ILLINOIS STATE WATER SURVEY
A Plan for Scientific Assessment
of Water Supplies
in Illinois
River
Illinois
Mississippi River
River
Illinois
Mississippi River
St. Louis
Missouri Ri ver
Mi ssouri Ri ver
St. Louis
Satellite images of the confluences of the Illinois, Mississippi, and Missouri Rivers during the 1988 drought and the 1993 flood.
A Plan for Scientific Assessment
of Water Supplies
in Illinois
Illinois State Water Survey
Information/Educational Material 2001-03
George H. Ryan, Governor
Brent Manning, Director
Illinois Department of Natural Resources
Derek Winstanley, Chief
Illinois State Water Survey
2204 Griffith Drive
Champaign, Illinois 61820
http://www.sws.uiuc.edu
Contributors
Kingsley M. Allan
James R. Angel
Kathleen J. Brown
Misganaw Demissie
Linda J. Hascall
Kenneth J. Hlinka
Thomas R. Holm
Walton R. Kelly
Eva C. Kingston
H. Vernon Knapp
Kenneth E. Kunkel
Xin-Zhong Liang
Sally A. McConkey
Scott C. Meyer
Debbie K. Mitchell
Robert W. Scott
Douglas Walker
H. Allen Wehrmann
Derek Winstanley
Cover Photo: Derek Winstanley
Cover Design: Linda Hascall
Frontspiece: Landsat imagery courtesy of the Earth Observation Satellite Company, Lanham, Maryland.
Page iv: Modified from NIPC Strategic Plan for Water Resource Management, 2001.
Page 2: Model data were obtained from the Data Distribution Centre, Intergovernmental Panel on
Climate Change (World Meteorological Organization and United Nations Environmental Progamme).
Page 2: Aerial photo courtesy of The State Journal-Register.
Page 4: Photo courtesy of The State Journal-Register.
Page 8: Municipal boundaries and county boundaries from Northeastern Illinois Planning Commission's
Digital Map of the Region; drinking water source information provided by Harza Engineering.
All uncredited photographs and maps provided by Water Survey staff.
Layout & Design: Publication Services, Inc.
10–01—Crouse—2M
The Need for Scientific Assessment of Water Supplies in Illinois
Recent projections by the Northeastern Illinois Planning Commission of population growth of one million and water
shortages in the Chicago metropolitan area by 2020 are a wake-up call for action. Similar analyses and projections for the
rest of Illinois have not yet been made.
Water is increasingly recognized as a precious renewable resource to be managed wisely. About two thirds of Illinois’ daily
water use comes from surface waters and one third from groundwater. Wise management of water resources is necessary to
continue to provide adequate supplies of clean water at a reasonable cost, to protect the state’s precious water resources and
ecosystems, to reduce conflicts, and to support economic growth. Wise management is based on sound technical information
and planning, taking into account such matters as climatic variations and change, renewable yields of surface waters and
aquifers, opportunities for the conjunctive use of surface water and groundwater, and water conservation and reuse.
The mission of the Illinois State Water Survey (ISWS) is to characterize and evaluate the availability, quality, and use of
the atmospheric, surface waters, and groundwater resources of the state and to make resulting data and information
available to the public, decision makers, planners, and managers. This plan identifies studies that ISWS can conduct, in
collaboration with others, to provide the technical data, information, tools, and training necessary for water supply
planning and management. The plan addresses all major components of statewide water availability as part of the natural
hydrologic cycle: atmosphere (precipitation); surface waters (rivers, streams, lakes, and reservoirs); and groundwater
(glacial, shallow, and deep bedrock aquifers). The plan also addresses the quality of water to the extent that the quality of
water influences both its suitability for use and the cost to supply clean water.
The studies identified in this plan are consistent with the priorities identified in the deliberations of Governor Ryan’s Water
Resources Advisory Committee and the Strategic Plan for Water Resource Management of the Northeastern Illinois Planning
Commission. The groundwater components of this plan also contribute to the requirements by the Illinois General Assembly
for the Illinois Department of Natural Resources to prepare a plan to study the aquifers of the state (92 HR0365 and 92
SR0137). However, consistent with the ISWS mission, I believe that Illinois needs a comprehensive assessment of water
resources that includes surface waters and climate variability and change, as well as groundwater. This comprehensive plan for
water supply assessment helps direct and organize ISWS programs and serves to inform constituents that the ISWS, working
with others, stands ready to provide an improved technical basis for water supply planning and management statewide. For
these reasons, the scope of the plan is broader than the General Assembly requested in its resolutions, and a comprehensive
statewide plan for aquifer assessment will necessitate additional input from other agencies and professionals.
It is a plan that first marshals existing data and information to identify water resources in need of immediate management
attention and then calls for the collection and analysis of new data, research, models, and training to improve permanently
the state’s water supply planning and management capabilities. Implementing the plan will require major efforts to improve
and restructure ISWS data collection, management, and delivery systems, and modeling capabilities.
The plan does not include lists of ongoing projects and services at ISWS but rather identifies complementary and
supplementary projects that can be implemented with additional resources and sustained effort over many years. Building
on existing projects and implementing the plan in a phased approach can lead to improved operational water supply
planning and management in the short-term and improved planning and management on the decadal time scale.
However, continuation of existing funds and projects will be adequate to implement only a fraction of the plan in a
timely manner. Clearly, the rate and order of implementation of the plan will depend on levels and sources of funds. I
plan to work with state, federal, county, and local government officials and other professionals to coordinate and
integrate relevant programs, set priorities, and seek funds to implement the plan. In addition to preparing and disseminating
data and project reports on an ongoing basis, I will prepare an annual report that summarizes the progress made each year,
whatever the level and sources of funding. I will also update the plan every three years.
I thank members of the Illinois State Water Plan Task Force, the Governor’s Water Resources Advisory Committee, state
agency officials, and other water resources experts for their reviews of an earlier draft and their comments and suggestions
for improvement.
