1

U.S. Department of Interior

U.S. Geological Survey

 May 2004

District Web Site: http://il.water.usgs.gov/ Compiled by D.M. Ayers

Water Resources Update

Illinois District Newsletter

The U.S. Geological Survey’s 

(USGS) National Water-Quality 

Assessment (NAWQA) Program began 

in the late 1980’s with the goal of 

answering the question, “Is the quality 

of the Nation’s waters getting better or 

worse?” The process began in 1987 

with six pilot studies (as a proof of concept) and began on a nationwide basis 

in 1991 with the beginnings of Cycle 1 

of NAWQA. The Illinois District has 

worked on two NAWQA studies: Upper 

Illinois River Basin (UIRB) and the 

Lower Illinois River Basin (LIRB), 

with Ottawa, Illinois, being the boundary between the two study areas. The 

LIRB study began in 1994, culminating 

with the summary report of this study 

issued in 2001. The UIRB study began 

as one of the pilot studies in 1987 

(examining only surface water-quality 

issues) and was restarted in 1997 as part 

of the last group of the Cycle 1 studies 

and examined both surface and ground 

water.

In 2001, while the last group of Cycle 

1 studies was completing the data-collection phase, Cycle 2 of NAWQA 

restarted those studies that begin in 

1991. Cycle 1 of NAWQA had the goal 

of assessing the occurrence and distribution of water quality in the Nation’s 

water resources. Cycle 2 maintains the 

data collection that has been the foundation of the NAWQA Program, however, the goal switches from solely 

assessing occurrence and distribution 

of water quality, to studying various 

water-quality topics of interest (topical 

studies) in some detail. There are five 

topical study issues being conducted as 

part of Cycle 2: Transport of Natural 

and Anthropogenic Contaminants, 

Effects of Urban Land Use, Mercury, 

Agricultural Chemical Transport, and 

Nutrient Effects on Ecosystems. Each 

Cycle 2 project study basin is evaluated 

for its suitability and adequacy in meeting the national goals of each topical 

study. In this current Fiscal Year 

(2004), the Lower Illinois River Basin 

(LIRB) NAWQA study begins the 

restart for Cycle 2. Illinois District 

Staff have prepared proposals for consideration by the National Leadership 

Team of NAWQA for the Transport of 

Natural and Anthropogenic Contaminants, Agricultural Chemical Transport, and Nutrient Effects on 

Ecosystems study topics. The Illinois 

District should be notified of the topical studies to be conducted as part of 

the LIRB by early summer.

The summary report for the UIRB 

study (Cycle 1) has just been released 

this spring (along with the summary 

reports from the other Cycle 1 1997 

studies), with the highlights from this 

study given in this issue of the Water 

Resources Update. I encourage you to 

read this article and read the summary 

report, which is available online and 

printed from the Illinois District 

(while copies last). NAWQA is the 

type of study that provides relevant 

scientific information to those who 

have the difficult task of making public policy dealing with waterresources issues.

Robert R. Holmes, Jr., PhD, P.E.

Illinois District Chief

MESSAGE FROM THE DISTRICT CHIEF

TABLE OF CONTENTS

Message from the District Chief . .1

Application of Extreme Flood 

Events in Model Verification and 

Flow Estimation in Ungaged Areas 

— A Case Study in Blackberry 

Creek Watershed, Kane County . .2

Methyl tert-Butyl Ether (MTBE) 

and Other Volatile Organic Compounds in Community DrinkingWater Supplies in the 

United States . . . . . . . . . . . . . . . . .4

Employee Spotlight. . . . . . . . . . . .5

Highlights of the Upper Illinois River 

Basin National WaterQuality Assessment, 

1999–2001. . . . . . . . . . . . . . . . . . .5

Cooperator Spotlight . . . . . . . . . . .7

From the Mailbag . . . . . . . . . . . . .8

Illinois District Publications . . . . .8
2

APPLICATION OF EXTREME FLOOD EVENTS IN MODEL VERIFICATION AND FLOW ESTIMATION IN UNGAGED

AREAS — A CASE STUDY IN BLACKBERRY CREEK WATERSHED, KANE COUNTY

BY

DAVID SOONG AND TIMOTHY STRAUB, HYDROLOGISTS

Introduction

Calibration and verification are 

essential procedures in practical application of computerized mathematical 

models. For hydrologic models used for 

simulating the rainfall-runoff process of 

a targeted watershed, two important 

issues are (1) verifying the capacity of 

the calibrated model in simulating 

extreme flood events, and (2) determining the reasonableness of estimated 

flows in ungaged areas.

