In cooperation with U.S. Army Corps of Engineers

Monitoring of Stage and Velocity, for Computation of 

Discharge in the Summit Conduit near Summit, Illinois, 

2010–2012

Open-File Report 2012–1244

U.S. Department of the Interior

U.S. Geological Survey

Monitoring of Stage and Velocity, for 

Computation of Discharge in the Summit 

Conduit near Summit, Illinois, 2010–2012

By Kevin K. Johnson and Greg E. Goodwin

In cooperation with U.S. Army Corps of Engineers

Open-File Report 2012–1244

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

SALLY JEWELL, Secretary

U.S. Geological Survey

Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2013

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Suggested citation:

Johnson, K.K. and Goodwin, G.E., 2013, Monitoring of stage and velocity for computation of discharge in the 

Summit Conduit near Summit, Illinois, 2010–2012: U.S. Geological Survey Open-File Report 2012-1244, 45 p.
iii

Contents

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

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

Background............................................................................................................................................1

Lake Michigan Diversion Accounting ......................................................................................3

Past Gaging and Modeling.........................................................................................................3

Hydrologic Setting .........................................................................................................................................3

Drainage Area .......................................................................................................................................3

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

Streamflow Data Collection .........................................................................................................................4

Gaging Station Establishment.............................................................................................................4

Gaging Station Equipment...................................................................................................................4

Site Layout..............................................................................................................................................6

Methods..................................................................................................................................................7

Stage Measurement....................................................................................................................7

Velocity Measurement................................................................................................................7

Discharge Computation ..............................................................................................................8

Data Accuracy and Limits .................................................................................................................10

Site Specific Data Limitations...........................................................................................................10

Drainage Area ............................................................................................................................10

Debris Accumulation.................................................................................................................11

Computed Discharge.................................................................................................................11

Data Loss.....................................................................................................................................14

Future Stream Gaging ........................................................................................................................14

Summary........................................................................................................................................................14

References Cited..........................................................................................................................................16

Appendix 1 

Expanded Rating Table for the Stage – Area Rating....................................................................18

Stage-Area Geometry ........................................................................................................................21

Appendix 2 - Annual Daily Value Tables for 2011 and 2012

Summit Conduit near Summit, Illinois (414757087490401) ............................................................22

Water Year October 2010 to September 2011........................................................................22

Water Year October 2011 to September 2012........................................................................25

Tinley Creek near Palos Park, Illinois (05536500)...........................................................................28

Water Year October 2010 to September 2011........................................................................28

Water Year October 2011 to September 2012........................................................................31

Midlothian Creek at Oak Park, Illinois (05536340)..........................................................................34

Water Year October 2010 to September 2011........................................................................34

Water Year October 2011 to September 2012........................................................................37

Sawmill Creek near Lemont, Illinois (05533400).............................................................................40

Water Year October 2010 to September 2011........................................................................40

Water Year October 2011 to September 2012........................................................................43
iv

Figures

1. Map of the location and orientation of the Summit Conduit .................................................2

2. Map showing the drainage area and tributaries of the Summit Conduit 

near Summit, Illinois.....................................................................................................................4

3. Photographs of the Summit Conduit near Summit, Illinois stream gage 

before and after October 10, 2012, showing the gage features............................................5

4. View of the stream gaging station at the Summit Conduit at Summit, Illinois. 

Locations of significant features, reference marks and gage equipment 

are indicated in the diagram.......................................................................................................6

5. Illustration of dynamic boundary adjustment of velocity profile from 

the SonTek Argonaut SW acoustic Doppler velocity meter 

(Levesque and Oberg, 2012)........................................................................................................7

6. The velocity-velocity plot of the mean index-velocity (in feet per second) 

measured by an acoustic Doppler velocity meter (ADVM) as compared 

to the mean channel velocity (in feet per second) as measured discharge 

divided by the rated area for the gaging station at the Summit Conduit at 

Summit, Illinois ..............................................................................................................................9

7. Diagram indicating the cross-sectional area geometry with dimensions for 

calculating the rated area in the area of the measured acoustic Doppler 

velocity meter (ADVM) velocity..................................................................................................9

8. The stage-area rating curve developed from equations 3 and 4 from 

the channel geometry in figure 7 .............................................................................................10

9. Plot of acoustic Doppler velocity meter (ADVM) data illustrating a 

period when debris covered the meter, January 27 to March 17, 2011.............................12

10. Hydrograph of water years 2011 and 2012 showing Summit Conduit at 

Summit, Sawmill Creek near Lemont, Midlothian Creek near Oak Park, 

and Tinley Creek near Palos Hills.............................................................................................13

11. Data lost during five medium to high flow events between 

June 9 and June 24, 2011...........................................................................................................15

Tables

1. Mean annual discharge for water years 2011 and 2012 for Summit Conduit 

stream gaging station and three comparison stream gaging stations..............................11
v

Conversion Factors

Inch/Pound to SI

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

inch (in.) 25.4 millimeter (mm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

square foot (ft2) 929.0 square centimeter (cm2)

square foot (ft2) 0.09290 square meter (m2)

Flow rate

cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s)

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

°F=(1.8×°C)+32

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows:

°C=(°F-32)/1.8

Vertical coordinate information is referenced to the insert datum name (and abbreviation) here 

for instance, “North American Vertical Datum of 1988 (NAVD 88).”

Horizontal coordinate information is referenced to the insert datum name (and abbreviation) 

here for instance, “North American Datum of 1983 (NAD 83).”

Altitude, as used in this report, refers to distance above the vertical datum.

Water year, defined as the 12-month period October 1, for any given year through September 

30, of the following year. The water year is designated by the calendar year in which it ends 

and which includes 9 of the 12 months. Thus, the year ending September 30, 2011 is called the 

“2011” water year
vi

Abbreviations

ADVM acoustic Doppler velocity meter

BOR Bureau of Reclamation

CSG Crest-stage gage

CSSC Chicago Sanitary and Ship Canal

dB Decibels

DCP Data collection platform

DOI Department of the Interior

GOES Geostationary operational environmental satellite

LMDA Lake Michigan diversion accounting

MSD Metropolitan Sanitary District

MWRD Metropolitan Water Reclamation District

NPDES National Pollutant Discharge Elimination System

RP reference point

SNR Signal to noise ratio

USACE U.S. Army Corps of Engineers

USGS U.S. Geological Survey

WY water year
Monitoring of Stage and Velocity, for Computation of 

Discharge in the Summit Conduit near Summit, Illinois 

2010–2012

By Kevin K. Johnson and Greg E. Goodwin

Abstract 

Lake Michigan diversion accounting is the process used 

by the U. S. Army Corps of Engineers to quantify the amount 

of water that is diverted from the Lake Michigan watershed 

into the Illinois and Mississippi River Basins. A network of 

streamgages within the Chicago area waterway system monitor 

tributary river flows and the major river flow on the Chicago 

Sanitary and Ship Canal near Lemont as one of the instrumental tools used for Lake Michigan diversion accounting. The 

mean annual discharges recorded by these streamgages are 

used as additions or deductions to the mean annual discharge 

recorded by the main stream gaging station currently used in 

the Lake Michigan diversion accounting process, which is the 

Chicago Sanitary and Ship Canal near Lemont, Illinois (station 

number 05536890).

A new stream gaging station, Summit Conduit near 

Summit, Illinois (station number 414757087490401), was 

installed on September 23, 2010, for the purpose of monitoring stage, velocity, and discharge through the Summit Conduit 

for the U.S. Army Corps of Engineers in accordance with 

Lake Michigan diversion accounting. Summit Conduit conveys flow from a small part of the lower Des Plaines River 

watershed underneath the Des Plaines River directly into the 

Chicago Sanitary and Ship Canal. Because the Summit Conduit 

discharges into the Chicago Sanitary and Ship Canal upstream 

from the stream gaging station at Lemont, Illinois, but does not 

contain flow diverted from the Lake Michigan watershed, it is 

considered a flow deduction to the discharge measured by the 

Lemont stream gaging station in the Lake Michigan diversion 

accounting process. This report offers a technical summary of 

the techniques and methods used for the collection and computation of the stage, velocity, and discharge data at the Summit 

Conduit near Summit, Illinois stream gaging station for the 

2011 and 2012 Water Years. 

The stream gaging station Summit Conduit near Summit, 

Illinois (station number 414757087490401) is an example of 

a nonstandard stream gage. Traditional methods of equating 

stage to discharge historically were not effective. Examples of 

the nonstandard conditions include the converging tributary 

flows directly upstream of the gage; the trash rack and walkway near the opening of the conduit introducing turbulence and 

occasionally entraining air bubbles into the flow; debris within 

the conduit creating conditions of variable backwater and the 

constant influx of smaller debris that escapes the trash rack 

and catches or settles in the conduit and on the equipment. An 

acoustic Doppler velocity meter was installed to measure stage 

and velocity to compute discharge. The stage is used to calculate area based the stage-area rating. The index-velocity from 

the acoustic Doppler velocity meter is applied to the velocityvelocity rating and the product of the two rated values is a rated 

discharge by the index-velocity method. Nonstandard site conditions prevalent at the Summit Conduit stream gaging station 

generally are overcome through the index-velocity method. 

Despite the difficulties in gaging and measurements, improvements continue to be made in data collection, transmission, and 

measurements. Efforts to improve the site and to improve the 

ratings continue to improve the quality and quantity of the data 

available for Lake Michigan diversion accounting. 

Introduction

Background

Summit Conduit, built in 1918, is a 6 feet (ft) wide by 

7 ft high irregular concrete conduit that extends approximately 

1/3 of a mile underneath the Des Plaines River near Summit, 

Illinois (fig. 1). A series of ditches, leading to the Summit 

Conduit, drain approximately 5.4 square miles (mi2 ) of the 

lower Des Plaines River floodplain and discharges the flow 

directly into the Chicago Sanitary and Ship Canal (CSSC). The 

drainage ditches and the conduit were originally constructed to 

drain the farmland behind the McCook Levee on the right bank 

of the Des Plaines River. The farmland has been replaced by 

a rock quarry, industrial facilities, and semipermeable parking 

lots. The ditches still function as a drainage for industry and 

parking as well as a receptor for a couple of National Pollutant 

Discharge Elimination System (NPDES) permits for elimination 

of stormwater discharges from construction site activities. Summit Conduit is located near Summit, Ill and enters the CSSC at 

U.S. Geological Survey (USGS) river mile 313.3, 22.2 miles 

upstream from the Lockport powerhouse (fig. 1, Kollias, 2008).
2

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

41°45'

41°30'

88°15' 87°45' 87°30'

Chicago

Sanitary

and

Ship

Canal

Calumet Sag

Channel

Salt

Creek

Little Calumet R

South Branch

Chicago River

 .N Shore

Channel

SIONILLI

ANAIDNI

LAKE

MICHIGAN

Chicago River

Controlling Works

O’Brien

Controlling Works

Wilmette 

Controlling Works

Lockport 

Powerhouse

88°

Des Plaines

River

N.

Des Plaines River

Grand Calumet R

Calumet R.

05536995

(CSSC at Romeoville)

Summit Conduit at 

Summit, IL

(4147570870490401)

05536998

(CSSC at Lockport 

Controlling Works)

05537000

(CSSC at Lockport 

powerhouse)

05536890

(CSSC near Lemont)

05533400

(Sawmill Cr.)

05536700

(Cal-Sag at Rt. 83)

05536123

(Chicago R. at Columbus Dr.)

05536140

(CSSC at 

Stickney)

Inset area showing 

Summit Conduit

05536121

(Chicago R. at 

Chicago Lock)

05536118

(N. Br. at Grand Ave.)

05536101

(N. Shore Channel 

at Wilmette)

05536290

(Little Calumet R. 

at S. Holland)

05536358

(Grand 

Calumet R.)

River

 Br. 

Chicago 

WILL CO.

COOK CO.

DU PAGE COUNTY

WILL COUNTY

DU PAGE COUNTY

COOK COUNTY

55

05536500

(Tinley Cr.)

05536340

(Midlothian Cr.)

42°

05536123

(Chicago R. at 

Columbus Dr.)

U.S. Geological Survey streamflow-

 gaging station, identifier, and name

Control structure

Conduit

EXPLANATION

Des Plaines

River

Chicago Sanitary and Ship Canal A melraH .S ve.

Archer Ave.

Orthography from the U.S. Department of Agriculture 

Farm Service Agency, Aerial Photography Field Office 2012 

National Agriculture Imagery Program (NAIP) Natural Color 

Imagery for Illinois, accessed in 2013 at 

http://gis.apfo.usda.gov/arcgis/services

10 MILES

10 KILOMETERS

5

0 5

0

Lake

Calumet

Map area

ILLINOIS

Base from U.S. Geological Survey digital data, 

1:100,000 Albers Equal-Area Conic projection

Standard parallels 33°N and 45°N, 

central meridian 89°W

Figure 1. Map of the location and orientation of the Summit Conduit.
Purpose and Scope

3

Lake Michigan Diversion Accounting

A U.S. Supreme Court ruling limits the amount of water 

that the State of Illinois is allowed to divert from Lake Michigan into the Illinois and Mississippi River Basins (Johnson 

and others, 2012). The U.S. Army Corps of Engineers 

(USACE) is tasked with accounting for the flows diverted 

from Lake Michigan. Lake Michigan diversion accounting 

(LMDA) is the process used by the USACE to quantify the 

amount of water diverted from Lake Michigan watershed by 

the State of Illinois. The LMDA depends on data collection 

from a network of streamgages and rain gages that monitor 

diverted flows as well as statistical models used to estimate 

diverted flows where gaging is not feasible. The resulting data 

is used by the USACE to calculate a series of additions and 

deductions to determine a final diversion discharge. Discharge 

data values recorded by USGS stream gaging station numbers 

05536995 (Chicago Sanitary and Ship Canal at Romeoville, 

Illinois; 1984 to 2005) and 05536890 (Chicago Sanitary and 

Ship Canal near Lemont, Illinois; 2006 to present), are the 

primary stream gaging stations that measure diverted flows 

used in the LMDA process (Espey and others, 1981, 1987, 

1994, 2001, 2004, 2009, Jackson and others, 2011, Johnson 

and others, 2012).

The location where the Summit Conduit discharges into 

the CSSC is upstream from the gaging station near Lemont, 

Illinois. Since the Summit Conduit conveys stormwater from 

outside of the Lake Michigan drainage basin and discharges 

upstream from the gaging station near Lemont, Illinois; a 

deduction, in the quantity of the Summit Conduit discharge, is 

applied to the Lemont stream gaging station discharge values 

in accordance with LMDA.

Past Gaging and Modeling

Previous attempts to monitor the discharge through the 

Summit Conduit have not yielded accurate results (Espey and 

others, 1981). The Metropolitan Sanitary District of Greater 

Chicago (MSD), now the Metropolitan Water Reclamation 

District of Greater Chicago (MWRD), operated a stream 

gaging station at the conduit for a period from the early 1960s 

into the 1980s. However, because of difficult monitoring 

conditions, the methods used during this time period were not 

satisfactory and data from this period contained substantial 

errors as noted by the First Technical Review Committee for 

LMDA (Espey and others, 1981). Since that time, the USACE 

has used a modeling approach to estimate discharge through 

the Summit Conduit. The USACE modeling approach used a 

rainfall-runoff model to simulate discharges through the conduit; however, the unsteady nature of the watershed and lack 

of validation data collection has led to uncertainty in modeled 

discharges.

Hydrologic Setting

Drainage Area

The watershed tributary to the Summit Conduit is located 

in southeastern Cook County and encompasses parts of the 

villages of Countryside, Hodgkins, McCook, La Grange and 

Lyons. As reported in the Detailed Watershed Plan for the 

Lower Des Plaines River Watershed: Volume 1 (Burke, 2011), 

the watershed area can be described as being: 

“roughly bounded by Willow Springs Road to the 

west, Joliet Road to the south and east, and 47th 

Street to the north. The northeast portion of the 

drainage area extends southeast past Joliet Road 

to the McCook Levee to the northeast and the 

Des Plaines River south of the McCook Levee to 

approximately East 55th Street”. 

Summit Conduit also conveys the flows from the 

McCook Ditch, the East Avenue Ditch subwatershed with the 

Plainfield Road storm sewer. The drainage area of the watershed that drains into the Summit Conduit is approximately 

5.4 mi2

 and can be seen in figure 2. The two main tributaries 

in addition to receiving surface runoff, also receive additional 

storm sewer flow and intermittent point discharges from the 

watershed. The McCook Ditch and the East Avenue Ditch with 

the Plainfield Road storm sewer are highlighted in figure 2. 

The area within the watershed generally can be described as 

flat to gently sloping. Land use for the area is primarily residential and commercial/industrial.

Purpose and Scope

The purpose of this report is to provide a technical 

description of the monitoring of stage, velocity, and discharge 

through the Summit Conduit near Summit, Illinois. The 

Summit Conduit near Summit, Illinois stream gaging station 

(station number 414757087490401) was installed by the 

USGS to accurately quantify the amount of discharge conveyed by the Summit Conduit into the CSSC in accordance 

with LMDA. The discharge data computed for this site may be 

used for validation and calibration of the rainfall runoff model 

and will be beneficial to improving the accuracy of another 

variable in LMDA.
4

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

55

1ST AVENUE

SOUTH LA GRANGE ROAD

WEST 47TH STREET

WILLOW SPRINGS ROAD

JOLIET ROAD

La Grange

WEST 47TH STREET

JOLIET ROAD

1ST AVENUE

SOUTH LA GRANGE ROAD

WILLOW SPRINGS ROAD

McCook

Countryside

Summit

87°53' 87°52' 87°51' 87°50' 87°49'

41°48'

41°47'

EXPLANATION

Summit Conduit

Summit Conduit drainage area

Ditch

McCook levee

Summit Conduit inlet

Summet Conduit outfall

0 0.5 1 MILE

0 0.5 KILOMETER 1

Elevation from U.S. Geological Survey 

National Elevation Dataset, 2007,

30-meter cell spacing. Roads and railroads

from 2012 TIGER/Line Shapefile for Dupage

County, Ill.

Figure 2. Map showing the drainage area and tributaries of the Summit Conduit near Summit, Illinois.

Streamflow Data Collection

Gaging Station Establishment

The stream gaging station was established by USGS 

personnel on September 23, 2010, and the official start of data 

collection was October 1, 2010. The stream gaging station 

consists of a reference gage, an acoustic Doppler velocity 

meter (ADVM) that continuously records stage and velocity, 

and a crest-stage gage (CSG) to validate high flow stage 

recordings. Recorded stage and velocity readings are applied 

to ratings to calculate discharge.