Derek Winstanley
Chief, Illinois State Water Survey
Champaign, October 2001
PREFACE
iii
Mississippi
Lake Michigan
Tennessee
Missouri
Illinois
Ohio
Mississippi
Yellowstone
Arkansas
Platte
Red
Atchafalaya
Atlantic
Ocean
Gulf of Mexico
Illinois
Basin
Major Rivers
The Mississippi/Atchafalaya River drainage basin.
ILLINOIS
Shortages
Lake
Michigan
Surpluses
LAKE
COOK
DUPAGE
WILL
KANE
MCHENRY
Projected water shortages and surpluses
in northeastern Illinois for the year 2020.
iv
Demand for water in Illinois is increasing, and water
shortages in the Chicago metropolitan area have
been projected. There are, however, limits to the
availability of clean water at a reasonable cost. Limits
to water availability are imposed by a number of
factors including droughts, legal requirements to
maintain minimum flows in rivers and streams, water
recharge rates, and a decree of the United States
Supreme Court limiting withdrawal of water from
Lake Michigan. In addition, the specter of regional
climate change could pose the greatest threat to
Illinois water supplies over the long term: some
projections show the possibility of persistent floods,
whereas other projections show persistent droughts.
Additional sources of water do exist and can be
tapped, but the cost of providing clean water
increases with the necessity of water treatment,
storage, and distribution, and the mitigation of
impacts of new withdrawals on existing water supplies.
Long lead times also are needed to construct major
water projects. Unless the water supplies of Illinois are
planned and managed in a comprehensive, regional,
and visionary manner—based on the concept of
renewable water supply capacity—water shortages
could soon occur in some parts of the state. Water
supply planning and management should be based on
improved understanding and prediction of water
supply and demand, and risk assessment.
The goal of this plan is to provide a framework for
Illinois State Water Survey (ISWS) water supply
programs and to document those studies that ISWS,
working with others, needs to conduct to provide
Illinois with comprehensive technical data and
information, models, and training for water supply
planning and management.
The following are the main tasks described in
the plan:
➤ Collaborate with other organizations to coordinate and
integrate relevant programs, set priorities, plan activities,
conduct studies, and seek additional resources.
➤ Assemble, archive, digitize, analyze, and synthesize
existing data.
➤ Determine areas of possible water shortages as a basis
for setting priorities.
➤ Evaluate the quantity and quality of water resources
throughout the state as they relate to water supply.
➤ Provide yield estimates for major aquifers and
surface waters under variable and changing climatic
conditions.
➤ Identify critical data gaps and conduct field studies to
gather additional data and monitor the state’s water
resources.
➤ Evaluate opportunities for water conservation and
reuse.
➤ Interpret and apply technical and economic data to
assist and train water resource planners and managers.
➤ Develop and improve methods and models to evaluate
water resources.
➤ Develop new quality-assured databases and an
Internet-based decision support system to make data
and models easily available for application by other
agencies, professionals, and the general public.
The rate and order of implementation of these studies
will depend upon the level and sources of funds and
priorities and upon collaborative efforts with other
organizations. Existing resources are addressing many of
these topics, but resources are limited so progress will
be slow. A major infusion of new resources is needed for
timely implementation of the studies described.
ABSTRACT
v
Ohio River
East St. Louis Major Aquifers
Major Watersheds and Rivers
1971-2000 Annual Average Precipitation (inches)
36
48
46
44
42
40
38
Chicago
Mississippi River
Regional variability of water resources in Illinois.
ABSTRACT v
INTRODUCTION 2
FACTORS CONSIDERED IN DEVELOPING THE PLAN 4
GOAL 6
Strategies 6
SCIENTIFIC STUDIES 7
•1•
Water Supply and Demand Projections 7
•2•
Surface Water Supplies and Quality 8
•3•
Groundwater Supplies and Quality 12
•4•
Understanding and Predicting the
Hydrologic Cycle and Water Resources 16
•5•
Reporting of Water Use 19
•6•
Comprehensive Water Supply
Planning and Management 20
CONTACTS AT THE ILLINOIS STATE WATER SURVEY 22
TABLE OF CONTENTS
1
Based upon consideration of relevant factors, this plan
contains an overall goal of supporting water supply
planning and management in Illinois. The plan
identifies Illinois State Water Survey (ISWS)
strategies to achieve that goal with associated prod-ucts
and outcomes. Section 1 addresses water supply
and demand projections; Section 2, surface water
supplies and quality; and Section 3, groundwater
supplies and quality. Section 4 focuses on the
understanding and prediction of the hydrologic cycle
in Illinois; Section 5, the reporting of water use; and
Section 6, comprehensive water supply planning and
management. Because the components of the
hydrologic cycle are intrinsically linked, there are
some necessary and unavoidable overlaps among
sections. A list of ISWS contacts also is provided.
On average, Illinois receives about 38 inches of
precipitation per year and has abundant water
resources. About 20 billion gallons of water are used
each day for domestic, municipal, commercial,
agricultural, industrial, mining, power generation,
recreation, navigation, and waste dilution purposes. Large
quantities of water also are needed to sustain healthy
ecosystems, including habitat for fish and other wildlife.
But it is not simply water that is needed: many uses
require clean water. Naturally occurring pollutants,
such as arsenic, radium, suspended solids, and chloride
can limit the availability of clean water in Illinois and
increase the costs of water treatment. Human activities
that produce pollutants such as pesticides, metals,
sediments, and nutrients can add to these problems
and costs. Precipitation also contains chemicals, some
natural, but many from human sources.
The sources of water in Illinois are Lake Michigan,
rivers, streams, lakes, reservoirs, shallow aquifers, and
deep aquifers. Ultimately, all these sources are dependent
on precipitation, and variations or changes in
precipitation can affect the supply and demand for
public and private water supplies. Excess water creates
damaging floods, such as those that occurred in 1993.
Drought, such as the one that occurred in 1988-1989, is
a consequence of insufficient rainfall and, often, high
temperatures.
INTRODUCTION
50
45
40
35
Precipitation (inches)
32
30
1900
1920
1940
1960
1980
2000
2020
2040
2060
2080
2100
Model # 2
Model # 3
10-Year Running Averages
Model #1
Historical
Historical 10-year annual average precipitation
for the Illinois River basin (green) and projections
from three different global climate models used
by the United Nations (blue, purple, and red).