The USGS, in cooperation with 

Kane County Department of Environmental Management (KCDEM), is conducting a flood-hazard study for 

Blackberry Creek in Kane County. The 

Blackberry Creek watershed (71.4 

square miles [mi2

] at the confluence 

with the Fox River) largely is an agricultural watershed located about 40 miles 

west of metropolitan Chicago. The 

watershed has undergone rapid urban 

development in recent decades. Both the 

population and proportion of urbanized 

land area for Kane County portion of the 

Blackberry Creek watershed are 

expected to double by 2020 from 1990 

levels.

Base- and 500-year floodplains and 

floodway are being remapped as part of 

the flood-hazard analysis. Peak-flood 

magnitudes at selected locations in the 

watershed are estimated by the floodfrequency analysis on synthesized flood 

series. The Hydrologic Simulation Program-Fortran (HSPF) is used to simulate 

the flows, where the annual maximum 

series is organized from the synthesized 

flow time series for flood-frequency 

analysis. The estimated flood quantities 

then are applied to the River Analysis 

System (HEC-RAS) model for estimating water-surface profiles. In order to 

gain confidence in the accuracy of flood 

estimates, 50 years (1949–99) of rainfall-runoff simulation is performed and 

the annual maximum series is organized 

at 49 locations inside the watershed for 

estimating flood frequencies. Verification of the HSPF and HEC-RAS models 

is crucial in the study and is discussed 

below.

For model calibration and verification, streamflow data from a USGS 

streamflow-gaging station located at 

Yorkville, at downstream near the watershed outlet (station number 05551700, 

Blackberry Creek at Yorkville). Available period of record at the Yorkville 

station is 1960 to the present. The drainage area above the Yorkville station is 

68.2 mi2

. There is also a streamflowgaging station at Jericho Road Crossing 

(station number 05551675, Blackberry 

Creek at Montgomery); the period of 

record is from 1998 to the present. By 

comparing data collected at Yorkville, 

the hydrologic model is calibrated with 

the HSPEXP program where users can 

apply judgment in determining model 

parameter values. With this approach, 

high correlation and model-fit coefficients for flood volumes, flood peaks, 

and flow-duration curves for the calibration period (1989–95) and verification 

period (1995–99) are achieved. However, there are no other data for assessing the hydrologic model and the 

reasonableness of estimated flood frequencies at other locations in the 

ungaged parts of the watershed.

The July 17-18, 1996 flood event is 

not included as part of the verification 

processes. This event is a major flood 

event with flood peaks observed at 

Yorkville exceeding the 500-year flood 

estimated by Curtis (1987). The Kane 

County Department of Transportation 

(KDOT) and the Illinois Department of 

Natural Resources-Office of Water 

Resources (IDNR-OWR) also collected 

valuable information immediately after 

the July 1996 event, which provided an 

opportunity for examining the two 

issues described earlier.

Application of NEXRAD rainfall

One of the main uncertainties in 

rainfall-runoff simulation comes from 

the representativeness of the precipitation data to field conditions. The gridded 

48-hour (July 17-18, 1996) radar rainfall 

totals (NEXRAD Stage III data that are 

adjusted using hourly point rainfall data) 

are averaged to each sub-basin. In this 

way, the NEXRAD analysis is equivalent to having 16 rain gages over the 

watershed. The simulated flood hydrographs for the July 18, 1996 event completed using Thiessen rainfall and 

NEXRAD rainfall are compared in figure 1. Apparently, by using more spatially and temporally representative 

rainfall information (NEXRAD), the 

volume of the simulated hydrograph is 

larger than that of the observed 

hydrograph. Possible reasons for this 

difference are variations between estimated NEXRAD and actual rainfall 

model deficiencies related to routing 

functions and/or model resolutions.