Gaging Station Equipment

The primary stage and velocity recorder at the gaging 

station is a SonTek Argonaut-SW ADVM, which consists of 

three “upward-looking” transducers for measuring water level 

and water velocity. The ADVM is bolted to the bottom of 

the Summit Conduit, and is located 20 ft inside the upstream 

opening. Water level is measured as a result of the reflection of 

the acoustic signal off of the water surface. The water velocity 

also is measured using the Doppler shift principle with 

acoustic signals reflected off of particulates moving within the 

water flow. For a more detailed description of the principles 
Streamflow Data Collection

5

involved in ADVM technology refer to Simpson (2001) and 

Levesque and Oberg (2012). The recorder enclosure is a 

6 inch (in.) x 8 in. x 18 in. steel box containing a voltage regulator and battery, which supply power to the ADVM. Power 

to the battery is supplemented by a solar panel. The reference 

gage is a reference point (RP-1) of known elevation from 

which “tape-down” measurements can be made to the water 

surface. RP-1 is a narrow aluminum plate bolted to the top of 

the Summit Conduit opening, with two file marks, located 2 ft 

to the right (if looking downstream) of the gage enclosure. A 

CSG, for verifying event peaks, also is installed at the gaging 

station and is located 3.5 ft to the right of RP-1 (if looking 

downstream). The CSG consists of a 10 ft long by 1 in. thick 

by 1.5 in. wide board enclosed in a 2 in. galvanized steel pipe 

bolted to the conduit abutment by two steel brackets. A second 

reference point for obtaining the water-surface elevation (RPC) consists of two file marks located on the upper bracket of 

the CSG. 

The original gage configuration was flooded a few times 

causing a short circuit in the battery and resulted in a loss of 

data. The lack of telemetry also resulted in loss of data because 

the ADVM would become covered with debris and there was 

no way of knowing until the next site visit and instrument 

inspection. To remedy this, on October 10, 2012, the gage 

equipment was upgraded to a Design Analysis WaterLog 522+ 

data collection platform (DCP) with a geostationary operational environmental satellite (GOES) radio transmitter, and 

the steel box was replaced with a new 24 in. x 24 in. x 10 in. 

environmental enclosure on a 4-foot high pedestal. The height 

of the pedestal is greater than the highest stage recorded in 

the 2 years of record. The DCP was installed to improve the 

quality and quantity of data collected. Real-time data can be 

monitored daily to ensure the ADVM is not covered with 

debris. The gage layout as it was originally installed, and from 

Oct 12, 2012, after the gage upgrade is shown in figure 3.

Figure 3. Photographs of the Summit Conduit near Summit, Illinois stream gage before and after October 10, 2012, showing 

the gage features.
6

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

Site Layout

The original stream gage elevation schematic of the site 

layout for the Summit Conduit stream gaging station, which 

is located at the conduit entrance, is depicted in figure 4. 

The figure identifies features of the gage as well as the relative 

locations of equipment, structures, and reference points.

Gage House

Solar Panel

Trash Rack

Sontek SW

RP-1 RP-C

Crest Stage Gage

Figure 4. View of the stream gaging station at the Summit Conduit at Summit, Illinois. Locations 

of significant features, reference marks and gage equipment are indicated in the diagram.
Streamflow Data Collection

7

Methods

Stage Measurement

The primary stage record for the Summit Conduit steam 

gaging station is recorded by the ADVM. The ADVM uses 

a vertical acoustic beam to measure the water-surface elevation. The vertical beam can measure depths ranging from 

0.6 to 16 ft of water over the sensor to an accuracy of ± 0.01 ft 

as reported by SonTek/YSI (SonTek/YSI, 2006). Stage for this 

gaging station is recorded on a 10-minute interval and is stored 

internally by the ADVM and DCP; the data is also transmitted 

by GOES radio through the DCP once every hour. During 

periodic discharge measurements described in the next section, 

the stage data is collected at a one minute interval.

Manual stage measurements are made on a periodic basis 

by USGS personnel for comparison to recorded values. These 

stage measurements are made from reference points (RP-1 

or RP-C) and collected according to USGS Techniques and 

Methods, book 3, chap. A7, “Stage Measurement at Gaging Stations” (Sauer and Turnipseed, 2010). Manual stage 

measurements also are applied to a stage-area rating that is 

part of the index-velocity ratings for this station and are an 

important part of calculating the mean channel velocity from 

the measured discharge. For a more detailed description of 

index-velocity ratings, refer to Levesque and Oberg (2012).

Velocity Measurement

Velocity measurements at the Summit Conduit stream 

gaging station are also recorded by the ADVM. The ADVM 

uses two beams (one facing upstream and one facing 

downstream), fixed at a 45° angle that measure velocity using 

the acoustic Doppler method (SonTek/YSI, 2006). The two 

beams use dynamic boundary adjustment based on the water 

level to output a vertically averaged velocity for the depth 

of the water column. There is a gap above the ADVM for 

blanking the acoustic signal and dampen the ringing of the 

transducers and another gap near the water surface where the 

beam impinges on the ceiling or the air-water interface (fig. 5). 

Velocities are collected on a 10-minute interval (and samples 

are averaged for 2 minutes). The velocity data is stored internally by the ADVM and DCP and is transmitted by GOES Satellite radio through the DCP once every hour. Manual velocity 

measurements are collected periodically by USGS personnel 

to validate the accuracy of the ADVM data. The velocity measurements are collected at the opening of the conduit, 25 feet 

upstream from the ADVM and are recorded with a handheld 

acoustic Doppler velocimeter (ADV) according to USGS 

Techniques and Methods, book 3, chap. A8, “Discharge Measurements at Gaging Stations” (Turnipseed and Sauer, 2010). 

When the measurements are made at the opening of the conduit the hydrographer generally is able to stand with one foot 

on each wall of the culvert to minimize any flow disturbance 

that would affect the velocity comparison. During the periodic discharge measurements that are made for creating and 

maintaining the velocity-velocity rating, the sampling interval 

and averaging intervals of the ADVM are changed to average 

and record every 60 seconds to obtain a more detailed record 

of stage and velocity during the manual measurement period. 

The data collection is completed according to the guidance 

found in Levesque and Oberg (2012). When the measurement 

is finished the recorder is set back to the 2-minute averaging 

interval and 10-minute sampling intervals.

Beam 2

Beam 1

Acoustic waterlevel beam

Set by acoustic waterlevel measurement

Blanking distance

Cell begin

Cell end

Range-averaged 

dynamic cell 

distance

Y

X

Flow

Figure 5. Illustration of dynamic boundary adjustment of velocity profile from the SonTek Argonaut SW acoustic Doppler velocity 

meter (Levesque and Oberg, 2012). 
8

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

Discharge Computation

Discharge at the Summit Conduit stream gaging station 

is computed using the Index-Velocity method which combines 

a velocity-velocity rating and a stage-area rating developed 

according to USGS Water-Supply Paper 2175, vol. 2 (Rantz 

and others, 1982) and Computing Discharge Using the Index 

Velocity Method—Techniques and Methods, book 3, chap. 

A23 (Levesque and Oberg, 2012). The method is explained by 

the following equation:

Qr = Vr × Ar (1)

where, 

Qr is computed discharge

Vr is the average velocity in the cross-section 

from the velocity-velocity rating

Ar is cross-sectional area of the channel from the 

stage-area rating

The index-velocity method uses the velocities collected 

by the ADVM as an index to the mean-channel velocities collected manually during discharge measurements. Mean-channel velocities are calculated from measured discharges divided 

by the rated flow area calculated from the time-weighted mean 

gage height during the measurement period. The rated flow 

area is the area of the channel determined geometrically from 

the channel dimensions and the resulting rating equations or 

table. Using linear regression, the ADVM velocities are then 

related to the mean-channel velocities to create the velocityvelocity rating (fig. 6). Twenty-seven discharge measurements 

were used to develop velocity-velocity rating 1.0. The range 

of measured discharges for the Summit Conduit was from 

0.56 to 13.1 cubuc feet per second (ft3/s) and stage ranging 

from 0.74 to 2.36 ft. The velocity used in creating the rating 

is the result of dividing the measured discharge by the rated 

area. The range of velocities used in developing the rating was 

0.25 to 1.93 ft3/s. Equation 2 was obtained from a regression 

analysis of the velocity data from the 27 measurements.

Vr = 0.8859 × Vi + 0.1255 (2)

where,

Vr is the average velocity in the cross-section 

from the velocity-velocity rating, and 

Vi is the index velocity from the time averaged 

velocity from the ADVM.

The cross-section where ADVM velocities are measured 

is diagrammed in figure 7. Area is dependent on the stage 

in the cross-section and can be computed using a stage-area 

rating. The stage area rating for the gaging station at Summit 

Conduit is represented by equations 3 through 5, which are 

represented by the plot in figure 8. Equations 3, 4, and 5 are 

based on the geometry of a trapezoid and a circle with adjustment for the overlap of the two shapes. A detailed discussion 

of this geometric site configuration can be found in Chow 

(1959), Lindburg (1992), and the U.S. Department of Interior (DOI) Bureau of Reclamation (BOR) Water Resources 

Research Laboratory: Water Measurement Manual (2001). An 

expanded rating table for the results of equations 3 through 5 

and the rating curve in figure 8 is provided in appendix 1.

From 0 2 ≤ < h . 5

A b = + ( ) zy y 1 1 (3)

From 2 5 ≤ < h 4.

A K= − Ktp (4)

d h =

From 4 7 ≤ ≤ h

A r = − π K K− tp

2 (5)

d r = − 2 h

where

 K r = ( ) − 2

2

θ θ sin

θ =  −



 



 − 2 1 cos

r d

r

where,

A is cross-sectional area (ft2)

h is water-surface elevation (ft)

r is the radius of the pipe part of the section

d is the part of depth contained in the circle 

with radius r

K is the circular segment area

K

tp is the circular segment area which is entirely 

contained within the trapezoidal part of the 

section

	 θ is the central angle of the circle

The computed discharge is simply the product of the 

rated average cross-sectional velocity and the cross-sectional 

area of the channel (equation 1).
Streamflow Data Collection

9

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

2.00

0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00

Measured discharge/area rated, in feet per second

Index velocity, in feet per second

y = 0.8859x – 0.1255 2 R = 0.9485

Figure 6. The velocity-velocity plot of the mean index-velocity (in feet per second) measured 

by an acoustic Doppler velocity meter (ADVM) as compared to the mean channel velocity (in 

feet per second) as measured discharge divided by the rated area for the gaging station at the 

Summit Conduit at Summit, Illinois.

D = 6.00’

y_2 = 7.00’

_r2 = 1.50’

z = 1.08’

1 y_1 = 2.50’

o zAngle = 42.70

b = 0.33’

Figure 7. Diagram indicating the cross-sectional area geometry with dimensions for 

calculating the rated area in the area of the measured acoustic Doppler velocity meter (ADVM) 

velocity.
10

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00

Stage, in feet

Area, in square feet

Figure 8. The stage-area rating curve developed from equations 3 and 4 from the channel 

geometry in figure 7.

Data Accuracy and Limits

Based on the data collected at the Summit Conduit stream 

gaging station, mean daily discharge records are considered fair (that is, 95 percent of mean daily discharges within 

±15 percent of actual) by USGS guidelines (Novak, 1985). 

This excludes mean daily discharges that are estimated, which 

are considered poor (that is, 95 percent of mean daily discharges within ±20 percent of actual). Currently, daily mean 

discharges greater than 10 ft3/s also are rated poor, because of 

lack of manual measurements collected at high flows to verify 

computed discharges calculated from the current velocity 

rating. 

Various factors contribute to the difficult monitoring 

conditions at the Summit Conduit stream gaging station, 

which have resulted in this rating. The small drainage area 

and the industrial nonpermeable surfaces present throughout 

the drainage area result in short lived, flashy events that are 

difficult measure. Travel time involved in getting personnel 

to the site and deployment of measurement equipment are 

prohibitive for capturing short lived events on a regular basis. 

The nonstandard site conditions with two tributaries converging immediately upstream from the conduit opening limit 

the places where discharge measurements can be made. The 

trash rack and walkway cause cavitation and air entrainment 

into the water that lead to loss of acoustic signal in the water 

and affect the measurement equipment. Outfall of the conduit 

is below a steep and unstable bank and the discharge flows 

onto a short concrete apron then directly into the CSSC. The 

tributaries also tend to carry a large quantity of woody debris 

and trash that clog the trash rack and settle to the bottom of 

the conduit, burying the meter. This has led to a relatively high 

amount of missing data compared to most gaging stations of 

a similar deployment. As a result, mean daily discharges for 

89 days in water year 2011 and 32 days in water year 2012 

were estimated. A water year is defined as the 12-month period 

October 1, for any given year through September 30, of the 

following year. The water year is designated by the calendar 

year in which it ends and which includes 9 of the 12 months. 

Thus, the year ending September 30, 2011 is called the “2011” 

water year. The next section offers further explanation of the 

non-standard site specific conditions at the Summit Conduit 

stream gaging station.

Site Specific Data Limitations

Drainage Area

Summit Conduit has a drainage area of approximately 

5.4 mi2. This drainage area is smaller than but similar in 

size to three nearby gaging stations, Tinley Creek near Palos 

Park, Illinois (05536500), Midlothian Creek at Oak Forest, 

Illinois (05536340), and Sawmill Creek near Lemont, Illinois 

(05533400). The drainage area for these three USGS stream 

gages is 11.2, 12.6, and 13.0 mi2 respectively. These three 

gages are also in the southern part of the greater Chicago 

area and encounter similar weather patterns. Summit Conduit 

drainage basin has approximately 2.5 mi2 of residential area 

that includes a 0.2 mi2 golf course; the remaining 2.9 mi2 is 

primarily industrial and rock quarry area. The other three 

nearby comparison drainage areas have substantially more 
Streamflow Data Collection

11

residential and forested area and little industrial drainage. The 

difference in percentages of forested compared to industrial 

area could account for the lower base flows at the comparison 

sites, because of phreatic uptake from vegetation in the riparian areas. Peak flow events at Summit Conduit are generally 

short lived depending on the duration and intensity of the 

precipitation, and last from as little as a few hours to a couple 

of days.

Debris Accumulation

The ADVM is mounted to the bottom of the conduit and 

is therefore susceptible to being covered up by debris, which 

blocks the acoustic transducers of the ADVM. This results 

in temporary loss of data until the debris is removed from 

the ADVM either by a hydrographer or a larger flow event. 

Although debris accumulation is inherent with this type of 

ADVM, debris has only been discovered and removed during 

the routine periodic visits because the gage was operated without telemetry until October 12, 2012, when a data collection 

platform (DCP) with a GOES satellite radio was installed. 

An example of this type of data loss can be seen during the 

period from February 23 to 27 and again on March 7 and 8, 

2011(fig. 9). In figure 9, the times when the signal to noise 

ratio (SNR) drops somewhere in the range of 50 decibels (dB) 

or below it is indicative of debris accumulating on the meter 

blocking or at least dampening the acoustic signal. Thus with a 

dampened or blocked signal the Doppler SNR drops resulting in compromised computed velocity and stage data. Drops 

in data are followed by a spike or rise in flow that appears to 

have scoured the debris from the meter. There are six small 

events that effectively cleaned the ADVM between hydrographer visits during the period shown in figure 9.

Computed Discharge

 Computed discharge during low flow (that is, less than 

1 ft3/s) may contain additional random errors at the Summit 

Conduit stream gaging station. The errors may be a result of 

shallow depths of water above the ADVM transducer face that 

approach the limits of the instrument accuracy. At low flows 

relatively small differences between measured discharge and 

rated discharge can result in large percentage differences. 

These differences have been observed at low flow discharges 

computed at this site using the index-velocity method and 

manually measured discharges. This is likely caused by the 

accuracy limitations of velocity measurement by the ADVM at 

low velocity (less than 0.25 ft/s). At these velocities, the standard error of velocity is approximately 0.07 ft/s for the given 

site conditions. This amount of standard error can produce 

differences in measured and computed discharges of as much 

as 20 percent during periods of low flow. 

A series of three hydrographs of water years 2011 and 

2012 showing the daily mean value discharge for Summit 

Conduit and the three comparison stations indicate that the 

Summit Conduit base flows are greater than the other sites 

for a substantial amount of the time during dry weather flow 

conditions (fig. 10). Hydrographic comparison between nearby 

stream gages shows they are well matched in terms of event 

response. The magnitude of events is larger with greater drainage area and smaller with the Summit Conduit. Despite the 

similar drainage area and weather patterns that effect precipitation, at base flow the hydrographs and associated discharge 

do not compare as well as expected. This base flow difference 

is likely because of the presence of artificial drainage from the 

NPDES permitted discharge and may have a contribution due 

to a high percentage of impermeable industrial land surface 

area in the Summit Conduit watershed. Rapid rises in stage 

generally follow rainfall events and then flows return to near 

base flow very quickly—usually over a period of hours. 

In water years 2011 and 2012, Summit Conduit discharge 

exceeded the base-flow discharge observed at Tinley Creek 

near Palos Park 352 of 731 days (48.2 percent), at Midlothian 

Creek at Oak Park 348 of 731 days (47.6 percent), and at 

Sawmill Creek near Lemont 513 of 731 days (70.2 percent). 

Daily value discharge tables that were used to create the plots 

and determine the percent flow exceedance are provided in 

appendix 2 for each water year and each site. Even though 

the base flow for Summit Conduit exceeds the base flow of 

the other three sites nearly 50 percent of the time, the event 

driven discharge effectively brings the mean annual discharge 

for each of these sites back into perspective of their respective 

drainage areas. In table 1, the computed mean annual discharge for water years 2011 and 2012 are proportionally larger 

for the larger drainage area sites.

Table 1. Mean annual discharge for water years 2011 and 2012 for Summit Conduit stream gaging station and three comparison 

stream gaging stations. 

[A water year is defined as the 12-month period October 1, for any given year through September 30, of the following year. The water year is designated by 

the calendar year in which it ends and which includes 9 of the 12 months. Thus, the year ending September 30, 2011 is called the “2011” water year] 

Mean annual discharge, in cubic feet per second

Water year

Summit Conduit Tinley Creek

(05536500)

Midlothian Creek

(05536500)

Sawmill Creek

(05533400)

2011 8.45 16.0 20.1 14.5

2012 6.39 10.8 11.3 7.73
12

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

FileName: SUMCD004.arg (Argonaut- SW 3000 kHz) 

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V elocity (ft/s)

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 60

 80

 100

S NR (dB)

14:40:04

03/02/201 1

13:20:04

10/02/201 1

12:00:04

17/02/201 1

10:40:04

24/02/201 1

09:20:04

03/03/201 1

08:00:04

10/03/201 1

06:40:04

17/03/201 1

Beam1/X/E Beam2/Y/N

Debris

on 

meter

Low signal to noise ratio (SNR) caused by debris on meter

1 2 3 4 5 6

Figure 9. Plot of acoustic Doppler velocity meter (ADVM) data illustrating a period when debris covered the meter, January 27 to 

March 17, 2011. The numbers on the plot represent a debris deposition event.
Streamflow Data Collection

13

0

100

50

150

250

350

450

200

400

300

500

0

20

40

60

80

100

120

140

160

180

200

0

100

200

300

400

500

450

350

250

150

50

Discharge, in cubic feet per second

2010 2011 2012

Oct. Nov. Dec. Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Jan. Feb. Mar. Apr. May June July Aug. Sept.