Aerial of Lake Springfield low lake level during the 1988 drought.
2
Water is usually in motion, and scientists use the
hydrologic cycle to study the flow of water between
the atmosphere, soils, vegetation, rivers, lakes, aquifers,
oceans, and its return to the atmosphere. These
components are linked and a systems approach is thus
needed to understand and predict how these components
interact and to provide a basis for comprehensive water
resources planning and management.
Surface waters, soil moisture, and shallow aquifers
respond fairly quickly to variation in precipitation:
rainfall recharges the water supplies in rivers, lakes,
reservoirs, and shallow aquifers; lack of rainfall causes
these water supplies to dry up. In a relative sense, these
rapid response systems have fast recharge rates
measured in terms of days or years. Deep aquifers are
different in that they contain water that is thousands
or, in some cases, tens of thousands of years old. These
aquifers are slow response systems with slow recharge
rates. Given an equal amount of water in two aquifers,
larger amounts of water can be withdrawn safely from
those aquifers that have faster recharge rates.
Water supply managers need data and information on
precipitation amounts, recharge rates, and other
variables to determine available quantities of water for
design of reservoirs, flood controls, well fields, and
water distribution systems. This information is also
necessary to protect the precious water resources of the
state from overuse, depletion, and contamination.
This plan emphasizes comprehensive regional
assessments of renewable water supply capacity
commensurate with the scientific data needs for
comprehensive regional water supply planning and
management. Consequently, the scope of the plan is
necessarily broad. Regional assessments will be based
on watersheds, aquifers, and/or groups of counties.
More detailed studies will be conducted at the county
and/or local levels. The time scale for water supply
planning and management must extend over decades,
commensurate with the long lead times needed for
infrastructure development and with the dimensions of
possible regional climate change.
The rate and order of implementation of the studies
will depend upon the level and sources of funds,
priorities, and upon collaborative efforts with other
agencies such as the Illinois State Geological Survey,
Office of Water Resources, Illinois Environmental
Protection Agency, and United States Geological
Survey. Existing resources at ISWS address many of
these topics, but resources are limited and progress
will be slow. A major infusion of new resources is
needed for timely implementation of the studies
described.
The hydrologic cycle.
3
FACTORS CONSIDERED
IN DEVELOPING THE PLAN
A number of developments, issues, and trends in
Illinois, the Nation, and the world influence water
resources and the need for water resources studies in
Illinois. These factors are identified below.
➤ Demand for water is increasing in many parts of the
state, primarily as a result of growth in the population
and the economy. The Northeastern Illinois Planning
Commission (NIPC) projects that population in the
Chicago metropolitan area will grow by about
one million by 2020.
➤ The demand for water in some parts of the state
already exceeds or soon will exceed practical
renewable yields, for example, from the deep bedrock
aquifer of northeastern Illinois. Water levels in some
central Illinois reservoirs were reduced to critical
levels in the moderate 1999–2000 drought. More
severe droughts do occur naturally and will have more
severe impacts. Even under normal climatic conditions,
NIPC projects water shortages for 11 townships in the
Chicago metropolitan area by 2020.
➤ Future water availability is highly uncertain, and the past
may not be a reliable guide to the future. Some projections
show that water availability in the Midwest could change
dramatically as a result of climate change: some models
used in the United Nations’ assessments project mean
annual precipitation in Illinois as low as 25 inches or as
high as 50 inches by the end of the 21st century, with
continuing changes thereafter. These projections, if
borne out, would, under current water management
schemes, mean a potentially disastrous situation of either
persistent floods or persistent droughts in Illinois. Other
models show more modest changes in mean annual
precipitation, but with a higher frequency of floods
and droughts from year to year.
➤ Scientific and engineering data, including risk
assessments, are needed for water supply planning and
management. Risk assessments include estimates of
uncertainties on factors that control the quantity and
quality of water resources.
➤ Water resources projects often require long lead times
to plan and implement.
➤ Many of the state’s waters contain natural minerals
and human-made pollutants that impair water quality
Excessive rainfall leads to flooding.
4
and either limit water availability or increase the cost
of supplying clean water.
➤ The availability and quality of water varies regionally,
posing challenges in meeting local and regional water
demands. It is not known how much water can be
withdrawn safely from many aquifers.
➤ The flows of surface waters and groundwater are linked
and need to be studied and managed conjunctively.
➤ Estimates of water use are often quite inadequate, as
many major uses are not reported.
➤ The geographical extent of watersheds and aquifers do
not coincide, and political boundaries do not coincide
with watersheds or aquifers.
➤ Withdrawal of water from Lake Michigan is set by
decree of the United States Supreme Court and by
agreement with other states and Canada. The
allocation is almost fully used and is unlikely to be
increased in the near future.
➤ Illinois does not have updated statewide or regional
water plans for the efficient and effective management
of water supplies.
➤ Technical data and models needed for water supply
planning and management are often outdated,
inadequate, or nonexistent.
➤ Management of the state’s water supplies is fragmentary
and decentralized.
➤ State laws permit reasonable use of water resources, but
the courts often determine what is reasonable and resolve
conflicts. Water withdrawals typically are not evaluated
based on cumulative impacts or renewable yields.
➤ Weaknesses identified in current water laws relate to the
protection of minimum instream flows, drought
emergencies, and renewable yields from surface waters
and aquifers. Various advisory bodies have recommended
strengthening laws to protect minimum instream flows
and groundwater resources and to improve drought
management.
A lack of rainfall parches the soil.
5
The following strategies will achieve this goal:
➤ Collaborate with other organizations and
professionals to coordinate and integrate
relevant programs, set priorities, plan
activities, conduct studies, and seek additional
funds.
➤ Assemble, archive, digitize, analyze, and
synthesize existing data, including appropriate
data from neighboring states.
➤ Incorporate estimates of uncertainty and
risk in water supply assessments.