Application of high watermarks and 

inundation map

With the more representative flood 

discharges available for the entire watershed for the July 18 flood event, high 

watermarks (HWMs) taken by the 

KDOT can be used for calibrating and 

verifying the hydraulic model (HECRAS). The IDNR-OWR and Kane 

County staffs conducted a fly-over the 

afternoon of July 18, 1996, to inspect 

flood damages in the watershed. Images 

captured with videos and still photographs taken during the fly-over were 

used in developing an observed inundation map. If the model estimates are reasonable, the simulated water-surface 

elevations corresponding to the peak 

discharges should be comparable to the 

observed HWMs; similarly, the simulated inundation map generated from the 
3

simulated river stages should be comparable to the observed inundation map. 

The comparison of inundation maps, in 

turn, is a means for evaluating the simulated discharges.

The fly-over was not intended specifically for developing the inundation 

map; and, therefore, did not cover the 

entire Blackberry Creek and tributaries. 

Also, determining inundation under 

trees and cloud shadows was difficult. 

Local causes of inundation, such as 

debris jams, also can affect the proper 

application of the inundation map. In the 

meantime, the timing of the flight, the 

capacity of steady-state hydraulic computation, possible changes in cross sections, as well as vegetation cover, and 

many other possible sources of error, 

should be considered in comparing the 

inundation.

The most complete inundation map 

developed during this study was at Lake 

Run (map provided by Paul Schuch, 

Kane County, 1996). Considering the 

timing of peak stages in actual and simulated conditions, and the information 

available for developing the observed 

inundation map, these results are considered reasonable.

The similarities to the observed 

flood hydrograph at Yorkville, HWMs 

along the main stem, and inundation 

maps at ungaged parts of the watershed 

gave confidence to users in applying the 

computerized mathematical model to 

represent the hydrologic processes of 

the targeted watershed, especially at 

locations where no data are available. 

After the HWMs and inundation analysis, long-term simulation (1949–99) is 

conducted with precipitation records at 

Argonne (a National Weather Service 

station, record length: 1948–present). 

Annual maximum flood series are organized and peak-flood magnitudes have 

been estimated at 49 sub-basins in the 

watershed. Other procedures to evaluate 

the reasonableness of estimated flood 

frequencies in ungaged areas have been 

conducted.

Figure 1. Observed and simulated flow 

hydrograph at Yorkville in the Blackberry Creek watershed, for the July 17-

18, 1996 event. Simulated hydrograph 

presented in (A) is obtained using 

Thiessen rainfall, simulated hydrograph 

presented in (B) is obtained using 

NEXRAD rainfall.

Figure 2. Comparison of observed and 

simulated inundation using NEXRAD rainfall at two sub-basins Lake Run tributary to 

Blackberry Creek, Kane County. the 

observed inundation image was developed from video taken in the afternoon of 

July 18, 1996, and presented as hatched 

areas. The inundation obtained from simulated peak discharges are presented in 

gray areas.
4

METHYL TERT-BUTYL ETHER (MTBE) AND OTHER VOLATILE ORGANIC COMPOUNDS IN

COMMUNITY DRINKING-WATER SUPPLIES IN THE UNITED STATES

BY

ANGEL MARTIN, JR., SUPERVISORY HYDROLOGIST

The large-scale use of the gasoline oxygenate methyl tert-butyl ether 

(MTBE) has resulted in its frequent 

detection in ground water and surface 

water in many places throughout the 

United States. MTBE, a water-soluble 

compound, may enter water resources 

from point sources (such as gasoline 

spills) and nonpoint sources (such as 

precipitation). MTBE is used as a fuel 

oxygenate and an octane booster. 

Studies by researchers, industry, water 

utilities, universities, and government 

agencies have discovered high concentrations (above background concentrations) of MTBE in soils and 

ground water at leaking underground 

gasoline-storage-tank sites and frequent occurrence of low to intermediate concentrations of MTBE in some 

reservoirs used for public-water supply and recreational boating.

