0.2 5.54 0.9 90 25 90 2 12 16 109 505 9.3 112 78 —  Std. dev. 0 1.31 0.21 5.77 6.27 39.2 .96 3.63 1.69 6.88 60.7 0.49 30.8 20.7 — 

N obs. 16 16 16 4 4 4 4 16 16 16 16 16 13 16 0 
 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: 

M551.3M Mean 0.2 2.14 0.07 100 36 44 1 2.29 13.1 94 413 8.4 58.3 13 —  Median 0.2 1.58 0 100 38 30 0 0.5 13.6 95 445 8.3 49 13 —  Minimum 0.2 1.29 0 100 20 0 0 0 9.1 63 299 7.3 28 3 —  Maximum 0.2 4.3 0.35 100 42 100 9 12 17.6 122 525 10.3 114 31 —  Std. dev. 0 1.02 0.13 0 5.85 47.4 2.6 3.46 2.11 11.6 81.3 0.64 26.1 8.91 — 

N obs. 17 17 17 13 13 13 13 17 16 16 17 17 12 17 0 

M551.3N Mean 0.2 4.14 0.24 100 15 35 1 2.19 12.7 92 419 8.2 77.2 13 15.1  Median 0.2 3.63 0.06 100 15 10 0 0.2 12.9 92 454 8.2 90 7 11.9  Minimum 0.2 2.95 0.03 100 2 0 0 0 9.9 68 306 7.5 26 5 4  Maximum 0.2 6.5 0.88 100 20 100 10 12.3 15.7 108 504 9.1 116 46 32.8  Std. dev. 0 1.11 0.33 0 5.35 43.3 3.1 3.66 1.58 7.98 73.8 0.39 30.7 10.8 13.8 

N obs. 17 17 17 10 10 10 10 17 17 17 17 17 17 17 4 

M554.8F Mean 0.2 2.09 0.31 98 16 42 1 5.27 12.3 95 415 8.2 51.4 21 38.8  Median 0.2 1.8 0.26 100 15 20 0 0.4 13.2 93 425 8.2 42 16 27.9  Minimum 0.2 1.1 0.11 90 10 0 0 0 6.1 71 320 6.9 22 4 3.9  Maximum 0.2 4 0.67 100 20 100 5 22.5 15.8 140 506 9.5 100 64 95.6  Std. dev. 0 0.91 0.18 4.47 4.04 49.2 2.2 7.13 2.54 13.5 64.5 0.57 22.1 17.2 43.9 

N obs. 21 21 19 5 5 5 5 21 20 20 21 21 16 21 4 

M556.4A Mean 0.2 2.16 0.24 33.3 4 20 0 8.79 11.3 94 431 8.1 50.3 22 36.3  Median 0.2 1.58 0.22 30 5 10 0 5 11.7 93 436 8.1 45 22 33.4  Minimum 0.2 0.9 0.02 20 2 0 0 0 5.3 61 325 7 16 4 4.6  Maximum 0.2 5.5 0.51 50 5 50 0 25.1 16 119 535 9.4 126 82 96.4  Std. dev. 0 1.12 0.17 15.3 1.73 26.5 0 9.33 2.83 11.5 52.3 0.51 26 18.4 25 

N obs. 36 36 18 3 3 3 3 36 35 35 36 36 28 36 15 

M563.9T Mean 0.2 1.14 0.06 95 3 0 0 15.6 10.4 99 413 8.1 42.6 27 36.5  Median 0.2 0.9 0.04 95 3 0 0 16.5 8.6 98 429 8 35.5 31 43  Minimum 0.2 0.4 0 90 2 0 0 0.6 5.3 61 247 6.9 22 6 6  Maximum 0.2 3.7 0.31 100 3 0 0 25.8 20 156 520 9.2 100 40 63.5  Std. dev. 0 0.87 0.08 7.07 0.71 0 0 8.52 4.4 27.4 57.7 0.62 22.6 11.4 17.8 

N obs. 17 17 17 2 2 2 2 17 17 17 17 17 16 17 14 

M574.2D Mean 0.2 2.74 0.66 — — — — 15.1 9.72 92 420 8 49 28 42.9  Median 0.2 2.74 0.66 — — — — 15.8 9 91 420 7.9 40 26 38.1  Minimum 0.2 0.6 0.66 — — — — 0.7 5.7 66 333 6.8 24 7 6.5  Maximum 0.2 5.5 0.66 — — — — 24.7 15 136 486 9.2 110 84 91.4  Std. dev. 0 1.36 — — — — — 8.13 3.2 17.3 39.3 0.59 26.6 18.6 27.3 

N obs. 17 17 1 0 0 0 0 17 17 17 17 17 17 17 14 
 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: 

M582.5B Mean 0.2 3.77 — 100 10 10 0 13.6 10.3 94 443 8.1 54.7 26 40  Median 0.2 3.4 — 100 10 10 0 15.5 10.3 96 449 7.9 40 25 32.7  Minimum 0.2 1.4 — 100 10 10 0 0 5.9 68 374 6.9 22 4 4.9  Maximum 0.2 6.1 — 100 10 10 0 24.7 15 136 495 9.1 125 55 91.9  Std. dev. 0 1.46 — — — — — 8.71 3.1 15.1 31.1 0.58 33.3 14.8 29.7 

N obs. 17 17 0 1 1 1 1 17 17 17 17 17 17 17 14 

MQ02.1M Mean 0.2 1.77 — 80 6 90 0 14 9.34 88 554 7.9 — 221 95.6  Median 0.2 1.3 — 80 6 90 0 14.9 9.15 90 578 8 — 36 57.7  Minimum 0.2 0.6 — 80 6 90 0 0 5.6 63 275 6.9 — 3 2.4  Maximum 0.2 5.5 — 80 6 90 0 23.8 12.8 99 677 8.8 — 2560 261  Std. dev. 0 1.31 — — — — — 7.55 2.16 9.01 106 0.49 — 598 83.9 

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

PR03.2M Mean 0.2 2.37 — 100 10 75 0 13.5 8.55 79 658 7.8 18 70 47.7  Median 0.2 2.35 — 100 10 75 0 15.1 8.1 81 652 7.9 18 31 54.2  Minimum 0.2 0.9 — 100 10 75 0 0 5.5 62 499 5.5 18 5 5  Maximum 0.2 3.8 — 100 10 75 0 24 12.7 92 818 8.7 18 690 134  Std. dev. 0 0.62 — — — — — 7.63 2.31 8.56 77.3 0.66 — 157 35.7 

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

RC01.7M Mean 0.2 0.86 — — — — — 13.1 9.5 88 652 8 15 75 49.7  Median 0.2 0.6 — — — — — 14.5 9.1 88 677 8.1 15 23 29.2  Minimum 0.2 0.3 — — — — — 0.2 6.9 76 485 7.3 15 7 8.2  Maximum 0.2 2.6 — — — — — 23 13.2 106 795 8.7 15 860 245  Std. dev. 0 0.67 — — — — — 7.25 2.05 6.84 71.5 0.37 — 198 62 

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

WP02.6M Mean 0.2 1.88 — 100 12 100 5 14.5 9.12 86 451 7.8 — 59 115  Median 0.2 1.79 — 100 12 100 5 16.4 8.75 89 478 8 — 33 52.8  Minimum 0.2 0.5 — 100 12 100 5 0 6.3 73 297 5.8 — 6 4.9  Maximum 0.2 3.6 — 100 12 100 5 25.5 12.7 100 591 8.4 — 276 692  Std. dev. 0 0.91 — — — — — 8.22 2.34 8.23 89.4 0.59 — 72.2 188 

N obs. 18 18 0 1 1 1 1 18 18 18 18 18 0 18 15 
 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 Middepth measurements: 

M535.9K Mean 1.08 1.55 0 — — — — 0.93 12.7 89 — — — — —  Median 1.05 1.55 0 — — — — 1.15 13 90 — — — — —  Minimum 1 1.44 0 — — — — 0 8.7 60 — — — — —  Maximum 1.3 1.77 0 — — — — 1.8 14.8 106 — — — — —  Std. dev. 0.1 0.1 0 — — — — 0.67 2.06 15.6 — — — — — 

N obs. 8 8 5 — — — — 8 8 8 0 0 — 0 0 

M545.5B Mean 1.91 3.87 — — — — — 18.7 7.52 82 — — — — —  Median 1.8 3.7 — — — — — 20.5 7.45 81 — — — — —  Minimum 1.5 2.92 — — — — — 7.8 3.1 36 — — — — —  Maximum 2.3 4.57 — — — — — 24.7 11.1 123 — — — — —  Std. dev. 0.32 0.62 — — — — — 5.75 3.19 32 — — — — — 

N obs. 7 7 0 — — — — 7 6 6 0 0 — 0 0 

1993 Near-bottom measurements: 

M532.3T Mean 1.36 1.57 0 — — — — 11.9 10.6 96 342 8.9 — 18 —  Median 1.4 1.58 0 — — — — 9.1 10.3 94 339 8.8 — 20 —  Minimum 0.9 1.06 0 — — — — 0 6.5 67 279 8 — 13 —  Maximum 2.2 2.4 0 — — — — 22.8 15.2 132 419 9.9 — 21 —  Std. dev. 0.36 0.36 0 — — — — 7.75 2.75 18.6 52.6 0.73 — 2.88 — 

N obs. 11 11 9 — — — — 11 10 10 7 7 — 7 0 

M540.2T Mean 2.21 2.43 0.16 — — — — 12.1 10.2 93 403 8.5 — 33 —  Median 2.3 2.52 0.13 — — — — 7.8 10.6 93 403 8.5 — 33 —  Minimum 1.1 1.28 0 — — — — 5.4 6.6 76 338 8 — 24 —  Maximum 3.2 3.4 0.43 — — — — 22.2 12.8 103 468 9 — 42 —  Std. dev. 0.66 0.67 0.17 — — — — 7.01 2.04 8.68 91.9 0.74 — 12.7 — 

N obs. 7 7 5 — — — — 7 7 7 2 2 — 2 0 

M544.2C Mean 2.73 3.02 0.01 — — — — 2.83 9.97 74 369 8.5 — 32 —  Median 2.3 2.63 0 — — — — 2.2 10.5 84 385 8.4 — 26 —  Minimum 2.1 2.4 0 — — — — 0.3 2 14 307 7.9 — 12 —  Maximum 5.1 5.3 0.13 — — — — 7.7 14.6 104 395 9 — 49 —  Std. dev. 0.9 0.86 0.04 — — — — 2.3 3.91 28.9 36 0.46 — 16.2 — 

N obs. 16 16 13 — — — — 15 15 15 5 5 — 5 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: 

M544.6F Mean 3.28 3.6 0 — — — — 3.28 8.48 64 370 8.1 — 36 —  Median 2.8 3.18 0 — — — — 2.9 9 75 383 7.9 — 32 —  Minimum 2.6 2.99 0 — — — — 0.7 0.3 2 313 7.8 — 12 —  Maximum 5.4 5.57 0.03 — — — — 7.5 16.6 124 400 8.8 — 69 —  Std. dev. 0.93 0.86 0.01 — — — — 2.08 4.69 35.1 39.2 0.46 — 24.5 — 

N obs. 13 13 9 — — — — 13 13 13 4 4 — 4 0 

M545.5B Mean 3.2 3.46 0 — — — — 9.33 8.93 74 388 8.2 — 26 39.2  Median 2.7 2.98 0 — — — — 6 9 79 397 8.2 — 19 24.3  Minimum 2.3 2.5 0 — — — — 0.1 0.1 1 317 7.4 — 10 19.7  Maximum 6.1 6.3 0.02 — — — — 24 18.1 139 457 9.1 — 97 73.7  Std. dev. 1 0.95 0 — — — — 8.04 4.74 36.3 49 0.59 — 23.6 29.9 

N obs. 27 27 19 — — — — 27 27 27 12 12 — 12 3 

M551.3N Mean 3.21 3.54 0.05 — — — — 0.61 13.4 93 — — — — —  Median 3.2 3.52 0.01 — — — — 0.1 13.5 92 — — — — —  Minimum 2.6 2.95 0 — — — — 0 11.2 86 — — — — —  Maximum 4.1 4.47 0.19 — — — — 5.3 15.8 108 — — — — —  Std. dev. 0.45 0.43 0.07 — — — — 1.65 1.18 6.32 — — — — — 

N obs. 10 10 7 — — — — 10 10 10 0 0 — 0 0 

1994 Near-surface measurements: 

AL02.3M Mean 0.2 2.86 — 100 23 70 0 12.3 10.9 102 634 8.1 170 34 39.8  Median 0.2 2.8 — 100 23 80 0 13.6 10.8 92 649 8 170 25 31.4  Minimum 0.2 2.2 — 100 16 30 0 0 7.2 73 467 6.3 170 5 2.8  Maximum 0.2 4.25 — 100 29 100 1 24.2 17 202 782 8.6 170 312 389  Std. dev. 0 0.48 — 0 6.51 36.1 .58 9.12 2.27 27.3 67.6 0.43 — 57.8 72.4 

N obs. 26 26 0 3 3 3 3 26 26 26 26 26 1 26 26 

M497.2B Mean 0.2 1.1 — 23.3 14 67 0 13 10.3 94 416 8.1 44.5 29 40.5  Median 0.2 1.04 — 20 16 90 0 14.4 10.3 91 416 8 42 26 38  Minimum 0.2 0.4 — 10 5 10 0 0 4.6 56 315 7.2 13 3 0.3  Maximum 0.2 2.4 — 40 22 100 1 25.5 18.8 186 555 9.3 125 120 112  Std. dev. 0 0.4 — 15.3 8.62 49.3 .58 10 3.27 23.1 55.7 0.44 22.2 22.1 26.8 

N obs. 26 26 0 3 3 3 3 26 26 26 26 26 24 26 26 
 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)

1994 Near-surface measurements: 

M508.1F Mean 0.2 1.27 0.01 100 20 50 2 13.9 12.8 124 451 8.4 47.7 22 25.4  Median 0.2 1.1 0 100 24 50 2 13.9 13.2 137 451 8.5 40 21 27  Minimum 0.2 0.82 0 100 2 0 0 0.2 5.2 36 240 7.6 12 5 2.7  Maximum 0.2 2.62 0.03 100 30 100 5 28 20 243 704 9.2 100 74 52.1  Std. dev. 0 0.41 0.01 0 12.1 54.8 2.6 10.5 4.39 47.5 110 0.47 23.9 14.3 14.6 

N obs. 26 26 26 6 6 6 6 26 26 26 26 26 25 26 26 

M511.4B Mean 0.2 0.92 — 80 7 95 10 13.4 10.2 93 420 8.1 33.9 33 51.3  Median 0.2 0.76 — 80 7 95 10 13.3 9.85 94 420 8 35 25 34.5  Minimum 0.2 0.4 — 80 3 90 0 0 5.3 67 316 7.6 12 3 0.6  Maximum 0.2 2.74 — 80 10 100 20 29 15.8 150 544 9.2 48 164 220  Std. dev. 0 0.52 — 0 4.95 7.07 14 10.5 3.14 17.1 55.9 0.43 9.19 31.8 49.9 

N obs. 26 26 0 2 2 2 2 26 26 26 26 26 19 26 26 

M525.5L Mean 0.2 1.09 0.2 100 26 60 6 12.9 10.7 98 405 8.2 38.7 38 54.5  Median 0.2 1.04 0.18 100 27 100 6 12 10.7 94 404 8.1 36 30 34.6  Minimum 0.2 0.88 0.11 100 20 0 0 0 5.9 72 330 7.6 8 3 1.6  Maximum 0.2 1.68 0.42 100 30 100 16 26.8 16.2 141 508 9.2 95 188 316  Std. dev. 0 0.19 0.07 0 3.78 54.8 6.6 9.83 2.81 16.9 51.1 0.42 18.7 36.8 63.1 

N obs. 26 25 18 5 5 5 5 25 25 25 25 25 23 25 25 

M532.3T Mean 0.2 1.11 0.11 98.3 23 67 4 12.9 11.2 102 425 8.3 34.4 35 38.8  Median 0.2 1 0.08 100 22 100 3 13 10.6 98 425 8.2 31 30 33.5  Minimum 0.2 0.9 0 90 7 0 0 0 4.6 60 300 7.2 9 3 1.7  Maximum 0.2 1.7 0.9 100 45 100 12 28.3 19.4 142 600 9.3 82 124 111  Std. dev. 0 0.22 0.18 4.08 14.4 51.6 4.6 10.1 3.72 26.4 71.7 0.53 15.7 27.4 28.4 

N obs. 25 25 24 6 6 6 6 25 25 25 25 25 21 25 25 

M540.2T Mean 0.2 1.24 0.04 100 32 57 3 12.9 10.8 99 421 8.2 34.9 33 34.7  Median 0.2 1.12 0.02 100 30 100 2 13.1 10.4 97 425 8.1 32 31 35.6  Minimum 0.2 0.8 0 100 11 0 0 0 5.3 65 311 7.6 10 3 2.1  Maximum 0.2 2.55 0.33 100 76 100 11 29.7 16.7 159 550 9.5 76 132 144  Std. dev. 0 0.41 0.07 0 21.8 53.5 4.1 10.4 2.92 21.6 59.1 0.44 14.1 26.8 27.6 

N obs. 27 27 27 7 7 7 7 27 27 27 27 27 24 27 27 

M545.5B Mean 0.2 2.84 0.01 100 26 57 3 13.7 11.9 113 410 8.4 53.2 23 24.8  Median 0.2 2.74 0 100 32 100 2 14.5 11.2 117 410 8.5 44 20 22.2  Minimum 0.2 2.13 0 100 8 0 0 0 5.2 41 295 7.2 17 3 2.1  Maximum 0.2 3.96 0.06 100 42 100 9 30.2 20 168 552 9.4 140 84 92.5  Std. dev. 0 0.5 0.02 0 13.7 53.5 3.5 10.3 3.74 34.4 69.6 0.56 27.6 19.8 19.5 

N obs. 26 26 26 7 7 7 7 26 26 26 26 26 26 26 26 
 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)

1994 Near-surface measurements: 

M551.3N Mean 0.2 3.33 0.17 — — — — 20.6 8.35 92 420 8.1 28.6 45 —  Median 0.2 3.35 0.15 — — — — 22 8.2 89 426 8.1 27 46 —  Minimum 0.2 2.44 0 — — — — 6.9 6.6 77 369 7.8 20 21 —  Maximum 0.2 4.27 0.31 — — — — 28.5 10.8 124 471 8.8 50 67 —  Std. dev. 0 0.51 0.09 — — — — 6.28 1.48 15 27.5 0.29 9.08 12 — 

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

M554.8F Mean 0.2 2.86 0.42 — — — — 18.5 9.31 97 406 8.2 30.8 43 —  Median 0.2 2.74 0.4 — — — — 20.6 8.25 92 414 8.1 29 45 —  Minimum 0.2 1.92 0.28 — — — — 6.9 6.4 75 285 7.8 22 20 —  Maximum 0.2 4.57 0.76 — — — — 25.8 17.4 153 474 9.2 48 61 —  Std. dev. 0 0.68 0.11 — — — — 6.07 2.88 21.1 47.4 0.37 8.64 14.1 — 

N obs. 16 16 16 0 0 0 0 16 16 16 16 16 16 16 0 

M556.4A Mean 0.2 1.37 — 96.7 18 100 5 12.2 10.7 96 414 8.2 43.4 24 35.2  Median 0.2 1.3 — 100 22 100 2 12.5 10.6 93 410 8.2 41 24 38.1  Minimum 0.2 0.4 — 90 8 100 2 0 6.6 79 301 7.4 22 3 1.9  Maximum 0.2 3.07 — 100 25 100 12 25.8 15.8 149 530 9.2 92 46 74.6  Std. dev. 0 0.61 — 5.77 9.07 0 5.8 9.84 2.77 15.6 47.7 0.41 16.3 12.3 19.9 

N obs. 26 26 0 3 3 3 3 26 26 26 26 26 22 26 26 

M563.9T Mean 0.2 0.7 0.03 98.3 22 67 5 13.8 10.5 100 415 8.2 30.9 35 41.1  Median 0.2 0.61 0.01 100 22 100 7 13.2 9.8 96 405 8.1 28 36 44.6  Minimum 0.1 0.3 0 90 10 0 0 0 1.7 12 268 7 16 4 3.6  Maximum 0.2 1.85 0.19 100 36 100 9 31 19.2 183 558 9.7 80 85 102  Std. dev. 0.02 0.32 0.04 4.08 9.52 51.6 4.1 10.4 3.88 32.9 68.3 0.63 13.5 22.3 27.6 