EXPLANATION

Sawmill Creek

Summit Conduit

EXPLANATION

Tinley Creek

Summit Conduit

EXPLANATION

Midlothian Creek

Summit Conduit

Figure 10. Hydrograph of water years 2011 and 2012 showing Summit Conduit at Summit, Sawmill Creek near Lemont, Midlothian 

Creek near Oak Park, and Tinley Creek near Palos Hills. 
14

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

Data Loss

Data loss has occurred at low and high flows at the Summit Conduit stream gaging station. Losses of stage and velocity data have occurred during high flow events where water 

levels have approached or reached the ceiling of the conduit. 

Although an event resulting in high flow data loss has not 

been physically observed, it can be inferred that this occurs 

because of the increased sediment load, debris, aeration, or 

turbulence because of the change in flow dynamics as a result 

of increased velocities. The trash rack near the opening of 

the conduit likely causes air to become entrained in the water 

column, which may cause interference in the acoustic signals 

used to measure stage and velocity by the ADVM. Examples 

of these high flow data losses can be seen during the five 

events shown in figure 11 between June 9 and 24, 2011.

Because of the relatively short time period that this gaging station has been operated it cannot be determined how 

often this type of data loss will occur during high flow events. 

Some events show little sign of signal to noise reduction 

or loss and yet other events have loss of signal. Thirteen of 

52 events reported some type of problem at Summit Conduit 

during this 2-year period. The cause of each problem is likely 

one or more of the issues noted previously. Relocation of the 

ADVM farther into the conduit, or an alternate method for 

measuring high stages and velocities may be necessary to 

reduce the number of lost events. The addition of telemetry 

has already helped to reduce the number of days with bad data.

Future Stream Gaging

Several improvements have been made through the 

2 years that the Summit Conduit stream gage has been operating. The gage improvements have resulted in less data loss 

because of instrument problems, more quantifiable discharge 

values for the permanent record, a more robust discharge 

value to be used in LMDA, and a better understanding of the 

nonstandard site characteristics that were associated with early 

efforts to monitor discharge at this site. On March 1, 2013, the 

ADVM and all gaging equipment were temporarily removed 

from the Summit Conduit. This was done to accommodate 

the construction of a new lining within the entire conduit. The 

MWRD hired a contractor to line the conduit with a mortar 

and vinyl lining. The wing walls of the inlet and outfall also 

are being refurbished. The construction is projected to begin 

between March and July 2013. Near completion and before 

water is allowed to resume flowing through the conduit, 

detailed geometric measurements will be made in the vicinity of where the ADVM will be mounted. The ADVM will be 

mounted 35 to 40 ft inside the conduit in an effort to reduce 

the amount of aeration from the trash rack and the additional 

20 ft into the conduit also may be less prone to settling debris. 

The DCP with the GOES transmitter will be reinstalled for 

real-time data transmission and the instrument configuration for the ADVM will remain as it was prior to removal. 

Because of the relining of the conduit the stage-area rating 

and the velocity-velocity ratings will have to be reestablished. 

This will take time; however the lessons learned from the first 

2 years are valuable for the improvement of the site setup and 

the records computation.

Summary

LMDA is the process used by the USACE to quantify 

the amount of water that is diverted from the Lake Michigan 

watershed into the Illinois and Mississippi River Basins. A 

network of streamgages within the Chicago area waterway 

system monitor tributary river flows and the major river flow 

on CSSC near Lemont as one of the instrumental tools used 

for LMDA. The mean annual discharges recorded by these 

streamgages are used as additions or deductions to the mean 

annual discharge recorded by the main stream gaging station 

currently used in the LMDA process, which is the CSSC near 

Lemont, Illinois (station number 05536890).

A new stream gaging station, Summit Conduit near 

Summit, Illinois (station number 414757087490401), was 

installed on September 23, 2010, for the purpose of monitoring stage, velocity, and discharge through the Summit Conduit 

for the USACE in accordance with LMDA. Summit Conduit 

conveys flow from a small part of the lower Des Plaines River 

watershed underneath the Des Plaines River directly into 

the CSSC. Because the Summit Conduit discharges into the 

CSSC upstream from the stream gaging station at Lemont, Ill, 

but does not contain flow diverted from the Lake Michigan 

watershed, it is considered a flow deduction to the discharge 

measured by the Lemont stream gaging station in the LMDA 

process. This report offers a technical summary of the techniques and methods used for the collection and computation of 

the stage, velocity, and discharge data at the Summit Conduit 

near Summit, Ill stream gaging station for a part of the 2011 

and 2012 Water Years. 

The stream gaging station Summit Conduit near Summit, 

Illinois (station number 414757087490401) is an example of 

a nonstandard stream gage. Traditional methods of equating 

stage to discharge historically were not effective. Examples of 

the nonstandard conditions include the converging tributary 

flows directly upstream of the gage; the trash rack and walkway near the opening of the conduit introducing turbulence 

and occasionally entraining air bubbles into the flow; debris 

within the conduit creating conditions of variable backwater 

and the constant influx of smaller debris that escapes the trash 

rack and catches or settles in the conduit and on the equipment. An ADVM was installed to measure stage and velocity 

to compute discharge. The stage is used to calculate area based 

on the stage-area rating. The index-velocity from the ADVM 

is applied to the velocity-velocity rating and the product of 

the two rated values is a rated discharge by the index-velocity 

method. Nonstandard site conditions prevalent at the Summit 

Conduit stream gaging station generally are overcome through 

the index-velocity method. Debris on the meter and aeration 

has continued to be an issue causing data loss. For this reason, 
Summary

15

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1

2

2

3

3

4

4

5

5

FileName: SUMCD037.arg (Argonaut- SW 3000 kHz) 

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V elocity (ft/s)

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S NR (dB)

06:15:57

11/06/201 1

23:55:57

12/06/201 1

17:35:57

14/06/201 1

11:15:57

16/06/201 1

04:55:57

18/06/201 1

22:35:57

19/06/201 1

16:15:57

21/06/201 1

09:55:57

23/06/201 1

 Beam1/X/E Beam2/Y/N

Figure 11. Data lost during five medium to high flow events between June 9 and June 24, 2011.
16

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

daily mean discharge records for this gaging station generally 

are considered fair by USGS guidelines. Despite the difficulties in gaging and measurements, improvements continue to 

be made in data collection, transmission, and measurements. 

Efforts to improve the site and to improve the ratings continue 

to improve the quality and quantity of the data available for 

LMDA. 

References Cited

Burke, Christopher B., Engineering Ltd., 2011, Detailed 

watershed plan for the lower Des Plaines River watershed: 

v. 1, accessed March 12, 2012, at http://www.mwrd.org/irj/

go/km/docs/documents/MWRD/internet/protecting_the_

environment/Stormwater_Management/htm/Lower_Des_

Plaines_River_Watershed/Lower_Des_Plaines_River_DWP.

htm.

Chow, Ven Te., 1959, Open channel hydraulics: New York, 

McGraw Hill, 621 p.

Espey, W.H., Barnes, H.H., Jr., and Vigander, S., 1981, 

Lake Michigan diversion—Findings of the technical 

committee for review of diversion flow measurements and 

accounting procedures: U.S. Army Corps of Engineers, 

Chicago District, 138 p.

Espey, W.H., Barnes, H.H., Jr., and Westfall, D.E., 1987, 

Lake Michigan diversion—Findings of the second technical committee for review of diversion flow measurements 

and accounting procedures: U.S. Army Corps of Engineers, 

Chicago District, 206 p.

Espey, W.H., Lara, O.G., and Barkau, R.L., 1994, 

Lake Michigan diversion—Findings of the third technical 

committee for review of diversion flow measurements and 

accounting procedures: U.S. Army Corps of Engineers, 

Chicago District, 125 p.

Espey, W.H., Schmidt, A.R.., and Barkau, R. L., 2001, 

Lake Michigan diversion, Findings of the fourth technical 

committee for review of diversion flow measurements and 

accounting procedures: U.S. Army Corps of Engineers, 

Chicago District, 117 p.

Espey, W.H., Melching, C.S., and Mades, D.M., 2004, 

Lake Michigan diversion—Findings of the fifth technical 

committee for review of diversion flow measurements and 

accounting procedures: Chicago, Illinois, U.S. Army Corps 

of Engineers, Chicago District, 181 p.

Espey, W.H., Melching, C.S., and Muste, M., 2009, 

Lake Michigan diversion—Findings of the sixth technical 

committee for review of diversion flow measurements and 

accounting procedures: U.S. Army Corps of Engineers, 

Chicago District, 162 p.

Jackson, P.R., Johnson, K.K., and Duncker, J.J., 2012, 

Comparison of index velocity measurements made with a 

horizontal acoustic Doppler current profiler and a three-path 

acoustic velocity meter for computation of discharge in the 

Chicago Sanitary and Ship Canal near Lemont, Illinois: 

U.S. Geological Survey Scientific Investigations Report 

2011–5205, 42 p.

Johnson, K.K., Duncker, J.J., and Jackson, P.R., 2012, The role 

of the U.S. Geological Survey in Lake Michigan diversion 

accounting in Illinois, 1984–2010: U.S. Geological Survey 

Open-File Report 2012–1243, 84 p.

Kollias, Louis, 2008, Description of the Chicago waterway 

system for the use attainability analysis, Metropolitan 

Water Reclamation District of Greater Chicago Report 

No. 08-15R: 29 p.

Levesque, V.A., and Oberg, K.A., 2012, Computing discharge 

using the index velocity method: U.S. Geological Survey 

Techniques and Methods, book 3, chap. A23, 148 p. (Also 

available at http://pubs.usgs.gov/tm/3a23/.) 

Lindeburg, Michael, R., 1992, Engineer in training reference 

manual, (8th): Professional Publication, Inc. 

Novak, Charles, E., 1985, WRD data reports preparation 

guide: U.S. Geological Survey Water-Resources Division, 

USGS Open-File Report 85–480, 199 p.

Rantz, S.E., and others, 1982, Measurement and computation of streamflow—Volume 2, Computation of discharge: 

U.S. Geological Survey Water-Supply Paper 2175, 631 p. 

Sauer, V.B., and Turnipseed, D.P., 2010, Stage measurement 

at gaging stations: U.S. Geological Survey Techniques 

and Methods, book 3, chap. A7, 45 p. (Also available at 

http://pubs.usgs.gov/tm/tm3-a7/.)

Simpson, Michael R., 2001, Discharge measurements 

using a broad-band Acoustic Doppler current profiler, 

U.S. Geological Survey Open-File Report 2001–01, 133 p.

SonTek/YSI, Inc., 2006, Argonaut—SW system manual, 

San Diego, Calif., USA, 279 p.

Turnipseed, D.P., and Sauer, V.B., 2010, Discharge measurements at gaging stations: U.S. Geological Survey Techniques and Methods, book 3, chap. A8, 87 p. 

(Also available at http://pubs.usgs.gov/tm/tm3-a8/.)

U.S. Department of Interior Bureau of Reclamation, 2001, 

Water Resources Research Laboratory—Water Measurement Manual: Washington, D.C. 
Appendix 1.

Expanded Rating Table for the Stage- Area Rating................................................................................18

Stage-Area Geometry .................................................................................................................................21

Appendix 2. Annual Daily Value Tables for 2011 and 2012 

Summit Conduit near Summit, Illinois (414757087490401)

Water Year October 2010 to September 2011.................................................................................22

Water Year October 2011 to September 2012.................................................................................25

Tinley Creek near Palos Park, Illinois (05536500)

Water Year October 2010 to September 2011.................................................................................28

Water Year October 2011 to September 2012.................................................................................31

Midlothian Creek at Oak Park, Illinois (05536340)

Water Year October 2010 to September 2011.................................................................................34

Water Year October 2011 to September 2012.................................................................................37

Sawmill Creek near Lemont, Illinois (05533400)

Water Year October 2010 to September 2011.................................................................................40

Water Year October 2011 to September 2012.................................................................................43
18

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

STATION: 414757087490401 Summit Conduit at Summit, IL.—Continued

Type: stream, Agency: USGS, State: 17, County: 031, Latitude: 414757, Longitude: 0874904 NAD83, 

Drainage area: Contributing drainage area: Datum: 

Date processed; 2013-03-07 02:36 By swreview

Rating for Discharge (INFLOW) (cfs)

Rating ID: 1.0, Type: stage-area, Expansion: linear Satus: working

Created by ggoodwin on 06-23-2011 14:50:26 CST, Updated by johnsonk on 03-05-2013 09:38:43 CST

Rating remarks:

EXPANDED RATING TABLE

Gage 

height, 

feet

Stream cross-section (in square feet (expanded precision)) Difference 

in Y per 0.1 

units .00 .01 .02 .03 .04 .05 .06 .07 .08 .09

0.00 0.000* 0.002 0.004 0.006 0.008 0.010 0.012 0.014 0.016 0.018 0.020

0.10 0.020 0.022 0.024 0.026 0.028 0.030 0.032 0.034 0.036 0.038 0.020

0.20 0.040* 0.054 0.067 0.081 0.094 0.108 0.121 0.135 0.148 0.162 0.135

0.30 0.175 0.189 0.202 0.216 0.229 0.243 0.256 0.270 0.283 0.297 0.135

0.40 0.310* 0.324 0.338 0.352 0.366 0.380 0.394 0.408 0.422 0.436 0.140

0.50 0.450 0.464 0.478 0.492 0.506 0.520 0.534 0.548 0.562 0.576 0.140

0.60 0.590* 0.609 0.627 0.646 0.664 0.683 0.701 0.720 0.738 0.757 0.185

0.70 0.775 0.794 0.812 0.831 0.849 0.868 0.886 0.905 0.923 0.942 0.185

0.80 0.960* 0.983 1.01 1.03 1.05 1.08 1.10 1.12 1.14 1.17 0.230

0.90 1.19 1.21 1.24 1.26 1.28 1.31 1.33 1.35 1.37 1.40 0.230

1.00 1.42* 1.45 1.47 1.50 1.53 1.56 1.58 1.61 1.64 1.66 0.270

1.10 1.69 1.72 1.74 1.77 1.80 1.83 1.85 1.88 1.91 1.93 0.270

1.20 1.96* 1.99 2.02 2.05 2.09 2.12 2.15 2.18 2.21 2.24 0.320

1.30 2.28 2.31 2.34 2.37 2.40 2.43 2.46 2.50 2.53 2.56 0.310

1.40 2.59* 2.63 2.66 2.70 2.73 2.77 2.81 2.84 2.88 2.91 0.360

1.50 2.95 2.99 3.02 3.06 3.09 3.13 3.17 3.20 3.24 3.27 0.360

1.60 3.31* 3.35 3.39 3.43 3.47 3.51 3.55 3.59 3.63 3.67 0.400

1.70 3.71 3.75 3.79 3.83 3.87 3.91 3.95 3.99 4.03 4.07 0.400

1.80 4.11* 4.15 4.20 4.24 4.29 4.33 4.38 4.42 4.47 4.51 0.450

1.90 4.56 4.60 4.64 4.69 4.73 4.78 4.82 4.87 4.91 4.96 0.440

2.00 5.00* 5.05 5.10 5.15 5.20 5.25 5.29 5.34 5.39 5.44 0.490

2.10 5.49 5.54 5.59 5.64 5.69 5.74 5.78 5.83 5.88 5.93 0.490

2.20 5.98* 6.03 6.09 6.14 6.19 6.25 6.30 6.35 6.40 6.46 0.530

2.30 6.51 6.56 6.62 6.67 6.72 6.78 6.83 6.88 6.93 6.99 0.530

2.40 7.04* 7.09 7.15 7.20 7.26 7.31 7.37 7.42 7.48 7.53 0.550

2.50 7.59 7.64 7.69 7.75 7.80 7.86 7.91 7.97 8.02 8.08 0.540

2.60 8.13* 8.18 8.24 8.29 8.35 8.40 8.45 8.51 8.56 8.62 0.540

2.70 8.67 8.72 8.78 8.83 8.89 8.94 8.99 9.05 9.10 9.16 0.540

2.80 9.21* 9.27 9.32 9.38 9.43 9.49 9.55 9.60 9.66 9.71 0.560

2.90 9.77 9.83 9.88 9.94 9.99 10.050 10.106 10.162 10.218 10.274 0.560

3.00 10.330* 10.387 10.444 10.501 10.558 10.615 10.672 10.729 10.786 10.843 0.570

3.10 10.900 10.957 11.014 11.071 11.128 11.185 11.242 11.299 11.356 11.413 0.570

3.20 11.470* 11.529 11.587 11.646 11.704 11.763 11.821 11.880 11.938 11.997 0.585

“*” indicates a rating descriptor point
Appendix 1

19

STATION: 414757087490401 Summit Conduit at Summit, IL.—Continued

Type: stream, Agency: USGS, State: 17, County: 031, Latitude: 414757, Longitude: 0874904 NAD83, 

Drainage area: Contributing drainage area: Datum: 

Date processed; 2013-03-07 02:36 By swreview

Rating for Discharge (INFLOW) (cfs)

Rating ID: 1.0, Type: stage-area, Expansion: linear Satus: working

Created by ggoodwin on 06-23-2011 14:50:26 CST, Updated by johnsonk on 03-05-2013 09:38:43 CST

Rating remarks:

EXPANDED RATING TABLE

Gage 

height, 

feet

Stream cross-section (in square feet (expanded precision)) Difference 

in Y per 0.1 

units .00 .01 .02 .03 .04 .05 .06 .07 .08 .09

3.30 12.055 12.114 12.172 12.231 12.289 12.348 12.406 12.465 12.523 12.582 0.585

3.40 12.640* 12.699 12.758 12.817 12.876 12.935 12.994 13.053 13.112 13.171 0.590

3.50 13.230 13.289 13.348 13.407 13.466 13.525 13.584 13.643 13.702 13.761 0.590

3.60 13.820* 13.880 13.940 14.000 14.060 14.120 14.180 14.240 14.300 14.360 0.600

3.70 14.420 14.480 14.540 14.600 14.660 14.720 14.780 14.840 14.900 14.960 0.600

3.80 15.020* 15.080 15.140 15.200 15.260 15.320 15.380 15.440 15.500 15.560 0.600

3.90 15.620 15.680 15.740 15.800 15.860 15.920 15.980 16.040 16.100 16.160 0.600

4.00 16.220* 16.280 16.340 16.400 16.460 16.520 16.580 16.640 16.700 16.760 0.600

4.10 16.820 16.880 16.940 17.000 17.060 17.120 17.180 17.240 17.300 17.360 0.600

4.20 17.420* 17.480 17.539 17.599 17.658 17.718 17.777 17.837 17.896 17.956 0.595