The USGS, in cooperation with 

the Metropolitan Water District of 

Southern California, the Oregon 

Health and Science University, and the 

American Water Works Association 

Research Foundation, completed 

national surveys of the extent and frequency of detections of MTBE, other 

gasoline compounds, and other volatile organic compounds (VOCs) in 

water used for drinking-water supplies 

in the United States. Source waters of 

954 community water systems 

(CWSs) were sampled during 1999–

2000 as part of a random survey to (1) 

ascertain the frequency of occurrence 

and to compare the concentrations of 

MTBE and other VOCs in groundwater and surface-water sources, and 

(2) determine whether the detection of 

MTBE and other VOCs differed by 

size of the CWS. A second focused 

survey sampled 134 CWSs source 

waters in the country during 1999–

2001. The selection of source-water 

sampling locations targeted locations 

where MTBE and other gasoline components were suspected or known to 

occur.

A total of 42 of 66 VOCs analyzed for during the random survey 

throughout the country were detected 

at or above the reporting level of 0.2 

micrograms per liter (μg/L). Twentyseven percent of source-water samples 

(257 of 954) contained at least one 

VOC, and 95 percent of the samples 

had concentrations less than 10 μg/L. 

Gasoline compounds collectively (as 

well as MTBE alone) were detected 

significantly more in surface-water 

sources (15 percent) than groundwater sources (6.6 percent). The more 

frequent detection of MTBE in surface 

water (14 percent) than in ground 

water (5.4 percent) likely is related to 

emissions, leaks, or spills from motorized watercraft. Furthermore, MTBE 

detections were five times more frequent in source waters from MTBE 

high-use areas than elsewhere. Interestingly, and in agreement with the 

results of the literature review completed before the surveys, MTBE 

detections did not appear to be related 

to the density of gasoline storage tanks 

near drinking-water sources.

In Illinois, 29 ground-water and 

surface-water samples were collected 

during the random survey. On the 

basis of results of the random survey, 

samples were collected (as part of the 

focused survey) from four groundwater sources serving less than 10,000 

people, at locations where MTBE concentrations were suspected. MTBE 

concentrations of these samples did 

not exceed U.S. Environmental Protection Agency (USEPA) drinkingwater advisory concentration of 20-40 

μg/L. In a separate USGS study in the 

lower Illinois River Basin, MTBE was 

detected (at a concentration below the 

USEPA advisory) only in one groundwater sample from the shallow glacial 

drift aquifer (not a source water for a 

CWS in the sampled area). In a study 

in the upper Illinois River Basin, 48 

wells were sampled for MTBE in 

2000 and 2001. MTBE was detected 

in samples from four wells. MTBE 

concentrations in these samples 

ranged from 0.2 to 4.6 μg/L.

CWSs in Illinois routinely sample 

for VOCs under the Safe Drinking 

Water Act monitoring program. Under 

the Illinois CWS Laboratory Fee Program, analyses for MTBE have been 

reported as part of standard laboratory 

methods since 1994. Approximately 

80 percent of the 1,200 CWSs that 

supply water participate in the program, and most (1,100 or 1,200) use 

ground water as the source of drinking 

water. The results reported by the Illinois Environmental Protection 

Agency (IEPA) in 2000 indicated that 

MTBE was detected at 26 active systems. In addition, three CWSs have 

had to discontinue use of wells as a 

result of MTBE contamination; these 

CWSs were in Kankakee County, 

Island Lake, and East Alton, Illinois. 

Although concentration data were not 

given for the water supplies with 

MTBE detections, the IEPA did indicate that most of the concentrations 

were unlikely to cause adverse human 

health effects.