➤ Provide yield estimates for major aquifers
and surface waters under variable and
changing climatic conditions, including a
worst drought scenario.
➤ Determine areas where water shortages
are likely to be most critical over the next
20 years.
➤ Establish databases and models of sufficient
resolution and accuracy for regional studies,
which can be enhanced for local studies.
These databases will include improved
reporting of water use.
➤ As improved geological and hydrological
data and models become available, use
these in the development of improved
water resources assessments.
➤ Identify critical data gaps and conduct field
studies to gather additional data, and
monitor the state’s water resources to
detect temporal trends in water supplies,
water quality, and water use.
➤ Work with and train water supply planners
and managers to interpret and apply scientific,
engineering, and economic data to assist in
water supply planning and management,
including water conservation and reuse.
➤ Develop a decision support system on the
Internet that presents and integrates
databases and models for climate,
watersheds, rivers, lakes, reservoirs, aquifers,
and water use that can be readily accessed
and used for any desired watershed, aquifer,
geographical region, or political unit in Illinois.
➤ Provide regular updates of databases,
models, and reports, and an annual
summary of progress.
GOAL
The goal of this plan is to provide a framework for ISWS water supply programs and to
document those studies that ISWS, working with others, needs to conduct to provide
Illinois with comprehensive technical data and information, models, and training for
water supply planning and management.
Strategies
6
7
• 1 •
Water Supply and Demand Projections
The most important requirements in water supply
planning and management are to know how much
water is required over a period of time, the quality
of water needed, and the water supply options
available. Decisions then can be made on how to
meet or reduce demand. Projections of water supply
and demand inevitably include significant
uncertainties, and the expression of uncertainties in
future projections provides a basis for water
resources planners and managers to conduct risk
assessments and to plan for the future.
1.i. Preliminary Statewide Estimates
of Water Supply and Demand
Issue. Increasing withdrawal of water from streams,
rivers, reservoirs, lakes and aquifers threatens to
exceed local water availability in some parts of
Illinois, yet resources for scientific analysis of water
availability and water resources management are
limited. Cost-effective expenditure of limited funds
will be facilitated by first conducting a coarse,
statewide comparison of water availability and demand
in order to identify priority areas for detailed analysis.
Activities. To accomplish this goal, the state will
be subdivided into study units, and estimates of
streamflow yield and groundwater availability will be
developed for each study unit. A preliminary estimate
of overall water availability will be provided for each
study unit for comparison with current and projected
water demand. Future water demand will be projected
on the basis of present per-capita demand and
economic and population projections.
Groundwater availability and streamflow yield will be
treated somewhat differently in this prioritization
study. For each study unit, groundwater availability
will be estimated from available aquifer mapping and
published estimates of natural recharge to these
aquifers. Within a study unit, the upper limit on the
amount of groundwater available from an aquifer will
be the product of the recharge rate and the aquifer
area within that study unit; actual well field yield will
be less than the natural recharge rate. Streamflow
yield is the amount of streamflow available to support
all instream and offstream uses. A critical need is to
define flow frequencies for various stream locations
throughout the state. The criteria needed to identify
potential regions of shortages and to prioritize regions
for further study can be established by comparing the
potential yield to current and/or future water demand.
Products. Preliminary statewide estimates of surface
water and groundwater availability and water
demand will be provided. A map illustrating the
ratio of projected water demand to water availability
will be developed and published for each study unit.
Outcome. Resource analysts and managers will be
able to use the data to focus limited resources on
data collection, scientific analysis, and management
in areas where projected water demand exceeds, or
threatens to exceed, water availability. Study units
having the highest proportion of projected demand
to overall water availability will be given priority for
further in-depth study.
<1
1-10
11-50
51-200
201-500
601-2000
>2000
Low Flows
cubic feet per second
Lake
Michigan
Average annual 2-year, 7-day low flows.
SCIENTIFIC STUDIES
8
•2•
Surface Water Supplies and Quality
About two-thirds of the water supplies in Illinois
are from lakes, rivers, streams, and reservoirs. In
northeastern Illinois, about 2 billion gallons of water
are withdrawn from Lake Michigan each day. In
southern Illinois, where groundwater resources are
not very abundant, there is heavy reliance on surface
waters. The amount and quality of water available are
dependent upon climate factors, human activities,
land use, sedimentation in the reservoirs and lakes,
requirements for the maintenance of minimum
instream flows, and the economics and financing of
water storage and distribution systems.
2.i. Streamflow Yield Analysis, Including
Minimum Instream Flows
Issue. Meeting the water demands of a growing
population and economy using the concept of
practical renewable yield provides a scientifically
sound framework for the protection of our streams
and natural resources through water supply
planning. A working definition of “adequate water
supply” is needed. Water uses must be prioritized
in the event that demand exceeds supply, be it
during a short-term drought or over the long-term.
An understanding of streamflow magnitudes and
frequencies for stream locations throughout Illinois
is critical for estimating the availability and yield
needed to support all instream and offstream uses.
Currently only the 7-day, 10-year low flow is defined
for all streams in the state. Other important flow
frequency characteristics, such as the 90 percent and
75 percent levels of flow exceedence have been
proposed for developing instream flow requirements,
but yield data for these flow frequency values have
been established only at United States Geological
Survey (USGS) streamgage locations. Additional
regional studies and analyses are needed to define
flow frequency yields and associated water quality for
ungaged locations throughout the state. Additional
streamgage locations, particularly for monitoring
smaller watersheds, are needed in support of these
regional analyses.
In Illinois, primary instream uses include water
needed for fish and wildlife habitat, water quality,
hydropower, navigation, recreational and aesthetic
interests, and overall biological integrity. Instream
flows refer to the amount of water required to protect
instream uses and to maintain sufficient water for
offstream users downstream. Acceptance of instream
Major Rivers
County Boundaries
Municipal Boundaries
Lake Michigan Water
Lake
Michigan
Chicago
WILL
KANE
COOK
MCHENRY
LAKE
DUPAGE
Communities using Lake Michigan water.
Barges on the Illinois, Mississippi, and Ohio Rivers
require 9 feet of water when fully loaded.