4.30 18.015 18.075 18.134 18.194 18.253 18.313 18.372 18.432 18.491 18.551 0.595

4.40 18.610* 18.669 18.728 18.787 18.846 18.905 18.964 19.023 19.082 19.141 0.590

4.50 19.200 19.259 19.318 19.377 19.436 19.495 19.554 19.613 19.672 19.731 0.590

4.60 19.790* 19.849 19.907 19.966 20.024 20.083 20.141 20.200 20.258 20.317 0.585

4.70 20.375 20.434 20.492 20.551 20.609 20.668 20.726 20.785 20.843 20.902 0.585

4.80 20.960* 21.017 21.074 21.131 21.188 21.245 21.302 21.359 21.416 21.473 0.570

4.90 21.530 21.587 21.644 21.701 21.758 21.815 21.872 21.929 21.986 22.043 0.570

5.00 22.100* 22.156 22.212 22.268 22.324 22.380 22.436 22.492 22.548 22.604 0.560

5.10 22.660 22.716 22.772 22.828 22.884 22.940 22.996 23.052 23.108 23.164 0.560

5.20 23.220* 23.274 23.328 23.382 23.436 23.490 23.544 23.598 23.652 23.706 0.540

5.30 23.760 23.814 23.868 23.922 23.976 24.030 24.084 24.138 24.192 24.246 0.540

5.40 24.300* 24.352 24.404 24.456 24.508 24.560 24.612 24.664 24.716 24.768 0.520

5.50 24.820 24.872 24.924 24.976 25.028 25.080 25.132 25.184 25.236 25.288 0.520

5.60 25.340* 25.390 25.439 25.489 25.538 25.588 25.637 25.687 25.736 25.786 0.495

5.70 25.835 25.885 25.934 25.984 26.033 26.083 26.132 26.182 26.231 26.281 0.495

5.80 26.330* 26.377 26.423 26.470 26.516 26.563 26.609 26.656 26.702 26.749 0.465

5.90 26.795 26.842 26.888 26.935 26.981 27.028 27.074 27.121 27.167 27.214 0.465

6.00 27.260* 27.303 27.345 27.388 27.430 27.473 27.515 27.558 27.600 27.643 0.425

6.10 27.685 27.728 27.770 27.813 27.855 27.898 27.940 27.983 28.025 28.068 0.425

6.20 28.110* 28.149 28.187 28.226 28.264 28.303 28.341 28.380 28.418 28.457 0.385

6.30 28.495 28.534 28.572 28.611 28.649 28.688 28.726 28.765 28.803 28.842 0.385

6.40 28.880* 28.913 28.946 28.979 29.012 29.045 29.078 29.111 29.144 29.177 0.330

6.50 29.210 29.243 29.276 29.309 29.342 29.375 29.408 29.441 29.474 29.507 0.330

“*” indicates a rating descriptor point
20

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

STATION: 414757087490401 Summit Conduit at Summit, IL.—Continued

Type: stream, Agency: USGS, State: 17, County: 031, Latitude: 414757, Longitude: 0874904 NAD83, 

Drainage area: Contributing drainage area: Datum: 

Date processed; 2013-03-07 02:36 By swreview

Rating for Discharge (INFLOW) (cfs)

Rating ID: 1.0, Type: stage-area, Expansion: linear Satus: working

Created by ggoodwin on 06-23-2011 14:50:26 CST, Updated by johnsonk on 03-05-2013 09:38:43 CST

Rating remarks:

EXPANDED RATING TABLE

Gage 

height, 

feet

Stream cross-section (in square feet (expanded precision)) Difference 

in Y per 0.1 

units .00 .01 .02 .03 .04 .05 .06 .07 .08 .09

6.60 29.540* 29.566 29.592 29.618 29.644 29.670 29.696 29.722 29.748 29.774 0.260

6.70 29.800 29.826 29.852 29.878 29.904 29.930 29.956 29.982 30.008 30.034 0.260

6.80 30.060* 30.075 30.089 30.104 30.118 30.133 30.147 30.162 30.176 30.191 0.145

6.90 30.205 30.220 30.234 30.249 30.263 30.278 30.292 30.307 30.321 30.336 0.145

7.00 30.350* 30.355 30.360 30.365 30.370 30.375 30.380 30.385 30.390 30.395 0.050

7.10 30.400 30.405 30.410 30.415 30.420 30.425 30.430 30.435 30.440 30.445 0.050

7.20 30.450*

“*” indicates a rating descriptor point

Rating Type: Rating type: stage-area

ID Starting Date Ending Date A Comments

1.0 09-23-2010 @ 12:00:00 CST W
Appendix 1

21

Stage-Area Geometry

D 6.00 ft pipe diameter

r_ 3.00 ft pipe radius

y_1 2.50 ft

y_2 7.00 ft

b 0.33 ft

zAngle 42.70 deg

z 1.08 ft

TA 7.61 ft^2 full trapezoid area

CA 5.53 ft^2 area of circular segment overlap (stipled line)

_r2 1.50 ft dist from top of trapezoid to base of pipe

_r3 1.00 ft dist from bottom to bottom of pipe

Culvert Dimensions

Reference Calcuations

Computed Constants

1

z

D

y_1

b

y_2

_r2

Description of Conduit Geometry

The conduit is a compound shape, consisting of a pipe with diameter (r_) and a

trapezoid of height (y_1), bottom width (b), and side wall slope (zAngle).  The

pipe and trapezoid overlap for a distance along the radius (r_) of (_r2).

h_pipe = cicular segment height

theta    = central angle

K = circular segment area

s = arc length

A_pipe   = area contain in pipe

A‐pipe ‐ CA = area in pipe minus segment overlaping trapezoid
22

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

STATION: 414757087490401 Summit Conduit at Summit, IL

Type: stream, Agency: USGS, State: 17, County: 031, Latitude: 414757, Longitude: 0874904 NAD83, Drainage area: 

Contributing drainage area: Datum: 

Date processed; 2013-04-11 23:58 By swreview

Lowest aging status in period is APPROVED

DD #3, (INFLOW)

Discharge, cubic feet per second

WATER YEAR OCTOBER 2010 TO SEPTEMBER 2011

DAILY MEAN VALUES

Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 5.6 e4.9 5.3 14 5.6 9.8 6.9 e8.9 9.8 4.5 e7.6 5.9 

2 6.4 e5.0 4.7 7.9 6.1 7.8 6.0 e8.0 8.2 4.2 e7.2 4.6

3 6.7 e5.0 4.5 6.9 6.5 7.8 5.6 e7.7 8.0 4.2 #9.4 #12

4 5.4 e5.4 5.3 #6.5 6.7 16 e7.9 e6.3 9.7 4.2 8.4 7.1

5 4.5 6.8 5.1 e6.3 5.7 26 e6.3 e7.7 7.7 4.1 7.9 5.2

6 4.2 6.8 4.3 e6.1 5.9 11 e6.0 7.4 6.4 4.2 8.4 5.0

7 5.5 8.2 4.2 e5.9 5.6 9.2 e6.5 6.4 5.6 4.8 14 4.9

8 5.4 5.6 4.1 e5.7 4.8 #8.5 29 6.2 5.6 3.9 11 5.0

9 5.5 3.8 4.0 e5.5 1.8 #21 10 6.1 e120 4.0 8.6 #5.8

10 5.6 3.7 4.2 e5.3 2.4 10 8.3 5.8 21 4.0 #5.9 e6.0

11 5.3 4.0 10 e5.1 2.7 8.0 8.0 6.9 13 #8.0 e7.0 e4.8

12 3.6 4.1 8.7 e5.1 5.5 6.5 6.6 6.3 10 5.6 e6.1 e3.9

13 8.7 4.4 5.5 e5.0 7.0 6.1 6.3 4.7 8.5 4.8 e6.5 e2.8

14 3.9 4.2 5.1 e4.9 6.5 5.6 5.9 #2.2 7.9 4.2 10 e2.8

15 3.6 4.4 4.9 e4.9 4.2 5.4 7.6 #11 e24 2.8 7.4 e2.0

16 5.2 4.1 4.8 e4.7 #8.6 5.3 9.3 6.7 12 2.2 6.6 #4.5

17 5.2 4.2 4.6 e4.8 28 5.2 6.7 5.9 7.8 3.8 5.4 4.7

18 5.0 4.6 4.4 e6.7 16 4.9 18 5.8 7.1 3.8 5.5 8.3

19 4.8 6.1 4.4 #6.2 9.9 4.7 27 5.5 6.9 3.5 5.1 16

20 4.8 5.5 4.4 4.5 e29 6.9 23 5.6 e23 3.2 #7.8 5.5

21 4.8 8.1 4.9 3.9 e35 7.4 8.8 5.5 #8.5 2.9 6.4 5.2

22 4.9 e35 4.9 0.78 #11 7.2 24 5.4 #11 e7.2 5.7 4.7

23 5.6 11 5.0 0.61 #9.6 9.2 16 5.2 7.9 e10 #12 4.6

24 9.1 5.7 5.0 0.62 e10 8.1 8.9 5.2 7.0 e35 7.9 4.3

25 9.1 8.9 5.2 0.81 e9.9 7.6 9.5 e38 7.1 e24 6.4 3.9

26 7.1 8.2 5.2 3.2 e8.5 6.3 33 e54 6.9 e15 5.9 30

27 5.2 6.9 5.0 5.5 e11 6.0 25 13 7.5 e9.5 4.3 10

28 4.7 5.0 4.9 7.9 21 5.9 13 12 6.6 e13 0.86 e8.6

29 e4.7 8.2 4.9 6.2 --- 6.0 #11 #59 5.8 e9.9 2.9 e6.0

30 e4.8 10 9.2 6.1 --- 6.1 e10 19 4.7 e8.0 4.9 e5.7

31 e4.8 --- e37 6.1 --- 6.0 --- 12 --- e9.1 7.2 ---

Total 169.7 207.8 193.7 163.72 284.5 261.5 370.1 359.4 395.2 227.6 220.26 199.8

Mean 5.47 6.93 6.25 5.28 10.2 8.44 12.3 11.6 13.2 7.34 7.11 6.66

Max 9.1 35 37 14 35 26 33 59 120 35 14 30

Min 3.6 3.7 4.0 0.61 1.8 4.7 5.6 2.2 4.7 2.2 0.86 2.0

e is Estimated

# Value is write-protected with a “1”
Appendix 2 Summit Conduit

23

STATION: 414757087490401 Summit Conduit at Summit, IL

DD #3 (INFLOW)

Discharge, cubic feet per second

WATER YEAR OCTOBER 2010 TO SEPTEMBER 2011—Continued

STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1951–2011, BY WATER YEAR (WY)

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Mean 5.47 6.93 6.25 5.28 10.2 8.44 12.3 11.6 13.2 7.34 7.11 6.66

Max 5.47 6.93 6.25 5.28 10.2 8.44 12.3 11.6 13.2 7.34 7.11 6.66

 (WY) 2011 2011 2011 2011 2011 2011 2011 2011 2011 2011 2011 2011

Min 5.47 6.93 6.25 5.28 10.2 8.44 12.3 11.6 13.2 7.34 7.11 6.66

 (WY) 2011 2011 2011 2011 2011 2011 2011 2011 2011 2011 2011 2011

SUMMARY STATISTICS

For 2011 Water Year Water Years 2010–2011

Annual total 3053.28

Annual mean 8.37 8.37

Highest annual mean 8.37 2011

Lowest annual mean 8.37 2011

Highest daily mean 120 Jun 9 120 Jun 9 2011

Lowest daily mean 0.61 Jan 23 0.61 Jan 23 2011

Annual seven-day minimum 2.1 Jan 20 2.1 Jan 20 2011

Maximum peak flow 220 Jul 23 220 Jul 23 2011

Maximum peak stage 7.18 May 29 7.18 May 29 2011

Instantaneous low flow 0.28 Aug 28 0.28 Aug 28 2011

10 percent exceeds 13 13

50 percent exceeds 6.1 6.1

90 percent exceeds 4.1 4.1
24

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

STATION: 414757087490401 Summit Conduit at Summit, IL

Type: stream, Agency: USGS, State: 17, County: 031, Latitude: 414757, Longitude: 0874904 NAD83, Drainage area: 

Contributing drainage area: Datum: 

Date processed: 2013-04-11 23:58 By swreview

Lowest aging status in period is APPROVED

DD #1 (INFLOW)

Gage height, feet

WATER YEAR OCTOBER 2010 TO SEPTEMBER 2011

DAILY MEAN VALUES

Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 2.35 --- 2.23 2.91 2.15 2.53 2.27 --- 2.48 2.00 --- 2.19

2 2.43 --- 2.19 2.44 2.15 2.37 2.20 --- 2.38 1.99 --- 2.11

3 2.47 --- 2.17 2.34 2.19 2.38 2.18 --- 2.35 1.99 #2.32 2.59

4 2.37 --- 2.22 #2.34 2.20 2.67 --- --- 2.46 2.02 2.24 2.32

5 2.23 2.52 2.20 --- 2.18 3.45 --- --- 2.31 2.03 2.20 2.16

6 2.20 2.51 2.17 --- 2.19 2.60 --- 2.28 2.18 2.01 2.23 2.13

7 2.34 2.63 2.15 --- 2.17 2.45 --- 2.22 2.12 2.03 2.74 2.11

8 2.34 2.39 2.14 --- 2.07 #2.40 3.34 2.20 2.12 1.96 2.56 2.10

9 2.34 2.22 2.14 --- 1.68 #3.13 2.44 2.19 --- 1.96 2.37 #2.18

10 2.34 2.21 2.15 --- 1.37 2.52 2.33 2.17 3.32 1.96 2.27 ---

11 2.33 2.23 2.60 --- 1.32 2.37 2.31 2.24 2.75 #2.31 --- ---

12 2.15 2.25 2.50 --- 1.96 2.27 2.21 2.21 2.47 2.08 --- ---

13 2.51 2.28 2.22 --- 2.29 2.22 2.19 2.21 2.34 1.99 --- ---

14 2.22 2.26 2.19 --- 2.27 2.19 2.17 2.26 2.27 1.94 2.54 ---

15 2.18 2.28 2.16 --- 2.07 2.18 2.29 2.63 --- 1.73 2.29 ---

16 2.38 2.26 2.16 --- #2.42 2.17 2.39 2.25 2.55 1.65 2.23 #2.11

17 2.38 2.27 2.15 --- 3.56 2.15 2.21 2.19 2.26 1.88 2.12 2.11

18 2.37 2.30 2.14 --- 2.97 2.14 2.91 2.19 2.18 1.87 2.13 2.38

19 2.36 2.44 2.14 #2.28 2.54 2.13 3.18 2.17 2.14 1.84 2.09 2.84

20 2.35 2.39 2.14 2.08 --- 2.31 3.19 2.16 --- 1.82 2.29 2.24

21 2.35 2.65 2.16 2.03 --- 2.34 2.44 2.15 #2.33 1.79 2.20 2.16

22 2.36 --- 2.16 1.56 2.62 2.35 3.30 2.15 #2.54 --- 2.09 2.12

23 2.42 2.66 2.16 1.43 #2.50 2.53 2.86 2.15 2.23 --- 2.63 2.10

24 2.61 2.26 2.16 1.43 --- 2.43 2.42 2.14 2.21 --- 2.29 2.10

25 2.67 2.52 2.17 1.46 --- 2.40 2.44 --- 2.24 --- 2.18 2.05

26 2.57 2.48 2.18 1.84 --- 2.26 3.79 --- 2.20 --- 2.10 3.37

27 2.41 2.36 2.16 2.13 --- 2.24 3.40 2.68 2.25 --- 1.92 2.51

28 2.37 2.18 2.15 2.33 3.13 2.23 2.76 2.64 2.16 --- 1.49 ---

29 --- 2.41 2.15 2.19 --- 2.21 2.55 4.20 2.11 --- 1.75 ---

30 --- 2.63 2.52 2.19 --- 2.18 --- 3.07 2.02 --- 1.98 ---

31 --- --- --- 2.19 --- 2.18 --- 2.61 --- --- 2.19 ---

Mean --- --- --- --- --- 2.39 --- --- --- --- --- ---

MAX --- --- --- --- --- 3.45 --- --- --- --- --- ---

MIN --- --- --- --- --- 2.13 --- --- --- --- --- ---

 # Value is write-protected with a “1”
Appendix 2 Summit Conduit

25

STATION: 414757087490401 Summit Conduit at Summit, IL

Type: stream, Agency: USGS, State: 17, County: 031, Latitude: 414757, Longitude: 0874904 NAD83, Drainage area: 

Contributing drainage area: Datum: 

Date processed; 2013-04-12 00:06 By swreview

Lowest aging status in period is APPROVED

DD #3, (INFLOW)

Discharge, cubic feet per second

WATER YEAR OCTOBER 2011 TO SEPTEMBER 2012

DAILY MEAN VALUES

Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 e7.0 4.5 6.1 5.3 5.6 6.9 4.6 14 e8.9 10 4.4 e8.5 