Additional information regarding 

the national surveys of MTBE and 

other VOCs in community drinkingwater sources is available at 

http://sd.water.usgs.gov/nawqa/vocns/

nat_survey.html.
5

Jennifer Hogan was born in the northwest suburbs of Chicago. She pursued 

an undergraduate degree in Liberal Studies at the University of Notre Dame and 

L’Universite Catholique de L’Ouest in France. After graduation, Jennifer 

decided to move to Florida to pursue a graduate degree in Wildlife Ecology at 

the University of Florida. Jennifer transitioned from the arts to science by volunteering her time to alligator hatchlings, sturgeon, and sea turtles. In the midst 

of her graduate studies in Florida, she decided to pursue an internship at the 

USGS in Austin, Texas in summer 2000. One summer in Austin turned into 3 

years, during which time she was involved in collecting and analyzing hydrological and biological data. She conducted her Master’s research along the 

Texas coast on the distribution and nesting of estuarine turtles. She documented 

the first terrapin nest in the State of Texas and published one of the only records 

of a sub-population in the State. After Jennifer graduated from the University of 

Florida in December 2002, she decided to move closer to home and accepted a 

permanent position as an Ecologist with the Illinois District in early 2003. Since 

her move to Illinois, Jennifer has been collecting biological and hydrological 

data for the National Water-Quality Assessment Program. Jennifer’s interests 

include outdoor activities, travel, biking, cave diving, scuba, rock climbing, 

writing, dance, art, and music.

EMPLOYEE SPOTLIGHT

JENNIFER LYNN HOGAN, ECOLOGIST

HIGHLIGHTS OF THE UPPER ILLINOIS RIVER BASIN NATIONAL WATER-QUALITY ASSESSMENT,

1999–2001

BY

GEORGE E. GROSCHEN, STUDY UNIT CHIEF

Stream and River Highlights

During 1999–2001, water quality in upper Illinois River Basin streams and rivers largely reflected the amount of agricultural or 

urban land in their basins. Since the mid-1850s, channel and drainage modifications, urban development in the Chicago area, agricultural runoff, and other activities have altered water quality, biological communities, and habitat for aquatic organisms. Concentrations 

of chemicals in stream water occasionally exceeded guidelines for the protection of aquatic life and drinking water, such as for 

nitrate, phosphorus, diazinon, and organic wastewater compounds. Concentrations in the Des Plaines and Kankakee Rivers were least 

likely to exceed standards and guidelines. Although area streams and rivers generally are not used as drinking-water sources, elevated 

concentrations can affect aquatic wildlife and the quality of water for downstream Illinois River water users.

• The ammonia concentration (flow-weighted mean) at the Chicago Sanitary and Ship Canal at Romeoville was 0.64 mg/L (milligrams per liter), the highest measured in the upper Illinois River Basin and the fourth highest of 109 streams and rivers measured 

nationwide by the National Water-Quality Assessment (NAWQA) Program during 2000–01.

• In every stream-water sample collected from urban or mixed land-use (agricultural and urban) watersheds, phosphorus concentrations exceeded the USEPA desired goal to prevent excessive growth of algae and other nuisance plants (0.10 mg/L).

• Nitrate concentrations of 12.3 mg/L (flow-weighted means of nitrate as nitrogen) at the agricultural stream sites Sugar Creek at 

Milford and Iroquois River near Chebanse were the highest among 109 streams sampled during 1999–2001 for the NAWQA 

Program nationwide.

• Natural features (including glacial geology, soils, and hydrology) and land-management practices (including artificial drainage 

of farmland) affect nutrients in streams, as indicated by nitrogen in runoff at the Iroquois River near Chebanse, Illinois and the 

Kankakee River near Momence, Illinois. The Iroquois River had some of the highest concentrations of nitrate (as nitrogen) and 

the Kankakee had some of the lowest concentrations for the upper Illinois River Basin.

• The insecticide diazinon was detected frequently in streams and rivers in urban and mixed land-use areas. Specifically, diazinon 

was detected in 93 percent of samples collected at Salt Creek at Western Springs (nearly 80 percent urban land) and concentra-
6

tions in 18 percent of samples exceeded the guideline for protection of aquatic life. Diazinon has been used extensively in residential areas.

• Benthic invertebrates that are sensitive to pollution and habitat disturbance, such as mayflies, stoneflies, and caddisflies, were 

most common in streams whose watersheds are less than 4 percent urban land. Aquatic communities were degraded where urban 

areas cover as little as 25 percent of the watershed.