9
flows as a legitimate water use, with rights similar
to other water uses, is important to be able to
provide protection for instream uses. To date,
protection of the stream environment in Illinois
has focused on water quality. But there is growing
recognition that water quantity is integral to water
quality and river health.
Activities. Building on existing designations,
streams and watersheds with the highest level of
use will be identified. An inventory of stream
factors will be developed for use in identifying
both regions of intense use and potential
conflicts in use. These factors include water
withdrawals and diversion, biological
significance, water quality, waste assimilation,
commercial navigation, recreational use,
hydropower, and aesthetic value.
Existing and allocated offstream water uses will be
identified and compared with streamflow yield.
For most streams in Illinois, the quantity of water
needed for instream uses has not been identified
and will require substantial future study. Surrogate
values of instream flow requirements, such as the
7-day, 10-year low flow, 90 percent flow duration,
etc., will be used to identify streams/regions of
potential shortage. Alternative approaches for
defining shortages and the adequacy of the water
supply will be investigated. Streams/regions will
be identified where streamflow yields are currently
inadequate to provide all existing and/or allocated
uses using the surrogate estimates of instream
flow. In addition, areas with potentially large
increases in water use will be evaluated for their
potential future impacts on water quality and
instream uses.
Products. Instream uses will be identified. An
inventory will be developed that lists streams,
rivers, lakes, and watersheds having the greatest
potential for water use conflicts and shortages based
on surrogate levels of instream flow requirements
and water quality. Basic data will be collected and
analyzed to refine estimates of water availability and
establish a defensible criterion for renewable yields.
A range of flow frequency characteristics will be
provided. Reports and Internet databases on
streamflows, water uses, and streams/regions of
potential shortage will be produced.
Outcome. Resource analysts and managers will
be able to use the inventory to focus limited
resources on protection and restoration of
streams with the greatest potential for water
shortages and water-use conflicts. Aquatic
habitat quality and abundance will be able to
be linked to return periods, and risk assessments
can be performed.
2.ii. Drought Assessment, Preparation,
and Management
Issue. Surface water supplies are particularly
vulnerable to potential water shortages during
drought periods. The practical renewable yield from
a surface water source is dependent upon both the
flow characteristics of the river or stream and the
volume of raw water storage made available through
reservoirs that store water during high flow periods.
Lake
Michigan
Locations
<1 mgd
1-10 mgd
10-50 mgd
>1000 mgd
Surface Water Withdrawals
Millions of gallons per day
Groundwater Wells
Community water supplies.
10
In certain locations, yields from surface water
sources also can be manipulated to meet demand
during low flow and drought periods by conjunctive
use of surface water and groundwater.
Surface waters are the source of most public water
supplies in southern and central Illinois, both from
direct withdrawals from streams and, more
commonly, through reservoirs formed by stream
impoundment. During drought conditions, it is
vital to monitor both stream and reservoir water
levels. Streamflow data on larger rivers and
reservoirs are generally available to evaluate the
water supply potential and drought status for many
larger public water supply systems in the state—for
example, Rend Lake—but data to evaluate smaller
public systems often are lacking. During the drought
of 1999–2000, potential water shortages threatened
a number of these communities. Only a few of these
reservoirs have continuous monitoring of water
levels or inflow. The current monitoring practice is
wholly inadequate to provide information critical
for decision-making during drought periods.
Detailed water level and inflow data also are needed
to develop water budgets and to assess yields from
these reservoirs for planning purposes and drought
preparation.
For water supply reservoirs, additional data related to
volume, sedimentation rates, and evaporation rates
during drought conditions also are sorely needed for
risk assessment, long-term planning, and drought
management. Volumetric measurements are available
for only a few water supply reservoirs, and estimates of
volume are often grossly inaccurate. Regular sediment
surveys also need to be conducted approximately
every 10 years to monitor changes in volume. These
are necessary for long-term planning and vital for
drought planning and estimation of critical draw-downs
and possible water shortages. In addition to
providing quantitative information on surface water
resources, the sedimentation data can be used to
evaluate regional sediment-delivery rates. Evaporation
losses represent a significant percent of the gross yield
from a reservoir, up to 25 percent during droughts,
and estimates of this fundamental process are crude.
Activities.
1. Identification of Drought-prone Communities.
Drought-prone community water supplies will be
identified and prioritized using published data
comparing current water withdrawals and 50-year
drought yields. Once these communities are
identified, a drought plan will be proposed for
each community that sets limits on the safe yield,
identifies cumulative rainfall deficits that trigger
water conservation measures, and suggests other
actions to reduce the risk of water shortages.
2. Reservoir Water-Level Monitoring. A network
of continuous, real-time, water-level monitoring
stations will be implemented at selected reservoirs
used for water supply. Real-time data collection will
provide valuable information during drought
periods. Long-term data collection will provide
information for development of water budgets and
resource planning. Continuously recording staff
gages will be installed over a 5-year period. After
this period, the program will continue data
collection, equipment replacement, and
rehabilitation.
3. Reservoir Sedimentation Monitoring.
A long-term program of reservoir sedimentation
monitoring will be established. Reservoirs
Instruments measure precipitation, wind,
soil moisture, temperature, and humidity.
11
throughout the state will be surveyed initially and
then re-surveyed on a rotational basis. Reservoir
sediment surveys will be conducted continuously
through summer and fall as weather permits.
Approximately five lake surveys will be conducted
each year. Public water-supply reservoirs will have
top priority for surveys, particularly those
reservoirs identified as being at-risk during
droughts.
4. Stream Monitoring. New gages will be added
to the Illinois Streamgage Network operated by
USGS. New streamgage locations on smaller
watersheds will be identified, with priority on
gages placed near reservoir systems that are most
at-risk for drought impacts.
5. Reservoir Evaporation Monitoring. A network
of seven long-term evaporation-monitoring stations
will be established at selected reservoirs across
Illinois. Weather stations at reservoirs will measure
the meteorological parameters required to accurately
calculate evaporation from the water surface. Data
collected at these stations will be used to establish
relationships between water surface evaporation and
parameters routinely measured at standard weather
stations and to develop models that simulate the
effects of evaporation on reservoir capacity.