N obs. 26 24 24 6 6 6 6 25 25 25 25 24 21 25 25 

M574.2D Mean 0.2 2.58 0.4 — — — — 16.7 9.78 98 404 8.3 40.8 28 40.7  Median 0.2 2.68 0.37 — — — — 18.1 9.6 96 399 8.2 40 28 40.2  Minimum 0.2 1.5 0.32 — — — — 1.4 6.6 79 320 7.8 30 17 15.8  Maximum 0.2 3.66 0.5 — — — — 27.8 15.4 146 479 9.2 56 46 66.5  Std. dev. 0 0.51 0.09 — — — — 7.71 2.4 15.3 40.9 0.4 7.67 7.68 12.6 

N obs. 19 19 3 0 0 0 0 19 19 19 19 19 18 19 19 

M582.5B Mean 0.2 2.16 — 96.3 26 95 6 12.2 10.8 97 421 8.2 55.4 23 32.5  Median 0.2 2.08 — 97.5 25 100 4 12.5 10.6 92 416 8.2 42 25 31.6  Minimum 0.2 0.5 — 90 20 80 0 0 6.7 75 329 7.3 28 3 2.3  Maximum 0.2 4.57 — 100 34 100 18 27.3 16.8 157 540 9.3 160 40 80.5  Std. dev. 0 0.92 — 4.79 6.32 10 8 9.9 2.74 18.4 51 0.42 36.5 10.5 19.1 

N obs. 26 26 0 4 4 4 4 26 26 26 26 26 25 26 26 
 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)

1994 Near-surface measurements: 

MQ02.1M Mean 0.2 0.87 — 100 41 93 2 12.4 10.6 99 575 8.1 — 45 78.7  Median 0.2 0.71 — 100 46 90 0 13.3 11 100 579 8.1 — 30 60  Minimum 0.2 0.48 — 100 28 90 0 0 6.8 46 354 7.3 — 5 8.1  Maximum 0.2 3.1 — 100 48 100 6 25.8 13 146 667 8.7 — 196 227  Std. dev. 0 0.55 — 0 11 5.77 3.5 8.96 1.64 19.4 67.4 0.34 — 45.9 62 

N obs. 26 26 0 3 3 3 3 26 26 26 26 26 0 26 26 

PR03.2M Mean 0.2 1.71 — 100 30 83 2 11.5 9.42 84 669 8 149 39 53.2  Median 0.2 1.6 — 100 34 80 0 13 10.2 83 683 8 149 31 39.8  Minimum 0.2 1.11 — 100 16 70 0 0 6.2 70 479 7.3 149 5 3.9  Maximum 0.2 2.8 — 100 39 100 5 24 13 106 790 8.4 149 292 415  Std. dev. 0 0.41 — 0 12.1 15.3 2.9 8.33 2.22 9.27 67.1 0.25 — 53.8 78.3 

N obs. 26 26 0 3 3 3 3 26 26 26 26 26 1 26 26 

RC01.7M Mean 0.2 0.54 — — — — — 11.1 10.3 91 668 8.1 — 46 67.4  Median 0.2 0.5 — — — — — 11.8 10.3 89 691 8.1 — 23 29.5  Minimum 0.2 0.2 — — — — — 0 7.2 70 483 7.6 — 5 3.4  Maximum 0.2 1.2 — — — — — 25.1 13.4 104 777 8.5 — 530 793  Std. dev. 0 0.21 — — — — — 8.08 1.99 8.86 67.7 0.23 — 100 151 

N obs. 26 26 0 0 0 0 0 26 26 26 26 26 0 26 26 

WP02.6M Mean 0.2 1 — 100 40 100 4 12.8 11.4 108 422 8.2 — 43 83.3  Median 0.2 0.83 — 100 25 100 5 14.7 11.9 102 399 8.2 — 33 88.1  Minimum 0.2 0.5 — 100 22 100 1 0 6.5 58 249 7.2 — 4 1.5  Maximum 0.2 2.9 — 100 74 100 6 26.8 13.2 156 584 8.9 — 116 198  Std. dev. 0 0.57 — 0 29.2 0 2.6 10 1.82 28.1 100 0.49 — 30.7 60.6 

N obs. 26 26 0 3 3 3 3 26 26 26 26 26 0 26 26 

1994 Middepth measurements: 

M545.5B Mean 1.47 2.98 — — — — — 21.7 9.25 103 458 8.4 — 23 —  Median 1.35 2.74 — — — — — 23.4 8.35 96 458 8.4 — 23 —  Minimum 1 2.13 — — — — — 13.5 6.6 86 458 8.4 — 23 —  Maximum 2 3.96 — — — — — 28.3 15.4 148 458 8.4 — 23 —  Std. dev. 0.37 0.69 — — — — — 5.24 3.12 22.7 — — — — — 

N obs. 6 6 0 — — — — 6 6 6 1 1 — 1 0 
 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-bottom measurements: 

M545.5B Mean 2.67 2.88 0 — — — — 14.1 8.72 80 416 8.4 — 28 33.9  Median 2.5 2.74 0 — — — — 16 8 81 424 8.5 — 25 34.8  Minimum 1.9 2.13 0 — — — — 0.6 0.8 6 302 7.3 — 16 21.4  Maximum 3.8 3.96 0 — — — — 27.2 19.4 144 531 9.4 — 47 45.5  Std. dev. 0.55 0.54 0 — — — — 9.05 4.71 33.8 57.4 0.47 — 8.34 9.92 

N obs. 22 22 16 — — — — 22 22 22 18 18 — 14 6 

1995 Near-surface measurements: 

AL02.3M Mean 0.2 2.82 — 98.3 10 23 0 11.5 11.3 102 639 8 — 31 34  Median 0.2 2.72 — 100 11 0 0 11.7 10.9 92 661 8 — 20 20.4  Minimum 0.2 1.8 — 90 1 0 0 0.1 6.6 75 485 7.6 — 5 4.3  Maximum 0.2 4 — 100 16 90 2 27.2 25 315 710 8.4 — 207 226  Std. dev. 0 0.63 — 4.08 5.28 38.3 .82 9.9 3.79 45.4 55.8 0.19 — 42.4 49 

N obs. 26 26 0 6 6 6 6 26 26 26 26 26 0 26 26 

M497.2B Mean 0.2 1.45 — 60 14 7 0 12.6 10.4 92 433 8.1 47.3 28 47.5  Median 0.2 1.5 — 50 15 0 0 11.7 10.8 92 439 8 40 25 32.2  Minimum 0.2 0.42 — 50 8 0 0 0.2 4.5 57 326 7.7 18 5 4.3  Maximum 0.2 1.98 — 80 20 20 1 28 17.9 130 532 8.7 150 100 274  Std. dev. 0 0.32 — 17.3 6.03 11.5 .58 10.4 3.75 17.6 61.9 0.25 27.7 21.1 56.4 

N obs. 26 26 0 3 3 3 3 26 26 26 26 26 22 26 26 

M508.1F Mean 0.2 1.66 0 100 20 50 2 13.4 13.1 123 505 8.3 52.7 17 20.9  Median 0.2 1.49 0 100 20 50 1 12.4 12.1 115 489 8.4 50 15 21.1  Minimum 0.2 0.9 0 100 1 0 0 1.1 2 14 335 7.1 28 6 3.4  Maximum 0.2 2.65 0.02 100 30 100 6 29.2 25 309 776 9.1 110 36 42.7  Std. dev. 0 0.49 0.01 0 9.17 51 2.7 10.3 6.64 61.6 122 0.63 21.5 8.57 11 

N obs. 26 26 25 8 8 8 8 26 26 26 26 26 25 26 26 

M511.4B Mean 0.2 0.96 — 30 8 60 1 12.6 10.9 96 435 8.1 38.2 24 38.4  Median 0.2 0.7 — 30 8 80 1 11.3 11.1 91 442 8.1 38 22 29.6  Minimum 0.2 0.25 — 20 6 0 0 0.2 4.9 63 324 7.6 24 5 3.9  Maximum 0.2 1.8 — 40 10 100 2 28.4 20.2 146 544 8.7 52 55 99.8  Std. dev. 0 0.48 — 10 2 52.9 1 10.4 4.09 19.6 66.3 0.27 7.67 13.9 28 

N obs. 26 26 0 3 3 3 3 26 26 26 26 26 18 26 26 
 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)

1995 Near-surface measurements: 

M525.5L Mean 0.2 1.1 0.2 100 25 55 2 13 10.8 97 414 8.2 44.9 30 52.5  Median 0.2 1.11 0.2 100 23 60 2 12.3 10.1 95 424 8.2 40 23 39.2  Minimum 0.2 1 0.1 100 19 0 0 0 5.9 74 305 7.8 16 5 2.8  Maximum 0.2 1.26 0.32 100 35 100 6 28.4 18.8 138 527 8.8 108 134 185  Std. dev. 0 0.07 0.07 0 6.25 49.7 2.6 10.7 3.33 15.6 64.4 0.26 23.6 28.1 53.6 

N obs. 26 24 23 6 6 6 6 24 24 24 24 24 21 24 24 

M532.3T Mean 0.2 1.1 0.1 100 18 36 2 12.6 11.9 108 446 8.3 44.2 25 28.3  Median 0.2 1.05 0.07 100 18 10 0 11.1 10.4 99 475 8.3 38.5 21 25.4  Minimum 0.2 0.86 0.01 100 4 0 0 0.4 5.8 70 315 7.6 19 5 4.2  Maximum 0.2 1.42 0.23 100 34 100 11 31.2 24.7 183 550 9 108 70 71  Std. dev. 0 0.17 0.08 0 10.1 46 3.9 10.6 4.49 27.2 72.8 0.33 22.7 17.2 19.5 

N obs. 26 26 26 8 8 8 8 26 25 25 26 26 22 26 26 

M540.2T Mean 0.2 1.33 0.06 100 24 39 4 12.3 11.2 99 436 8.2 45 25 28.4  Median 0.2 1.09 0.04 100 25 5 0 10.8 11.3 99 448 8.2 39 19 24.5  Minimum 0.2 0.84 0 100 6 0 0 0 3.5 43 313 7.8 18 5 2.6  Maximum 0.2 2.22 0.23 100 36 100 12 29.1 19 148 548 9 95 59 67.9  Std. dev. 0 0.43 0.06 0 8.89 50.8 5.1 10.7 3.84 23.4 68.9 0.35 20.8 16.7 20.7 

N obs. 26 26 26 8 8 8 8 26 26 26 26 26 22 26 26 

M541.7L Mean 0.2 1.24 0.01 — — — — 25.7 12.3 158 455 8.4 33.9 35 —  Median 0.2 1.18 0 — — — — 28.1 10.3 134 472 8.6 38 27 —  Minimum 0.2 1 0 — — — — 16 7.7 86 367 7.9 24 23 —  Maximum 0.2 1.71 0.05 — — — — 31.3 25 346 510 8.8 44 54 —  Std. dev. 0 0.25 0.02 — — — — 5.79 6.09 91.5 56 0.37 7.45 13.4 — 

N obs. 7 7 7 0 0 0 0 7 7 7 7 7 7 7 0 

M543.6G Mean 0.2 1.48 0 — — — — 24.9 10 124 444 8.4 34.4 33 —  Median 0.2 1.4 0 — — — — 27.3 7.1 93 443 8.4 32 32 —  Minimum 0.2 1.21 0 — — — — 15.2 5.4 69 383 8.1 24 15 —  Maximum 0.2 1.98 0.02 — — — — 28.8 25 329 492 8.9 53 50 —  Std. dev. 0 0.28 0.01 — — — — 5.46 6.86 93 39.3 0.34 9.32 14.4 — 

N obs. 7 7 7 0 0 0 0 7 7 7 7 7 7 7 0 

M544.6E Mean 0.2 2.8 0.01 — — — — 24.7 7.2 87 453 8.1 32.4 32 —  Median 0.2 2.74 0 — — — — 26.7 6.4 75 451 8 30 28 —  Minimum 0.2 2.48 0 — — — — 14.9 3.2 40 393 7.6 18 14 —  Maximum 0.2 3.28 0.03 — — — — 28.9 10.3 136 502 8.6 54 70 —  Std. dev. 0 0.29 0.01 — — — — 5.5 2.68 33.7 40.7 0.34 11.8 17.9 — 

N obs. 7 7 7 0 0 0 0 7 7 7 7 7 7 7 0 
 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)

1995 Near-surface measurements: 

M545.5B Mean 0.2 2.87 0.02 100 24 49 3 13.4 12.5 114 422 8.5 54.4 19 23.5  Median 0.2 2.6 0.02 100 24 20 1 12.3 13.9 119 428 8.6 47 19 22.8  Minimum 0.2 2.18 0 100 16 0 0 0.2 3 38 296 7.5 21 4 2.8  Maximum 0.2 3.96 0.07 100 32 100 10 28.8 18.7 176 548 9.2 110 46 50.2  Std. dev. 0 0.54 0.02 0 5.5 48.8 3.9 10.6 4.79 40.1 71.6 0.51 24.1 10.4 12.4 

N obs. 26 25 24 7 7 7 6 25 25 25 25 25 25 25 25 

M551.3N Mean 0.2 3.29 0.23 — — — — 20.2 8.29 90 412 8.1 33.3 38 —  Median 0.2 3.24 0.2 — — — — 21.7 7.7 94 420 8.2 33.5 36 —  Minimum 0.2 2.4 0.06 — — — — 3.5 5 62 312 7.7 16 23 —  Maximum 0.2 4.57 0.49 — — — — 29.9 12.2 116 527 8.4 46 92 —  Std. dev. 0 0.64 0.14 — — — — 8.58 2.15 15.5 75.1 0.22 8.03 17.2 — 

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

M556.4A Mean 0.2 1.98 — 50 11 0 0 11.9 11.1 96 417 8.1 56.8 19 25.4  Median 0.2 1.83 — 50 11 0 0 11 11.4 92 425 8 48 21 27.9  Minimum 0.2 1.2 — 20 2 0 0 0 4.8 61 309 7.4 30 5 3  Maximum 0.2 2.9 — 80 20 0 0 27.2 19.5 154 529 8.8 128 42 49.4  Std. dev. 0 0.47 — 42.4 12.7 0 0 10.7 3.9 20.1 66.2 0.33 25.5 9.86 14.9 

N obs. 26 26 0 2 2 2 2 26 26 26 26 26 24 26 26 

M563.9T Mean 0.2 0.69 0.03 100 23 63 4 13.1 11.4 103 416 8.2 34.1 30 38.6  Median 0.2 0.64 0.01 100 25 75 5 12.6 12 98 417 8.2 31 22 30.6  Minimum 0.2 0.4 0 100 12 0 0 0 3.7 46 305 7.7 18 5 4  Maximum 0.2 1.3 0.12 100 30 100 8 30.3 20 162 554 9 52 170 225  Std. dev. 0 0.24 0.04 0 7.03 43.2 3.5 11.1 4.05 27 71.6 0.33 11.7 32.7 43.2 

N obs. 25 25 25 6 6 6 6 25 25 25 25 25 18 25 25 

M564.5T Mean 0.2 0.87 0 100 18 67 4 3.37 13.9 106 491 8.1 61.8 11 17.1  Median 0.2 0.78 0 100 17 75 3 2.3 15.4 112 498 8 61 8 11.9  Minimum 0.2 0.7 0 100 10 0 0 1.6 3 21 323 7.4 45 6 5  Maximum 0.2 1.25 0 100 26 100 10 8.5 20.7 177 577 9.3 80 23 37.9  Std. dev. 0 0.19 0 0 5.99 37.8 4 2.38 6.46 53.5 86 0.75 17.8 6.18 13.1 

N obs. 7 7 7 6 6 6 6 7 7 7 7 7 4 7 5 

M574.2D Mean 0.2 2.7 0.54 — — — — 16 9.44 92 410 8.1 46.2 25 37.6  Median 0.2 2.74 0.54 — — — — 17.2 9 90 417 8.1 44 26 36.1  Minimum 0.2 1 0.17 — — — — 0.1 5 63 309 7.7 30 14 19.8  Maximum 0.2 3.96 0.82 — — — — 27.6 15.9 148 527 8.8 76 41 58.2  Std. dev. 0 0.7 0.19 — — — — 9.31 2.92 17.7 74.5 0.28 10.1 6.31 11.2 

N obs. 19 19 14 0 0 0 0 19 19 19 19 19 19 19 19 
 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)

1995 Near-surface measurements: 

M582.5B Mean 0.2 2.53 — 96 9 0 0 11.7 11.3 98 422 8.2 52.5 20 28.5  Median 0.2 2.76 — 100 10 0 0 11.1 10.8 91 431 8.1 42 21 32.8  Minimum 0.2 1 — 80 3 0 0 0 5.4 68 313 7.7 30 4 2.7  Maximum 0.2 4.57 — 100 16 0 0 27.3 20.2 169 526 8.8 122 39 72.2  Std. dev. 0 0.98 — 8.94 5.08 0 0 10.6 3.99 22.5 65.2 0.29 23.4 10.2 17.8 

N obs. 26 26 0 5 5 5 5 26 25 25 26 26 22 26 26 

MQ02.1M Mean 0.2 0.88 — 100 16 36 16 11.5 10.7 98 596 8.1 — 97 159  Median 0.2 0.76 — 100 15 1 0 10.2 10.9 93 603 8 — 34 57.7  Minimum 0.2 0.4 — 100 8 0 0 0 7.3 73 508 7.6 — 6 7.6  Maximum 0.2 1.85 — 100 20 100 80 28.3 14 180 700 8.5 — 1170 1722  Std. dev. 0 0.43 — 0 4.93 49.6 36 10.3 1.75 24 48.4 0.26 — 231 344 

N obs. 26 26 0 5 5 5 5 26 26 26 26 26 0 26 26 

PR03.2M Mean 0.2 1.62 — 100 8 33 1 10.5 9.92 85 682 7.9 — 33 46.2  Median 0.2 1.5 — 100 9 5 0 10.4 9.75 85 687 7.9 — 26 29.1  Minimum 0.2 1.08 — 100 1 0 0 0 6.4 76 569 7.5 — 6 4.7  Maximum 0.2 2.72 — 100 13 100 2 23.9 14 98 758 8.2 — 185 306  Std. dev. 0 0.43 — 0 4.82 48 .84 9.03 2.48 6.36 40.9 0.16 — 38.8 65.6 

N obs. 26 25 0 6 6 6 6 26 26 26 26 26 0 26 26 

RC01.7M Mean 0.2 0.51 — — — — — 10.4 10.9 94 684 8 — 44 72  Median 0.2 0.45 — — — — — 9.4 10.6 94 683 8 — 22 29.6  Minimum 0.2 0.3 — — — — — 0 8.1 80 577 7.7 — 6 4.3  Maximum 0.2 1 — — — — — 25.7 14.4 133 821 8.4 — 265 441  Std. dev. 0 0.19 — — — — — 9.37 2.23 10.3 47.1 0.19 — 57.6 103 

N obs. 26 26 0 0 0 0 0 26 26 26 26 26 0 26 26 

WP02.6M Mean 0.2 0.92 — 100 27 50 3 11.8 11.3 104 466 8.2 — 39 77.6  Median 0.2 0.69 — 100 28 50 3 11.7 11.3 92 473 8.1 — 33 74.9  Minimum 0.2 0.4 — 100 15 0 0 0 7.8 72 329 7.5 — 5 4.6  Maximum 0.2 2.1 — 100 40 100 9 28.2 15.1 158 654 9 — 105 195  Std. dev. 0 0.56 — 0 8.39 54.8 3.9 10.3 1.72 27.3 86.9 0.45 — 27.2 58.2 

N obs. 26 26 0 6 6 6 6 26 26 26 26 26 0 26 26 
 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 Middepth measurements: 

M545.5B Mean 1.43 2.87 — — — — — 19.5 6.69 71 427 8.1 — — —  Median 1.5 3.05 — — — — — 20.3 7.7 67 415 8 — — —  Minimum 1.1 2.18 — — — — — 1.7 2.5 32 333 7.5 — — —  Maximum 1.8 3.66 — — — — — 27.9 10.3 113 506 8.9 — — —  Std. dev. 0.27 0.57 — — — — — 9.28 3.12 31.3 60 0.56 — — — 

N obs. 7 7 0 — — — — 7 7 7 7 7 — 0 0 

1995 Near-bottom measurements: 

M545.5B Mean 2.68 2.87 0 — — — — 12.5 9.44 80 430 8.2 — 24 27.3  Median 2.4 2.6 0 — — — — 12 9.3 69 440 8 — 22 27.6  Minimum 2 2.18 0 — — — — 1 1 13 299 7.4 — 11 8.6  Maximum 3.8 3.96 0 — — — — 27 17.6 142 549 9.8 — 46 53.1  Std. dev. 0.55 0.54 0 — — — — 9.49 5.82 42.6 72 0.63 — 11.1 13.6 