2 e4.9 4.4 5.8 4.7 6.7 9.2 5.1 8.2 3.8 4.5 3.2 e8.1

3 e4.5 6.9 7.4 6.0 5.9 6.2 5.5 5.3 2.9 3.2 3.1 e7.0

4 e4.3 5.6 9.0 6.9 4.8 4.8 4.8 14 3.8 3.5 e14 e6.5

5 e4.4 5.3 6.2 6.2 4.5 5.7 4.4 4.5 4.2 4.1 11 e8.4

6 e4.7 5.3 6.0 5.3 5.9 5.8 5.1 7.1 3.1 4.4 5.8 e4.1

7 e3.9 5.2 5.8 4.2 6.8 4.5 3.4 23 3.6 3.7 3.0 e8.1

8 e4.0 43 5.7 4.1 5.7 6.7 3.2 8.8 5.0 3.3 3.4 e5.6

9 e3.5 29 5.2 5.5 4.0 4.7 3.6 6.3 3.3 4.1 5.5 #7.3

10 e3.9 11 3.9 6.0 4.9 3.9 3.6 5.6 3.2 4.9 7.5 4.9

11 e4.0 8.4 3.8 4.8 4.0 3.8 3.6 5.4 3.5 3.6 4.0 3.6

12 #6.4 7.2 4.7 5.1 4.1 8.4 4.7 9.5 4.0 3.5 3.5 4.4

13 11 6.5 5.2 4.2 5.2 5.6 4.6 6.7 2.9 #3.3 6.9 5.2

14 7.8 6.3 #40 4.0 5.3 4.3 5.4 5.1 2.8 #5.8 5.7 5.1

15 6.3 #5.3 16 4.1 4.3 4.7 44 5.0 3.5 3.7 4.7 4.4

16 7.2 #4.9 9.8 6.5 8.1 4.6 20 4.7 #2.1 4.5 9.7 4.0

17 6.3 #4.6 8.1 10 6.1 3.7 7.9 5.1 #5.5 4.2 4.8 6.7

18 6.1 #4.3 7.0 6.6 4.1 3.6 6.4 4.9 3.7 #3.9 3.5 6.3

19 12 4.2 6.2 5.5 4.0 4.6 6.3 3.4 4.5 #21 3.3 4.5

20 15 4.3 6.0 4.6 5.0 5.1 5.5 3.1 4.0 10 11 3.9

21 6.2 4.2 4.7 4.1 6.0 4.0 3.8 4.2 3.7 6.4 8.3 4.0

22 3.9 8.7 4.1 5.1 4.8 3.6 3.7 4.2 3.8 5.7 4.4 4.9

23 5.2 6.7 6.1 #51 5.6 25 4.8 2.1 3.1 5.6 3.1 3.4

24 9.5 4.5 5.9 12 13 8.5 5.0 4.5 2.8 12 4.0 3.9

25 5.7 4.8 5.8 8.3 6.0 6.3 5.2 4.2 3.6 #5.5 3.2 4.1

26 #6.0 19 5.7 7.1 4.9 4.8 4.8 3.0 4.1 7.1 #14 4.1

27 5.4 #25 7.2 6.8 5.5 3.2 4.0 2.9 3.8 4.8 #31 4.1

28 5.0 8.6 5.7 6.0 6.0 4.9 5.8 2.9 4.6 4.0 14 3.6

29 4.7 7.0 6.5 5.1 14 4.7 3.9 3.5 4.9 4.0 11 3 .4

30 4.9 6.5 13 6.3 --- 11 9.6 3.7 5.0 4.5 7.7 3.2

31 4.7 --- 7.0 6.8 --- 4.7 --- e9.2 --- 5.1 7.5 ---

Total 188.4 271.2 239.6 228.2 170.8 187.5 202.3 194.1 117.7 173.9 226.2 155.3

Mean 6.08 9.04 7.73 7.36 5.89 6.05 6.74 6.26 3.92 5.61 7.30 5.18

Max 15 43 40 51 14 25 44 23 8.9 21 31 8.5

Min 3.5 4.2 3.8 4.0 4.0 3.2 3.2 2.1 2.1 3.2 3.0 3.2

 e is Estimated

 # Value is write-protected with a “1”
26

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

STATION: 414757087490401 Summit Conduit at Summit, IL

DD #3 (INFLOW)

Discharge, cubic feet per second

WATER YEAR OCTOBER 2011 TO SEPTEMBER 2012—Continued

STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1951–2011, BY WATER YEAR (WY)

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Mean 5.78 7.98 6.99 6.32 7.99 7.24 9.54 8.93 8.55 6.48 7.20 5.92

Max 6.08 9.04 7.73 7.36 10.2 8.44 12.3 11.6 13.2 7.34 7.30 6.66

 (WY) 2012 2012 2012 2012 2011 2011 2011 2011 2011 2011 2012 2011

Min 5.47 6.93 6.25 5.28 5.89 6.05 6.74 6.26 3.92 5.61 7.11 5.18

 (WY) 2011 2011 2011 2011 2012 2012 2012 2012 2012 2012 2011 2012

SUMMARY STATISTICS

For 2011 Calendar Year For 2012 Water Year Water Years 2010–2012

Annual total 3181.28 2355.2

Annual mean 8.72 6.43 7.40

Highest annual mean 8.37 2011

Lowest annual mean 6.43 2012

Highest daily mean 120 Jun 9 51 Jan 23 120 Jun 9 2011

Lowest daily mean 0.61 Jan 23 2.1 May 23 0.61 Jan 23 2011

Annual seven-day minimum 2.1 Jan 20 3.1 Jun 10 2.1 Jan 20 2011

Maximum peak flow 129 Apr 15

Maximum peak stage 6.75 Apr 15

Instantaneous low flow 0.31 Jun 16

10 percent exceeds 14 9.6 11

50 percent exceeds 6.3 5.1 5.6

90 percent exceeds 4.1 3.5 3.7
Appendix 2 Summit Conduit

27

STATION: 414757087490401 Summit Conduit at Summit, IL

Type: stream, Agency: USGS, State: 17, County: 031, Latitude: 414757, Longitude: 0874904 NAD83, Drainage area: 

Contributing drainage area: Datum: 

Date processed: 2013-04-12 00:06 By swreview

Lowest aging status in period is APPROVED

DD #1 (INFLOW)

Gage height, feet

WATER YEAR OCTOBER 2011 TO SEPTEMBER 2012

DAILY MEAN VALUES

Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 --- 1.98 1.79 1.69 1.72 1.90 1.57 2.30 --- 2.18 1.60 --- 

2 --- 1.98 1.75 1.60 1.87 2.07 1.64 2.03 1.54 1.58 1.37 ---

3 --- 2.13 1.91 1.76 1.76 1.80 1.70 1.72 1.39 1.32 1.37 ---

4 --- 1.97 2.06 1.89 1.61 1.64 1.64 2.44 1.49 1.44 --- ---

5 --- 1.91 1.78 1.79 1.58 1.77 1.58 1.61 1.54 1.55 2.34 ---

6 --- 1.91 1.76 1.67 1.76 1.79 1.66 1.85 1.33 1.56 1.80 ---

7 --- 1.97 1.72 1.52 1.89 1.61 1.44 2.99 1.38 1.43 1.31 ---

8 --- 4.09 1.71 1.51 1.74 1.87 1.43 2.08 1.63 1.38 1.37 ---

9 --- 3.60 1.64 1.70 1.53 1.65 1.50 1.80 1.38 1.52 1.74 1

#2.03

10 --- 2.69 1.49 1.75 1.64 1.53 1.50 1.72 1.34 1.64 1.99 1.78

11 --- 2.52 1.48 1.59 1.52 1.52 1.49 1.67 1.45 1.40 1.58 1.50

12 #2.07 2.41 1.60 1.63 1.51 2.06 1.64 2.06 1.54 1.39 1.49 1.62

13 2.41 2.35 1.66 1.53 1.68 1.77 1.62 1.84 1.31 #1.32 1.94 1.81

14 2.22 2.17 3.60 1.50 1.69 1.61 1.53 1.67 1.27 #1.79 1.81 1.80

15 2.12 1.88 2.66 1.49 1.55 1.66 3.72 1.67 1.47 1.46 1.68 1.66

16 2.17 1.40 2.19 1.79 2.01 1.63 2.81 1.63 #1.13 1.57 2.13 1.59

17 2.10 #1.59 2.04 2.20 1.79 1.47 2.01 1.69 #1.81 1.48 1.71 1.89

18 2.08 #1.52 1.91 1.86 1.53 1.47 1.83 1.67 1.52 #1.42 1.52 1.90

19 2.44 1.54 1.81 1.72 1.51 1.63 1.80 1.40 1.59 #3.05 1.47 1.68

20 2.69 1.57 1.78 1.62 1.64 1.70 1.73 1.37 1.55 2.27 2.20 1.58

21 2.11 1.56 1.61 1.53 1.76 1.50 1.51 1.58 1.55 1.87 2.05 1.49

22 1.89 1.93 1.49 1.60 1.60 1.38 1.48 1.56 1.55 1.75 1.59 1.72

23 2.05 1.76 1.80 4.06 1.69 2.91 1.63 1.11 1.38 1.72 1.35 1.49

24 2.39 1.53 1.78 2.37 2.39 2.09 1.68 1.61 1.31 2.29 1.57 1.57

25 2.09 1.55 1.77 2.06 1.77 1.84 1.71 1.57 1.42 #1.80 1.46 1.60

26 2.13 2.43 1.76 1.93 1.65 1.60 1.66 1.35 1.51 1.94 #2.01 1.60

27 2.05 3.01 1.88 1.88 1.72 1.34 1.54 1.33 1.46 1.65 #3.28 1.61

28 2.03 2.07 1.74 1.77 1.78 1.63 1.74 1.30 1.61 1.52 2.49 1.44

29 2.01 1.89 1.84 1.67 2.41 1.70 1.51 1.45 1.75 1.55 2.25 1.47

30 2.03 1.84 2.35 1.82 --- 2.14 2.08 1.49 1.75 1.63 1.98 1.46

31 2.02 --- 1.89 1.88 --- 1.59 --- --- --- 1.71 1.89 ---

Mean --- 2.09 1.88 1.82 1.73 1.74 1.75 --- --- 1.68 --- ---

MAX --- 4.09 3.60 4.06 2.41 2.91 3.72 --- --- 3.05 --- ---

MIN --- 1.40 1.48 1.49 1.51 1.34 1.43 --- --- 1.32 --- ---

1

# Value is write-protected with a “1”
28

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

STATION: 05536500 Tinley Creek near Palos Park, IL

Type: stream, Agency: USGS, State: 17, County: 031, Latitude: 413848, Longitude: 0874559 NAD27, Drainage area:11.2, 

Contributing drainage area:11.20*, Datum: 607.40 NGVD29

Date processed; 2012-01-19 10:31 by adrobl

Lowest aging status in period is APPROVED

DD #4

Discharge, cubic feet per second

WATER YEAR OCTOBER 2010 TO SEPTEMBER 2011

DAILY MEAN VALUES

Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 0.30 0.99 12 42 e1.4 31 5.1 33 30 4.7 6.5 0.97

2 0.35 0.82 5.4 22 e1.3 20 6.7 26 26 4.3 5.1 0.83

3 0.61 0.83 3.2 e11 e1.2 13 5.3 21 25 4.1 5.4 2.8

4 0.50 0.87 2.8 6.5 e1.3 31 8.3 17 27 3.6 4.4 14

5 0.39 0.89 3.0 5.6 e1.4 141 8.0 15 34 3.3 3.7 5.5

6 0.37 0.80 2.4 4.3 e1.5 40 6.1 18 25 2.7 5.2 2.8

7 0.34 0.79 1.8 3.3 e1.4 26 5.3 16 19 3.0 4.0 1.9

8 0.27 0.74 1.5 2.8 e1.3 18 39 14 15 3.2 10 1.3

9 0.20 0.87 1.3 2.6 e1.2 31 27 13 502 2.9 35 11

10 0.22 0.87 1.4 2.3 e1.1 29 16 12 111 2.4 17 6.8

11 0.26 0.89 3.2 2.2 e1.2 20 23 11 45 3.3 8.3 3.5

12 0.28 0.96 35 2.5 e1.5 14 13 12 30 5.0 4.9 2.1

13 0.37 0.93 25 2.1 e2.0 11 8.6 24 23 3.5 4.3 1.4

14 1.7 0.98 10 1.9 5.3 8.7 6.7 25 17 2.7 10 1.1

15 1.3 0.99 5.4 1.9 26 8.0 5.8 44 32 2.3 4.9 0.95

16 0.84 1.1 4.0 1.9 21 7.4 12 35 36 2.1 3.2 0.88

17 0.84 1.0 2.7 1.8 128 6.3 12 28 26 1.9 2.2 1.0

18 0.73 1.0 2.4 5.6 57 5.3 24 24 19 1.9 1.4 0.86

19 0.73 1.1 2.7 e4.0 29 5.0 43 19 15 2.0 1.5 10

20 0.76 0.92 3.3 e2.5 52 5.3 87 16 46 1.8 12 6.3

21 0.65 0.92 2.1 e2.0 79 6.1 33 14 37 1.6 14 2.0

22 0.68 4.8 1.8 e2.1 34 28 103 12 32 11 6.7 0.69

23 0.95 20 1.5 e2.2 21 28 58 11 #24 46 18 0.22

24 6.4 6.2 1.3 e2.3 16 19 33 9.4 18 158 26 1.3

25 21 19 e1.2 e2.1 14 12 26 115 13 69 11 0.90

26 17 7.4 e1.2 e1.9 13 9.2 89 192 11 34 6.1 28

27 9.5 3.6 e1.2 e1.7 14 7.3 62 60 9.0 19 3.7 30

28 4.8 5.7 e1.3 e1.6 61 6.3 39 47 8.6 32 2.2 13

29 2.7 2.3 1.5 e1.7 --- 5.4 26 72 6.6 22 1.7 7.8

30 2.1 31 6.0 e1.6 --- 5.0 26 56 5.5 13 1.2 6.2

31 1.4 --- 104 e1.5 --- 4.6 --- 37 --- 9.1 1.0 ---

Total 78.54 119.26 251.6 149.5 588.1 601.9 856.9 1048.4 1267.7 475.4 240.6 166.10

Mean 2.53 3.98 8.12 4.82 21.0 19.4 28.6 33.8 42.3 15.3 7.76 5.54

Max 21 31 104 42 128 141 103 192 502 158 35 30

Min 0.20 0.74 1.2 1.5 1.1 4.6 5.1 9.4 5.5 1.6 1.0 0.22

CFSM 0.23 0.35 0.72 0.43 1.88 1.73 2.55 3.02 3.77 1.37 0.69 0.49

In. 0.26 0.40 0.84 0.50 1.95 2.00 2.85 3.48 4.21 1.58 0.80 0.55

 e is Estimated

 # Value is write-protected with a “1”
Appendix 2 Tinley Creek

29

STATION: 05536500 Tinley Creek near Palos Park, IL

DD #4

Discharge, cubic feet per second

WATER YEAR OCTOBER 2010 TO SEPTEMBER 2011—Continued

STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1951–2011, BY WATER YEAR \(WY\)

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Mean 6.95 9.90 10.7 11.3 13.8 21.0 21.5 15.7 12.5 6.95 6.32 6.51

Max 87.0 47.1 57.7 43.1 69.8 90.2 50.7 43.7 56.9 58.5 31.6 49.5

\(WY\) 1955 2004 1983 1999 1997 1979 1970 2002 2000 1996 2007 2008

Min 0.00 0.17 0.15 0.06 0.19 2.24 1.52 1.79 0.67 0.15 0.00 0.00

\(WY\) 1953 1954 1964 1977 1963 1981 1963 1963 1965 1956 1964 1953

SUMMARY STATISTICS

For 2010 Calendar Year For 2011 Water Year Water Years 1951–2011

Annual total 4610.60 5844.00

Annual mean 12.6 16.0 11.9

Highest annual mean 22.7 1993

Lowest annual mean 2.27 1963

Highest daily mean 316 Aug 3 502 Jun 9 891 Oct 10 1954

Lowest daily mean 0.18 Aug 30 0.20 Oct 9 0.00 Sep 29 1952

Annual seven-day minimum 0.26 Aug 26 0.28 Oct 6 0.00 Oct 1 1952

Maximum peak flow 1500 Jun 9 2010 Jul 18 1996

Maximum peak stage 9.53 Jun 9 10.30 Oct 10 1954

Instantaneous low flow 0.08 Sep 23

Annual runoff\(CFSM\) 1.13 1.43 1.06

Annual runoff \(inches\) 15.31 19.41 14.44

10 percent exceeds 30 35 26

50 percent exceeds 5.0 5.5 3.0

90 percent exceeds 0.73 0.91 0.20
30

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

STATION: 05536500. Tinley Creek near Palos Park, IL

Type:stream, Agency:USGS, State:17, County: 031, Latitude: 413848, Longitude: 0874559 NAD27, Drainage area:11.2, 

Contributing drainage area:11.20*, Datum: 607.40 NGVD29

Date processed: 2012-01-19 10:31 by adrobl

Lowest aging status in period is APPROVED

DD #3

Gage height, feet

WATER YEAR OCTOBER 2010 TO SEPTEMBER 2011

DAILY MEAN VALUES

Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 2.29 2.37 2.67 3.12 2.29 2.94 2.49 2.97 2.92 2.52 2.58 2.34

2 2.30 2.35 2.55 2.77 2.35 2.76 2.54 2.85 2.84 2.50 2.54 2.32

3 2.33 2.35 2.48 2.76 2.46 2.67 2.50 2.77 2.82 2.49 2.55 2.38

4 2.32 2.36 2.47 2.44 2.41 2.89 2.57 2.73 2.89 2.47 2.52 2.72

5 2.31 2.36 2.47 2.41 2.40 4.25 2.57 2.69 2.98 2.46 2.49 2.55

6 2.30 2.35 2.45 2.36 2.38 3.08 2.52 2.74 2.84 2.43 2.54 2.45

7 2.30 2.35 2.42 2.33 2.37 2.85 2.50 2.71 2.75 2.44 2.50 2.41

8 2.28 2.35 2.41 2.31 2.35 2.74 3.07 2.69 2.69 2.46 2.61 2.37

9 2.27 2.36 2.39 2.30 2.33 2.95 2.87 2.66 6.14 2.44 3.05 2.66

10 2.27 2.36 2.40 2.29 2.33 2.90 2.71 2.65 4.07 2.41 2.77 2.59

11 2.28 2.36 2.44 2.29 2.35 2.76 2.80 2.63 3.25 2.45 2.62 2.48

12 2.29 2.37 3.00 2.30 2.34 2.69 2.67 2.64 3.01 2.52 2.53 2.42

13 2.30 2.37 2.83 2.29 2.35 2.63 2.58 2.82 2.87 2.47 2.51 2.38

14 2.41 2.37 2.64 2.28 2.40 2.58 2.54 2.82 2.79 2.43 2.66 2.35

15 2.40 2.37 2.55 2.28 2.84 2.57 2.51 3.16 3.03 2.41 2.53 2.34

16 2.36 2.38 2.51 2.28 2.77 2.56 2.63 3.00 3.10 2.39 2.47 2.33

17 2.36 2.38 2.46 2.27 4.19 2.53 2.64 2.88 2.92 2.38 2.42 2.35

18 2.35 2.38 2.45 2.41 3.34 2.50 2.82 2.81 2.81 2.38 2.38 2.33

19 2.35 2.38 2.46 2.41 2.90 2.49 3.08 2.75 2.76 2.39 2.37 2.63

20 2.35 2.36 2.49 2.37 3.22 2.50 3.70 2.71 3.25 2.37 2.63 2.61

21 2.34 2.36 2.44 2.37 3.63 2.52 2.96 2.68 3.12 2.36 2.73 2.50

22 2.34 2.49 2.42 2.38 2.99 2.90 3.86 2.66 3.04 2.60 2.59 2.44

23 2.36 2.77 2.40 2.36 2.78 2.88 3.36 2.63 #2.88 3.27 2.75 2.40

24 2.57 2.57 2.39 2.33 2.72 2.75 2.97 2.60 2.79 4.38 2.90 2.55

25 2.79 2.75 2.41 2.31 2.68 2.66 2.84 3.89 2.73 3.56 2.68 2.51

26 2.74 2.59 2.41 2.29 2.67 2.60 3.78 4.78 2.68 3.03 2.57 3.07

27 2.63 2.49 2.41 2.29 2.68 2.55 3.42 3.40 2.64 2.79 2.49 3.12

28 2.53 2.53 2.41 2.30 3.41 2.53 3.08 3.21 2.63 3.00 2.43 2.89

29 2.46 2.44 2.41 2.30 --- 2.50 2.84 3.54 2.58 2.84 2.40 2.79

30 2.44 2.94 2.51 2.29 --- 2.49 2.86 3.34 2.54 2.72 2.36 2.75

31 2.40 --- 3.91 2.28 --- 2.48 --- 3.04 --- 2.64 2.34 ---

Mean 2.39 2.44 2.54 2.38 2.71 2.73 2.88 2.95 3.01 2.65 2.56 2.53

MAX 2.79 2.94 3.91 3.12 4.19 4.25 3.86 4.78 6.14 4.38 3.05 3.12

MIN 2.27 2.35 2.39 2.27 2.29 2.48 2.49 2.60 2.54 2.36 2.34 2.32
Appendix 2 Tinley Creek