Long-term monitoring also will provide information
to track climate change impacts on evaporation, and
statistical analyses of data sets will assess water
reliability.
6. Hydrologic Analysis. From historical data and
the data collected above, improved methodologies
will be developed for the assessment and design of
yields for water supply systems. This includes the
development of regional models for estimating
drought streamflow conditions for existing water
supply systems as well as ungaged stream locations
throughout the state. Worst drought scenarios will
be defined. Approaches for drought forecasting
and management strategies during drought
conditions also will be examined.
Products. Reports and databases that identify
drought-prone communities will be prepared,
disseminated, and made available on the
Internet. Assistance will be provided to at-risk
communities and, with their cooperation, water
supply and drought management plans will be
prepared. Continuous, real-time water levels on
streams and reservoirs will be measured, and data
collections and analyses will be provided on the
Internet and in reports. Real-time monitoring
will provide critical information for assessing
potential drought and flood conditions and for
system management during these extreme
events. Data for reservoir budget analysis and
long-term data sets will provide information for
improved water supply management. Data
collections and data analyses of estimated
volume losses for measured and unmeasured
reservoirs will be provided in reports and on the
Internet. Data from streamgages will be used for
developing better regional models that estimate
flow characteristics on ungaged streams.
Outcome. Communities will be better able to
plan and manage water supplies for drought
emergencies, thus minimizing the risk of water
shortages. Water supply planners and managers
will be better able to track the water supply status
of reservoirs during droughts, develop water
budget and reservoir models to forecast drought
impacts on individual water supplies, and analyze
the adequacy of systems. High-flow data also can
be used to improve regional relationships of flood
discharge and frequency. Assessment of
appropriate options for rehabilitating reservoirs
and maintaining adequate water supplies will be
based on data and knowledge of the rate of
sedimentation.
12
•3•
Groundwater Supplies and Quality
Groundwater is withdrawn for large public, industrial,
and commercial purposes from three principal
categories of aquifers in Illinois: (1) unconsolidated
sand-and-gravel aquifers contained within the
glacial drift, (2) shallow bedrock aquifers, and (3)
deep bedrock aquifers. The amount of groundwater
that can be withdrawn safely varies tremendously
from aquifer to aquifer, as does the quality of the
water. In addition, thousands of private wells tap
water in the shallow aquifers. Withdrawals of
groundwater in Illinois average about 1 billion
gallons per day and serve about a third of Illinois’
population.
Many factors influence the practical renewable
yield of aquifers and water quality, and these
factors have not been quantified well enough to
permit an accurate statewide assessment of
renewable yields and water quality. Records of
aquifer characteristics are needed to establish the
aquifers’ physical and hydraulic properties,
groundwater withdrawals, spatial and temporal
changes in groundwater levels and groundwater
quality, and to provide input to mathematical
computer models. However, comprehensive
digitized records of the hydrologic, hydraulic,
and water quality properties of the state’s
aquifers either do not exist or need to be updated
and made more accessible: agencies have their
own databases, and much ISWS data remain to
be digitized. The need for improved databases is
revealed every time a groundwater flow model or
statistical assessment of aquifer properties is
conducted.
High-capacity wells also may have adverse impacts
on nearby wells and the base flows of rivers and
streams, regardless of whether or not the practical
renewable yield of the source aquifer is exceeded.
Unfortunately, modern computer flow models that
can simulate aquifer conditions and calculate
renewable yields and the impacts of new wells on
existing wells do not exist for Illinois aquifers. In
addition, adverse impacts are not well defined.
3.i. Regional Aquifer Characterization
and Monitoring
Issue. For decades, the ISWS has collected
important groundwater data for many of Illinois’
major regional aquifer systems. However, the
ISWS does not have comprehensive, easily
accessible digital records of the spatial and
temporal distribution of many key aquifer
characteristics. Data resolution is very
inconsistent across the state, many data gaps
exist, and many data sets need to be updated.
Activities. Existing data will be assembled and
organized to characterize the shape, depth, physical
(hydraulic) properties, boundary conditions, rates
of recharge under normal and drought conditions,
Lake
Michigan
Limit of data
400
400
1000
2000
1000
High concentrations (mg/L) of dissolved solids limit the use of
water in southern parts of the deep sandstone aquifer.
140
100
120
80
40
60
Cl (mg/L)
20
0
1950 1960 1970 1980 1990 2000
Change in chloride concentrations in four municipal wells
(<200 feet deep) in Kane County.
13
hydraulic heads, locations of wells and groundwater
withdrawals, and water quality in the state’s major
regional aquifers. Existing ISWS databases will be
updated with additional data collected through the
multitude of projects previously conducted by
ISWS and other scientists. New databases will be
created from data mined from ISWS paper files and
publications. A comprehensive literature review
will be conducted to glean data from previous
ISWS investigations. Original well-construction
records will be scanned and digitized. Priority will
be placed on those aquifers most in need of study
and management attention, based on the
use-to-yield analysis discussed previously. A
preliminary list of the state’s major aquifers is
provided below.
➤ The “deep bedrock” aquifer system of northeastern
Illinois (Cambrian-Ordovician System)
➤ The Mahomet aquifer of east-central Illinois from
Indiana to the Illinois River
➤ The shallow sand-and-gravel and bedrock aquifers
in northeastern Illinois
➤ The Sankoty aquifer of Lee and Whiteside
Counties and from Hennepin to Washington
➤ The alluvial aquifer systems along the Mississippi
River
➤ The shallow dolomite in Kankakee, Iroquois,
Will, and Cook Counties
➤ The Saline Valley in Saline and Gallatin
Counties
➤ The alluvial system along the Wabash River
Valley
➤ The alluvial system of the Lower Illinois River
from Beardstown to Alton
➤ The alluvial system of the Rock River from
Wisconsin to Sterling
➤ The alluvial system of the Kaskaskia River Valley
➤ The alluvial system of the Cache River Valley
➤ The alluvial system of the Embarras River Valley
➤ The “ridged-drift” aquifer near Taylorville
Products. Data will be assimilated, disseminated,
and made available in reports and via the
Internet. Existing ISWS databases to be updated
for documentation of water use, aquifer hydraulic
properties, groundwater levels, and groundwater
quality include the Private Well Data Base, the
Public-Industrial-Commercial Survey, and the
Illinois Water Inventory Program. Improved links
to other databases will be established (e.g., Illinois
State Geological Survey geological records and
Illinois Environmental Protection Agency and
Illinois Natural History Survey water quality
records) and efforts strengthened to minimize
overlap and duplication. Guidelines for the
definition of adverse impacts will be provided.