N obs. 25 25 23 — — — — 25 25 25 24 24 — 7 7 

1996 Near-surface measurements: 

AL02.3M Mean 0.2 3.31 — 95 6 17 0 11.6 10.7 96 614 8.2 — 28 31.8  Median 0.2 3.1 — 100 4 0 0 12.2 9.6 93 635 8.1 — 24 28  Minimum 0.2 2.1 — 80 1 0 0 0.1 7.7 66 440 7.5 — 5 3.2  Maximum 0.2 5.5 — 100 13 100 2 25.5 15.9 137 706 9.2 — 122 157  Std. dev. 0 0.8 — 8.37 5.5 40.8 .82 8.97 2.46 16.6 72.2 0.36 — 25.1 31.4 

N obs. 25 24 0 6 6 6 6 24 24 24 24 24 0 24 24 

M497.2B Mean 0.2 1.53 — 90 2 0 0 12 9.52 84 386 7.9 54 35 45.8  Median 0.2 1.5 — 90 2 0 0 11.6 9.2 85 374 7.8 50 21 23.2  Minimum 0.2 1.2 — 90 2 0 0 0.1 5.7 68 273 7.5 10 3 4  Maximum 0.2 2.38 — 90 2 0 0 26.5 13.2 99 491 8.5 130 350 445  Std. dev. 0 0.27 — — — — — 9.81 2.41 7.86 54.8 0.26 28.1 66.9 85.9 

N obs. 25 25 0 1 1 1 1 25 25 25 25 25 22 25 25 

M508.1F Mean 0.2 1.73 0.03 100 17 43 1 12.8 12.9 121 431 8.3 53.2 22 25.9  Median 0.2 1.46 0 100 20 35 0 10.8 10.8 101 421 8.1 45 22 24  Minimum 0.2 1.2 0 100 3 0 0 0.6 5.6 39 264 7.2 25 4 3  Maximum 0.2 3.3 0.55 100 30 100 2 28.6 25 317 734 9.4 110 61 54.1  Std. dev. 0 0.56 0.11 0 10.8 45.9 1 9.9 6.12 62.2 104 0.69 23.3 13.4 14.5 

N obs. 25 25 25 6 6 6 6 25 25 25 25 25 25 25 25 
 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)

1996 Near-surface measurements: 

M511.4B Mean 0.2 0.97 — — — — — 12.3 9.78 87 386 7.9 40.9 36 46.5  Median 0.2 0.7 — — — — — 11.5 9.3 88 380 7.8 35 26 30.7  Minimum 0.2 0.32 — — — — — 0.6 5.5 68 262 7.2 10 4 3.1  Maximum 0.2 2.8 — — — — — 28 13.3 103 491 8.5 90 310 352  Std. dev. 0 0.6 — — — — — 10.2 2.54 8.52 58.4 0.3 22.5 58.9 68 

N obs. 25 25 0 0 0 0 0 25 25 25 25 25 13 25 25 

M525.5L Mean 0.2 1.14 0.19 100 40 100 4 13.6 9.86 92 361 8.1 47.1 32 52.1  Median 0.2 1.1 0.18 100 40 100 4 14.4 9.9 92 359 8.1 46 19 28.5  Minimum 0.2 0.92 0.08 100 36 100 3 0.1 6.1 72 227 7.5 15 5 3  Maximum 0.2 2.3 0.37 100 44 100 4 26.1 13.2 110 448 8.9 90 196 421  Std. dev. 0 0.28 0.08 0 5.66 0 .71 9.35 2.24 10.2 53.5 0.35 17.7 39.3 86.9 

N obs. 23 21 18 2 2 2 2 21 21 21 21 21 20 21 21 

M532.3T Mean 0.2 1.12 0.08 98 11 40 1 12.9 10.4 95 396 8.2 41.1 27 30.8  Median 0.2 1.05 0.06 100 11 10 0 14.4 9.95 92 397 8.3 38 25 28.2  Minimum 0.2 0.75 0 90 1 0 0 0.1 6.7 68 222 7.6 20 4 2.1  Maximum 0.2 2.5 0.2 100 25 100 2 26.8 14.4 128 489 8.7 70 62 65.6  Std. dev. 0 0.37 0.06 4.47 9.81 50.5 1.1 9.42 2.44 15.2 62.3 0.32 14.8 15.5 18.8 

N obs. 23 22 21 5 5 5 5 22 22 22 22 22 20 22 22 

M540.2T Mean 0.2 1.37 0.08 96.7 27 50 2 11.9 9.65 85 379 8.1 43.7 31 35.9  Median 0.2 1.18 0.04 100 34 50 0 12 9.9 84 381 8 36 25 29.1  Minimum 0.2 0.65 0 80 1 0 0 0 4.3 52 208 7.6 18 4 3.7  Maximum 0.2 2.9 0.63 100 42 100 8 25.7 14.3 128 490 8.7 110 82 101  Std. dev. 0 0.57 0.13 8.16 16 44.7 3.2 9.7 2.78 15.1 60.9 0.31 23.5 21.9 26.9 

N obs. 24 24 23 6 6 6 6 24 24 24 24 24 23 24 24 

M545.5B Mean 0.2 2.85 0.01 100 25 47 2 12.5 11.6 104 392 8.4 64 15 18.2  Median 0.2 2.6 0 100 32 45 1 13.3 10.4 98 398 8.2 59 15 16.5  Minimum 0.2 2.03 0 100 1 0 0 0.1 5.4 65 260 7.5 35 4 1.8  Maximum 0.2 4.9 0.1 100 39 100 10 26.5 25 193 527 9.4 130 30 42.4  Std. dev. 0 0.72 0.02 0 15.1 42.7 3.9 9.23 4.81 33.7 74.5 0.58 26.2 7.54 10.2 

N obs. 24 24 24 6 6 6 6 24 24 24 24 24 24 24 24 

M551.3N Mean 0.2 2.44 0.15 — — — — 20.8 8.27 91 374 8.1 36.7 33 —  Median 0.2 2.5 0.14 — — — — 23.9 8.1 86 364 8.1 32 30 —  Minimum 0.2 1.41 0 — — — — 8.6 4.2 50 292 7.6 21 13 —  Maximum 0.2 3.35 0.42 — — — — 27.6 14.6 125 472 8.6 62 58 —  Std. dev. 0 0.64 0.14 — — — — 5.67 2.6 20.4 49.5 0.34 12.4 13 — 

N obs. 15 15 15 0 0 0 0 15 15 15 15 15 15 15 0 
 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)

1996 Near-surface measurements: 

M556.4A Mean 0.2 2.08 — 83.3 10 33 0 11.9 9.68 86 359 8 62.4 18 27.9  Median 0.2 1.72 — 80 4 0 0 12.2 10.2 86 350 8.1 54 18 22.4  Minimum 0.2 1.36 — 70 2 0 0 0 5.8 69 251 7.4 31 5 2.9  Maximum 0.2 5.1 — 100 25 100 1 26.5 12.7 115 481 8.9 170 38 101  Std. dev. 0 0.85 — 15.3 12.7 57.7 .58 9.9 2.26 11.9 54.7 0.36 30.9 7.77 21.4 

N obs. 24 24 0 3 3 3 3 24 24 24 24 24 23 23 24 

M563.9T Mean 0.2 0.84 0.05 100 23 50 0 14.1 10.3 98 364 8.2 42.6 27 28.8  Median 0.2 0.66 0.02 100 23 50 0 15.1 10.9 97 356 8.2 38 23 26.8  Minimum 0.2 0.48 0 100 8 0 0 0.1 4.7 42 202 7.5 18 5 3.9  Maximum 0.2 2.5 0.33 100 38 100 0 27.6 15.3 155 470 9 72 85 55.1  Std. dev. 0 0.46 0.08 0 21.2 70.7 — 9.51 3.43 28.9 66.7 0.41 14.7 17.1 13.7 

N obs. 22 21 21 2 2 2 1 21 21 21 21 21 19 21 21 

M582.5B Mean 0.2 1.53 — 86 16 39 1 11.2 9.82 87 369 8 67.3 22 29.2  Median 0.2 1.5 — 100 18 0 0 10.3 9.8 88 361 8 57.5 20 28.8  Minimum 0.2 1.2 — 30 2 0 0 0 5.8 62 263 7.4 16 3 1.9  Maximum 0.2 3 — 100 25 100 5 25.7 14.9 119 477 9.1 160 104 103  Std. dev. 0 0.32 — 31.3 8.61 53.4 2.2 10.1 2.24 14.8 54.3 0.38 34.8 19.1 21.2 

N obs. 25 25 0 5 5 5 5 25 25 25 25 25 24 25 25 

MQ02.1M Mean 0.2 0.98 — 98.8 24 100 5 11.5 10.6 97 564 8.1 — 138 382  Median 0.2 0.8 — 100 29 100 4 10.3 10.3 94 587 8.2 — 28 47.8  Minimum 0.2 0.3 — 95 2 100 3 0 7.6 52 316 7.3 — 8 8.5  Maximum 0.2 2.5 — 100 36 100 8 25.8 14.6 150 693 8.6 — 1020 3772  Std. dev. 0 0.61 — 2.5 15.8 0 2.6 9.57 1.8 24.2 96.7 0.34 — 281 961 

N obs. 25 25 0 4 4 3 3 25 25 25 25 25 0 25 25 

PR03.2M Mean 0.2 1.46 — 100 8 18 0 10.1 10 86 649 7.9 — 37 46.3  Median 0.2 1.4 — 100 6 0 0 10.6 9.3 87 671 8 — 26 28  Minimum 0.2 0.85 — 100 1 0 0 0 5.7 62 337 7.6 — 5 4.3  Maximum 0.2 2.58 — 100 21 80 0 22.8 14.8 119 750 8.2 — 128 140  Std. dev. 0 0.51 — 0 8.29 34.9 0 8.4 2.32 11.9 91.7 0.17 — 32.5 39.7 

N obs. 25 25 0 5 5 5 5 25 25 25 25 25 0 25 25 

RC01.7M Mean 0.2 0.59 — 80 1 — — 10.2 10.6 92 639 8.1 — 88 142  Median 0.2 0.4 — 80 1 — — 10.1 9.9 92 661 8.1 — 28 31.1  Minimum 0.2 0.3 — 80 1 — — 0 6.9 57 216 7.4 — 6 6.6  Maximum 0.2 1.7 — 80 1 — — 24.4 15.6 139 770 8.5 — 1340 2383  Std. dev. 0 0.45 — — — — — 8.66 2.51 16.2 109 0.25 — 263 469 

N obs. 25 25 0 1 1 0 0 25 25 25 25 25 0 25 25 
 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: 

RK00.1M Mean 0.2 0.64 — 100 3 0 0 13 8.61 79 667 7.3 — 18 19.3  Median 0.2 0.6 — 100 3 0 0 15.6 9 76 700 7.5 — 17 19.6  Minimum 0.2 0.4 — 100 2 0 0 0.3 4.3 51 427 6 — 7 9.7  Maximum 0.2 1.1 — 100 3 0 0 23.7 12.6 127 736 8 — 38 27.9  Std. dev. 0 0.19 — 0 0.71 0 0 8.55 2.66 18.4 83 0.49 — 7.96 5.78 

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

RK03.7M Mean 0.2 0.3 — — — — — 12 10.9 99 633 7.8 — 10 12.5  Median 0.2 0.3 — — — — — 14.5 10.7 101 638 7.8 — 8 10.4  Minimum 0.2 0.3 — — — — — 0.4 7.8 81 584 7.1 — 3 4.9  Maximum 0.2 0.3 — — — — — 20.3 14.6 120 660 8.2 — 30 36.5  Std. dev. 0 0 — — — — — 6.82 1.92 10.2 19.2 0.26 — 6.98 8.41 

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

WP02.6M Mean 0.2 1.03 — 98.3 21 67 2 11.2 10.8 99 413 8.1 — 226 455  Median 0.2 0.85 — 100 28 100 2 10.4 11.1 89 393 7.8 — 56 106  Minimum 0.2 0.4 — 95 3 0 0 0.1 4.5 46 220 7.4 — 5 5.5  Maximum 0.2 2.7 — 100 33 100 3 25.8 16 174 610 9.1 — 2700 6966  Std. dev. 0 0.57 — 2.89 16.1 57.7 1.5 9.5 2.77 35.6 103 0.54 — 569 1386 

N obs. 25 25 0 3 3 3 3 25 25 25 25 25 0 25 25 

1996 Middepth measurements: 

M545.5B Mean 1.57 3.16 — — — — — 18.8 6.75 70 353 8.1 — — —  Median 1.7 3.38 — — — — — 20.1 6.45 77 348 8.1 — — —  Minimum 1 2.13 — — — — — 12.5 1.2 14 282 7.4 — — —  Maximum 2 3.96 — — — — — 24.3 12.3 115 437 9 — — —  Std. dev. 0.38 0.72 — — — — — 5.4 3.99 36.7 57.4 0.57 — — — 

N obs. 6 6 0 — — — — 6 6 6 6 6 — 0 0 

1996 Near-bottom measurements: 

M508.1F Mean 1.46 1.65 0 — — — — 16 9.46 86 460 8.1 — 35 41.1  Median 1.35 1.54 0 — — — — 18.6 8.45 95 456 7.9 — 34 40.2  Minimum 1 1.2 0 — — — — 2.2 0.8 9 319 7.4 — 16 19.4  Maximum 2.2 2.34 0 — — — — 27.2 25 220 650 9.3 — 55 67.9  Std. dev. 0.38 0.37 0 — — — — 9.49 7.18 56.6 84.2 0.64 — 13 16.5 

N obs. 14 14 7 — — — — 14 14 14 14 14 — 6 6 
 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-bottom measurements: 

M545.5B Mean 2.67 2.87 0 — — — — 11.8 8.71 74 408 8 — 22 23.3  Median 2.4 2.6 0 — — — — 11.7 9.15 84 431 8 — 22 22.9  Minimum 1.8 2.03 0 — — — — 0.2 0.5 6 260 7.2 — 16 18  Maximum 4.7 4.9 0 — — — — 23.9 25 192 551 9.2 — 28 30.8  Std. dev. 0.74 0.74 0 — — — — 8.1 6.32 48.8 81.5 0.58 — 5.16 4.98 

N obs. 22 22 17 — — — — 22 22 22 22 22 — 4 5 
 E-21

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)

Sodium 

1993 Near-surface measurements: 

AL02.3M Mean 5.18 0.1 4.48 0.25 0.1 3.69 86.3 2.29 47.5 27. Median 5.02 0.09 4.53 0.24 0.093 3.64 86 2.16 47.5 27. Minimum 3.95 0.04 3.15 0.06 0.024 2.1 76 1.83 47.5 27. Maximum 8.22 0.3 5.37 0.56 0.23 5.89 97 3.6 47.5 27. Std. dev. 1.138 0.069 0.685 0.139 0.055 1.162 8.459 0.531 — — 

N obs. 15 18 18 15 18 18 5 10 1 

M497.2B Mean 4.04 0.04 2.98 0.23 0.088 4.6 55.2 2.47 24.3 25. Median 3.86 0.03 2.91 0.21 0.075 4.6 55.3 2.5 24.3 25. Minimum 2.91 -0.02 1.83 0.096 -0.01 1.63 41.5 2.15 24.3 25. Maximum 5.24 0.1 4.06 0.39 0.18 7.26 67.4 2.9 24.3 25. Std. dev. 0.762 0.032 0.658 0.076 0.057 1.553 9.536 0.225 — — 

N obs. 14 17 17 14 17 17 5 9 1 

M508.1F Mean 5.1 0.1 4.06 0.22 0.065 4.16 57.3 2.41 36.4 25. Median 4.07 0.06 2.85 0.21 0.042 3.94 51.8 1.94 36.4 25. Minimum 2.1 -0.02 1.58 0.074 -0.01 0.15 44.6 1.68 36.4 25. Maximum 8.66 0.3 8.3 0.3 0.18 7.6 70.7 3.4 36.4 25. Std. dev. 2.42 0.087 2.231 0.063 0.065 2.596 12.34 0.684 — — 

N obs. 13 16 16 13 16 16 5 10 1 

M511.4B Mean 3.33 0.06 2.21 0.26 0.098 4.74 57.1 2.7 24 2 Median 3.21 0.05 2.04 0.23 0.093 4.31 56.9 2.58 24 2 Minimum 2.44 -0.02 1.13 0.12 -0.01 1.08 48.3 2.29 24 2 Maximum 5.23 0.1 3.42 0.53 0.2 7.58 65.8 3.4 24 2 Std. dev. 0.7 0.034 0.566 0.114 0.054 1.85 6.321 0.388 — — 

N obs. 15 18 18 15 18 18 5 10 1 

M525.5L Mean 3.29 0.1 1.96 0.23 0.083 4.86 49.3 2.9 — —  Median 3.18 0.03 1.87 0.22 0.077 4.42 50.1 2.64 — —  Minimum 1.99 -0.02 0.94 0.075 -0.01 0.93 34.6 2.21 — —  Maximum 5.11 0.8 2.87 0.41 0.18 7.43 57.4 4.6 — —  Std. dev. 0.755 0.194 0.536 0.088 0.054 1.677 7.695 0.588 — — 

N obs. 18 22 22 18 22 22 8 14 0 0 

M532.3T Mean 2.63 0.07 1.47 0.18 0.064 3.57 49.3 2.49 33 11. Median 2.5 0.02 1.68 0.19 0.039 3.35 47 2.6 33 11. Minimum 1.23 -0.02 -0.01 0.046 -0.01 -0.05 36 1.4 33 11. Maximum 5.97 0.7 3.29 0.34 0.24 7.5 71.1 3.1 33 11. Std. dev. 1.126 0.146 0.95 0.078 0.066 2.417 12.09 0.477 — — 

N obs. 19 23 23 19 23 23 9 15 1 
 E-22

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)

Sodium 

1993 Near-surface measurements: 

M540.2T Mean 2.93 0.05 1.71 0.2 0.073 4.53 56 2.75 33.8 8.5 Median 2.87 0.04 1.78 0.2 0.061 4.1 56 2.7 33.8 8.5 Minimum 0.87 -0.02 0.17 0.079 -0.01 0.82 36.3 2.18 33.8 8.5 Maximum 4.47 0.2 2.97 0.32 0.16 7.15 77.3 3.3 33.8 8.5 Std. dev. 0.764 0.042 0.608 0.065 0.048 1.811 12.4 0.328 — — 

N obs. 19 22 22 19 22 22 8 14 1 

M545.5B Mean 2.57 0.04 1.09 0.21 0.054 3.08 62.1 2.76 27.3 10. Median 2.2 0.03 0.32 0.22 0.021 3.05 61.9 2.9 27.3 10. Minimum 1.16 -0.02 -0.01 0.075 -0.01 0.27 61 2.09 27.3 10. Maximum 5.2 0.1 3.2 0.32 0.18 6.93 62.8 3.2 27.3 10. Std. dev. 1.095 0.032 1.276 0.069 0.057 1.713 0.798 0.434 — — 

N obs. 15 17 17 15 17 17 4 9 1 

M556.4A Mean 3.01 0.05 1.95 0.21 0.084 5.02 54.6 2.62 24 24. Median 3.17 0.05 1.86 0.24 0.059 4.69 54.9 2.56 24 24. Minimum 1.65 -0.02 0.95 0.096 -0.01 1.11 50.5 2.18 24 24. Maximum 4.12 0.1 2.88 0.36 0.19 7.66 57.2 3.2 24 24. Std. dev. 0.707 0.027 0.502 0.074 0.057 1.936 2.598 0.327 — — 

N obs. 15 18 18 15 18 18 5 10 1 

M563.9T Mean 2.81 0.05 1.63 0.2 0.073 4.5 54.5 2.72 — —  Median 2.74 0.05 1.72 0.2 0.063 3.89 54 2.86 — —  Minimum 2.37 -0.02 0.85 0.093 -0.01 0.82 52.1 2.14 — —  Maximum 3.54 0.1 2.38 0.38 0.16 7.05 57.6 3.1 — —  Std. dev. 0.366 0.031 0.414 0.069 0.05 1.708 2.304 0.344 — — 

N obs. 14 17 17 14 17 17 4 9 0 0 

M574.2D Mean 3.17 0.06 2.02 0.24 0.088 5.07 55.4 2.65 — —  Median 3.09 0.07 1.91 0.19 0.085 4.76 55.4 2.64 — —  Minimum 2.6 0.02 0.99 0.095 -0.01 1.32 52.5 2.23 — —  Maximum 4.25 0.1 3 0.56 0.19 7.74 57.8 3.2 — —  Std. dev. 0.456 0.026 0.537 0.127 0.059 1.865 2.201 0.324 — — 