31

STATION: 05536500 Tinley Creek near Palos Park, IL

Type: stream, Agency: USGS, State: 17, County: 031, Latitude: 413848, Longitude: 0874559 NAD27, Drainage area:11.2, 

Contributing drainage area:11.20*, Datum: 607.40 NGVD29

Date processed; 2013-02-07 11:42 by swreview

Lowest aging status in period is APPROVED

DD #4

Discharge, cubic feet per second

WATER YEAR OCTOBER 2011 TO SEPTEMBER 2012

DAILY MEAN VALUES

Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 5.3 10 8.5 14 22 28 6.4 15 24 4.8 0.51 2.7

2 3.2 7.1 7.8 10 15 22 5.8 23 9.8 2.9 0.39 4.5

3 1.8 5.6 6.7 7.9 12 26 5.0 14 5.3 1.3 0.19 2.5

4 1.4 8.6 11 6.9 26 17 4.4 92 3.2 0.73 9.8 1.7

5 0.75 7.6 9.2 6.5 25 11 4.0 35 2.2 0.66 24 2.5

6 0.41 6.2 7.2 6.3 17 6.8 3.5 27 1.8 0.35 6.9 2.2

7 0.25 4.9 6.0 5.8 12 6.5 3.2 225 1.8 0.51 2.9 1.9

8 0.35 52 5.6 5.2 9.7 20 3.0 62 1.2 0.26 1.6 2.8

9 0.33 60 5.1 5.0 8.3 16 3.2 32 0.96 0.15 1.1 3.0

10 0.47 32 4.3 4.6 7.5 10 2.6 19 0.80 0.11 0.85 1.9

11 0.42 21 4.3 5.0 7.5 8.3 2.4 12 0.67 0.33 0.87 1.2

12 0.52 14 4.1 4.5 6.3 20 2.3 43 0.89 0.50 0.79 0.65

13 4.3 11 4.1 5.1 5.9 18 2.2 29 0.62 0.15 3.3 0.42

14 16 8.4 103 4.6 5.8 11 2.2 17 0.57 1.6 12 0.42

15 6.5 6.5 98 4.4 6.2 9.7 3.1 11 0.61 9.2 11 0.49

16 4.0 5.6 40 4.7 26 9.3 19 7.7 0.54 3.8 7.2 0.31

17 2.8 4.8 24 22 20 6.9 8.9 5.7 8.4 2.0 5.2 0.22

18 2.0 4.1 17 27 13 5.8 5.9 4.6 4.9 e1.5 2.5 1.1

19 4.2 3.8 13 13 9.2 5.4 4.4 3.8 2.5 e65 1.4 0.98

20 38 3.8 10 e9.0 7.8 5.2 3.8 3.3 1.4 14 0.92 0.51

21 25 3.3 9.2 e8.1 8.4 5.0 3.3 5.2 1.2 4.7 2.0 0.23

22 14 4.6 8.2 e8.3 9.2 4.6 2.9 3.9 0.75 2.4 1.1 0.25

23 8.9 13 8.1 225 8.3 40 2.6 2.9 0.57 1.4 0.61 0.26

24 17 8.9 7.1 68 27 50 2.4 2.4 0.66 5.1 0.39 0.23

25 13 6.6 6.4 39 27 27 2.3 2.1 0.44 3.6 0.23 0.20

26 14 6.1 5.7 29 16 16 2.2 2.0 0.41 11 2.9 0.18

27 12 47 16 23 12 10 2.2 1.8 0.35 5.6 49 0.14

28 8.6 29 13 24 8.8 7.8 4.0 1.4 0.32 2.8 11 0.15

29 6.5 17 10 18 40 6.3 4.2 1.5 1.3 1.8 4.5 0.08

30 5.3 11 17 13 --- 5.5 9.4 1.2 7.5 0.87 2.7 0.07

31 11 --- 20 20 --- 5.1 --- 2.8 --- 0.58 1.6 ---

Total 228.30 423.5 509.6 646.9 418.9 440.2 130.8 708.3 85.66 149.70 169.45 33.79

Mean 7.36 14.1 16.4 20.9 14.4 14.2 4.36 22.8 2.86 4.83 5.47 1.13

Max 38 60 103 225 40 50 19 225 24 65 49 4.5

Min 0.25 3.3 4.1 4.4 5.8 4.6 2.2 1.2 0.32 0.11 0.19 0.07

CFSM 0.66 1.26 1.47 1.86 1.29 1.27 0.39 2.04 0.25 0.43 0.49 0.10

In. 0.76 1.41 1.69 2.15 1.39 1.46 0.43 2.35 0.28 0.50 0.56 0.11

 e is Estimated
32

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

STATION: 05536500 Tinley Creek near Palos Park, IL

DD #4

Discharge, cubic feet per second

WATER YEAR OCTOBER 2011 TO SEPTEMBER 2012—Continued

STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1951–2012, BY WATER YEAR (WY)

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Mean 6.95 9.97 10.8 11.4 13.8 20.9 21.2 15.9 12.3 6.91 6.30 6.43

Max 87.0 47.1 57.7 43.1 69.8 90.2 50.7 43.7 56.9 58.5 31.6 49.5

 (WY) 1955 2004 1983 1999 1997 1979 1970 2002 2000 1996 2007 2008

Min 0.00 0.17 0.15 0.06 0.19 2.24 1.52 1.79 0.67 0.15 0.00 0.00

 (WY\ 1953 1954 1964 1977 1963 1981 1963 1963 1965 1956 1964 1953

SUMMARY STATISTICS

For 2011 Calendar Year For 2012 Water Year Water Years 1951–2012

Annual total 6556.00 3945.10

Annual mean 18.0 10.8 11.9

Highest annual mean 22.7 1993

Lowest annual mean 2.27 1963

Highest daily mean 502 Jun 9 225 Jan 23 891 Oct 10 1954

Lowest daily mean 0.22 Sep 23 0.07 Sep 30 0.00 Sep 29 1952

Annual seven-day minimum 0.39 Oct 6 0.15 Sep 24 0.00 Oct 1 1952

Maximum peak flow 446 May 7 2010 Jul 18 1996

Maximum peak stage 6.67 May 7 10.30 Oct 10 1954

Instantaneous low flow 0.06 Sep 29

Annual runoff\(CFSM\) 1.60 0.962 1.06

Annual runoff \(inches\) 21.78 13.10 14.42

10 percent exceeds 38 24 26

50 percent exceeds 8.4 5.2 3.0

90 percent exceeds 1.5 0.51 0.20
Appendix 2 Tinley Creek

33

STATION: 05536500. Tinley Creek near Palos Park, IL

Type: stream, Agency: USGS, State: 17, County: 031, Latitude: 413848, Longitude: 0874559 NAD27, Drainage area:11.2, 

Contributing drainage area:11.20*, Datum: 607.40 NGVD29

Date processed: 2013-02-07 11:42 by swreview

Lowest aging status in period is APPROVED

DD #3

Gage height, feet

WATER YEAR OCTOBER 2011 TO SEPTEMBER 2012

DAILY MEAN VALUES

Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 2.73 2.61 2.58 2.68 2.74 2.81 2.53 2.67 2.86 2.52 2.36 2.49

2 2.65 2.55 2.56 2.61 2.67 2.74 2.51 2.75 2.65 2.45 2.33 2.59

3 2.58 2.51 2.54 2.57 2.63 2.78 2.49 2.65 2.54 2.36 2.29 2.51

4 2.55 2.58 2.62 2.54 2.79 2.69 2.47 3.54 2.46 2.30 2.51 2.46

5 2.50 2.56 2.60 2.53 2.77 2.62 2.46 2.89 2.42 2.30 2.94 2.50

6 2.45 2.52 2.55 2.53 2.69 2.54 2.44 2.79 2.39 2.25 2.66 2.50

7 2.42 2.48 2.52 2.51 2.64 2.53 2.43 4.85 2.39 2.27 2.53 2.47

8 2.44 3.24 2.51 2.50 2.60 2.72 2.41 3.29 2.35 2.23 2.46 2.53

9 2.43 3.40 2.49 2.49 2.58 2.68 2.43 2.94 2.33 2.20 2.42 2.54

10 2.46 2.95 2.47 2.48 2.56 2.61 2.40 2.78 2.31 2.18 2.40 2.48

11 2.45 2.77 2.47 2.49 2.56 2.58 2.39 2.69 2.30 2.23 2.40 2.43

12 2.47 2.68 2.46 2.47 2.53 2.71 2.38 3.16 2.32 2.27 2.39 2.37

13 2.58 2.62 2.46 2.49 2.52 2.69 2.38 2.95 2.29 2.20 2.49 2.34

14 2.92 2.58 3.67 2.48 2.51 2.63 2.38 2.76 2.28 2.25 2.75 2.34

15 2.76 2.53 3.61 2.47 2.52 2.60 2.42 2.66 2.29 2.63 2.74 2.35

16 2.69 2.51 2.99 2.48 2.78 2.59 2.71 2.60 2.28 2.49 2.66 2.32

17 2.64 2.48 2.81 2.76 2.72 2.54 2.58 2.55 2.60 2.40 2.61 2.30

18 2.60 2.46 2.72 2.84 2.65 2.51 2.51 2.52 2.52 --- 2.51 2.40

19 2.66 2.45 2.66 2.66 2.59 2.50 2.47 2.49 2.43 --- 2.44 2.41

20 3.07 2.45 2.62 2.61 2.56 2.49 2.45 2.47 2.37 2.78 2.40 2.35

21 2.83 2.43 2.60 2.60 2.58 2.49 2.43 2.53 2.35 2.60 2.48 2.30

22 2.68 2.47 2.57 2.58 2.60 2.48 2.41 2.49 2.31 2.51 2.42 2.31

23 2.59 2.66 2.57 4.78 2.58 2.95 2.40 2.45 2.28 2.45 2.37 2.31

24 2.71 2.59 2.55 3.27 2.80 3.07 2.39 2.42 2.29 2.58 2.34 2.30

25 2.66 2.54 2.53 2.95 2.79 2.80 2.38 2.41 2.26 2.56 2.30 2.30

26 2.68 2.52 2.51 2.82 2.68 2.68 2.38 2.41 2.26 2.72 2.37 2.29

27 2.65 3.19 2.69 2.75 2.63 2.61 2.37 2.40 2.25 2.63 3.32 2.27

28 2.58 2.90 2.66 2.75 2.59 2.56 2.45 2.37 2.24 2.53 2.75 2.28

29 2.53 2.72 2.61 2.70 2.96 2.53 2.46 2.37 2.35 2.47 2.59 2.25

30 2.50 2.64 2.71 2.65 --- 2.51 2.54 2.35 2.58 2.40 2.52 2.24

31 2.61 --- 2.76 2.72 --- 2.49 --- 2.40 --- 2.36 2.46 ---

Mean 2.62 2.65 2.67 2.70 2.65 2.64 2.45 2.73 2.38 --- 2.52 2.38

MAX 3.07 3.40 3.67 4.78 2.96 3.07 2.71 4.85 2.86 --- 3.32 2.59

MIN 2.42 2.43 2.46 2.47 2.51 2.48 2.37 2.35 2.24 --- 2.29 2.24
34

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

STATION: 05536340 Midlothian Creek at Oak Forest, IL

Type: stream, Agency: USGS, State: 17, County: 031, Latitude: 413651, Longitude: 0874346 NAD27, Drainage area:12.6*, 

Contributing drainage area: , Datum: 620.41 NGVD29

Date processed; 2012-01-18 15:32 by adrobl

Lowest aging status in period is APPROVED

DD #4

Discharge, cubic feet per second

WATER YEAR OCTOBER 2010 TO SEPTEMBER 2011

DAILY MEAN VALUES

Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 0.28 4.3 23 104 1

e1.8 48 5.1 19 34 8.1 2.1 1.3

2 0.44 4.3 9.8 58 e1.6 24 6.3 20 26 3.4 5.5 1.1

3 0.40 3.8 6.9 36 e1.7 18 4.3 37 24 2.5 5.9 5.3

4 0.43 4.1 6.7 26 e1.8 22 14 17 29 2.2 1.9 10

5 2.6 5.2 8.4 20 e2.0 111 7.5 11 27 1.7 1.3 2.4

6 3.3 3.9 8.6 e13 e2.2 63 5.2 8.6 9.8 1.4 4.9 1.2

7 3.1 3.0 4.8 e8.5 e2.0 37 4.8 9.5 6.6 2.8 5.0 1.1

8 4.1 2.6 4.4 e5.2 e1.9 28 60 7.5 4.8 2.9 19 2.2

9 3.8 2.5 3.9 e4.0 e1.6 46 31 6.4 197 1.4 41 15

10 2.1 3.0 4.0 e3.2 e1.6 31 15 6.5 188 1.3 11 3.8

11 1.3 2.9 17 e3.1 e1.8 18 15 6.0 163 11 5.2 1.9

12 1.4 3.1 58 e3.7 e2.0 14 10 12 102 5.0 3.1 1.1

13 3.3 4.0 98 e2.9 e5.5 9.6 11 28 49 2.2 3.0 0.90

14 2.1 3.8 105 e2.6 e20 24 6.4 19 40 1.6 6.6 0.77

15 2.3 3.6 59 e2.5 104 15 5.1 50 55 1.3 2.4 0.83

16 1.8 3.2 11 e2.3 49 7.9 14 25 36 1.0 5.6 0.57

17 1.7 2.6 e3.3 e2.5 140 5.9 12 15 32 1.1 2.2 0.52

18 1.4 2.5 e2.3 e6.0 107 5.0 26 11 9.3 0.74 0.86 0.77

19 1.4 2.4 e2.4 e4.0 44 4.4 47 9.0 6.8 0.64 4.1 9.8

20 1.9 3.8 e2.7 e2.9 64 5.2 110 7.1 82 0.52 30 3.3

21 2.6 3.9 e1.7 e2.3 108 6.5 47 6.2 69 0.83 15 1.3

22 1.4 25 e1.4 e2.3 56 62 99 5.4 35 17 5.0 0.83

23 5.3 40 e1.3 e2.6 25 31 120 5.2 25 64 29 0.70

24 18 12 e1.2 e2.6 22 18 62 4.5 25 80 25 3.0

25 42 42 e1.2 e2.4 14 11 41 86 7.5 65 5.6 1.5

26 38 14 e1.1 e2.1 14 6.5 117 151 5.7 15 3.0 56

27 18 7.9 e1.2 e2.3 18 5.3 113 134 4.9 9.0 1.8 50

28 7.5 6.4 e1.3 e2.0 98 4.6 78 96 8.9 24 1.3 23

29 5.8 14 4.4 e2.3 --- 8.2 50 89 5.8 9.5 1.1 16

30 4.6 61 30 e2.2 --- 4.3 30 76 7.9 4.7 0.88 10

31 4.2 --- 125 e1.9 --- 3.2 --- 37 --- 2.8 1.9 ---

Total 86.55 294.8 609.0 335.4 910.5 697.6 1166.7 1014.9 1316.0 344.63 250.24 226.19

Mean 6.02 9.83 19.6 10.8 32.5 22.5 38.9 32.7 43.9 11.1 8.07 7.54

Max 42 61 125 104 140 111 120 151 197 80 41 56

Min 0.28 2.4 1.1 1.9 1.6 3.2 4.3 4.5 4.8 0.52 0.86 0.52

CFSM 0.48 0.78 1.56 0.86 2.58 1.79 3.09 2.60 3.48 0.88 0.64 0.60

In. 0.55 0.87 1.80 0.99 2.69 2.06 3.44 3.00 3.89 1.02 0.74 0.67

e is Estimated
Appendix 2 Midlothian Creek

35

STATION: 05536340 Midlothian Creek at Oak Forest, IL

DD #4

Discharge, cubic feet per second

WATER YEAR OCTOBER 2010 TO SEPTEMBER 2011—Continued

STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1951–2011, BY WATER YEAR \(WY\)

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Mean 7.88 10.4 12.1 11.2 15.0 22.4 22.3 17.0 15.1 9.33 8.17 8.86

Max 70.9 40.7 70.9 43.9 64.8 86.9 53.5 46.1 61.2 57.0 47.5 85.0

\(WY\) 1955 1986 1983 1993 1997 1979 1973 1990 2000 1996 2007 2008

Min 0.04 0.17 0.00 0.00 0.00 3.13 1.41 1.84 0.88 0.29 0.25 0.11

\(WY\) 1964 1965 1963 1963 1963 1964 1963 1968 1965 1964 1966 1963

SUMMARY STATISTICS

For 2010 Calendar Year For 2011 Water Year Water Years 1951–2011

Annual total 6627.96 7352.51

Annual mean 18.2 20.1 13.3

Highest annual mean 22.7 2008

Lowest annual mean 2.68 1963

Highest daily mean 157 Aug 4 197 Jun 9 448 Oct 11 1954

Lowest daily mean 0.24 Aug 30 0.28 Oct 1 0.00 Oct 30 1950

Annual seven-day minimum 0.44 Sep 28 0.78 Sep 12 0.00 Nov 22 1962

Maximum peak flow 347 Jun 9 569 Oct 10 1954

Maximum peak stage 5.69 Jun 9 9.00 Jul 13 1957

Instantaneous low flow 0.160 Oct 1

Annual runoff\(CFSM\) 1.44 1.60 1.06

Annual runoff \(inches\) 19.57 21.71 14.34

10 percent exceeds 58 60 35

50 percent exceeds 5.3 5.8 3.9

90 percent exceeds 1.1 1.3 0.60
36

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

STATION: 05536340. Midlothian Creek at Oak Forest, IL

Type: stream, Agency: USGS, State: 17, County: 031, Latitude: 413651, Longitude: 0874346 NAD27, Drainage area:12.6*, 

Contributing drainage area: Datum: 620.41 NGVD29

Date processed: 2012-01-18 15:32 by adrobl

Lowest aging status in period is APPROVED

DD #3

Gage height, feet

WATER YEAR OCTOBER 2010 TO SEPTEMBER 2011

DAILY MEAN VALUES

Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 1.24 1.50 1.85 2.39 1.45 2.11 1.62 1.79 1.94 1.58 1.44 1.39