• Diverse fish communities that include species sensitive to pollution (as indicated by high Index of Biotic Integrity scores) were 

found at Indian Creek, which drains less than 1 percent urban land (score of 57); Big Rock Creek, which drains less than 1 percent 

urban land (score of 52); and Genesee Creek, which drains about 7 percent urban land (score of 52).

• Herbicides were detected frequently in streams and rivers, particularly those draining agricultural land. For example, atrazine was 

detected in every sample from streams and rivers draining agricultural or mixed land-use watersheds.

Trends in Stream-Water Quality

• Ammonia concentrations decreased during 1978–97 in areas where sewage-treatment processes were enhanced, however, nitrate 

concentrations increased. The enhancements generally transformed ammonia to nitrate, making effluent less toxic to fish.

• Detections of alachlor and cyanazine have decreased in streams and rivers since the early 1990s because of decreased use of these 

herbicides.

Ground-Water Highlights

Ground water is the largest source of drinking water in the upper Illinois River Basin (15 percent of the drinking water), except 

for Lake Michigan (82 percent). Commonly used herbicides and nitrate were less frequently detected in well-water samples than in 

stream and river samples.

• Shallow ground water in the upper Illinois River Basin generally meets drinking-water standards and guidelines; standards or 

guidelines have not been established for many pesticides and most breakdown products detected.

• Detections of synthetic chemicals were frequent in samples collected from monitoring wells and domestic-supply wells in 

recently urbanized areas. For example, volatile organic compounds (VOCs) were detected in 75 percent of the well samples. At 

least one pesticide, pesticide breakdown product, or VOC was detected in 90 percent of the wells. However, concentrations were 

near the laboratory method detection limit, and none of these constituents exceeded drinking-water standards or guidelines.

• Ground-water recharge is reduced in urban areas because of widespread impervious surfaces, such as roads and parking lots. 

Urbanization effects on potential recharge, along with droughts, could affect ground-water supplies.

• Shallow ground water collected from monitoring wells and domestic-supply wells exceeded the drinking-water standard for 

nitrate in only two sampled wells.

• Breakdown products of pesticides were detected in 60 percent of the agricultural-area wells; however, no pesticide or breakdown 

product exceeded drinking-water standards or guidelines. Breakdown products of acetochlor, alachlor, and metolachlor were 

detected more frequently and at higher concentrations than were their parent compounds.

NAWQA biologists Mitch Harris and Jennifer Hogan electrofishing during a yearly fish population survey in an Illinois 

River tributary.
7

The Metropolitan Water Reclamation 

District of Greater Chicago (District) is an 

independent government and taxing body 

encompassing approximately 91 percent of 

the land area and 98 percent of the assessed 

valuation of Cook County, Illinois. The 

District originally was organized as the 

Sanitary District of Chicago in 1889 under 

an act of the Illinois General Assembly, 

which has been modified from time to time 

to increase the District’s powers and jurisdiction. The 1889 enabling act was in direct 

response to a public health and nuisance 

problem caused by sewage discharges to the 

Chicago River and Lake Michigan. The 

District eventually reversed the flow of the 

Chicago and Calumet River Systems to 

divert wastewater away from Lake Michigan to the Des Plaines River and eventually 

the Mississippi River. These river systems 

have been tributary to the Illinois River 

since 1900 and 1922, respectively. The District operates the 78-mile long waterway 

system under Federal regulations. Flow 

within the entire waterway system and 

water diverted from Lake Michigan under 

U.S. Supreme Court Decree and State of 

Illinois allocation orders are controlled by 

four lock and dam structures: Chicago 

River Controlling Works; O’Brien Lock 

and Dam; Lockport Powerhouse, Lock and 

Dam; and Wilmette Pumping Station. A 

major portion of the waterway system is 

part of the Illinois Waterway, a Federal navigation project.

The mission of the District is to keep 

sewage pollution out of Lake Michigan, the 

area’s primary drinking-water supply, and 

to properly treat sewage to avoid contamination of the waterway system, and the Des 

Plaines and Illinois Rivers. One of the most 

important aspects of treating wastewater is 

monitoring the kinds of waste that are 

deposited into the sewer system. Whereas 

the District’s modern treatment plants can 

clean normal household and industrial 

wastes, there are some hazardous substances, such as toxic metals and chemicals, 

that should not be discharged to the sewer. 