N obs. 14 17 17 14 17 17 4 9 0 0 

M582.5B Mean 3.14 0.03 2.14 0.21 0.083 5.18 51.7 2.59 23.7 25. Median 3.06 0.02 2.04 0.18 0.068 4.69 55.4 2.59 23.7 25. Minimum 2.07 -0.02 1.23 0.061 -0.01 1.56 43.2 2 23.7 25. Maximum 4.23 0.08 3.44 0.45 0.19 8.02 56.9 3.1 23.7 25. Std. dev. 0.641 0.026 0.592 0.109 0.061 1.822 6.264 0.338 — — 

N obs. 14 17 17 14 17 17 5 10 1 
 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)

Sodium 

1993 Near-surface measurements: 

MQ02.1M Mean 7.72 0.05 7.6 0.29 0.14 5.58 93.1 2.15 38 27. Median 7.7 0.03 7.7 0.29 0.14 5.7 87.4 2.06 38 27. Minimum 5.23 -0.02 5.59 0.08 0.053 2.79 79.5 1.63 38 27. Maximum 10.4 0.3 9.15 0.51 0.27 7.3 113 2.5 38 27. Std. dev. 1.395 0.068 0.926 0.136 0.065 1.11 13.38 0.267 — — 

N obs. 15 18 17 15 18 18 5 10 1 

PR03.2M Mean 6.79 0.1 6.21 0.24 0.081 5.34 71.2 2.74 47.6 27. Median 6.94 0.09 6.12 0.23 0.077 5.35 80.3 2.49 47.6 27. Minimum 5.15 -0.02 4.75 0.046 -0.01 3.25 31.4 1.74 47.6 27. Maximum 7.99 0.8 7.54 0.53 0.17 7.27 88.8 4.4 47.6 27. Std. dev. 0.751 0.178 0.817 0.139 0.05 0.908 23.48 0.869 — — 

N obs. 15 17 17 15 17 17 5 10 1 

RC01.7M Mean 4.29 0.09 3.65 0.32 0.14 5.45 90.3 2.69 49.9 25. Median 3.97 0.08 3.56 0.29 0.13 5.51 88.8 2.43 49.9 25. Minimum 2.87 -0.02 2.32 0.069 0.037 3.55 86.5 1.88 49.9 25. Maximum 7.28 0.4 4.8 0.85 0.3 7.38 96 4.2 49.9 25. Std. dev. 1.167 0.079 0.716 0.192 0.066 0.973 3.841 0.708 — — 

N obs. 15 18 18 15 18 18 5 10 1 

WP02.6M Mean 6.37 0.05 5.56 0.28 0.099 4.84 80.4 2.15 28.7 26. Median 6.65 0.03 5.5 0.23 0.072 4.75 79.4 1.84 28.7 26. Minimum 3.85 -0.02 3.53 0.072 0.017 2.72 69.5 1.48 28.7 26. Maximum 9.36 0.2 7.93 0.73 0.3 6.62 90.6 5.3 28.7 26. Std. dev. 1.33 0.05 1.178 0.174 0.077 1.05 7.957 1.122 — — 

N obs. 15 18 18 15 18 18 5 10 1 

1994 Near-surface measurements: 

AL02.3M Mean 3.67 0.1 3.71 0.22 0.033 3.54 68.9 2.62 39.4 7.7 Median 3.46 0.06 3.97 0.17 0.016 3.94 67.9 2.52 39.9 7.2 Minimum 1.7 -0.02 0.83 0.069 -0.01 -0.05 54.5 1.38 29.7 3.0 Maximum 6.47 0.6 11 1.19 0.22 5.51 80.9 5.7 44.8 27. Std. dev. 1.181 0.135 2.065 0.212 0.045 1.57 6.192 0.975 3.755 4.31

N obs. 26 26 26 26 26 26 26 26 26 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)

Sodium 

1994 Near-surface measurements: 

M497.2B Mean 2.62 0.1 2.12 0.19 0.037 3.95 47.4 2.92 19 10. Median 2.46 0.05 2.13 0.16 0.03 4.45 45.6 2.82 18 9.9 Minimum 1.4 -0.02 0.38 0.062 -0.01 0.14 35.8 2.24 13.9 5.8 Maximum 4.87 0.8 7.39 0.59 0.2 6.6 64.4 4.53 24.4 13. Std. dev. 0.87 0.168 1.509 0.112 0.041 1.871 7.861 0.54 3.074 1.60

N obs. 26 26 26 26 26 26 26 26 26 2

M508.1F Mean 4.08 0.3 2.9 0.21 0.03 3.16 44.9 2.81 23 10. Median 2.87 0.03 2.46 0.16 0.018 3.25 43.4 2.67 23.2 11. Minimum 1.62 -0.02 0.13 0.053 -0.01 -0.05 2.47 1.91 1.03 0.8 Maximum 12.4 2.4 11.8 0.57 0.23 6.57 74.3 5.6 35.9 15. Std. dev. 2.789 0.577 2.895 0.134 0.049 1.656 14.09 0.755 7.785 3.42

N obs. 26 25 25 26 26 26 26 26 26 2

M511.4B Mean 2.44 0.1 1.65 0.26 0.05 4.17 45.9 3.04 19.4 12. Median 2.32 0.07 1.65 0.18 0.038 4.52 43.9 3 19.9 12. Minimum 1.7 -0.02 0.43 0.069 -0.01 0.16 37.7 2.22 14.3 9.1 Maximum 4.38 0.9 3.88 1.18 0.27 6.29 60.9 4.2 25 24. Std. dev. 0.66 0.194 0.809 0.249 0.053 1.769 6.267 0.528 2.996 2.99

N obs. 26 26 26 26 26 26 26 26 26 2

M525.5L Mean 2.26 0.1 1.41 0.21 0.037 4.11 44.8 2.81 18.9 1 Median 2.09 0.04 1.38 0.2 0.032 4.67 43.9 2.7 19.1 10. Minimum 1.48 -0.02 0.46 0.071 -0.01 0.051 37.8 1.98 15.3 7.3 Maximum 3.83 0.7 2.32 0.71 0.13 6.44 57.6 4.44 24.1 13. Std. dev. 0.565 0.162 0.606 0.137 0.034 1.879 5.066 0.563 2.776 1.67

N obs. 25 25 25 25 25 25 25 25 25 2

M532.3T Mean 2.72 0.1 1.46 0.21 0.034 4.22 47.3 2.92 21.7 10. Median 2.42 0.03 1.25 0.19 0.03 4.76 45.6 2.91 22 9.5 Minimum 1.29 -0.02 -0.01 0.073 -0.01 0.61 32 1.89 15.2 6.0 Maximum 6.32 1 3.21 0.55 0.12 6.02 67 4.9 32 25. Std. dev. 1.173 0.218 0.895 0.119 0.028 1.622 8.754 0.71 4.453 3.60

N obs. 25 25 25 25 25 25 25 25 25 2

M540.2T Mean 2.26 0.1 1.44 0.21 0.035 4.26 46.8 2.92 21.3 9.9 Median 2.24 0.04 1.62 0.18 0.03 4.74 45.6 2.85 21.2 9.4 Minimum 0.96 -0.02 0.21 0.061 -0.01 0.18 35.1 2.13 15.4 6.1 Maximum 3.97 0.8 2.61 0.6 0.16 6.51 58.4 4.11 28 2 Std. dev. 0.603 0.181 0.659 0.125 0.033 1.779 6.589 0.5 3.634 3.45

N obs. 27 27 27 27 27 27 27 27 27 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)

Sodium 

1994 Near-surface measurements: 

M545.5B Mean 1.66 0.1 0.69 0.21 0.036 2.79 44.5 3.06 22.8 8.5 Median 1.41 0.03 0.15 0.14 0.023 2.32 43.3 2.91 22.3 8.9 Minimum 0.63 -0.02 -0.01 0.034 -0.01 -0.05 32.6 2.17 14.3 2.1 Maximum 3.63 1 3 0.98 0.21 6.64 66.5 4.29 31.1 11. Std. dev. 0.789 0.23 0.927 0.198 0.049 2.198 8.331 0.585 4.112 2.06

N obs. 26 26 26 26 26 26 26 26 26 2

M556.4A Mean 2.26 0.1 1.44 0.18 0.035 4.17 44.4 3.01 19.1 10. Median 2.13 0.05 1.39 0.15 0.025 4.65 45.2 2.61 18.9 10. Minimum 1.7 -0.02 0.33 0.065 -0.01 0.6 -0.01 2.19 14.4 7.5 Maximum 4.11 0.6 2.26 0.33 0.13 6.73 63.3 5.76 24.5 12. Std. dev. 0.452 0.144 0.581 0.081 0.03 1.888 10.86 0.858 2.816 1.57

N obs. 26 26 26 26 26 26 26 26 26 2

M563.9T Mean 2.16 0.1 1.2 0.22 0.029 4.09 44.8 2.85 19.5 9.8 Median 1.97 0.07 1.24 0.15 0.024 4.66 44.3 2.79 19.6 9.9 Minimum 1.32 -0.02 0.18 0.061 -0.01 0.21 30 2.16 12.1 6.9 Maximum 5.35 0.6 2.59 0.96 0.12 6.55 63.3 3.84 28.9 13. Std. dev. 0.794 0.149 0.71 0.188 0.026 1.846 6.937 0.473 3.689 1.5

N obs. 25 25 25 25 25 25 25 25 25 2

M574.2D Mean 2.12 0.06 1.22 0.18 0.026 4.01 44.5 2.83 18.6 9.8 Median 2.11 0.06 1.25 0.18 0.026 4.69 44.3 2.79 19 9.7 Minimum 1.67 -0.02 0.36 0.065 -0.01 -0.05 38 2.34 14.7 7.9 Maximum 2.81 0.1 2.14 0.3 0.056 6.26 50.4 3.63 23.3 12. Std. dev. 0.324 0.034 0.562 0.064 0.017 1.875 4.266 0.333 2.554 1.2

N obs. 19 19 19 19 19 19 19 19 19 1

M582.5B Mean 2.31 0.07 1.49 0.18 0.031 4.5 46.2 2.79 19 9.9 Median 2.24 0.02 1.64 0.16 0.023 4.94 45.7 2.64 18.9 10. Minimum 1.59 -0.02 0.29 0.072 -0.01 0.31 38.2 1.89 14.6 7.1 Maximum 4.25 0.5 2.41 0.37 0.11 6.71 59.6 4.47 24.3 13. Std. dev. 0.533 0.12 0.632 0.088 0.028 1.692 5.054 0.528 2.545 1.70

N obs. 26 26 26 26 26 26 26 26 26 2

MQ02.1M Mean 5.84 0.1 5.31 0.28 0.05 4.77 68.3 2.83 28.6 7.3 Median 5.55 -0.02 5.43 0.21 0.019 4.73 68.8 2.55 29.9 7.5 Minimum 1.33 -0.02 1.19 0.097 -0.01 1.16 39.4 1.5 15.9 2. Maximum 10.3 1.4 8.66 1.06 0.39 6.67 84.1 7.3 35.4 9.5 Std. dev. 1.88 0.283 1.651 0.22 0.08 1.221 8.742 1.363 5.001 1.52

N obs. 26 26 26 26 26 26 26 26 26 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)

Sodium 

1994 Near-surface measurements: 

PR03.2M Mean 5.4 0.1 4.96 0.22 0.032 4.94 71.6 2.61 39.5 7.5 Median 5.59 0.06 5.12 0.18 0.016 5.08 71.2 2.46 39.9 7.9 Minimum 1.35 0.02 0.14 0.07 -0.01 2.44 47.3 1.38 24.9 2.7 Maximum 7.91 0.6 7.78 1.27 0.26 6.44 92.2 6.24 49.4 10. Std. dev. 1.219 0.132 1.877 0.229 0.053 1.178 8.911 1.005 4.942 1.64

N obs. 26 26 26 26 26 26 26 26 26 2

RC01.7M Mean 3.14 0.1 2.54 0.3 0.046 4.9 73.7 2.91 39.1 10. Median 2.83 0.04 2.5 0.21 0.028 5.31 73.1 2.4 40.7 9.3 Minimum 1.78 -0.02 0.56 0.12 -0.01 1.68 49.8 1.35 -0.01 4.4 Maximum 8.62 0.7 4.79 2.42 0.34 6.26 90.8 8.7 49 2 Std. dev. 1.398 0.166 1.152 0.448 0.065 1.158 8.176 1.55 9.029 3.69

N obs. 25 26 26 25 26 26 26 26 26 2

WP02.6M Mean 4.25 0.09 3.54 0.21 0.028 3.21 51.1 2.48 17.3 9.6 Median 4.11 -0.02 3.71 0.16 0.014 3.69 44.5 2.4 15.9 8.8 Minimum 0.97 -0.02 0.14 0.05 -0.01 -0.05 25.1 1.44 11.4 5. Maximum 9.07 0.8 8.55 0.62 0.23 6.46 83.4 4.83 25.4 26. Std. dev. 1.962 0.171 2.265 0.148 0.048 2.192 17.57 0.806 4.145 4.0

N obs. 25 26 26 26 26 26 26 26 26 2

1994 Near-bottom measurements: 

M545.5B Mean 1.46 0.1 0.53 0.33 0.025 3.12 43.3 3.01 21.5 8.3 Median 1.4 0.06 0.21 0.21 0.011 2.45 43.5 3 21.4 8.8 Minimum 0.94 -0.02 0.14 0.055 -0.01 0.16 34.1 2.49 18.8 5.2 Maximum 2.02 0.2 1.32 0.98 0.076 6.6 48.6 3.45 23.8 9.9 Std. dev. 0.386 0.085 0.541 0.331 0.027 2.496 5.355 0.333 2.073 1.60

N obs. 6 6 6 6 6 6 6 6 6 6 

1995 Near-surface measurements: 

AL02.3M Mean 4.46 0.1 4.11 0.16 0.024 3.67 72.8 2.79 42 7  Median 4.43 0.07 4.32 0.14 0.018 3.58 73.8 2.25 42.5 6.5 Minimum 2.96 -0.02 2.04 0.034 -0.01 1.7 -0.01 0.99 -0.01 1.6 Maximum 6.57 0.3 7.01 0.56 0.078 5.13 139 5.31 84.5 17. Std. dev. 1.016 0.085 1.207 0.117 0.019 1.138 21.55 1.22 13.14 2.

N obs. 26 26 26 26 26 25 26 26 26 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)

Sodium 

1995 Near-surface measurements: 

M497.2B Mean 2.97 0.08 2.19 0.15 0.038 4.45 51.1 2.97 21 11. Median 2.8 0.08 2.08 0.15 0.027 4.94 51 2.7 20.1 10. Minimum 1.23 0.02 0.56 0.036 -0.01 1.68 32 1.92 14.2 6. Maximum 5.51 0.2 5.58 0.27 0.11 6.02 62.8 6.63 28.6 17. Std. dev. 1.151 0.044 1.269 0.065 0.031 1.352 8.968 0.924 4.113 2.63

N obs. 26 26 26 26 26 25 26 26 26 2

M508.1F Mean 4.81 0.3 3.85 0.17 0.033 3.83 54.7 2.67 28.1 11. Median 2.96 0.09 2.85 0.15 -0.01 3.76 53 2.52 26.4 1 Minimum -0.1 -0.02 0.21 0.03 -0.01 0.27 31.5 1.23 14.8 8.1 Maximum 19.3 1.5 14.2 0.4 0.17 8.59 94.8 7.23 44.3 1 Std. dev. 4.383 0.473 3.721 0.095 0.047 2.365 16.56 1.138 8.189 2.0

N obs. 26 26 26 26 26 25 26 26 26 2

M511.4B Mean 2.52 0.09 1.83 0.16 0.044 4.58 48.3 2.98 21 12. Median 2.49 0.09 1.83 0.16 0.032 4.9 47.4 2.67 19.8 11. Minimum 1.33 -0.02 0.57 0.042 -0.01 1.09 30.1 1.77 13.6 7. Maximum 3.75 0.2 4.44 0.29 0.12 8.53 64.1 7.02 29.9 17. Std. dev. 0.631 0.042 0.9 0.062 0.033 1.817 9.335 1.022 4.272 2.60

N obs. 26 26 26 26 26 25 26 26 26 2

M525.5L Mean 2.38 0.06 1.55 0.16 0.034 4.56 48.8 3 21.3 10. Median 2.47 0.05 1.55 0.14 0.019 5.25 50.3 2.55 20.9 10. Minimum 1.3 -0.02 0.53 0.034 -0.01 0.89 31.4 1.98 13.3 5.6 Maximum 3.5 0.2 3.27 0.54 0.085 6.24 63.2 7.47 29.6 15. Std. dev. 0.576 0.036 0.639 0.108 0.026 1.671 8.767 1.099 4.827 2.55

N obs. 24 24 24 24 24 23 24 24 24 2

M532.3T Mean 2.51 0.07 1.64 0.14 0.03 4.4 51.7 3.07 24.1 10. Median 2.48 0.05 1.59 0.14 0.02 4.72 52.8 2.73 24.6 9.6 Minimum 1.37 -0.02 0.26 0.015 -0.01 1.32 30.5 1.68 13.4 5.9 Maximum 3.55 0.3 3.09 0.34 0.096 6.76 71.7 7.95 36.6 15. Std. dev. 0.639 0.065 0.832 0.084 0.024 1.66 10.78 1.25 6.146 2.50

N obs. 26 25 25 26 26 25 26 26 26 2

M540.2T Mean 2.26 0.07 1.44 0.15 0.036 4.47 50.1 2.96 22.4 1 Median 2.26 0.05 1.46 0.13 0.025 4.85 49.5 2.58 22.7 9.7 Minimum 1.25 -0.02 0.03 0.025 -0.01 1.4 31.1 1.83 13.6 5.6 Maximum 3.21 0.4 2.77 0.3 0.12 6.94 62.2 7.56 30 14. Std. dev. 0.514 0.074 0.695 0.085 0.031 1.707 9.272 1.128 4.848 2.16

N obs. 26 26 26 26 26 25 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)

Sodium 

1995 Near-surface measurements: 

M545.5B Mean 1.93 0.08 0.73 0.18 0.022 3.46 48.9 3.14 25.5 9.6 Median 1.61 0.04 0.066 0.14 -0.01 3.18 48.6 3.06 25 9.3 Minimum 1.2 -0.02 -0.01 0.033 -0.01 -0.05 24.9 2.22 15.8 5.6 Maximum 3.75 0.4 3.43 0.47 0.17 8.83 75 7.59 46.3 13. Std. dev. 0.783 0.098 1.141 0.121 0.036 2.833 12.68 1.054 6.423 2.06

N obs. 25 25 25 25 25 23 25 25 25 2

M556.4A Mean 2.29 0.09 1.53 0.14 0.039 4.62 48.5 3.02 20.8 10. Median 2.44 0.08 1.58 0.13 0.028 5.31 45.9 2.7 19.4 9.9 Minimum 1.24 -0.02 0.48 0.036 -0.01 0.97 30.3 1.47 12.9 6.3 Maximum 3.68 0.3 3.13 0.3 0.097 6.42 61.5 7.35 28.5 14. Std. dev. 0.576 0.057 0.608 0.058 0.027 1.675 9.266 1.175 4.564 2.62

N obs. 26 26 26 26 26 25 26 26 26 2

M563.9T Mean 2.22 0.08 1.33 0.14 0.033 4.41 48.7 3.08 21.3 10. Median 2.24 0.07 1.42 0.14 0.028 4.92 46 2.85 20 10. Minimum 1.33 -0.02 0.42 0.018 -0.01 0.88 31.9 1.89 13.6 5.7 Maximum 3.57 0.4 2.32 0.31 0.088 6.72 66.7 7.65 31 15. Std. dev. 0.546 0.072 0.59 0.079 0.025 1.633 10.54 1.221 5.222 2.5

N obs. 25 25 25 25 25 24 25 25 25 2

M574.2D Mean 2.37 0.1 1.49 0.17 0.05 4.4 47 3.19 20 9.7 Median 2.57 0.1 1.56 0.17 0.049 4.88 45.4 3.06 18.9 9.6 Minimum 1.38 0.05 0.5 0.083 -0.01 1.07 30.6 1.98 13.1 5. Maximum 3.67 0.3 3.07 0.32 0.11 6.6 61.8 6.27 28.5 15. Std. dev. 0.65 0.06 0.692 0.058 0.03 1.742 9.62 1.055 4.853 2.53

N obs. 19 19 19 19 19 18 19 19 19 1

M582.5B Mean 2.44 0.07 1.65 0.13 0.035 4.73 49.7 2.96 21 10. Median 2.47 0.06 1.83 0.13 0.023 5.36 48.4 2.58 20.1 10. Minimum 1.25 -0.02 0.5 0.051 -0.01 1.21 30.9 1.77 13.4 6.0 Maximum 3.91 0.3 3.24 0.2 0.093 6.75 66.1 7.05 29.6 16. Std. dev. 0.638 0.056 0.666 0.049 0.025 1.686 9.889 1.134 4.7 2.66