Outcome. Scientists, analysts, and decision makers
will be able to access a wealth of groundwater data
statewide. These data will be useful as data input
to the development of regional and local aquifer
models. The outcome will be more scientific and
reliable water supply planning and management
across the state and conflict
resolution.
3.ii. Preliminary Groundwater Modeling
Issue. Groundwater flow models are needed to
determine renewable yields from aquifers, capture
zones of wells, water quality, and to evaluate the
Drilling a well to tap groundwater.
14
impacts of water withdrawals. The ISWS has
developed flow models for only a few aquifers, and
these models are not up to date. Flow models need
to be constructed and/or updated for all the major
aquifers in the state.
Activities. As data are assembled and organized on
Illinois’ high priority aquifers, simple groundwater
models will be constructed to provide estimates
of groundwater availability (practical renewable
yield) and water quality for that aquifer. Existing
models will be evaluated, updated, and used as
appropriate. Priority will be placed on those
aquifers most in need of study and management
attention, based on the use-to-yield analysis
discussed previously.
Products. Estimates of groundwater availability,
with uncertainty estimates, and water quality
characterizations will be provided for each major
aquifer in Illinois. For those aquifers experiencing
potential water-use conflicts, a computer flow
model will be constructed such that estimates of
well interference on groundwater levels and
streamflows can be provided.
Outcome. These models will provide tools for water
planners and managers to assess regional groundwater
availability, water quality, and impacts of withdrawals.
In tandem with surface water assessments,
alternatives for new water-resource developments to
alleviate water shortages can be examined. In
addition, such models can provide important
feedback to help identify additional data needed to
reduce model uncertainty. This will form the basis
for additional new data collection efforts.
3.iii. Field Studies
Issue. Preliminary groundwater models will
contain a fairly high degree of uncertainty because
specific field studies have not been conducted to
gather data for model development and validation.
However, these models will provide a basis for
planning aquifer-specific field studies.
Activities. Based on model uncertainties and
priority aquifers, field studies will be conducted
to collect new data through short-term sampling
and long-term monitoring. Priority will be placed
on those aquifers most in need of study and
management attention, based on the use-to-yield
analysis discussed previously. Such new data
collection activities will include:
➤ Improving estimates of groundwater recharge and
estimates of the impacts of climate variability and
change on recharge.
➤ Determining surface water/groundwater interactions
under normal and drought conditions.
Irrigation of crops uses large quantities of groundwater in some parts of Illinois.
15
➤ Determining aquifer hydraulic properties in
untested areas.
➤ Improving geologic maps to provide better estimates
of aquifer physical properties.
➤ Collecting water-level data for the creation of
potentiometric surface (water-level) maps.
➤ Collecting water samples to characterize water
quality.
Products. Databases, graphics, and maps for
Illinois’ major aquifers, providing improved spatial
resolution of aquifer physical, hydraulic, and
chemical properties, will be produced. These
products will be disseminated in reports and made
available via the Internet.
Outcome. Improved resolution of field data will
provide input for the development of more
detailed and accurate groundwater flow models
and for managing water-use conflicts.
3.iv. Detailed Mathematical Computer
Models
Issue. Decision makers need “living” numerical
computer models to evaluate alternative strategies
for resource development. Such models must be
capable of a) accurately simulating hydraulic head
and transport of chemicals in the aquifers, b)
estimating practical renewable yields of the state’s
major aquifers, c) identifying capture zones around
public water supply wells, d) identifying interference
drawdown, and e) providing scientific input for
management of groundwater resources.
Activities. All existing data and the results of
field studies will be incorporated into detailed
groundwater flow models of the state’s major
regional aquifers. Priority will be placed on those
aquifers most in need of study and management
attention based on the use-to-yield analysis
discussed previously. Models will be updated
routinely as new data are collected to improve
model calibrations and predictive capabilities.
Computer flow models will be migrated to new
software and hardware platforms for improved
model performance.
Products. Computer flow models for Illinois’
major aquifers, with uncertainty analysis, will be
placed on Internet-based decision support systems
(see Section 6) for use by analysts in evaluating
water management options. The flow models will
include the transport of chemicals.
Outcome. With higher resolution data,
detailed computer groundwater models can be
constructed to make more accurate predictions
of impacts of withdrawals on water levels,
water quality, surface water interactions, and,
ultimately, aquifer yield. Such models can be
applied to evaluate:
➤ Long-term practical renewable yields from the
state’s major aquifers.
➤ Impacts of withdrawals on the quality and
quantity of the resources.
➤ Interaction between shallow groundwater supplies
and streamflows.
➤ Options for the artificial recharge of aquifers.
➤ Water use conflicts.
The overall outcome will be the protection of
groundwater resources, the identification of
options for the renewable use of groundwater
resources, and the resolution of water-use conflicts.
16
•4•
Understanding and Predicting the
Hydrologic Cycle and Water Resources
All components of the hydrologic cycle are
interdependent: precipitation affects soil moisture
and surface water; soil moisture also affects
precipitation and aquifer recharge; and surface waters
and aquifers are interconnected. It is, therefore,
appropriate and necessary to study the hydrologic
cycle and water resources in Illinois as a system.
Mathematical computer models provide an
opportunity to simulate this system and to possibly
predict future changes of this system and water
resources in Illinois. Such a systems approach
provides a scientific basis for comprehensive regional
water supply planning and management (Section 6).