2 1.28 1.50 1.66 2.10 1.42 1.95 1.66 1.79 1.86 1.45 1.52 1.38

3 1.27 1.48 1.59 1.97 1.43 1.88 1.59 1.92 1.84 1.42 1.57 1.48

4 1.28 1.50 1.59 1.88 1.44 1.87 1.81 1.76 1.81 1.40 1.43 1.67

5 1.40 1.54 1.63 1.81 1.47 2.44 1.69 1.66 1.85 1.38 1.39 1.45

6 1.47 1.49 1.62 1.81 1.49 2.18 1.63 1.62 1.64 1.37 1.54 1.39

7 1.46 1.46 1.52 1.74 1.47 2.05 1.61 1.64 1.56 1.42 1.55 1.38

8 1.50 1.44 1.51 1.69 1.48 1.98 2.15 1.59 1.50 1.43 1.68 1.41

9 1.48 1.44 1.49 1.65 1.46 2.08 2.00 1.56 3.74 1.36 2.00 1.75

10 1.42 1.46 1.49 1.53 1.45 2.01 1.85 1.56 3.53 1.36 1.70 1.51

11 1.38 1.46 1.67 1.53 1.73 1.89 1.85 1.54 3.18 1.61 1.56 1.43

12 1.38 1.46 2.10 1.54 1.81 1.82 1.76 1.61 2.39 1.51 1.48 1.38

13 1.47 1.49 2.35 1.53 1.60 1.75 1.78 1.87 2.03 1.41 1.47 1.36

14 1.42 1.49 2.40 1.51 1.90 1.87 1.66 1.77 1.98 1.38 1.59 1.35

15 1.43 1.48 2.10 1.49 2.45 1.84 1.62 2.04 2.06 1.35 1.45 1.35

16 1.41 1.47 1.67 1.49 2.06 1.71 1.82 1.85 1.94 1.33 1.52 1.32

17 1.40 1.45 1.55 1.49 2.85 1.65 1.79 1.74 1.91 1.33 1.44 1.31

18 1.39 1.44 1.53 1.76 2.42 1.62 1.96 1.67 1.63 1.30 1.36 1.34

19 1.38 1.44 1.54 1.65 2.08 1.60 2.07 1.63 1.57 1.29 1.45 1.67

20 1.41 1.49 1.50 1.60 2.17 1.62 2.44 1.58 2.19 1.27 1.82 1.49

21 1.44 1.49 1.53 1.56 2.40 1.67 2.10 1.55 2.15 1.31 1.76 1.40

22 1.38 1.75 1.53 1.55 2.14 2.16 2.44 1.53 1.94 1.64 1.55 1.35

23 1.51 1.97 1.51 1.58 1.96 2.01 2.58 1.52 1.85 2.12 1.79 1.33

24 1.72 1.70 1.50 1.58 1.92 1.88 2.18 1.49 1.85 2.22 1.86 1.46

25 1.99 2.00 1.53 1.53 1.83 1.78 2.07 2.28 1.59 2.15 1.57 1.41

26 1.95 1.73 1.55 1.51 1.82 1.67 2.52 3.00 1.53 1.76 1.48 2.04

27 1.78 1.62 1.54 1.50 1.86 1.63 2.45 2.75 1.51 1.64 1.43 2.01

28 1.61 1.58 1.53 1.51 2.35 1.60 2.21 2.32 1.59 1.88 1.39 1.82

29 1.56 1.65 1.51 1.51 --- 1.68 2.04 2.28 1.53 1.67 1.38 1.73

30 1.52 2.12 1.81 1.50 --- 1.59 1.90 2.20 1.55 1.54 1.36 1.63

31 1.50 --- 2.62 1.47 --- 1.56 --- 1.96 --- 1.47 1.43 ---

Mean 1.48 1.57 1.69 1.64 1.85 1.84 1.96 1.84 1.97 1.53 1.55 1.50

MAX 1.99 2.12 2.62 2.39 2.85 2.44 2.58 3.00 3.74 2.22 2.00 2.04

MIN 1.24 1.44 1.49 1.47 1.42 1.56 1.59 1.49 1.50 1.27 1.36 1.31
Appendix 2 Midlothian Creek

37

STATION: 05536340 Midlothian Creek at Oak Forest, IL

Type: stream, Agency: USGS, State: 17, County: 031, Latitude: 413651, Longitude: 0874346 NAD27, Drainage area:12.6*, 

Contributing drainage area: Datum: 620.41 NGVD29

Date processed; 2013-02-09 09:07 by swreview

Lowest aging status in period is APPROVED

DD #4

Discharge, cubic feet per second

WATER YEAR OCTOBER 2011 TO SEPTEMBER 2012

DAILY MEAN VALUES

Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 8.6 4.6 8.1 11 22 18 5.4 17 30 6.1 3.7 11

2 5.2 3.7 5.3 8.6 13 16 3.8 20 5.9 2.8 1.9 11

3 3.8 3.7 4.7 9.7 15 18 2.2 9.6 2.8 1.6 1.1 4.2

4 3.2 6.6 11 7.6 32 11 1.9 78 1.9 1.3 27 2.4

5 6.8 4.1 6.1 8.6 19 8.1 1.7 24 1.5 1.1 41 12

6 4.2 3.2 4.5 8.1 12 6.9 1.4 33 1.3 0.90 7.0 4.8

7 1.6 3.1 4.0 5.4 9.3 5.6 1.3 146 1.2 0.86 2.6 6.6

8 1.5 73 3.5 4.8 7.6 26 1.3 107 1.1 0.91 1.6 7.8

9 3.1 96 3.4 4.8 6.4 15 1.2 41 0.90 1.0 1.3 7.6

10 2.5 43 3.2 3.8 e6.2 8.5 1.2 25 0.85 0.93 3.8 3.1

11 1.2 20 2.6 3.1 e5.8 6.9 1.4 25 0.89 0.74 1.5 1.6

12 1.2 12 2.5 3.2 e5.3 15 1.2 62 0.80 0.64 0.93 1.1

13 16 7.5 2.6 3.3 5.1 10 1.2 26 0.90 1.6 14 0.88

14 21 5.9 73 3.3 4.9 7.5 1.3 9.9 0.75 14 21 1.8

15 6.1 5.4 117 3.0 5.5 6.5 4.2 6.2 0.73 13 12 1.4

16 3.9 4.9 67 3.5 24 9.5 29 5.9 2.1 2.4 14 0.91

17 3.3 4.0 36 26 14 6.3 6.7 4.8 28 1.5 8.9 2.1

18 2.6 3.2 24 60 9.4 4.9 3.0 3.4 4.5 5.0 2.8 11

19 14 2.3 24 e21 7.6 4.6 2.2 2.2 1.8 74 1.6 2.4

20 48 2.2 15 e9.8 6.5 4.2 2.2 2.8 3.0 23 3.9 1.2

21 15 2.0 15 e8.0 7.5 3.7 1.8 6.9 1.8 7.8 5.9 0.88

22 7.3 7.6 9.6 e8.7 8.0 3.2 1.6 2.9 1.4 3.6 2.1 0.77

23 5.3 17 7.5 126 7.3 50 1.4 2.1 0.93 2.1 1.3 0.65

24 18 7.4 6.0 94 25 43 1.3 1.8 0.75 11 0.97 0.60

25 7.8 5.5 5.3 56 19 14 1.2 1.9 0.72 14 0.75 0.56

26 14 7.0 4.8 33 11 7.6 1.3 1.4 0.76 21 16 0.52

27 6.8 59 19 22 8.2 5.2 1.2 1.4 0.60 8.3 76 0.47

28 4.8 24 11 19 7.0 4.2 5.8 1.3 1.2 3.0 15 0.42

29 3.7 12 7.5 15 35 3.0 3.1 1.2 6.4 2.0 8.2 0.38

30 3.3 11 15 11 --- 3.0 13 1.1 20 1.7 5.8 0.53

31 7.7 --- 16 31 --- 2.8 --- 8.7 --- 3.4 3.4 ---

Total 251.5 460.9 534.2 632.3 358.6 348.2 105.5 679.5 125.48 231.28 307.05 100.67

Mean 8.11 15.4 17.2 20.4 12.4 11.2 3.52 21.9 4.18 7.46 9.90 3.36

Max 48 96 117 126 35 50 29 146 30 74 76 12

Min 1.2 2.0 2.5 3.0 4.9 2.8 1.2 1.1 0.60 0.64 0.75 0.38

CFSM 0.64 1.22 1.37 1.62 0.98 0.89 0.28 1.74 0.33 0.59 0.79 0.27

In. 0.74 1.36 1.58 1.87 1.06 1.03 0.31 2.01 0.37 0.68 0.91 0.30

e is Estimated
38

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

STATION: 05536340 Midlothian Creek at Oak Forest, IL

DD #4

Discharge, cubic feet per second

WATER YEAR OCTOBER 2011 TO SEPTEMBER 2012—Continued

STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1951–2012, BY WATER YEAR (WY)

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Mean 7.88 10.5 12.2 11.4 14.9 22.2 22.0 17.1 15.0 9.30 8.19 8.77

Max 70.9 40.7 70.9 43.9 64.8 86.9 53.5 46.1 61.2 57.0 47.5 85.0

\(WY\) 1955 1986 1983 1993 1997 1979 1973 1990 2000 1996 2007 2008

Min 0.04 0.17 0.00 0.00 0.00 3.13 1.41 1.84 0.88 0.29 0.25 0.11

\(WY\) 1964 1965 1963 1963 1963 1964 1963 1968 1965 1964 1966 1963

SUMMARY STATISTICS

For 2011 Calendar Year For 2012 Water Year Water Years 1951–2012

Annual total 7508.76 4135.18

Annual mean 20.6 11.3 13.3

Highest annual mean 22.7 2008

Lowest annual mean 2.68 1963

Highest daily mean 197 Jun 9 146 May 7 448 Oct 11 1954

Lowest daily mean 0.52 Jul 20 0.38 Sep 29 0.00 Oct 30 1950

Annual seven-day minimum 0.78 Sep 12 0.50 Sep 24 0.00 Nov 22 1962

Maximum peak flow 207 Jan 23 569 Oct 10 1954

Maximum peak stage 3.81 Jan 23 9.00 Jul 13 1957

Instantaneous low flow 0.08 Aug 3

Annual runoff (CFSM) 1.63 0.897 1.05

Annual runoff (inches) 22.17 12.21 14.30

10 percent exceeds 62 25 34

50 percent exceeds 6.8 5.2 3.9

90 percent exceeds 1.6 1.1 0.60
Appendix 2 Midlothian Creek

39

STATION: 05536340. Midlothian Creek at Oak Forest IL

Type: stream, Agency: USGS, State: 17, County: 031, Latitude: 413651, Longitude: 0874346 NAD27, Drainage area:12.6*, 

Contributing drainage area: Datum: 620.41 NGVD29

Date processed: 2013-02-09 09:07 by swreview

Lowest aging status in period is APPROVED

DD #3

Gage height, feet

WATER YEAR OCTOBER 2011 TO SEPTEMBER 2012

DAILY MEAN VALUES

Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 1.59 1.48 1.57 1.65 1.86 1.81 1.63 1.81 1.92 1.63 1.59 1.68

2 1.50 1.44 1.50 1.59 1.75 1.78 1.60 1.83 1.65 1.56 1.51 1.74

3 1.44 1.44 1.48 1.61 1.76 1.81 1.53 1.70 1.56 1.48 1.40 1.61

4 1.43 1.54 1.64 1.57 1.95 1.70 1.50 2.21 1.51 1.45 1.67 1.55

5 1.51 1.46 1.53 1.59 1.83 1.64 1.48 1.87 1.47 1.41 1.99 1.76

6 1.45 1.43 1.47 1.58 1.73 1.61 1.46 1.91 1.45 1.39 1.68 1.63

7 1.36 1.42 1.45 1.51 1.67 1.57 1.44 2.93 1.44 1.38 1.55 1.65

8 1.35 2.14 1.44 1.48 1.63 1.88 1.43 2.47 1.42 1.39 1.48 1.70

9 1.42 2.32 1.43 1.48 1.60 1.77 1.42 2.00 1.39 1.41 1.44 1.70

10 1.40 1.97 1.43 1.45 1.59 1.65 1.42 1.91 1.38 1.39 1.58 1.57

11 1.33 1.77 1.40 1.42 1.62 1.61 1.44 1.90 1.38 1.36 1.46 1.49

12 1.33 1.66 1.40 1.43 1.57 1.77 1.42 2.12 1.37 1.34 1.39 1.45

13 1.61 1.57 1.40 1.43 1.55 1.69 1.42 1.90 1.39 1.45 1.73 1.42

14 1.77 1.52 2.13 1.43 1.55 1.63 1.44 1.74 1.36 1.61 1.86 1.50

15 1.52 1.50 2.51 1.42 1.57 1.60 1.57 1.67 1.35 1.76 1.77 1.48

16 1.45 1.48 2.13 1.43 1.87 1.65 1.90 1.66 1.38 1.53 1.77 1.42

17 1.43 1.45 1.93 1.80 1.75 1.59 1.67 1.63 1.90 1.46 1.71 1.46

18 1.41 1.42 1.83 2.08 1.67 1.55 1.57 1.58 1.62 1.52 1.56 1.74

19 1.60 1.39 1.82 1.96 1.63 1.54 1.53 1.53 1.50 2.18 1.48 1.54

20 2.00 1.39 1.70 1.98 1.60 1.52 1.53 1.55 1.56 1.88 1.56 1.46

21 1.71 1.38 1.68 2.02 1.63 1.50 1.49 1.68 1.50 1.70 1.64 1.42

22 1.56 1.51 1.61 1.76 1.64 1.49 1.47 1.57 1.46 1.59 1.52 1.40

23 1.50 1.73 1.57 2.65 1.62 2.00 1.45 1.52 1.39 1.53 1.45 1.38

24 1.74 1.56 1.53 2.32 1.88 2.02 1.43 1.50 1.36 1.71 1.40 1.37

25 1.57 1.51 1.50 2.10 1.83 1.76 1.43 1.51 1.35 1.79 1.36 1.36

26 1.69 1.53 1.48 1.96 1.70 1.63 1.43 1.46 1.36 1.86 1.55 1.36

27 1.55 2.07 1.75 1.87 1.65 1.56 1.42 1.45 1.34 1.70 2.21 1.35

28 1.48 1.82 1.64 1.83 1.61 1.52 1.60 1.44 1.38 1.57 1.80 1.33

29 1.44 1.67 1.57 1.77 1.96 1.52 1.57 1.43 1.66 1.51 1.71 1.33

30 1.43 1.64 1.69 1.72 --- 1.57 1.70 1.41 1.84 1.49 1.65 1.36

31 1.56 --- 1.73 1.90 --- 1.57 --- 1.57 --- 1.56 1.58 ---

Mean 1.52 1.61 1.64 1.74 1.70 1.66 1.51 1.76 1.49 1.57 1.61 1.51

MAX 2.00 2.32 2.51 2.65 1.96 2.02 1.90 2.93 1.92 2.18 2.21 1.76

MIN 1.33 1.38 1.40 1.42 1.55 1.49 1.42 1.41 1.34 1.34 1.36 1.33
40

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

STATION: 05533400 Sawmill Creek near Lemont, IL

Type: stream, Agency: USGS, State: 17, County: 043, Latitude: 414228, Longitude: 0875746 NAD83, Drainage area:13.0, 

Contributing drainage area:13.00 *, Datum: 630.00 NGVD29

Date processed; 2012-10-12 13:37 by mjlee

Lowest aging status in period is WORKING

DD #5

Discharge, cubic feet per second

WATER YEAR OCTOBER 2010 TO SEPTEMBER 2011

DAILY MEAN VALUES

Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 0.11 0.41 5.3 77 1.1 19 3.1 6.9 12 1.8 4.1 0.71

2 0.20 0.38 2.9 36 1.3 10 2.8 5.3 6.3 1.6 4.4 0.61

3 0.36 0.42 2.1 19 #1.7 6.2 1.9 4.0 4.1 1.4 9.8 15

4 0.30 0.58 2.3 7.1 1.6 25 3.6 3.2 3.8 1.2 2.8 3.5

5 0.19 #0.41 #2.7 5.7 1.6 108 2.3 3.3 2.8 1.0 1.9 1.2

6 0.13 e0.33 #1.9 3.7 1.3 29 1.6 4.2 2.0 0.92 4.3 0.83

7 0.10 e0.31 e1.6 3.2 1.3 16 2.2 2.9 1.6 1.7 17 0.70

8 0.06 #0.20 e1.3 2.6 1.2 9.3 58 2.3 1.3 1.0 11 0.56

9 0.04 0.50 e1.2 2.1 1.3 44 16 2.0 481 0.81 9.0 0.66

10 0.04 0.30 1.2 2.0 #1.7 21 8.8 1.8 96 0.72 3.0 0.68

11 0.02 0.19 21 1.8 1.5 11 7.3 2.1 46 5.1 1.8 0.56

12 0.06 0.13 32 1.8 1.2 6.5 4.0 3.0 27 2.0 1.3 0.76

13 0.52 0.13 7.5 1.6 1.5 4.6 2.8 1.9 15 1.1 4.8 0.59

14 0.49 0.12 3.3 1.4 19 3.9 2.2 1.6 8.8 1.1 3.8 0.48

15 0.40 0.11 2.1 1.4 21 3.7 2.7 4.6 56 0.71 1.8 0.46

16 0.38 0.14 2.3 1.3 32 3.0 8.1 2.2 34 0.54 1.2 0.41

17 0.28 0.26 1.5 1.3 163 2.6 4.5 1.5 15 0.34 1.4 0.39

18 0.28 0.18 1.4 9.6 82 2.3 27 1.2 7.3 0.29 0.91 0.86

19 0.32 e0.17 1.2 3.4 29 1.9 65 1.1 5.2 0.42 0.77 11

20 0.16 e0.15 2.0 2.0 93 4.6 87 1.0 59 0.28 6.6 1.6

21 0.05 e0.12 1.4 1.9 103 7.5 25 0.95 58 0.32 2.6 0.95

22 0.00 e4.1 1.3 2.8 28 29 114 0.87 58 22 1.3 0.64

23 0.00 e16 1.2 2.4 15 24 82 0.88 21 253 36 0.55

24 2.5 e4.6 1.2 1.9 12 11 29 0.73 12 171 13 0.53

25 5.2 13 1.4 1.7 8.6 6.2 18 131 6.7 39 4.1 0.52

26 6.6 3.8 1.5 1.3 7.3 4.0 116 185 4.6 17 1.8 45

27 1.3 2.1 1.3 1.2 9.1 3.1 81 37 4.6 8.6 1.1 35

28 0.83 1.7 1.2 1.2 62 2.5 42 24 3.5 60 0.87 21

29 0.72 6.1 1.1 1.2 --- 2.1 20 138 2.6 28 0.79 14

30 0.56 24 24 1.2 --- 1.9 12 65 2.3 11 0.76 5.3

31 0.47 --- 196 1.1 --- 1.7 --- 21 --- 6.5 0.95 ---

Total 22.67 80.94 328.4 201.9 702.3 424.6 849.9 660.53 1057.5 640.45 154.95 165.05