N obs. 26 26 26 26 26 25 26 26 26 2

MQ02.1M Mean 6.82 0.08 5.9 0.4 0.036 5.15 74.3 2.99 31.5 7.6 Median 6.23 0.04 5.98 0.17 0.019 5.03 75.3 2.55 30.4 7.1 Minimum 1.91 -0.02 2.1 0.045 -0.01 2.1 37.2 1.23 17.5 5.2 Maximum 18.8 0.5 10 4.65 0.13 6.38 97.7 5.94 41.3 11. Std. dev. 2.958 0.106 1.655 0.882 0.031 0.95 12.39 1.259 6.197 1.55

N obs. 26 26 26 26 26 24 26 26 26 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)

Sodium 

1995 Near-surface measurements: 

PR03.2M Mean 6.72 0.1 5.9 0.16 0.025 5.14 77.3 2.86 42.8 7. Median 6.62 0.08 6.06 0.16 0.015 5.34 79.3 2.4 42.9 7.6 Minimum 3.94 -0.02 1.74 0.027 -0.01 2.4 37.6 1.44 17.4 5.6 Maximum 8.88 0.4 7.18 0.48 0.16 6.92 95.9 6.81 53.2 10. Std. dev. 1.175 0.079 1.082 0.103 0.031 1.083 11.47 1.303 7.087 1.61

N obs. 26 26 26 26 26 24 26 26 26 2

RC01.7M Mean 3.38 0.09 2.89 0.24 0.038 4.97 76.5 3.19 42.7 9.9 Median 3.2 0.06 2.68 0.19 0.031 5.19 78.7 2.88 43.7 9.8 Minimum 1.76 -0.02 1.12 0.081 -0.01 3.27 8.39 1.65 4.3 0.6 Maximum 5.48 0.4 4.53 0.63 0.16 6.18 107 6.21 59.9 15. Std. dev. 0.94 0.081 1.054 0.153 0.03 0.767 19.16 1.246 11.23 3.00

N obs. 26 26 26 26 26 25 26 26 26 2

WP02.6M Mean 5.34 0.06 4.47 0.16 0.016 3.26 60.7 2.42 21.7 9.1 Median 5.09 0.05 5.06 0.13 0.011 4.17 63.2 2.01 21.1 9.2 Minimum 1.7 -0.02 0.072 0.032 -0.01 -0.05 31 1.26 11.9 5.4 Maximum 10.8 0.2 10.3 0.47 0.062 5.84 94 6.69 45.3 15. Std. dev. 2.607 0.049 3.023 0.105 0.015 2.104 17.22 1.153 6.279 2.60

N obs. 26 26 26 26 26 25 26 26 26 2

1995 Near-bottom measurements: 

M545.5B Mean 1.91 0.2 0.57 0.21 0.028 2.76 49 3.12 26.3 9.2 Median 1.66 0.2 0.089 0.2 0.014 2.04 45.4 3.21 27.3 9.4 Minimum 1.51 -0.02 -0.01 0.041 -0.01 -0.05 35.7 2.31 20.9 7.1 Maximum 2.99 0.4 2.13 0.33 0.11 6.04 69 3.75 30.7 1 Std. dev. 0.514 0.183 0.893 0.108 0.039 2.159 11.08 0.553 3.749 1.75

N obs. 7 7 7 7 7 6 7 7 7 7 

1996 Near-surface measurements: 

AL02.3M Mean 3.8 0.2 3.47 0.27 0.046 3.23 71.1 3.63 40.5 5.9 Median 2.7 0.07 2.72 0.14 0.01 3.41 72.9 3.06 42 5.8 Minimum 1.32 -0.02 0.088 0.049 -0.01 -0.05 38.3 1.44 22.9 3.3 Maximum 8.15 1.7 7.3 0.85 0.57 5.02 94 15.6 49.9 8. Std. dev. 1.913 0.42 1.982 0.257 0.116 1.164 14.62 2.648 7.665 1.23

N obs. 24 19 24 16 24 23 24 24 24 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)

Sodium 

1996 Near-surface measurements: 

M497.2B Mean 2.73 0.2 2.07 0.18 0.047 3.86 42.6 3.45 16.9 8.9 Median 2.78 0.1 1.93 0.16 0.039 3.95 39.3 3.42 17 9.1 Minimum 0.84 0.06 0.19 0.064 -0.01 0.66 18.3 2.49 8.62 5.1 Maximum 6.38 0.4 7.94 0.62 0.14 6.91 67.8 4.92 26.6 12. Std. dev. 1.495 0.116 1.729 0.127 0.03 1.755 10.49 0.67 3.804 2.10

N obs. 25 20 25 17 25 24 25 25 25 2

M508.1F Mean 3.31 0.6 3.32 0.24 0.05 2.8 43.1 3.46 21.9 9.1 Median 2.86 0.06 1.56 0.18 0.015 2.98 39.7 3.39 22.3 9.2 Minimum 0.85 -0.02 0.13 0.047 -0.01 -0.05 20.2 1.47 8.03 4.7 Maximum 10.3 4.5 13.6 0.79 0.51 6.16 86.2 5.64 47 14. Std. dev. 1.96 1.124 3.859 0.2 0.108 1.939 14.31 0.879 7.893 2.64

N obs. 25 20 25 17 25 24 25 25 25 2

M511.4B Mean 2.24 0.2 1.38 0.24 0.053 3.92 40.5 3.41 16.9 10. Median 2.51 0.1 1.4 0.15 0.047 4.31 39 3.48 16.8 11. Minimum 0.95 0.07 0.22 0.085 -0.01 0.85 18.2 1.95 8.46 6.2 Maximum 4.09 0.4 2.59 1.17 0.11 6.68 61 5.37 24.8 1 Std. dev. 0.888 0.104 0.802 0.256 0.029 1.877 9.95 0.729 4.05 2.3

N obs. 25 20 25 17 25 24 25 25 25 2

M525.5L Mean 1.86 0.1 1.03 0.18 0.041 3.41 38.5 3.3 16 7.8 Median 1.75 0.08 0.99 0.14 0.044 3.1 37.9 3.03 16.4 7.7 Minimum 0.97 -0.02 0.12 0.08 -0.01 0.47 18.2 2.16 8.26 4.2 Maximum 3.29 0.4 2.28 0.38 0.079 6.69 57.6 4.77 22.2 11. Std. dev. 0.737 0.117 0.709 0.098 0.021 1.915 8.96 0.743 3.696 1.94

N obs. 21 16 21 14 21 20 21 21 21 2

M532.3T Mean 2.09 0.09 1.35 0.18 0.037 3.99 41.9 3.43 18.7 7.6 Median 2.14 0.04 1.32 0.13 0.034 4.29 41.7 3.27 19.3 7.7 Minimum 0.76 -0.02 -0.01 0.067 -0.01 0.15 25.6 2.25 9.09 4.6 Maximum 3.96 0.4 3.18 0.54 0.091 7.12 59.6 5.13 29 12. Std. dev. 0.984 0.111 0.929 0.124 0.022 1.706 8.672 0.725 4.857 1.91

N obs. 22 17 22 14 22 21 22 22 22 2

M540.2T Mean 1.98 0.1 1.3 0.24 0.039 3.74 40.7 3.38 17.7 8.0 Median 2.1 0.1 1.31 0.14 0.035 3.58 40.1 3.3 17.7 8.1 Minimum 0.65 -0.02 0.095 0.058 -0.01 0.59 18.9 2.07 8.56 4. Maximum 3.75 0.6 5.47 1.61 0.15 5.95 59.9 4.89 26.4 10. Std. dev. 0.872 0.143 1.133 0.371 0.029 1.595 9.877 0.722 4.761 1.90

N obs. 24 19 24 16 24 22 24 24 24 2
 E-31

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)

Sodium 

1996 Near-surface measurements: 

M545.5B Mean 1.64 0.1 0.45 0.14 0.019 2.49 40.2 3.67 20.5 6.6 Median 1.49 0.03 0.041 0.13 -0.01 1.65 43.6 3.51 20.5 6.0 Minimum 0.73 -0.02 -0.01 0.049 -0.01 -0.05 12.8 2.07 5.36 3.0 Maximum 3.44 0.5 2.42 0.29 0.11 6.47 62.8 4.89 29.9 11. Std. dev. 0.705 0.138 0.786 0.068 0.026 2.327 11.71 0.712 6.642 2.21

N obs. 24 19 24 17 24 22 24 24 24 2

M556.4A Mean 1.9 0.2 1.05 0.18 0.045 3.78 38.9 3.29 16.1 8.1 Median 1.98 0.1 0.89 0.11 0.046 3.83 36.7 3.12 15.6 7.6 Minimum 0.7 0.06 -0.01 0.067 -0.01 0.44 17.2 2.25 7.32 4.2 Maximum 3.27 0.4 2.07 0.75 0.093 6.67 58.2 4.83 25 11. Std. dev. 0.82 0.105 0.72 0.174 0.027 2.087 8.746 0.63 3.807 2.01

N obs. 24 19 24 16 24 23 24 24 24 2

M563.9T Mean 1.81 0.1 0.87 0.17 0.036 3.17 39.4 3.35 16.7 8.0 Median 1.69 0.1 0.73 0.12 0.032 3.08 39.4 3.27 16.7 8. Minimum 0.79 -0.02 -0.01 0.06 -0.01 0.5 18.1 2.28 7.62 4.1 Maximum 3.66 0.5 2.6 0.79 0.13 5.56 57.4 5.16 23.9 12. Std. dev. 0.732 0.115 0.662 0.182 0.033 1.634 9.426 0.7 4.476 1.95

N obs. 21 16 21 14 21 20 21 21 21 2

M582.5B Mean 2 0.2 1.28 0.15 0.043 3.94 40.5 3.34 16.5 8.1 Median 2.08 0.1 1.4 0.12 0.043 4.3 38.8 3.24 16.1 7.9 Minimum 0.8 0.04 -0.01 0.064 -0.01 0.37 18.1 2.34 7.92 4.3 Maximum 3.71 0.8 3.53 0.5 0.13 6.84 58.8 5.4 25 12. Std. dev. 0.961 0.182 0.925 0.1 0.029 2.083 9.463 0.707 4.005 2.14

N obs. 25 20 25 17 25 24 25 25 25 2

MQ02.1M Mean 6.35 0.2 5.19 0.51 0.07 4.49 67.4 4.04 27.8 6.7 Median 5.01 0.02 4.52 0.23 0.032 4.44 72.8 3.15 29.7 6.8 Minimum 0.71 -0.02 -0.01 0.068 -0.01 0.67 -0.01 1.71 -0.01 -0.0 Maximum 13.3 1.7 12.3 3.25 0.69 6.98 93.8 11.1 44.1 1 Std. dev. 3.206 0.488 3.009 0.795 0.141 1.377 21.81 1.999 9.758 2.73

N obs. 25 20 25 18 25 24 25 25 25 2

PR03.2M Mean 7.02 0.2 6.05 0.38 0.052 4.05 74.2 3.62 40.5 7.0 Median 7.02 0.07 6.43 0.14 0.015 4.35 76.3 3.12 42.5 6.9 Minimum 4.22 -0.02 1.95 0.032 -0.01 2.03 25.2 1.89 14 3.2 Maximum 12.5 2 8.33 3.26 0.71 6.28 94.1 10.3 52.3 15. Std. dev. 1.755 0.433 1.686 0.774 0.139 1.151 16.64 1.78 9.141 2.22

N obs. 25 20 25 17 25 24 25 25 25 2
 E-32

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)

Sodium 

1996 Near-surface measurements: 

RC01.7M Mean 3.35 0.4 2.35 0.75 0.09 4.05 72.2 4.2 39.5 1 Median 2.33 0.06 1.91 0.19 0.028 4.35 73.3 3.48 41.9 10. Minimum 0.98 -0.02 0.5 0.08 -0.01 0.16 16.1 1.5 9.04 4.5 Maximum 9.19 4.4 5.48 4.72 1.17 5.82 101 13.4 52.6 17. Std. dev. 2.249 0.987 1.499 1.412 0.235 1.307 18.69 2.45 10.1 3.78

N obs. 25 20 25 18 25 24 25 25 25 2

RK00.1M Mean 15.9 2.4 11.6 0.11 0.032 4.94 73.2 2.83 32.4 8.0 Median 15.2 2.4 12.9 0.093 -0.01 4.84 73.1 2.34 33.2 8.0 Minimum 11.7 0.4 -0.01 0.023 -0.01 3.21 36.1 2.01 15 5.0 Maximum 21.2 5.9 15.4 0.2 0.3 6.7 97.7 6.06 44.4 1 Std. dev. 2.639 1.409 4.703 0.065 0.075 0.948 17.24 1.169 8.291 1.77

N obs. 15 14 15 8 15 15 15 15 15 1

RK03.7M Mean 7.45 0.07 6.56 0.1 0.016 4.94 73.3 2.02 30.5 7.3 Median 6.68 0.06 6.35 0.068 -0.01 4.82 75.6 1.74 32.8 6.6 Minimum 5.15 -0.02 1.99 0.016 -0.01 2.95 40.7 1.23 18.4 4.2 Maximum 11.3 0.2 11.3 0.27 0.071 6.03 92.6 4.95 37.3 18. Std. dev. 1.972 0.052 2.465 0.082 0.02 0.95 15.55 0.907 5.578 3.41

N obs. 15 14 15 8 15 15 15 15 15 1

WP02.6M Mean 5.8 0.2 3.66 0.65 0.059 2.73 49.4 3.89 16.6 8.3 Median 5.19 0.03 2.71 0.25 0.016 2.6 42.7 3.12 17.8 7.8 Minimum 1.7 -0.02 0.076 0.049 -0.01 -0.05 15.9 1.14 9.38 4.6 Maximum 13.1 1.4 11.5 3.5 0.77 5.71 90.2 10.4 28 23. Std. dev. 3.335 0.335 2.991 0.969 0.158 1.835 21.47 2.097 5.02 3.66

N obs. 25 20 25 19 25 24 25 25 25 2

1996 Near-bottom measurements: 

M508.1F Mean 3.54 0.5 1.96 0.11 0.03 4.28 43.3 3.38 20.3 7.1 Median 2.85 0.3 0.66 0.097 0.034 4.03 40.9 3.39 19.2 5.7 Minimum 1.76 0.1 0.28 0.097 -0.01 1.73 25.2 2.43 14.6 5.4 Maximum 6.16 0.9 4.62 0.13 0.047 6.28 61 4.26 24.6 9. Std. dev. 1.836 0.368 1.765 0.022 0.016 1.684 13.48 0.702 4.392 1.80

N obs. 6 6 6 2 6 6 6 6 6 6 
E-33

Figure E-1a. Monthly means of temperature (oC), dissolved oxygen (mg/L), oxygen saturation (%), pH, specific

conductivity (:S), turbidity (NTU), and Secchi transparency (cm) in upper and lower Pool 12 from 1993 through 1996.
E-34

Figure E-1b. Monthly means of temperature (°C), dissolved oxygen (mg/L), oxygen saturation (%), pH, specific

conductivity (:S), and turbidity (NTU) in upper and lower Pool 13 from 1993 through 1996.
E-35

Figure E-1c. Monthly means of temperature (°C), dissolved oxygen (mg/L), oxygen saturation (%), pH, specific

conductivity (:S), and turbidity (NTU) in upper and lower Pool 14 from 1993 through 1996.
E-36

Figure E-1d. Monthly means of temperature (°C), dissolved oxygen (mg/L), oxygen saturation (%), pH, specific

conductivity (:S), and turbidity (NTU) in the Maquoketa River from 1993 through 1996.
E-37

Figure E-1e. Monthly means of temperature (°C), dissolved oxygen (mg/L), oxygen saturation (%), pH,

specific conductivity (:S), and turbidity (NTU) in the Wapsipinicon River from 1993 through 1996.
E-38

Figure E-1f. Monthly means of temperature (°C), dissolved oxygen (mg/L), oxygen saturation (%), pH, specific

conductivity (:S), and turbidity (NTU) in upper Pool 12 (upstream) and lower Pool 14 (downstream) from 1993 through

1996.
E-39

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) in upper and lower Pool 12 from 1993 through 1996.
E-40

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), total suspended solids (mg/L), and

chlorophyll a (:g/L) in upper and lower Pool 13 from 1993 through 1996.
E-41

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), total suspended solids (mg/L), and

chlorophyll a (:g/L) in upper and lower Pool 14 from 1993 through 1996.
E-42

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), total suspended solids (mg/L), and

chlorophyll a (:g/L) in the Maquoketa River from 1993 through 1996.
E-43

Figure E-2e. 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) in the Wapsipinicon River from 1993 through 1996.
E-44

Figure E-2f. 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) in upper Pool 12 (upstream) and lower Pool 14 (downstream) 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 a

depth categories: near surface (less than or equal to 0.2 m below the surface), middepth, and near bottom (less than or equal to 0.2 m abov

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 4.79 — — — — — 23.6 7.02 83 438 8 33 38 70.9  Median 0.2 4.9 — — — — — 23.7 7 84 437 8 34 37 71.2  Minimum 0.2 0.6 — — — — — 23 6.6 77 420 7.4 24 32 51  Maximum 0.2 9.9 — — — — — 24.5 7.3 87 460 8.1 38 54 93.8  Std. dev. 0 2.26 — — — — — 0.52 0.2 2.27 8.6 0.12 3.27 4.5 9.8 

N obs. 30 30 0 0 0 0 0 30 30 30 30 30 30 30 30 

2. Side channel Mean 0.2 3.56 0.48 — — — — 23.7 7.01 83 436 8 33.6 36 64.6  Median 0.2 3.4 0.48 — — — — 23.9 7 83 438 8 34 35 65.9  Minimum 0.2 0.9 0.48 — — — — 22.3 6.6 79 424 7.9 30 31 46.1  Maximum 0.2 6.4 0.48 — — — — 24.5 7.4 89 458 8.1 40 42 84.1  Std. dev. 0 1.36 — — — — — 0.44 0.23 2.69 9.33 0.06 2.99 3 9.48 

N obs. 30 30 1 0 0 0 0 30 30 30 30 30 30 30 30 

3. Backwater Mean 0.2 2.44 0.14 — — — — 23 7.07 83 430 8 36.3 29 42.7  Median 0.2 1.5 0.07 — — — — 23 7 83 435 8 36 28 35.9  Minimum 0.2 0.4 0 — — — — 21 1.7 19 300 7.2 24 3 0.8  Maximum 0.2 55 0.69 — — — — 24 16.6 198 456 8.7 56 49 152  Std. dev. 0 6.94 0.18 — — — — 0.83 1.81 21.9 26.3 0.21 6.21 9.84 24.9 

N obs. 60 60 58 0 0 0 0 60 60 60 60 60 57 60 60 

5. Impounded Mean 0.2 1.24 0.3 — — — — 23.8 7.66 91 437 8.1 31.9 40 78.6  Median 0.2 1.2 0.33 — — — — 23.9 7.25 86 436 8.1 32 39 78.3  Minimum 0.2 0.4 0 — — — — 20.8 6.6 78 415 7.5 16 9 4.4  Maximum 0.2 3.1 0.54 — — — — 25.5 15.3 176 484 8.8 44 84 188  Std. dev. 0 0.67 0.16 — — — — 1.21 1.74 19.4 16.3 0.2 6.43 15.7 41.2 

N obs. 30 30 30 0 0 0 0 30 30 30 30 30 29 30 30 

1993 Near-surface measurements: fall

1. Main channel Mean 0.2 4.77 — — — — — 12.2 13.3 124 412 8.8 43.6 22 33.3  Median 0.2 4.9 — — — — — 12 13.1 122 411 8.8 44 21 32.9  Minimum 0.2 0.5 — — — — — 11.7 11.4 106 404 8.6 30 16 17  Maximum 0.2 9.2 — — — — — 13.9 14.7 136 419 9 55 43 56.5  Std. dev. 0 2.16 — — — — — 0.47 0.83 7.44 4.02 0.09 6.26 5.26 6.79 

N obs. 30 30 0 0 0 0 0 30 30 30 30 30 30 30 30 
 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-surface measurements: fall

2. Side channel Mean 0.2 2.27 — — — — — 12.7 13.6 128 417 8.8 40.1 23 38  Median 0.2 2.1 — — — — — 12.3 13.6 128 411 8.8 40 23 38.1  Minimum 0.2 0.4 — — — — — 11.5 11.8 109 392 8.1 32 2 26.6  Maximum 0.2 5.8 — — — — — 14.8 17 160 519 9.3 52 32 59.8  Std. dev. 0 1.53 — — — — — 0.85 1.02 9.37 23.3 0.19 5.64 5.74 6.87 