The District monitors the contributing 

industries to assure that wastes are disposed 

of in an environmentally responsible way 

and in compliance with Federal, State, and 

local laws.

The District is located primarily 

within Cook County and serves an area of 

872 square miles, which include the city 

of Chicago and 125 suburban communities. The District’s wastewater load is 

equivalent to a population of 10.4 million 

people and is derived from 5.3 million 

people, a commercial and industrial 

equivalent of 4.5 million people, and a 

storm runoff equivalent of 0.6 million 

people. The District’s 554 miles of intercepting sewers and force mains range in 

size from 12 inches to 27 feet in diameter, 

and are fed from approximately 10,000 

connections to local municipal sewers. 

The District owns and operates seven 

water-reclamation plants, ranging in size 

from 3 to 1,200 million gallons per day, 

and 23 pumping stations. The District 

treats an average of 1,500 million gallons 

per day of sewage. The District’s total 

wastewater-treatment capacity is over 

2,000 million gallons per day.

The District’s Tunnel and Reservoir 

Project (TARP) is one of the country’s 

largest public works projects for contamination and flood control and consists of 

109 miles of tunnels, 9 to 33 feet in diameter and 150 to 300 feet underground, and 

three combined sewer overflow reservoirs, having an aggregate storage capacity of 18 billion gallons. Two of the three 

reservoirs presently (2004) are under construction.

The District is governed by a ninemember Board of Commissioners elected 

at large and each serving 6-year terms. 

The Board elects from its membership a 

President, Vice-President, and Finance 

Committee Chairman. 

Operation and control of all facilities 

and the waterway system is performed by 

the Maintenance & Operations Department and monitoring of water and sediment quality is performed by the 

Research & Development Department. 

Both departments use extensive instrumentation systems to provide the extensive amounts of data needed to carry out 

their operational and monitoring responsibilities. Whereas the District provides 

for its own instrumentation and manages 

its own data, reliance is placed on the 

USGS for discharge and stage measureCOOPERATOR SPOTLIGHT

METROPOLITAN WATER RECLAMATION DISTRICT OF GREATER CHICAGO

ment in the waterway system. Much of 

the data used by the District derives 

from the extensive monitoring of stage 

and discharge by the USGS in the metropolitan Chicago area supported by 

other USGS cooperators. However, the 

District directly supports stage and discharge measurements at three location.

USGS measurements in the Chicago River indicated the presence of 

density currents during the cold weather 

season when flows are low. The finding 

of these currents led the District to work 

with the Hydrosystems Laboratory at 

the University of Illinois at Urbana 

Champaign (UIUC) to perform a study 

of these currents. The study required 

intensive data collection by the USGS 

on the Chicago River to downtown Chicago and the nearby North and South 

Branches to obtain field measurements 

for UIUC model calibration. Eventually, the UIUC will investigate measures to disrupt the density currents so 

that lower quality water from the North 

Branch will not penetrate into the Chicago River.

The District worked with the Water 

Quality Center at Marquette University 

in Milwaukee to develop an unsteadystate hydraulic and water-quality model 

for the water system. An unsteady-state 

model is necessary because of shortterm spatial and temporal changes in 

flow and because of the complex 

hydraulics in this artificially controlled 

man-made waterway system. Calibration and verification of the hydraulic 

portion of the model requires the use of 

USGS stage and discharge data for 

boundary conditions. This model also is 

being used by the Corps of Engineers 

for a navigation study and eventually 

may be used by the District for guidance or real-time decision making in 

waterway system operations during 

storm runoff periods. It also will be 

used as an analytical tool in a current 

study of water quality and use classification for the waterway system being 

conducted by the Illinois Environmental Protection Agency.
8

FY 2003

WRIR 01-4121, Monitoring and Analysis of Combined Sewer Overflows, 

Riverside and Evanston, Illinois, by 

A.M. Waite, N.J. Hornewer, and 

G.P. Johnson

WRIR 02-4062, Delineation of the Troy 

Bedrock Valley and Particle-Tracking Analysis of Ground-Water Flow 

Underlying Belvidere, Illinois, by 

P.C. Mills, K.J. Halford, and R.P. 