Mean 0.73 2.70 10.6 6.51 25.1 13.7 28.3 21.3 35.2 20.7 5.00 5.50

Max 6.6 24 196 77 163 108 116 185 481 253 36 45

Min 0.00 0.11 1.1 1.1 1.1 1.7 1.6 0.73 1.3 0.28 0.76 0.39

CFSM 0.06 0.21 0.81 0.50 1.93 1.05 2.18 1.64 2.71 1.59 0.38 0.42

In. 0.06 0.23 0.94 0.58 2.01 1.22 2.43 1.89 3.03 1.83 0.44 0.47

e is Estimated

# Value is write-protected with a “1”
Appendix 2 Sawmill Creek

41

STATION: 05533400 Sawmill Creek near Lemont, IL

DD #4

Discharge, cubic feet per second

WATER YEAR OCTOBER 2010 TO SEPTEMBER 2011—Continued

STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1986–2011, BY WATER YEAR (WY)

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Mean 7.06 10.1 11.0 11.0 14.7 17.3 18.1 16.5 13.1 9.76 9.59 8.15

Max 27.2 37.4 49.3 30.6 54.5 56.3 53.4 49.3 57.6 58.6 29.9 55.6

 (WY) 2010 1991 2009 1993 1997 2009 1999 1990 1993 1996 2007 2008

Min 0.19 0.68 0.22 0.17 0.16 3.54 4.88 1.25 0.77 0.14 0.31 0.10

 (WY) 2006 2003 2003 2003 2003 2000 2004 1992 2005 1991 2005 1995

SUMMARY STATISTICS

For 2010 Calendar Year For 2011 Water Year Water Years 1986–2011

Annual total 4930.47 5289.19

Annual mean 13.5 14.5 12.1

Highest annual mean 20.2 2009

Lowest annual mean 5.39 2003

Highest daily mean 440 Jul 24 481 Jun 9 1220 Jul 18 1996

Lowest daily mean 0.00 Oct 22 0.00 Oct 22 0.00 Oct 9 1988

Annual seven-day minimum 0.06 Oct 6 0.06 Oct 6 0.00 Jul 24 1991

Maximum peak flow 1040 Jun 9 3070 Jul 18 1996

Maximum peak stage 13.67 Jun 9 17.53 Jul 18 1996

Instantaneous low flow 0.00 Oct 11

Annual runoff (CFSM) 1.04 1.11 0.930

Annual runoff (inches) 14.11 15.14 12.63

10 percent exceeds 32 35 35

50 percent exceeds 2.7 2.2 3.4

90 percent exceeds 0.31 0.34 0.60
42

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

STATION: 05533400 Sawmill Creek near Lemont, IL

Type: stream, Agency: USGS, State: 17, County: 043, Latitude: 414228, Longitude: 0875746 NAD83, Drainage area:13.0, 

Contributing drainage area:13.00 *, Datum: 630.00 NGVD29

Date processed; 2012-10-12 13:37 by mjlee

Lowest aging status in period is WORKING

DD #4

Gage height, feet

WATER YEAR OCTOBER 2010 TO SEPTEMBER 2011

DAILY MEAN VALUES

Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 7.96 8.10 8.65 9.70 8.28 9.27 8.62 8.90 9.09 8.40 8.61 8.22 

2 8.04 8.08 8.51 9.29 8.32 9.03 8.62 8.81 8.87 8.37 8.57 8.17

3 8.20 8.10 8.44 9.03 #8.46 8.86 8.53 8.73 8.73 8.33 8.84 8.67

4 8.15 8.19 8.45 8.73 8.37 9.03 8.69 8.67 8.71 8.29 8.50 8.63

5 8.05 #8.10 #8.49 8.67 8.37 10.07 8.57 8.66 8.63 8.25 8.41 8.36

6 7.98 --- #8.42 8.56 8.33 9.43 8.49 8.74 8.55 8.21 8.57 8.26

7 7.95 --- --- 8.53 8.32 9.21 8.50 8.64 8.49 8.35 8.95 8.21

8 7.91 #7.94 --- 8.48 8.31 9.00 9.69 8.58 8.43 8.25 8.90 8.15

9 7.89 8.14 --- 8.44 8.33 9.51 9.21 8.54 11.62 8.18 8.84 8.19

10 7.89 8.02 8.31 8.43 #8.39 9.31 8.98 8.52 10.06 8.14 8.52 8.20

11 7.88 7.92 8.67 8.41 8.37 9.05 8.91 8.54 9.61 8.52 8.40 8.15

12 7.91 7.87 9.18 8.41 8.32 8.87 8.73 8.64 9.32 8.42 8.33 8.20

13 8.27 7.86 8.74 8.38 8.34 8.77 8.63 8.53 9.07 8.26 8.51 8.16

14 8.27 7.84 8.54 8.35 8.92 8.72 8.57 8.49 8.86 8.23 8.59 8.11

15 8.22 7.84 8.44 8.34 9.06 8.70 8.60 8.76 9.61 8.13 8.40 8.10

16 8.21 7.87 8.45 8.33 9.14 8.64 8.95 8.56 9.44 8.06 8.30 8.06

17 8.13 7.99 8.37 8.32 10.31 8.61 8.76 8.47 9.05 7.94 8.32 8.05

18 8.12 7.91 8.34 8.80 9.80 8.58 9.33 8.42 8.80 7.91 8.21 8.06

19 8.16 --- 8.32 8.54 9.37 8.53 9.55 8.40 8.69 7.98 8.16 8.89

20 8.03 --- 8.39 8.43 9.81 8.70 9.91 8.37 9.54 7.90 8.55 8.45

21 7.91 --- 8.34 8.41 10.03 8.91 9.37 8.34 9.49 7.92 8.48 8.30

22 7.86 --- 8.34 8.49 9.42 9.39 10.06 8.32 9.69 8.72 8.30 8.18

23 7.84 --- 8.31 8.46 9.17 9.35 9.90 8.32 9.21 10.70 9.07 8.15

24 8.30 --- 8.30 8.42 9.10 9.05 9.43 8.27 8.96 10.45 9.01 8.14

25 8.64 8.89 8.35 8.38 8.97 8.86 9.27 9.75 8.77 9.51 8.68 8.13

26 8.62 8.57 8.36 8.32 8.92 8.73 10.13 10.47 8.65 9.10 8.47 9.29

27 8.41 8.44 8.34 8.30 8.97 8.66 9.89 9.52 8.64 8.85 8.34 9.40

28 8.29 8.39 8.30 8.32 9.74 8.60 9.57 9.35 8.57 9.68 8.28 9.17

29 8.25 8.47 8.29 8.31 --- 8.56 9.31 10.08 8.49 9.33 8.25 9.07

30 8.18 9.08 8.89 8.30 --- 8.53 9.09 9.76 8.45 8.92 8.24 8.77

31 8.13 --- 10.43 8.28 --- 8.51 --- 9.31 --- 8.76 8.30 ---

Mean 8.12 --- --- 8.52 8.90 8.94 9.13 8.82 9.07 8.58 8.51 8.40

MAX 8.64 --- --- 9.70 10.31 10.07 10.13 10.47 11.62 10.70 9.07 9.40

MIN 7.84 --- --- 8.28 8.28 8.51 8.49 8.27 8.43 7.90 8.16 8.05

 # Value is write-protected with a “1”
Appendix 2 Sawmill Creek

43

STATION: 05533400 Sawmill Creek near Lemont, IL

Type: stream, Agency: USGS, State: 17, County: 043, Latitude: 414228, Longitude: 0875746 NAD83, Drainage area:13.0, 

Contributing drainage area:13.00 *, Datum: 630.00 NGVD29

Date processed; 2013-01-25 09:16 by johnsonk

Lowest aging status in period is APPROVED

DD #5

Discharge, cubic feet per second

WATER YEAR OCTOBER 2011 TO SEPTEMBER 2012

DAILY MEAN VALUES

Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 3.0 1.8 6.1 8.4 12 12 6.3 21 6.3 0.25 0.34 3.0

2 2.2 1.7 4.8 6.0 8.1 16 4.5 18 1.5 0.25 0.14 2.0

3 1.6 3.3 6.5 5.6 6.8 17 3.4 7.2 0.91 0.11 0.09 1.1

4 1.5 3.0 16 4.3 8.3 9.1 2.9 70 0.71 0.01 21 0.91

5 1.2 2.6 7.1 4.0 6.8 6.9 2.6 16 0.56 0.00 7.1 2.4

6 1.0 1.7 5.5 4.4 5.7 6.1 2.3 24 0.41 0.00 2.3 1.3

7 2.0 1.4 4.7 3.8 5.2 5.6 2.1 187 0.25 0.00 0.93 2.6

8 1.2 103 4.1 3.3 4.6 10 2.0 46 0.21 0.00 0.55 1.4

9 0.68 101 3.9 3.2 4.3 5.9 1.8 18 0.18 #0.00 0.28 2.8

10 0.63 33 3.3 3.0 4.3 4.7 1.7 8.5 0.15 #0.00 0.69 1.1

11 0.87 15 3.0 3.1 4.2 4.4 2.2 4.4 0.17 #0.00 0.35 0.86

12 0.70 8.9 3.5 3.1 3.9 10 1.8 15 0.13 #0.00 0.13 0.93

13 7.0 6.6 3.0 3.4 3.6 #6.5 1.6 8.2 0.29 #0.00 0.38 0.62

14 4.2 5.3 116 3.1 3.6 5.7 2.2 3.3 0.20 2.5 1.1 0.95

15 1.7 4.5 73 2.7 3.7 4.7 84 2.4 0.09 0.94 0.50 0.70

16 1.2 3.8 28 3.4 12 4.3 55 2.2 0.01 0.18 2.5 0.43

17 1.3 3.2 15 20 6.1 3.9 16 1.5 4.8 0.07 1.3 0.35

18 0.90 2.8 9.6 12 5.0 3.7 8.7 1.2 0.77 2.9 0.83 2.4

19 9.2 2.6 8.5 7.4 4.3 3.5 6.6 1.1 0.22 30 0.43 0.86

20 20 2.4 6.9 6.1 4.0 3.3 5.3 1.0 0.17 3.1 0.73 0.62

21 4.2 2.1 5.4 5.3 5.0 3.0 4.4 2.9 0.16 1.5 1.3 0.42

22 2.5 4.1 4.8 5.0 4.8 3.4 3.8 1.5 0.05 0.72 0.67 0.41

23 1.9 6.6 5.1 143 4.3 30 3.3 1.1 0.00 0.44 0.31 0.51

24 11 3.6 4.1 46 18 12 2.9 0.80 0.00 3.8 0.15 0.37

25 3.4 3.1 3.6 23 10 6.4 2.6 0.70 0.00 1.6 0.07 0.18

26 4.7 35 3.3 13 6.6 5.5 2.5 0.69 0.00 1.8 47 0.11

27 2.9 86 7.4 11 5.7 4.2 2.1 0.50 0.00 0.92 56 0.09

28 2.3 27 4.8 12 4.9 3.9 4.5 0.43 0.00 0.60 8.1 0.09

29 2.1 12 4.0 8.7 32 3.4 3.2 0.34 0.00 0.24 3.4 0.08

30 1.9 8.1 23 7.4 --- 10 11 0.25 0.94 0.13 2.1 0.06

31 2.1 --- 16 12 --- 5.3 --- 6.7 --- 0.88 1.3 ---

Total 101.08 495.2 410.0 396.7 207.8 230.4 253.3 471.91 19.18 52.94 162.07 29.65

Mean 3.26 16.5 13.2 12.8 7.17 7.43 8.44 15.2 0.64 1.71 5.23 0.99

Max 20 103 116 143 32 30 84 187 6.3 30 56 3.0

Min 0.63 1.4 3.0 2.7 3.6 3.0 1.6 0.25 0.00 0.00 0.07 0.06

CFSM 0.25 1.27 1.02 0.98 0.55 0.57 0.65 1.17 0.05 0.13 0.40 0.08

In. 0.29 1.42 1.17 1.14 0.59 0.66 0.72 1.35 0.05 0.15 0.46 0.08

# Value is write-protected with a “1”
44

Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit near Summit, Illinois, 2010 - 2012

STATION: 05533400 Sawmill Creek near Lemont, IL

DD #4

Discharge, cubic feet per second

WATER YEAR OCTOBER 2011 TO SEPTEMBER 2012—Continued

STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1986–2012, BY WATER YEAR (WY)

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Mean 6.91 10.4 11.1 11.1 14.4 16.9 17.7 16.4 12.7 9.46 9.42 7.89

Max 27.2 37.4 49.3 30.6 54.5 56.3 53.4 49.3 57.6 58.6 29.9 55.6

 (WY) 2010 1991 2009 1993 1997 2009 1999 1990 1993 1996 2007 2008

Min 0.19 0.68 0.22 0.17 0.16 3.54 4.88 1.25 0.64 0.14 0.31 0.10

 (WY) 2006 2003 2003 2003 2003 2000 2004 1992 2012 1991 2005 1995

SUMMARY STATISTICS

For 2011 Calendar Year For 2012 Water Year Water Years 1986–2012

Annual total 5863.46 2830.23

Annual mean 16.1 7.73 11.9

Highest annual mean 20.2 2009

Lowest annual mean 5.39 2003

Highest daily mean 481 Jun 9 187 May 7 1220 Jul 18 1996

Lowest daily mean 0.28 Jul 20 0.00 Jun 23 0.00 Oct 9 1988

Annual seven-day minimum 0.41 Jul 15 0.00 Jun 23 0.00 Jul 24 1991

Maximum peak flow 375 May 7 3070 Jul 18 1996

Maximum peak stage 11.38 May 7 17.53 Jul 18 1996

Instantaneous low flow 0.00 Jun 13

Annual runoff (CFSM) 1.24 0.595 0.917

Annual runoff (inches) 16.78 8.10 12.46

10 percent exceeds 40 16 26

50 percent exceeds 3.5 3.1 3.3

90 percent exceeds 0.87 0.17 0.29
Appendix 2 Sawmill Creek

45

STATION: 05533400 Sawmill Creek near Lemont, IL

Type: stream, Agency: USGS, State: 17, County: 043, Latitude: 414228, Longitude: 0875746 NAD83, Drainage area:13.0, 

Contributing drainage area:13.00 *, Datum: 630.00 NGVD29

Date processed; 2012-10-12 13:37 by mjlee

Lowest aging status in period is WORKING

DD #4

Gage height, feet

WATER YEAR OCTOBER 2010 TO SEPTEMBER 2011

DAILY MEAN VALUES

Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 8.61 8.48 8.68 8.78 8.90 8.92 8.68 8.92 8.74 7.96 8.02 8.46

2 8.53 8.47 8.60 8.67 8.77 8.93 8.58 9.02 8.38 7.97 7.86 8.42

3 8.45 8.60 8.69 8.65 8.71 9.02 8.51 8.73 8.26 7.83 7.80 8.30

4 8.43 8.60 8.99 8.57 8.78 8.81 8.46 9.60 8.20 7.71 8.40 8.24

5 8.38 8.57 8.73 8.55 8.71 8.72 8.43 8.99 8.14 7.66 8.75 8.44

6 8.33 8.47 8.65 8.57 8.66 8.68 8.39 9.05 8.07 7.65 8.46 8.33

7 8.43 8.41 8.60 8.54 8.63 8.65 8.37 10.42 7.97 7.63 8.24 8.44

8 8.35 9.81 8.55 8.50 8.59 8.82 8.36 9.47 7.94 7.61 8.10 8.34

9 8.21 9.91 8.54 8.48 8.57 8.66 8.34 9.15 7.91 #7.58 7.95 8.49

10 8.18 9.27 8.50 8.47 8.57 8.60 8.32 8.90 7.87 --- 8.10 8.29

11 8.25 8.98 8.47 8.48 8.56 8.57 8.38 8.71 7.90 --- 7.98 8.22

12 8.21 8.80 8.50 8.48 8.54 8.82 8.33 8.99 7.85 --- 7.80 8.22

13 8.55 8.70 8.47 8.50 8.52 #8.70 8.30 8.87 7.91 --- 7.89 8.13

14 8.68 8.63 9.84 8.47 8.52 8.65 8.36 8.62 7.92 8.46 8.28 8.24

15 8.47 8.58 9.68 8.44 8.53 8.60 9.72 8.54 7.81 8.24 8.07 8.16

16 8.37 8.53 9.21 8.49 8.88 8.57 9.50 8.52 7.72 7.91 8.29 8.05

17 8.38 8.48 8.99 9.07 8.68 8.54 9.00 8.43 8.55 7.79 8.32 8.00

18 8.29 8.45 8.83 8.90 8.62 8.52 8.79 8.37 8.21 8.13 8.21 8.45

19 8.65 8.43 8.78 8.74 8.57 8.51 8.70 8.34 7.94 9.23 8.04 8.22

20 9.15 8.41 8.72 8.67 8.54 8.49 8.63 8.32 7.89 8.53 8.02 8.13

21 8.70 8.38 8.64 8.64 8.61 8.47 8.58 8.55 7.88 8.38 8.33 8.04

22 8.56 8.50 8.60 8.61 8.60 8.49 8.54 8.40 7.77 8.20 8.15 8.03

23 8.49 8.68 8.62 10.15 8.57 9.17 8.49 8.33 7.69 8.08 7.96 8.09

24 8.94 8.51 8.56 9.42 9.02 8.90 8.46 8.24 7.68 8.46 7.82 8.01

25 8.64 8.48 8.52 9.14 8.84 8.69 8.43 8.20 7.67 8.38 7.73 7.85

26 8.73 8.96 8.50 8.94 8.71 8.64 8.42 8.20 7.66 8.40 8.78 7.77

27 8.60 9.77 8.73 8.87 8.66 8.56 8.38 8.11 7.65 8.26 9.64 7.75

28 8.54 9.19 8.60 8.91 8.61 8.54 8.56 8.07 7.64 8.15 8.82 7.75

29 8.52 8.91 8.55 8.80 9.22 8.51 8.48 8.01 7.65 7.96 8.56 7.73

30 8.50 8.77 9.02 8.74 --- 8.75 8.79 7.94 8.15 7.85 8.44 7.72

31 8.51 --- 8.99 8.90 --- 8.63 --- 8.38 --- 8.16 8.34 ---

Mean 8.50 8.76 8.75 8.75 8.68 8.68 8.58 8.66 7.95 --- 8.23 8.14

MAX 9.15 9.91 9.84 10.15 9.22 9.17 9.72 10.42 8.74 --- 9.64 8.49

MIN 8.18 8.38 8.47 8.44 8.52 8.47 8.30 7.94 7.64 --- 7.73 7.72

# Value is write-protected with a “1”


Johnson and Goodwin—Monitoring of Stage and Velocity, for Computation of Discharge in the Summit Conduit, Summit, Illinois—Open-File Report 2012–1244

2010–2012