N obs. 30 30 0 0 0 0 0 30 30 30 30 30 28 30 30 

3. Backwater Mean 0.2 0.97 0.06 — — — — 12.7 14.8 139 426 8.9 33.8 29 42.3  Median 0.2 0.8 0.01 — — — — 12.8 14.2 134 412 8.9 34 26 38.8  Minimum 0.2 0.4 0 — — — — 10 10.4 99 333 7.8 20 14 15.2  Maximum 0.2 2.4 0.41 — — — — 15.1 20 195 730 9.5 48 54 164  Std. dev. 0 0.56 0.1 — — — — 0.98 2.6 26 53.5 0.28 7.65 9.88 20.2 

N obs. 63 59 55 0 0 0 0 59 59 59 59 59 55 59 59 

5. Impounded Mean 0.2 1.33 — — — — — 12.5 13.3 125 409 8.9 38.4 25 36.7  Median 0.2 1.3 — — — — — 12.5 13.4 126 409 8.9 40 22 33.1  Minimum 0.2 0.5 — — — — — 11.1 11.2 103 398 8.6 18 17 19.2  Maximum 0.2 3.1 — — — — — 13.8 15.4 147 423 9 50 67 90.5  Std. dev. 0 0.55 — — — — — 0.7 1.19 12 6.62 0.12 6.14 9.06 12.5 

N obs. 32 31 0 0 0 0 0 31 31 31 31 31 31 31 31 

1994 Near-surface measurements: winter

1. Main channel Mean 0.19 3.82 0.17 100 30 100 11 0.12 11.8 81 456 7.8 126 4 2.5  Median 0.2 3.4 0.17 100 28 100 11 0.1 11.8 81 454 7.8 124 4 2.1  Minimum 0 0.7 0.15 100 16 100 4 0 10.9 75 433 7.5 90 3 1.6  Maximum 0.2 9.8 0.18 100 46 100 16 0.3 12.5 86 500 8.5 170 6 5.5  Std. dev. 0.05 2.52 0.02 0 7.82 0 3.8 0.09 0.44 3.14 15.2 0.24 23.9 0.88 1 

N obs. 15 15 2 15 15 15 14 15 15 15 15 15 12 15 15 

2. Side channel Mean 0.2 2.44 0.14 100 29 100 8 0.11 11.7 80 461 7.8 146 4 2.5  Median 0.2 2.5 0.15 100 30 100 8 0.1 11.7 80 460 7.8 139 4 2.4  Minimum 0.2 0.3 0.03 100 14 100 3 0 11.1 76 442 7.5 116 3 1.5  Maximum 0.2 6 0.22 100 40 100 19 0.3 12.5 86 499 8 192 6 4  Std. dev. 0 1.33 0.06 0 7.17 0 5 0.08 0.38 2.61 13.8 0.14 26.4 1.01 0.65 

N obs. 30 30 14 30 30 30 30 29 29 29 29 29 22 29 29 
 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/

1994 Near-surface measurements: winter

3. Backwater Mean 0.2 0.9 0.02 100 31 100 9 0.24 8.49 58 509 7.9 106 7 4.7  Median 0.2 0.7 0 100 30 100 8 0 9.2 65 506 7.9 110 5 2.8  Minimum 0 0.3 0 100 16 100 2 0 0.1 1 330 7 42 3 1.1  Maximum 0.2 3.7 0.15 100 46 100 22 1 12 83 713 8.3 168 66 22.8  Std. dev. 0.03 0.66 0.04 0 5.79 0 5.2 0.34 3.51 24.1 72.1 0.25 43 10.1 4.74 

N obs. 58 56 51 58 58 58 58 51 51 51 51 51 12 51 51 

5. Impounded Mean 0.2 1.22 0.06 100 27 100 9 0.15 11.1 76 470 7.9 121 5 2.2  Median 0.2 1 0.06 100 26 100 9 0.2 11 76 463 7.8 126 4 2.1  Minimum 0.2 0.4 0 100 10 100 5 0 9 62 447 7.3 60 4 1.6  Maximum 0.2 4.3 0.17 100 38 100 13 0.3 12.4 85 531 8.6 165 6 3.4  Std. dev. 0 0.95 0.05 0 6.98 0 1.9 0.1 1.08 7.47 26 0.36 34.1 0.74 0.56 

N obs. 16 15 13 16 16 16 16 15 15 15 15 15 6 15 15 

1994 Near-surface measurements: spring

1. Main channel Mean 0.2 5.43 — — — — — 16.2 12.9 131 301 9.2 25.9 49 120  Median 0.2 5.49 — — — — — 16.1 13.7 140 299 9.2 28 47 95.2  Minimum 0.2 0.78 — — — — — 14.7 10.1 100 289 9 16 24 56.4  Maximum 0.2 12.1 — — — — — 17.6 16.4 166 318 9.6 40 70 195  Std. dev. 0 2.49 — — — — — 0.68 2.11 21.9 8.15 0.17 7.48 11.7 45.9 

N obs. 27 27 0 0 0 0 0 27 27 27 27 15 27 27 26 

2. Side channel Mean 0.2 2.82 0.52 — — — — 16.3 12.9 132 304 9.2 25.8 50 103  Median 0.2 2.74 0.52 — — — — 16.6 13.5 139 300 9.3 28 49 90.4  Minimum 0.2 0.3 0.1 — — — — 14.1 10.1 98 287 9 14 31 57.2  Maximum 0.2 5.79 1.12 — — — — 17.8 16.1 164 329 9.7 33 75 188  Std. dev. 0 1.31 0.21 — — — — 1.08 1.93 22.1 13.6 0.16 4.89 11.6 32.7 

N obs. 31 31 31 0 0 0 0 31 31 31 29 23 31 31 31 

3. Backwater Mean 0.2 1.2 0.17 — — — — 16.6 14.2 146 311 9.3 30.5 36 70.5  Median 0.2 1.13 0.07 — — — — 16.4 15.1 153 308 9.3 30 35 60  Minimum 0.2 0.42 0 — — — — 13.5 7.5 73 287 8.7 20 14 16.6  Maximum 0.2 2.5 0.69 — — — — 21 17.9 190 390 9.8 48 76 183  Std. dev. 0 0.51 0.2 — — — — 1.52 2.57 27.2 18.3 0.24 5.64 14.5 36.7 

N obs. 54 54 54 0 0 0 0 54 54 54 52 43 54 54 54 
 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-surface measurements: spring

5. Impounded Mean 0.2 1.87 0.39 — — — — 12.7 11.6 110 329 9 25.7 54 110  Median 0.2 1.55 0.38 — — — — 12.8 11 102 332 9 27.5 45 86.3  Minimum 0.2 0.5 0.14 — — — — 10.4 10.2 94 285 8.5 14 23 47.7  Maximum 0.2 6.4 0.82 — — — — 17.1 18.1 188 350 9.6 37 96 232  Std. dev. 0 1.25 0.17 — — — — 1.43 2.06 23.6 13.9 0.32 6.1 22 52.2 

N obs. 38 38 35 0 0 0 0 38 38 38 38 38 38 38 38 

1994 Near-surface measurements: summer

1. Main channel Mean 0.2 4.45 — — — — — 25.3 7.7 95 410 8.2 36.7 36 49  Median 0.2 4.88 — — — — — 25.2 7.55 93 410 8.2 38 34 41.9  Minimum 0.2 0.4 — — — — — 24.9 6.9 84 397 7.9 18 18 23.3  Maximum 0.2 7.92 — — — — — 25.9 9 112 433 8.6 46 95 257  Std. dev. 0 1.93 — — — — — 0.28 0.57 7.29 8.84 0.17 5.44 13.6 40.7 

N obs. 30 30 0 0 0 0 0 30 30 30 30 30 30 30 30 

2. Side channel Mean 0.2 2.51 0.36 — — — — 25.4 7.68 94 412 8.2 34.4 38 50.3  Median 0.2 2.29 0.38 — — — — 25.6 7.6 93 410 8.2 34 37 50.2  Minimum 0.2 0.25 0.02 — — — — 21.9 6.9 83 400 7.9 28 23 26.6  Maximum 0.2 5.18 0.72 — — — — 26.5 8.7 108 442 8.4 44 52 78.9  Std. dev. 0 1.21 0.19 — — — — 0.87 0.46 6.24 8.82 0.15 4.61 8.55 13.6 

N obs. 30 30 30 0 0 0 0 30 30 30 30 30 29 30 30 

3. Backwater Mean 0.2 1.03 0.08 — — — — 25.1 8.42 103 418 8.3 28.7 46 52.4  Median 0.2 0.74 0.03 — — — — 25 8.2 101 416 8.2 28 46 47.5  Minimum 0.2 0.21 0 — — — — 21.9 4.9 61 360 7.7 18 18 13.5  Maximum 0.2 7.32 0.38 — — — — 27 13.1 159 543 9.7 48 84 126  Std. dev. 0 1.01 0.1 — — — — 1.16 1.79 22.1 32.4 0.37 5.93 11.9 18.6 

N obs. 62 59 59 0 0 0 0 59 59 59 59 59 57 59 59 

5. Impounded Mean 0.2 1.41 0.15 — — — — 25.7 8.25 102 402 8.2 48.3 23 25.9  Median 0.2 1.24 0.16 — — — — 25.5 7.7 93 404 8.2 40 23 26.7  Minimum 0.2 0.3 0 — — — — 24.1 6.6 82 333 8 28 5 4.8  Maximum 0.2 3.07 0.4 — — — — 28 16 207 410 9 100 39 46.3  Std. dev. 0 0.76 0.08 — — — — 0.93 1.91 25.8 13.5 0.21 19.6 9.49 13.1 

N obs. 31 31 30 0 0 0 0 31 31 31 31 31 27 31 31 
 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-surface measurements: fall

1. Main channel Mean 0.2 4.1 0.2 — — — — 14.7 8.78 86 371 7.9 40.3 31 41  Median 0.2 3.94 0.2 — — — — 14.5 8.65 85 369 7.9 40 31 41.1  Minimum 0.2 0.54 0.2 — — — — 13.7 7.8 77 362 7.8 32 18 15.1  Maximum 0.2 9.14 0.2 — — — — 15.6 9.6 94 391 8 58 42 55.9  Std. dev. 0 2.23 — — — — — 0.69 0.67 5.64 6.02 0.09 5.45 5.69 8.74 

N obs. 30 30 1 0 0 0 0 30 30 30 30 30 30 30 30 

2. Side channel Mean 0.2 2.84 0.42 — — — — 14.6 9.04 89 376 7.9 35.5 33 42.4  Median 0.2 3.07 0.39 — — — — 14.4 9.45 91 376 7.9 38 32 40.9  Minimum 0.2 0.34 0.04 — — — — 13.7 7.8 78 365 7.7 24 25 23.4  Maximum 0.2 5.2 0.86 — — — — 16.2 10.3 105 401 8.1 44 49 61.2  Std. dev. 0 1.47 0.21 — — — — 0.81 0.79 7.06 7.8 0.11 6.23 6.94 9.01 

N obs. 32 30 30 0 0 0 0 30 30 30 30 30 29 30 30 

3. Backwater Mean 0.2 1.1 0.08 — — — — 14.3 9.14 90 393 8 33.6 33 38.5  Median 0.2 0.88 0.02 — — — — 14.8 8.8 84 391 7.9 32 34 33.4  Minimum 0.2 0.2 0 — — — — 11.5 4.8 44 333 7.4 20 14 14.6  Maximum 0.2 7.4 0.5 — — — — 16.6 14.2 146 465 9 54 64 95.9  Std. dev. 0 0.98 0.13 — — — — 1.32 1.69 17.6 26.1 0.33 8.11 10.5 17.6 

N obs. 64 60 60 0 0 0 0 60 60 60 60 60 54 60 60 

5. Impounded Mean 0.2 1.22 0.16 — — — — 14.5 8.69 85 372 7.9 48.2 24 26.1  Median 0.2 1.19 0.16 — — — — 14.4 8.5 85 371 7.9 40 20 20.3  Minimum 0.2 0.2 0.02 — — — — 12.4 8 77 362 7.8 22 11 8  Maximum 0.2 3.08 0.36 — — — — 16 10.3 98 385 8.2 80 44 60.8  Std. dev. 0 0.57 0.08 — — — — 0.92 0.52 5.38 6.54 0.09 16.8 10.4 16.5 

N obs. 30 30 29 0 0 0 0 30 30 30 30 30 29 30 30 

1995 Near-surface measurements: winter

1. Main channel Mean 0.2 4.76 0.21 98.3 19 91 5 0 12.8 88 427 7.8 124 5 2.6  Median 0.2 4.68 0.21 100 20 90 5 0 12.8 87 430 7.8 119 5 2.8  Minimum 0.2 0.21 0.21 90 8 50 0 0 12.2 83 414 7.6 100 3 0.3  Maximum 0.2 9.25 0.21 100 34 100 10 0.1 13.2 90 438 7.9 180 8 4.9  Std. dev. 0 2.1 — 3.4 6.24 9.34 2.6 0.02 0.23 1.58 8.03 0.09 19.3 0.93 0.95 

N obs. 30 30 1 27 27 27 27 29 29 29 29 29 28 29 29 
 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/

1995 Near-surface measurements: winter

2. Side channel Mean 0.2 1.88 0.13 95.3 16 90 4 0.03 12.7 87 444 7.8 122 5 4.4  Median 0.2 1.36 0.15 100 16 90 3 0 12.7 87 442 7.8 120 5 3.1  Minimum 0.2 0.2 0 60 4 40 0 0 12 82 417 7.7 60 4 1.6  Maximum 0.2 6.9 0.28 100 32 100 13 0.2 15.1 104 507 8 190 12 32.7  Std. dev. 0 1.58 0.08 10.4 5.93 11.6 3.6 0.06 0.54 3.77 23.8 0.07 32.5 1.39 5.85 

N obs. 30 30 27 30 30 30 30 30 30 30 30 30 17 30 30 

3. Backwater Mean 0.2 0.76 0.03 99.9 19 92 6 0.78 11.5 80 489 7.7 90.3 5 3.8  Median 0.2 0.61 0 100 20 90 5 0.45 12.6 86 474 7.7 104 5 3.2  Minimum 0.2 0.11 0 94 6 50 0 0 1.9 14 351 7.1 28 3 0.8  Maximum 0.2 3.3 0.21 100 30 100 17 3 20 137 702 8.3 125 12 12.3  Std. dev. 0 0.58 0.05 0.77 5.7 7.7 4.1 0.92 3.8 25.8 66 0.22 33.7 1.52 2.2 

N obs. 60 52 50 60 60 60 60 50 50 50 50 50 10 50 50 

5. Impounded Mean 0.2 1.19 0.08 100 18 90 6 0.01 12.8 88 451 7.7 116 5 3  Median 0.2 1.08 0.07 100 18 90 4 0 12.8 87 449 7.7 113 5 2.6  Minimum 0.2 0.2 0 100 10 90 0 0 8.5 58 432 7.2 106 4 0.4  Maximum 0.2 4.75 0.16 100 26 90 20 0.2 16.4 113 542 8 130 6 17.4  Std. dev. 0 0.89 0.04 0 3.9 0 5.3 0.05 1.15 7.93 23 0.13 8.29 0.53 2.96 

N obs. 30 29 27 30 30 30 30 27 27 27 27 27 10 27 27 

1995 Near-surface measurements: spring

1. Main channel Mean 0.2 5.87 — — — — — 10.2 13.7 122 406 8.6 40.3 27 52  Median 0.2 5.23 — — — — — 9.9 13.7 120 405 8.6 40 27 48.8  Minimum 0.2 0.98 — — — — — 9.4 12.2 108 376 8.4 30 18 33.2  Maximum 0.2 17.7 — — — — — 11.6 14.7 135 446 8.8 48 45 89.7  Std. dev. 0 3.16 — — — — — 0.71 0.59 6.84 14.7 0.11 4.25 6.22 13.7 

N obs. 30 30 0 0 0 0 0 30 30 30 30 30 30 30 30 

2. Side channel Mean 0.2 3.23 0.54 — — — — 10.3 13.9 124 407 8.7 40.7 26 47.8  Median 0.2 3.35 0.57 — — — — 9.95 13.7 122 403 8.7 40.5 25 47.8  Minimum 0.2 0.46 0.1 — — — — 9.6 12.8 113 377 8.5 30 21 26  Maximum 0.2 10 1 — — — — 11.9 17.5 162 437 9 48 34 74.6  Std. dev. 0 1.97 0.22 — — — — 0.66 0.91 9.69 15.2 0.12 4.05 3.21 9.32 

N obs. 30 30 30 0 0 0 0 30 29 29 30 30 30 30 30 
 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/

1995 Near-surface measurements: spring

3. Backwater Mean 0.2 1.65 0.17 — — — — 10.6 14.6 132 396 8.8 42.5 25 42.1  Median 0.2 1.34 0.07 — — — — 10.3 13.8 124 400 8.7 42 22 30.4  Minimum 0.2 0.25 0 — — — — 9.3 12.4 110 306 8.4 20 12 15.1  Maximum 0.2 4.27 0.9 — — — — 12.4 20.5 192 434 9.2 60 69 128  Std. dev. 0 0.93 0.2 — — — — 0.92 1.92 19.9 27.5 0.2 9.56 10.4 26.1 

N obs. 61 59 59 0 0 0 0 59 59 59 59 59 58 59 59 

5. Impounded Mean 0.2 1.17 0.27 — — — — 11 14.9 135 415 8.7 40.7 26 55.4  Median 0.2 1.22 0.28 — — — — 10.7 14.7 134 407 8.7 40 25 52.4  Minimum 0.2 0.58 0.06 — — — — 9.6 13.2 116 386 8.5 33 16 22.2  Maximum 0.2 2.44 0.45 — — — — 14.5 17.2 160 541 8.9 50 37 163  Std. dev. 0 0.43 0.09 — — — — 1.12 1.03 11.7 29 0.11 3.93 5.33 25 

N obs. 31 30 30 0 0 0 0 30 30 30 30 30 30 30 30 

1995 Middepth measurements: spring

3. Backwater Mean 0.4 1.52 0.2 — — — — 10.1 14.4 128 405 8.9 — 31 58  Median 0.4 1.52 0.2 — — — — 10.1 14.4 128 405 8.9 — 31 58  Minimum 0.4 1.52 0.2 — — — — 10.1 14.4 128 405 8.9 — 31 58  Maximum 0.4 1.52 0.2 — — — — 10.1 14.4 128 405 8.9 — 31 58  Std. dev. — — — — — — — — — — — — — — — 

N obs. 1 1 1 — — — — 1 1 1 1 1 — 1 1 

1995 Near-surface measurements: summer

1. Main channel Mean 0.2 4.55 — — — — — 27.9 6.96 90 497 8.3 40.7 30 49.1  Median 0.2 4.55 — — — — — 27.8 6.9 90 486 8.3 40 29 41.8  Minimum 0.2 0.75 — — — — — 26.7 6 76 477 8.1 32 24 29.9  Maximum 0.2 8.97 — — — — — 29.6 8.6 115 521 8.4 48 38 211  Std. dev. 0 2.13 — — — — — 0.69 0.66 9.55 16.2 0.08 4.66 3.77 33 

N obs. 30 30 0 0 0 0 0 30 30 30 30 30 30 25 30 

2. Side channel Mean 0.2 2.6 0.31 — — — — 27.7 6.88 89 500 8.2 37.1 33 51.8  Median 0.2 2.3 0.35 — — — — 27.7 7 90 493 8.2 37 33 46.8  Minimum 0.2 0.3 0 — — — — 26.6 5.6 71 479 8.1 25 22 24  Maximum 0.2 7.88 0.69 — — — — 29.1 9.1 120 525 8.4 46 40 217  Std. dev. 0 1.69 0.16 — — — — 0.67 0.87 12.1 15.8 0.1 4.87 4.68 32.8 

N obs. 30 30 30 0 0 0 0 30 30 30 30 30 29 30 30 
 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/

1995 Near-surface measurements: summer

3. Backwater Mean 0.2 1.05 0.07 — — — — 28.2 7.56 99 486 8.3 31 39 55.4  Median 0.2 0.85 0.04 — — — — 28 7.1 91 504 8.3 32 35 46.3  Minimum 0 0.28 0 — — — — 26 1.4 18 247 7.1 18 4 2.7  Maximum 0.2 7 0.42 — — — — 30.8 12.2 160 539 9 49 150 268  Std. dev. 0.03 0.97 0.1 — — — — 1.12 2.41 32.6 53.8 0.33 8 19.5 47.5 