Cobb

WRIR 02-4213, Use of Isotopes to Identify Sources of Ground Water, Estimate Ground-Water-Flow Rates, 

and Assess Aquifer Vulnerability in 

the Calumet Region of Northwestern Indiana and Northeastern Illinois, by R.T. Kay, E. R. Bayless, 

and R.A. Solak

OFR 02-487, Flooding in Illinois, 

April–June 2002, by C.F. Avery and 

D.F. Smith

WRIR 02-4097, Pesticides in Surface 

Water in the Lower Illinois River 

Basin, 1996–98, by R.B. King

WRIR 02-4293, Anthropogenic Constituents in Shallow Ground Water in 

the Upper Illinois River Basin, by 

W.S. Morrow

Water-Data Report IL-02, Water 

Resources Data Illinois, by A.D. 

Robl, J.W. Angel, and J.R. Norris

WRIR 03-4105, Concentrations of Polynuclear Aromatic Hydrocarbons 

and Inorganic Constituents in 

Ambient Surface Soils, Chicago, 

Illinois: 2001-02, by R.T. Kay, T.L. 

Arnold, W.F. Cannon, D.Graham, 

E. Morton, and R. Bienert

WRIR 03-4103, Arsenic in Illinois 

Ground Water—Community and 

Private Supplies, by K.L. Warner, 

A. Martin, Jr., and T.L. Arnold

FY 2004

OFR 03-206, Hydrogeologic and 

Ground-Water-Quality Data for 

Belvidere, Illinois, and Vicinity, 

2001–02, by P.C. Mills and R.T. 

Kay

ILLINOIS DISTRICT

PUBLICATIONS

Listed below are publications that 

were published recently. Federal 

Fiscal Year (FY) covers October 1 

through September 30. District 

policy is to provide copies of our 

publications to requestors at no 

cost as long as the publication is in 

stock in the District office. To 

obtain copies of the following, or 

any other Illinois District publication, you may contact Donna Ayers 

at (217) 344-0037, extension 3053 

or by email at dmayers@usgs.gov. 

Reports can also be found at: 

http://il.water.usgs.gov/pubs/ 

search.html

From the Mailbag

If you have comments about 

our newsletter or our Web 

site, please use the form on 

the back page. Comments 

also can be sent to 

dc_il@usgs.gov.

“Read about Waterwatch in the 

May 2003 Water Resources Update. 

Have bookmarked the page as it has 

some fascinating information. 

Thanks.”

“Thanks for all the information on 

the Rock River dams. Everything you 

have provided to me has been of great 

help. I can’t wait to get on the water!”

“... By the way your website is 

excellent. Easy to navigate and full of 

useful info.”

“Thank you so much for the materials. I just received them. I will share 

them with other teachers.”

“Thanks for your call and sending 

out the data!! It looks like it is going 

to be just what we needed!!! Thanks 

again for your expediency on this 

request!!”

“I just wanted to thank you for the 

very informative session you had 

with Michael yesterday. You are 

obviously gifted as a teacher, as well 

as being an enthusiastic expositor of 

the value of the services rendered by 

the U.S. Geological Survey. Although 

Michael has practiced the indifferent 

look of the bored teenager, he is actually quite brilliant and with a definite 

bent toward the sciences, so I think 

this was a worthwhile tour in a sense 

that goes beyond merely completing 

badge requirements!”

“I think the newsletter is great!”

“Thanks for sending that mail. I 

have got some really, really good info 

on volcanoes from the USGS Web 

site. . .”

“. . . I’m impressed with your 

agency/division and how quickly I 

have gotten what I needed. I really 

appreciate it!”

“Thanks a lot. I am impressed with 

the service. . .”

“. . . I received access to the 

USGS/IEPA mapserver some time 

ago now and have been going 

through it -- it’s one of the best I’ve 

ever seen. My compliments here are 

really an understatement.”