N obs. 63 60 60 0 0 0 0 60 60 60 60 60 54 59 60 

5. Impounded Mean 0.2 1.16 0.12 — — — — 29.2 7.62 101 481 8.3 31.3 32 44.3  Median 0.2 1.09 0.14 — — — — 29.1 7.7 102 482 8.3 30 33 39.7  Minimum 0.2 0.44 0 — — — — 28.3 6.2 81 403 8.1 20 23 11.4  Maximum 0.2 3.05 0.25 — — — — 30.8 10.6 141 497 8.7 51 42 202  Std. dev. 0 0.59 0.07 — — — — 0.73 1.09 15.4 16.1 0.13 6.65 5.69 31.5 

N obs. 31 30 30 0 0 0 0 30 30 30 30 30 29 14 30 

1995 Near-surface measurements: fall

1. Main channel Mean 0.2 5.35 — — — — — 11.1 9.65 88 334 8 38.9 33 45.8  Median 0.2 5.2 — — — — — 12 9.45 87 336 8 40 32 47.5  Minimum 0.2 0.4 — — — — — 8.4 9.1 84 305 7.9 18 17 14.4  Maximum 0.2 9.5 — — — — — 13.6 10.6 92 366 8.1 46 50 72.2  Std. dev. 0 2.1 — — — — — 1.4 0.42 1.7 15.6 0.05 6.04 7.25 13 

N obs. 30 30 0 0 0 0 0 30 30 30 30 30 30 30 30 

2. Side channel Mean 0.2 3.12 0.45 — — — — 11.2 9.71 88 332 8 39 33 44.8  Median 0.2 3.25 0.46 — — — — 11.4 9.6 88 331 8 40 31 40.7  Minimum 0.2 0.4 0.02 — — — — 9.2 8.9 83 308 7.9 20 23 27.8  Maximum 0.2 7 0.8 — — — — 12.9 10.7 93 360 8.1 48 45 67.6  Std. dev. 0 1.64 0.18 — — — — 1.18 0.5 2.79 16.7 0.07 5.14 6.14 10.7 

N obs. 30 30 29 0 0 0 0 30 30 30 30 30 30 30 30 

3. Backwater Mean 0.2 1.47 0.13 — — — — 12.7 9.87 93 329 8.1 36.1 32 35.8  Median 0.2 1.23 0.07 — — — — 13.2 9.7 92 320 8 38 31 33.6  Minimum 0.2 0.4 0 — — — — 8.7 7.3 67 305 7.7 20 12 15.2  Maximum 0.2 4.12 0.59 — — — — 16.2 14.1 136 390 9 59 51 87.1  Std. dev. 0 0.84 0.14 — — — — 1.76 1.16 11.5 24.3 0.26 7.62 9.05 14.9 

N obs. 62 60 60 0 0 0 0 60 59 59 60 60 59 60 60 
 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-surface measurements: fall

5. Impounded Mean 0.2 1.33 0.16 — — — — 9.2 10.7 93 352 8.1 41 30 34.3  Median 0.2 1.29 0.18 — — — — 9.1 10.6 92 349 8.1 39 28 29.1  Minimum 0.2 0.4 0 — — — — 8.4 10.2 89 332 8.1 18 15 14.5  Maximum 0.2 2.5 0.38 — — — — 10.8 12 107 393 8.4 60 90 155  Std. dev. 0 0.58 0.1 — — — — 0.6 0.4 4.46 10.1 0.08 9.45 13.9 26.2 

N obs. 30 30 30 0 0 0 0 30 30 30 30 30 30 30 30 

1996 Near-surface measurements: winter

1. Main channel Mean 0.2 4.93 — 100 30 100 8 0.1 10.8 74 412 7.4 102 5 2.3  Median 0.2 4.5 — 100 31 100 7 0.1 10.8 74 412 7.4 94 5 2.3  Minimum 0.2 2.1 — 100 21 100 4 0.1 10.2 70 395 7.3 64 4 0.6  Maximum 0.2 8.6 — 100 40 100 11 0.1 11.4 78 437 7.6 150 6 3.2  Std. dev. 0 1.62 — 0 4.77 0 1.9 0 0.41 2.83 10.9 0.08 27.6 0.63 0.69 

N obs. 16 16 0 16 16 16 16 16 16 16 16 16 16 16 16 

2. Side channel Mean 0.19 2.64 0.22 100 29 89 7 0.09 10.7 73 412 7.4 91.4 8 5.6  Median 0.2 2.92 0.24 100 29 100 9 0.1 10.5 72 415 7.4 96 5 2.7  Minimum 0 0.25 0 100 18 0 0 0 9.6 66 356 7.3 29 5 1.8  Maximum 0.2 5.5 0.4 100 50 100 11 0.1 11.9 81 453 7.7 150 31 32.5  Std. dev. 0.04 1.52 0.11 0 7.54 30.7 3.7 0.03 0.56 3.84 22.7 0.1 30.8 7.47 7.91 

N obs. 30 30 29 30 30 30 30 29 29 29 29 29 25 27 29 

3. Backwater Mean 0.17 0.94 0.04 100 31 87 7 0.24 8.8 61 464 7.4 75.2 10 7.2  Median 0.2 0.77 0 100 31 100 9 0.2 10 69 450 7.4 77 7 4  Minimum 0 0.2 0 100 17 0 0 0 0.7 5 320 7.1 28 4 1.2  Maximum 0.2 3.4 0.3 100 43 100 16 1 12.3 86 691 7.7 139 51 38.9  Std. dev. 0.06 0.62 0.08 0 6.2 34.3 4.2 0.23 2.7 18.6 77 0.12 31.5 9.26 8.83 

N obs. 60 60 57 60 60 60 60 57 57 57 57 57 30 55 56 

5. Impounded Mean 0.18 1.17 0.09 100 34 93 5 0.09 10.8 74 438 7.5 98.1 6 3.6  Median 0.2 1.11 0.11 100 34 100 5 0.1 10.7 73 428 7.6 105 5 2.2  Minimum 0 0.38 0 100 25 0 0 0 9.6 66 380 7.3 29 4 1.4  Maximum 0.2 3.87 0.25 100 45 100 9 0.1 11.8 81 531 7.8 150 24 25.7  Std. dev. 0.06 0.65 0.06 0 5.56 25.4 2.1 0.03 0.57 3.94 30.8 0.14 32.5 4.57 5.54 

N obs. 30 30 30 30 30 30 30 30 30 30 30 30 18 30 30 
 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/

1996 Near-surface measurements: spring

1. Main channel Mean 0.2 5.64 — — — — — 10.3 10.8 96 285 7.9 46.6 26 48.8  Median 0.2 5.8 — — — — — 10.5 10.7 97 295 7.9 48 26 49.7  Minimum 0.2 1.28 — — — — — 9.2 10.2 89 215 7.7 34 14 21.7  Maximum 0.2 10.8 — — — — — 11.6 11.6 104 308 8.2 60 34 73.1  Std. dev. 0 2.66 — — — — — 0.68 0.41 4.93 25.8 0.13 5.99 4.55 11.4 

N obs. 30 30 0 0 0 0 0 30 30 30 30 30 30 30 30 

2. Side channel Mean 0.2 4.38 0.68 — — — — 10.7 10.9 98 294 7.9 48.4 24 41.3  Median 0.2 4.57 0.68 — — — — 10.8 10.9 98 292 7.9 49 25 39.8  Minimum 0.2 1.22 0.15 — — — — 9.5 10.3 91 230 7.8 36 15 16.9  Maximum 0.2 8.33 1.32 — — — — 11.6 11.4 103 313 8.1 62 32 72.1  Std. dev. 0 1.56 0.26 — — — — 0.56 0.31 3.67 16.2 0.07 5.89 3.65 12.8 

N obs. 30 30 28 0 0 0 0 30 30 30 30 30 30 30 30 

3. Backwater Mean 0.2 2.1 0.16 — — — — 10.8 11.2 101 268 8.1 51.8 20 27.3  Median 0.2 2 0.1 — — — — 10.8 10.8 97 284 8 50 21 26.8  Minimum 0.2 0.8 0 — — — — 8.4 9.8 88 217 7.8 32 10 10.3  Maximum 0.2 4.88 0.76 — — — — 13.5 15 140 320 9.3 72 30 69.5  Std. dev. 0 0.68 0.18 — — — — 1.17 1.14 12.3 39.9 0.33 9.54 6.27 13 

N obs. 60 60 53 0 0 0 0 60 60 60 60 60 60 60 60 

5. Impounded Mean 0.2 1.94 0.37 — — — — 10.6 11.1 100 259 8.1 46.9 24 44  Median 0.2 2 0.38 — — — — 10.5 11.1 99 257 8.1 50 20 32.4  Minimum 0.2 1 0.08 — — — — 9.9 10.5 93 214 7.8 28 14 17.1  Maximum 0.2 3.05 0.62 — — — — 13 12.7 118 310 8.5 62 45 107  Std. dev. 0 0.57 0.14 — — — — 0.56 0.57 6.21 32.9 0.2 8.92 8.92 22 

N obs. 30 30 13 0 0 0 0 30 30 30 30 30 30 30 30 

1996 Near-surface measurements: summer

1. Main channel Mean 0.2 4.59 — — — — — 24.4 7.13 86 426 8 56 20 25.8  Median 0.2 4.69 — — — — — 24.4 7 84 428 8.1 54 20 27.8  Minimum 0.2 0.52 — — — — — 23.1 6.5 78 405 7.8 34 11 10.8  Maximum 0.2 9.14 — — — — — 25 8.9 109 454 8.3 82 29 41.9  Std. dev. 0 1.92 — — — — — 0.42 0.54 6.55 16.4 0.09 9.92 4.42 6.25 

N obs. 30 30 0 0 0 0 0 30 30 30 30 30 30 30 30 
 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/

1996 Near-surface measurements: summer

2. Side channel Mean 0.2 3.25 0.35 — — — — 24.2 7.22 87 428 8.1 48.4 21 28.1  Median 0.2 3.13 0.31 — — — — 24.2 7.15 86 420 8 49 22 27.9  Minimum 0.2 1.01 0.18 — — — — 23.3 6.2 74 405 7.8 38 13 16.2  Maximum 0.2 8.84 0.75 — — — — 25.2 8.9 109 463 8.2 70 31 40.6  Std. dev. 0 1.64 0.13 — — — — 0.43 0.66 8.37 19.3 0.13 7.58 4.16 5.96 

N obs. 30 30 30 0 0 0 0 30 30 30 30 30 30 30 30 

3. Backwater Mean 0.2 0.9 0.05 — — — — 24.2 7.9 95 430 8.2 31 34 44.4  Median 0.2 0.74 0.02 — — — — 24.1 7.85 94 439 8.1 29 36 44  Minimum 0.2 0.35 0 — — — — 22.5 1.1 13 266 7.4 12 7 7  Maximum 0.2 2.7 0.31 — — — — 27.1 15.4 192 530 9.2 58 64 111  Std. dev. 0 0.54 0.07 — — — — 1.04 2.45 30.6 52.8 0.33 11.4 15.5 22.4 

N obs. 64 60 60 0 0 0 0 60 60 60 60 60 51 60 60 

5. Impounded Mean 0.2 1.26 0.13 — — — — 24.4 8.2 99 428 8.2 55.1 19 23.3  Median 0.2 1.21 0.15 — — — — 24.4 8.3 100 430 8.2 51 19 21.1  Minimum 0.2 0.36 0 — — — — 22.9 6.7 79 405 7.9 21 8 6  Maximum 0.2 2.8 0.23 — — — — 26.7 10.6 124 455 8.9 120 44 79.5  Std. dev. 0 0.58 0.06 — — — — 0.75 0.8 10.1 16.5 0.18 23.1 8.33 14.3 

N obs. 30 30 30 0 0 0 0 30 30 30 30 30 27 30 30 

1996 Near-surface measurements: fall

1. Main channel Mean 0.2 4.62 — — — — — 14.6 9.38 92 366 8.5 55.7 17 21.6  Median 0.2 4.6 — — — — — 14.8 9.1 89 365 8.4 58 16 20.5  Minimum 0.2 0.4 — — — — — 13 8.5 84 357 8.2 40 13 14.6  Maximum 0.2 8.6 — — — — — 16.4 12.3 126 389 8.9 64 23 35.4  Std. dev. 0 2.19 — — — — — 0.77 0.94 9.99 6.58 0.19 6.86 2.53 4.17 

N obs. 30 30 0 0 0 0 0 30 30 30 30 30 29 30 30 

2. Side channel Mean 0.2 2.46 0.2 — — — — 14.4 9.04 89 370 8.4 48.9 20 26.1  Median 0.2 2.59 0.17 — — — — 14.3 9.1 88 370 8.4 48 20 24.9  Minimum 0.2 0.78 0.01 — — — — 13 8.6 83 358 8.1 34 13 17.6  Maximum 0.2 5.2 0.46 — — — — 15.4 10.6 103 409 8.8 65 30 37.6  Std. dev. 0 1.28 0.13 — — — — 0.76 0.38 3.37 10.5 0.12 8.3 4.38 5.55 

N obs. 32 30 30 0 0 0 0 30 30 30 30 30 30 30 30 
 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/

1996 Near-surface measurements: fall

3. Backwater Mean 0.2 0.79 0.03 — — — — 13.4 9.97 96 396 8.5 33.6 34 39.2  Median 0.2 0.57 0 — — — — 13.4 10 95 397 8.5 30 31 38.4  Minimum 0.2 0.3 0 — — — — 10.8 7.1 66 326 7.8 16 12 12.2  Maximum 0.2 2.74 0.23 — — — — 16.4 13.1 126 484 9.2 60 86 85.3  Std. dev. 0 0.57 0.05 — — — — 1.06 1.36 13.2 29.8 0.3 11.8 17.1 16.5 

N obs. 70 60 60 0 0 0 0 60 59 59 60 60 50 60 60 

5. Impounded Mean 0.2 1.2 0.06 — — — — 13.6 9.86 95 369 8.5 51.3 18 20.6  Median 0.2 1.14 0.06 — — — — 14.2 9.6 95 369 8.5 50 17 20  Minimum 0.2 0.4 0 — — — — 9.7 9.1 82 362 8.1 32 10 12.7  Maximum 0.2 4.5 0.14 — — — — 17.2 12.2 125 378 8.9 90 30 31  Std. dev. 0 0.72 0.04 — — — — 1.86 0.8 10.4 4.13 0.24 11.9 4.36 4.87 

N obs. 32 30 30 0 0 0 0 30 29 29 30 30 27 30 30 
 F-14

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 2.735 0.03 2.35 0.315 0.13 — — — —  Median 2.494 0.03 2.311 0.31 0.114 — — — —  Minimum 2.078 -0.02 2.019 0.27 0.051 — — — —  Maximum 3.621 0.054 3.299 0.365 0.184 — — — —  Std. dev. 0.522 0.011 0.331 0.03 0.038 — — — — 

N obs. 16 16 16 16 16 0 0 0 0 

2. Side channel Mean 2.467 0.026 2.244 0.329 0.123 — — — —  Median 2.26 0.023 2.249 0.314 0.109 — — — —  Minimum 1.801 -0.02 1.994 0.289 0.1 — — — —  Maximum 3.396 0.048 2.789 0.415 0.186 — — — —  Std. dev. 0.45 0.013 0.234 0.032 0.029 — — — — 

N obs. 16 16 16 16 16 0 0 0 0 

3. Backwater Mean 2.496 0.03 2.162 0.305 0.104 — — — —  Median 2.321 0.029 2.132 0.304 0.105 — — — —  Minimum 2 -0.02 0.91 0.213 0.031 — — — —  Maximum 3.465 0.057 3.146 0.384 0.162 — — — —  Std. dev. 0.394 0.012 0.425 0.046 0.033 — — — — 

N obs. 32 32 32 32 32 0 0 0 0 

5. Impounded Mean 3.27 0.037 2.531 0.355 0.137 — — — —  Median 3.144 0.038 2.307 0.322 0.165 — — — —  Minimum 2.434 -0.02 1.92 0.258 -0.01 — — — —  Maximum 4.306 0.065 3.81 0.807 0.186 — — — —  Std. dev. 0.574 0.015 0.599 0.132 0.053 — — — — 

N obs. 16 15 15 16 15 0 0 0 0 

1993 Near-surface measurements: fall

1. Main channel Mean 3.14 0.011 1.755 0.216 0.045 — — — —  Median 3.141 -0.02 1.738 0.211 0.047 — — — —  Minimum 1.428 -0.02 1.299 0.157 -0.01 — — — —  Maximum 4.839 0.023 2.589 0.275 0.064 — — — —  Std. dev. 0.785 0.003 0.335 0.039 0.016 — — — — 

N obs. 16 16 16 16 16 0 0 0 0 
 F-15

Table F-2. Continued.

Samplingstratum 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

2. Side channel Mean 3.102 0.01 1.799 0.223 0.042 — — — —  Median 3.018 -0.02 1.557 0.222 0.05 — — — —  Minimum 2.168 -0.02 1.214 0.173 0.015 — — — —  Maximum 4.086 -0.02 2.629 0.283 0.065 — — — —  Std. dev. 0.479 0 0.474 0.033 0.018 — — — — 

N obs. 14 16 16 16 16 0 0 0 0 

3. Backwater Mean 3.133 0.012 1.445 0.237 0.032 — — — —  Median 3.222 -0.02 1.475 0.222 0.032 — — — —  Minimum 1 -0.02 -0.01 0.171 -0.01 — — — —  Maximum 4.423 0.043 3.113 0.412 0.071 — — — —  Std. dev. 0.809 0.007 0.888 0.056 0.021 — — — — 

N obs. 31 31 31 31 31 0 0 0 0 

5. Impounded Mean 3.071 0.012 1.74 0.223 0.052 — — — —  Median 3.136 -0.02 1.633 0.203 0.053 — — — —  Minimum 2.408 -0.02 1.4 0.167 0.032 — — — —  Maximum 3.619 0.036 2.451 0.379 0.066 — — — —  Std. dev. 0.329 0.006 0.317 0.055 0.01 — — — — 

N obs. 17 17 17 17 17 0 0 0 0 

1994 Near-surface measurements: winter

1. Main channel Mean 2.556 0.163 2.364 0.1 0.059 — — — —  Median 1.992 0.159 2.298 0.09 0.059 — — — —  Minimum 1.595 0.145 2.164 0.08 0.053 — — — —  Maximum 6.711 0.188 2.733 0.146 0.064 — — — —  Std. dev. 1.347 0.013 0.183 0.024 0.003 — — — — 

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

2. Side channel Mean 2.182 0.156 2.362 0.088 0.055 — — — —  Median 2.172 0.156 2.319 0.091 0.056 — — — —  Minimum 1.544 0.123 2.131 0.034 0.039 — — — —  Maximum 3.153 0.193 2.669 0.106 0.064 — — — —  Std. dev. 0.453 0.015 0.169 0.017 0.006 — — — — 

N obs. 15 15 15 15 15 0 0 0 0 
 F-16

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: winter

3. Backwater Mean 2.652 0.261 2.055 0.11 0.038 — — — —  Median 2.299 0.168 2.346 0.088 0.035 — — — —  Minimum 1.169 0.078 -0.01 0.055 -0.01 — — — —  Maximum 5.686 1.27 3.353 0.35 0.077 — — — —  Std. dev. 1.117 0.26 0.996 0.069 0.021 — — — — 

N obs. 26 27 27 27 27 0 0 0 0 

5. Impounded Mean 3.269 0.171 2.525 0.097 0.055 — — — —  Median 2.88 0.165 2.401 0.094 0.056 — — — —  Minimum 1.378 0.135 2.137 0.081 0.036 — — — —  Maximum 10.25 0.241 3.163 0.128 0.062 — — — —  Std. dev. 2.032 0.028 0.293 0.012 0.007 — — — — 

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

1994 Near-surface measurements: spring

1. Main channel Mean 1.813 0.022 0.198 0.28 0.005 -0.01 — — —  Median 1.82 -0.02 0.183 0.314 -0.01 -0.05 — — —  Minimum 0.965 -0.02 0.13 0.129 -0.01 -0.05 — — —  Maximum 2.252 0.077 0.347 0.386 -0.01 0.18 — — —  Std. dev. 0.316 0.019 0.068 0.081 0 0.071 — — — 

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

2. Side channel Mean 1.902 0.029 0.186 0.283 0.005 0.032 — — —  Median 1.854 0.024 0.149 0.23 -0.01 -0.05 — — —  Minimum 1.565 -0.02 -0.01 0.193 -0.01 -0.05 — — —  Maximum 2.587 0.131 0.351 0.4 -0.01 0.176 — — —  Std. dev. 0.259 0.03 0.101 0.081 0 0.094 — — — 

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

3. Backwater Mean 1.825 0.021 0.209 0.211 0.005 0.034 — — —  Median 1.731 -0.02 0.14 0.195 -0.01 -0.05 — — —  Minimum 1.408 -0.02 0.12 0.159 -0.01 -0.05 — — —  Maximum 2.425 0.047 0.62 0.328 -0.01 0.369 — — —  Std. dev. 0.294 0.013 0.132 0.042 0 0.123 — — — 

N obs. 30 30 30 30 30 30 0 0 0 
 F-17

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

5. Impounded Mean 1.863 0.023 0.53 0.309 0.005 0.593 — — —  Median 1.878 0.023 0.528 0.289 -0.01 0.099 — — —  Minimum 1.6 -0.02 0.147 0.214 -0.01 -0.05 — — —  Maximum 2.05 0.056 0.965 0.428 -0.01 1.531 — — —  Std. dev. 0.125 0.014 0.277 0.066 0 0.642 — — — 

N obs. 20 20 20 20 20 20 0 0 0 

1994 Near-surface measurements: summer

1. Main channel Mean 2.263 0.033 0.89 0.142 0.052 3.932 — — —  Median 2.219 0.023 0.923 0.13 0.026 4.091 — — —  Minimum 1.768 -0.02 0.446 0.109 -0.01 1.193 — — —  Maximum 2.878 0.15 1.336 0.217 0.34 5.244 — — —  Std. dev. 0.277 0.035 0.299 0.03 0.08 0.993 — — — 

N obs. 16 16 16 16 16 16 0 0 0 

2. Side channel Mean 2.168 0.024 1.131 0.151 0.025 3.722 — — —  Median 2.13 -0.02 1.076 0.142 0.025 3.977 — — —  Minimum 1.252 -0.02 0.744 0.023 -0.01 1.164 — — —  Maximum 3.106 0.054 1.964 0.332 0.063 5.332 — — —  Std. dev. 0.398 0.017 0.271 0.061 0.018 1.135 — — — 

N obs. 16 16 16 16 16 16 0 0 0 

3. Backwater Mean 1.996 0.034 0.5 0.176 0.037 4.216 — — —  Median 2.182 0.023 0.502 0.159 0.032 4.706 — — —  Minimum 1.083 -0.02 -0.01 0.124 0.013 0.972 — — —  Maximum 2.937 0.176 1.12 0.313 0.091 5.899 — — —  Std. dev. 0.493 0.036 0.308 0.047 0.022 1.32 — — — 

N obs. 31 31 31 31 29 30 0 0 0 

5. Impounded Mean 1.951 0.039 0.393 0.151 0.029 3.99 — — —  Median 2.004 0.023 0.3 0.132 0.026 4.237 — — —  Minimum 0.981 -0.02 -0.01 0.059 -0.01 0.896 — — —  Maximum 2.332 0.136 0.824 0.254 0.096 4.436 — — —  Std. dev. 0.323 0.038 0.22 0.057 0.019 0.832 — — — 

N obs. 17 17 17 17 17 17 0 0 0 
 F-18

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 1.922 0.029 1.249 0.201 0.059 5.187 — — —  Median 1.901 0.02 1.2 0.187 0.058 5.206 — — —  Minimum 1.516 -0.02 1.107 0.146 0.03 4.078 — — —  Maximum 2.298 0.084 1.675 0.262 0.082 5.977 — — —  Std. dev. 0.181 0.02 0.157 0.033 0.014 0.425 — — — 

N obs. 16 16 16 16 16 16 0 0 0 

2. Side channel Mean 2.035 0.03 1.32 0.207 0.052 5.272 — — —  Median 1.959 0.026 1.199 0.199 0.052 5.294 — — —  Minimum 1.75 -0.02 1.014 0.162 0.027 4.063 — — —  Maximum 2.554 0.065 2.006 0.333 0.074 5.935 — — —  Std. dev. 0.21 0.017 0.252 0.044 0.013 0.409 — — — 

N obs. 16 16 16 16 16 16 0 0 0 

3. Backwater Mean 1.912 0.047 1.001 0.22 0.037 4.738 — — —  Median 1.913 0.032 1.133 0.213 0.041 5.123 — — —  Minimum 1.048 -0.02 -0.01 0.095 -0.01 2.54 — — —  Maximum 2.638 0.271 1.788 0.337 0.063 6.29 — — —  Std. dev. 0.35 0.052 0.544 0.054 0.019 0.972 — — — 

N obs. 32 32 32 32 32 32 0 0 0 

5. Impounded Mean 2.087 0.051 1.346 0.165 0.062 5.364 — — —  Median 2.056 0.052 1.369 0.163 0.061 5.336 — — —  Minimum 1.75 -0.02 1.134 0.125 0.044 5.082 — — —  Maximum 2.492 0.078 1.557 0.215 0.084 5.599 — — —  Std. dev. 0.221 0.018 0.156 0.03 0.01 0.168 — — — 

N obs. 16 16 16 16 16 16 0 0 0 

1995 Near-surface measurements: winter

1. Main channel Mean 2.391 0.066 1.86 0.078 0.011 5.631 — — —  Median 2.373 0.065 1.871 0.075 0.013 5.601 — — —  Minimum 2.262 0.032 1.098 0.039 -0.01 4.959 — — —  Maximum 2.625 0.095 2.108 0.148 0.02 6.168 — — —  Std. dev. 0.097 0.018 0.229 0.027 0.005 0.289 — — — 

N obs. 16 16 16 16 16 16 0 0 0 
 F-19

Table F-2. Continued.

Samplingstratum 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

2. Side channel Mean 2.565 0.065 2.12 0.07 0.011 5.474 — — —  Median 2.457 0.065 2.054 0.069 -0.01 5.499 — — —  Minimum 2.204 0.044 1.784 0.032 -0.01 4.821 — — —  Maximum 3.252 0.089 2.965 0.129 0.046 5.8 — — —  Std. dev. 0.311 0.012 0.37 0.023 0.01 0.236 — — — 

N obs. 16 16 16 16 16 16 0 0 0 

3. Backwater Mean 2.439 0.19 2.048 0.072 0.011 5.038 — — —  Median 2.347 0.065 1.859 0.059 0.01 5.38 — — —  Minimum 0.815 0.04 0.164 0.013 -0.01 2.802 — — —  Maximum 3.799 0.815 6.992 0.167 0.027 6.212 — — —  Std. dev. 0.629 0.247 1.463 0.042 0.007 0.866 — — — 

N obs. 24 24 24 24 24 24 0 0 0 

5. Impounded Mean 2.655 0.082 2.533 0.075 0.008 5.038 — — —  Median 2.71 0.068 2.328 0.049 -0.01 5.485 — — —  Minimum 2.321 0.055 1.912 0.031 -0.01 0.055 — — —  Maximum 2.859 0.247 6.296 0.212 0.018 5.937 — — —  Std. dev. 0.182 0.047 1.059 0.052 0.005 1.434 — — — 

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

1995 Near-surface measurements: spring

1. Main channel Mean 2.842 0.022 2.411 0.124 0.007 3.256 — — —  Median 2.768 0.023 2.347 0.119 -0.01 3.366 — — —  Minimum 2.197 -0.02 1.845 0.066 -0.01 2.369 — — —  Maximum 4.084 0.037 3.584 0.174 0.014 4.008 — — —  Std. dev. 0.463 0.007 0.49 0.032 0.004 0.448 — — — 

N obs. 16 16 16 16 16 14 0 0 0 

2. Side channel Mean 2.813 0.026 2.353 0.148 0.01 2.85 — — —  Median 2.761 0.025 1.982 0.133 -0.01 3.027 — — —  Minimum 2.076 -0.02 1.432 0.079 -0.01 1.731 — — —  Maximum 4.598 0.043 3.735 0.258 0.02 3.463 — — —  Std. dev. 0.596 0.01 0.67 0.052 0.005 0.492 — — — 

N obs. 16 16 16 16 16 16 0 0 0 
 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

1995 Near-surface measurements: spring

3. Backwater Mean 2.67 0.032 1.978 0.166 0.007 2.391 — — —  Median 2.702 0.033 1.85 0.141 -0.01 2.624 — — —  Minimum 0.78 -0.02 0.212 0.084 -0.01 -0.05 — — —  Maximum 4.756 0.057 3.868 0.311 0.02 4.027 — — —  Std. dev. 0.735 0.009 0.731 0.064 0.004 0.92 — — — 

N obs. 32 32 32 32 32 29 0 0 0 

5. Impounded Mean 3.118 0.025 2.691 0.124 0.008 3.513 — — —  Median 2.986 0.027 2.591 0.113 -0.01 3.55 — — —  Minimum 2.428 -0.02 1.794 0.08 -0.01 3.158 — — —  Maximum 4.202 0.048 4.462 0.208 0.015 3.744 — — —  Std. dev. 0.471 0.011 0.666 0.036 0.004 0.209 — — — 

N obs. 16 16 16 16 16 10 0 0 0 

1995 Near-surface measurements: summer

1. Main channel Mean 2.379 0.055 1.29 0.208 0.08 5.415 — — —  Median 2.295 0.046 1.323 0.203 0.085 5.414 — — —  Minimum 2.121 0.022 -0.01 0.172 0.047 5.072 — — —  Maximum 2.652 0.099 1.865 0.235 0.106 5.814 — — —  Std. dev. 0.181 0.024 0.407 0.019 0.017 0.195 — — — 

N obs. 16 16 16 16 16 16 0 0 0 

2. Side channel Mean 2.389 0.074 0.941 0.216 0.091 5.585 — — —  Median 2.362 0.069 1.199 0.211 0.101 5.568 — — —  Minimum 2.159 0.033 -0.01 0.191 0.053 5.169 — — —  Maximum 2.733 0.169 1.541 0.259 0.124 5.989 — — —  Std. dev. 0.175 0.04 0.581 0.018 0.026 0.209 — — — 

N obs. 16 16 16 16 16 16 0 0 0 

3. Backwater Mean 2.425 0.07 0.929 0.32 0.099 5.659 — — —  Median 2.322 0.044 1.075 0.27 0.097 5.595 — — —  Minimum 1.643 -0.02 -0.01 0.151 0.035 1.988 — — —  Maximum 4.545 0.184 1.845 1.134 0.264 9.725 — — —  Std. dev. 0.492 0.051 0.564 0.176 0.047 1.166 — — — 

N obs. 32 32 32 32 32 32 0 0 0 
 F-21

Table F-2. Continued.

Samplingstratum 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

5. Impounded Mean 2.227 0.053 1.108 0.225 0.096 5.463 — — —  Median 2.198 0.043 1.242 0.213 0.096 5.449 — — —  Minimum 2.02 0.022 -0.01 0.176 0.073 5.134 — — —  Maximum 2.416 0.1 1.552 0.278 0.117 5.867 — — —  Std. dev. 0.13 0.024 0.401 0.029 0.01 0.224 — — — 

N obs. 16 16 16 16 16 16 0 0 0 

1995 Near-surface measurements: fall

1. Main channel Mean 1.655 0.059 0.8 0.128 0.038 — — — —  Median 1.616 0.055 0.812 0.128 0.039 — — — —  Minimum 1.404 0.043 0.611 0.098 0.03 — — — —  Maximum 1.97 0.085 1.023 0.158 0.044 — — — —  Std. dev. 0.178 0.012 0.16 0.017 0.005 — — — — 

N obs. 18 18 18 18 18 0 0 0 0 

2. Side channel Mean 1.683 0.057 0.803 0.132 0.037 — — — —  Median 1.728 0.058 0.771 0.128 0.036 — — — —  Minimum 1.379 -0.02 0.575 0.1 0.023 — — — —  Maximum 2.009 0.08 1.115 0.179 0.05 — — — —  Std. dev. 0.198 0.017 0.176 0.021 0.008 — — — — 

N obs. 16 16 16 16 16 0 0 0 0 

3. Backwater Mean 1.526 0.048 0.599 0.135 0.035 — — — —  Median 1.541 0.046 0.592 0.135 0.037 — — — —  Minimum 1.013 0.03 0.018 0.084 -0.01 — — — —  Maximum 1.943 0.074 1.097 0.173 0.057 — — — —  Std. dev. 0.238 0.013 0.264 0.024 0.013 — — — — 

N obs. 33 33 33 33 33 0 0 0 0 

5. Impounded Mean 1.899 0.064 1.033 0.129 0.036 — — — —  Median 1.849 0.061 1.012 0.123 0.035 — — — —  Minimum 1.725 0.036 0.916 0.099 0.029 — — — —  Maximum 2.125 0.085 1.146 0.215 0.045 — — — —  Std. dev. 0.118 0.012 0.083 0.028 0.005 — — — — 

N obs. 16 16 16 16 16 0 0 0 0 
 F-22

Table F-2. Continued.

Samplingstratum 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 2.48 0.314 1.713 0.087 0.046 6.792 — — —  Median 2.462 0.322 1.717 0.087 0.047 6.777 — — —  Minimum 2.076 0.247 1.564 0.07 0.031 6.609 — — —  Maximum 2.791 0.373 2.028 0.099 0.061 6.973 — — —  Std. dev. 0.181 0.032 0.119 0.009 0.009 0.134 — — — 

N obs. 16 16 16 16 16 7 0 0 0 

2. Side channel Mean 2.67 0.378 1.86 0.11 0.067 6.679 — — —  Median 2.523 0.325 1.629 0.088 0.044 6.823 — — —  Minimum 2.35 0.253 1.546 0.068 0.024 5.589 — — —  Maximum 3.532 0.954 3.028 0.351 0.278 7.012 — — —  Std. dev. 0.358 0.172 0.463 0.075 0.068 0.408 — — — 

N obs. 17 17 17 17 17 11 0 0 0 

3. Backwater Mean 2.929 0.461 2.038 0.136 0.058 6.418 — — —  Median 2.914 0.395 2.059 0.105 0.052 6.092 — — —  Minimum 2.295 0.135 -0.01 0.042 -0.01 5.188 — — —  Maximum 3.737 1.31 4.186 0.723 0.188 8.216 — — —  Std. dev. 0.371 0.227 0.743 0.118 0.04 1.031 — — — 

N obs. 31 31 31 31 31 6 0 0 0 

5. Impounded Mean 2.925 0.305 1.975 0.095 0.049 6.459 — — —  Median 2.795 0.279 1.918 0.089 0.044 6.994 — — —  Minimum 2.552 0.099 1.581 0.062 0.021 0.086 — — —  Maximum 3.488 0.588 2.537 0.197 0.158 7.951 — — —  Std. dev. 0.337 0.099 0.296 0.029 0.031 2.064 — — — 

N obs. 16 16 16 16 16 12 0 0 0 

1996 Near-surface measurements: spring

1. Main channel Mean 1.938 — 0.97 0.139 0.052 — — — —  Median 1.977 — 1.061 0.14 0.051 — — — —  Minimum 0.684 — 0.029 0.118 0.038 — — — —  Maximum 3.819 — 1.267 0.151 0.092 — — — —  Std. dev. 0.712 — 0.354 0.01 0.012 — — — — 

N obs. 16 0 16 10 16 0 0 0 0 
 F-23

Table F-2. Continued.

Samplingstratum 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

2. Side channel Mean 1.898 — 1.083 0.123 0.047 — — — —  Median 1.945 — 1.032 0.122 0.045 — — — —  Minimum 1.485 — 0.921 0.084 0.039 — — — —  Maximum 2.237 — 1.444 0.149 0.055 — — — —  Std. dev. 0.223 — 0.132 0.018 0.005 — — — — 

N obs. 16 0 16 10 16 0 0 0 0 

3. Backwater Mean 1.589 — 0.761 0.119 0.043 — — — —  Median 1.62 — 0.61 0.116 0.044 — — — —  Minimum 0.675 — -0.01 0.024 0.028 — — — —  Maximum 2.51 — 1.232 0.192 0.053 — — — —  Std. dev. 0.5 — 0.342 0.038 0.006 — — — — 

N obs. 31 0 32 14 32 0 0 0 0 

5. Impounded Mean 1.645 — 0.749 0.149 0.042 — — — —  Median 1.48 — 0.515 0.152 0.042 — — — —  Minimum 0.612 — 0.137 0.139 0.034 — — — —  Maximum 2.597 — 1.185 0.157 0.051 — — — —  Std. dev. 0.576 — 0.368 0.009 0.005 — — — — 

N obs. 15 0 16 3 16 0 0 0 0 

1996 Near-surface measurements: summer

1. Main channel Mean 2.135 0.055 1.24 — 0.04 — — — —  Median 2.164 0.054 1.352 — 0.039 — — — —  Minimum 1.69 -0.02 0.792 — 0.02 — — — —  Maximum 2.679 0.091 1.758 — 0.067 — — — —  Std. dev. 0.274 0.025 0.288 — 0.013 — — — — 

N obs. 19 19 19 0 19 0 0 0 0 

2. Side channel Mean 2.056 0.053 1.157 — 0.046 — — — —  Median 1.998 0.045 1.091 — 0.042 — — — —  Minimum 1.623 -0.02 0.813 — 0.024 — — — —  Maximum 2.551 0.135 1.929 — 0.081 — — — —  Std. dev. 0.262 0.036 0.333 — 0.015 — — — — 

N obs. 17 17 17 0 17 0 0 0 0 
 F-24

Table F-2. Continued.

Samplingstratum 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: summer

3. Backwater Mean 1.949 0.058 0.702 — 0.051 — — — —  Median 1.902 0.038 0.767 — 0.037 — — — —  Minimum 0.666 -0.02 -0.01 — -0.01 — — — —  Maximum 3.308 0.261 1.973 — 0.203 — — — —  Std. dev. 0.514 0.066 0.592 — 0.043 — — — — 

N obs. 32 32 32 0 32 0 0 0 0 

5. Impounded Mean 2.054 0.013 1.143 — 0.042 — — — —  Median 2.091 -0.02 1.149 — 0.04 — — — —  Minimum 1.656 -0.02 0.838 — 0.019 — — — —  Maximum 2.38 0.045 1.533 — 0.074 — — — —  Std. dev. 0.227 0.009 0.198 — 0.013 — — — — 

N obs. 16 16 16 0 16 0 0 0 0 

1996 Near-surface measurements: fall

1. Main channel Mean 0.857 0.063 0.356 0.088 0.018 — — — —  Median 0.813 0.061 0.3 0.088 0.016 — — — —  Minimum 0.701 -0.02 0.195 0.063 -0.01 — — — —  Maximum 1.156 0.129 0.718 0.114 0.029 — — — —  Std. dev. 0.129 0.032 0.145 0.014 0.008 — — — — 

N obs. 16 16 16 16 16 0 0 0 0 

2. Side channel Mean 0.926 0.061 0.363 0.1 0.018 — — — —  Median 0.897 0.061 0.348 0.092 0.017 — — — —  Minimum 0.762 -0.02 0.241 0.062 -0.01 — — — —  Maximum 1.159 0.098 0.627 0.198 0.038 — — — —  Std. dev. 0.111 0.02 0.103 0.031 0.009 — — — — 

N obs. 16 16 16 16 16 0 0 0 0 

3. Backwater Mean 1.126 0.035 0.299 0.177 0.018 — — — —  Median 1.037 0.024 0.296 0.146 0.013 — — — —  Minimum 0.637 -0.02 -0.01 0.074 -0.01 — — — —  Maximum 1.875 0.1 0.934 0.598 0.093 — — — —  Std. dev. 0.302 0.028 0.275 0.109 0.021 — — — — 

N obs. 33 33 33 33 33 0 0 0 0 
 F-25

Table F-2. Continued.

Samplingstratum 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

5. Impounded Mean 0.858 0.048 0.35 0.147 0.015 — — — —  Median 0.837 0.043 0.362 0.083 0.014 — — — —  Minimum 0.646 -0.02 0.195 0.062 -0.01 — — — —  Maximum 1.097 0.103 0.484 0.78 0.04 — — — —  Std. dev. 0.113 0.033 0.074 0.192 0.011 — — — — 

N obs. 18 18 18 18 18 0 0 0 0 
F-26

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-27

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-28

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-29

Figure F-4. Specific 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-30

Figure F-5. Secchi 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-31

 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-32

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-33

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-34

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-35

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-36

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-37

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-38

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

October 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

Bellevue Field Station

5. FUNDING NUMBERS

6. AUTHOR(S)

David M. Soballe,1

 David E. Gould,2 Scott A.Gritters,2 Russ D. Gent,2 and Michael J. Steuck2

7. PERFORMING ORGANIZATION NAME AND ADDRESS

1

U.S. Geological Survey, Upper Midwest Environmental Sciences Center, 2630 Fanta Reed Road, La Crosse, Wisconsin

54603;

2

Iowa Department of Natural Resources, 206 Rose Street, Bellevue, Iowa 52031

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-P004

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 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. Several short-term trends were noted during 1993–96. Total nitrogen, nitrate–nitrite

nitrogen, soluble reactive phosphorus, total phosphorus, and turbidity generally decreased while ammonia increased in all study pools (12, 13, and 14). Sediment and plant

nutrient concentrations were higher in two tributaries (the Maquoketa and Wapsipinicon Rivers, Iowa) than in the main channel of the Mississippi River.

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.