Mean annual precipitation varies from about 34
inches in northern Illinois to 50 inches in
southern Illinois. Precipitation in any given year is
much more variable and can be as low as 25 inches
in the north to as high as 65 inches in the south.
These climate variations fundamentally influence the
amount of water available in rivers, streams, lakes,
reservoirs, and aquifers. Statewide, about 25 percent
of the precipitation runs off the land surface or
infiltrates the soil in an average year. Statewide,
about 75 percent of precipitation is returned to the
atmosphere through evapotranspiration in an
average year. During droughts, this percentage
approaches 100 percent, leaving little
precipitation for runoff or aquifer recharge.
The amount of water that runs off the land surface
or percolates into the soil also is influenced by
temperature, the nature of the land cover, and
drainage systems.
For the above reasons, climate variables are
important to the water resources of Illinois. In
addition, climate regimes change naturally and
could change in response to human modifications
of the climate system. The buildup of pollutants
in the atmosphere has given rise to projections
that regional climate conditions could change
WISCONSIN
INDIANA
ILLINOIS
IOWA
Meredosia
Snicarte
Valley City
Lake
Michigan
Upper Mississippi River
Illinois River
10-Year Running Averages
Watershed precipitation
Illinois River streamflow at Meredosia/Valley City
(minus Lake Michigan diversion)
Groundwater elevation at Snicarte
39
40
38
15
16
14
37
36
35
Precipitation (inches)
Streamflow (inches)
Groundwater Elevation (feet)
34
33
32
31
447.0
447.5
448.0
448.5
449.0
30
13
12
11
10
9
8
7
6
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
A comparison of 10-year running averages of Illinois River watershed precipitation, streamflow
(minus Lake Michigan diversion), and groundwater level.
17
dramatically due to global warming caused by an
enhanced greenhouse effect. The fact that
different models produce different scenarios of
climate change points to the large scientific
uncertainties that exist in projecting climate
change. Nevertheless, there are risks that climate
change, even in the next 20 years, could impact
water resources in Illinois due to changes in
precipitation and temperature and to changes in
the frequencies of droughts and floods. It would
be shortsighted to assume that the future climate
of Illinois will be the same as the present climate
to which ecosystems, society, and the economy
have adapted. The risk of climate change and the
possible impacts of climate change on Illinois
water resources need to be evaluated.
4.i. Monitoring of Climate, Soil,
and Land-use Changes
Issue. A 19-station array of sensors across the
state provides continuous observations of climate
and soil conditions. Data from the Illinois Climate
Network (ICN) are becoming increasingly
important to a growing number of governmental,
university, private enterprise, and public users.
Data are used by the Illinois State Water Plan
Task Force to monitor and evaluate water and soil
conditions across Illinois and to plan for drought
emergencies. For security and station longevity
considerations, the network’s original stations were
placed on state or university property. Increased
demands for data often are not met because the
existing distribution of stations is not sufficiently
dense.
In addition, runoff into rivers, streams, and
reservoirs can be altered from present rates by
changes in land-use cover and related variables
within a basin—for example, crops, reforestation
and restoration. A better understanding of the
overall impacts of changes in these variables on
water supplies can be achieved by monitoring key
climate, land-use, and other watershed conditions
at selected locations within a basin and then
developing a model to extend these analyses to
other basins and other conditions.
Activities. Twelve additional ICN sites need to
be installed in Illinois to provide improved water
resources data across the state. The sites need to
be equipped with weather and soil observation
sensors, towers, dataloggers, weather shelters, and
communications and other equipment.
Also, a small stream basin will be selected for
intensive monitoring. One criterion for basin
selection will be the availability of streamgages and
reservoir water-level monitors. To represent likely
within-basin differences in evapotranspiration and
soil moisture, four sites will be selected for routine
monitoring of, for example, upland crop, upland
forest, lowland crop, and lowland forest. Each site
will be instrumented to obtain measurements of
precipitation, evapotranspiration, soil conditions,
vegetation, and related variables. Data will be
collected routinely for 10 years to establish temporal
variations in the relationship of these elements to
runoff. Data will be analyzed and a model
developed to simulate a water budget for the basin.
Once the validity of the model is established, it
can be applied to other basins.
Products. Continuous observations of weather and
soil conditions statewide, a 10-year record, and a
model of the water budget in a basin will be provided.
Data sets, models, and reports will be prepared,
disseminated, and made available via the Internet.
Outcome. Water supply planners and managers,
weather- and climate-sensitive industries, and the
public will be able to incorporate the data into
improved operational models and decision making.
The effects of land-use changes on water supplies
will be quantified, and the basin model will be
applied to better plan and manage water resources
under changing basin conditions.
4.ii. Modeling the Linked Climate/Surface
Water/Groundwater System
Issue. Potential future climate variability and
change pose threats to water supplies. Assessment of
the effects of climate variability and climate change
on water resources requires data at the spatial scales
of watersheds. Watersheds feed many water supplies
18
much smaller than the resolution of global climate
models. Therefore, the projections by these models
cannot be used directly to assess impacts on specific
water supplies. Regional climate modeling is
required to address these issues. However, regional
climate models are still under development, and
more research is required to improve model
accuracy so that they can be applied with
confidence to address water resources issues. The
ISWS has initiated a regional climate modeling
program, but limited resources restrict progress on
this very important issue.
Activities. Four major activities will be undertaken
to improve the usefulness of regional climate model
information for water resources applications.
One activity will focus on improvement of the model
through a sequence of model simulations of selected
historical events, comparisons of model results with
observed events, and identification of potential
model improvements to enhance model capabilities
to simulate droughts and heavy precipitation events
that cause flooding. The goal will be to accurately
simulate these events for a variety of climate
conditions under which they occur. Accurate
simulations of past events will increase confidence
in the ability of models to project future climate
extremes and climate changes.
The second task, undertaken in parallel with the
first, will be the coupling of the regional climate
model with surface hydrologic models to directly
produce estimates of runoff, discharge, and
infiltration.
The third task will be to link climate, surface
hydrology, and groundwater flow models to
evaluate system impacts of possible climate
variations and changes.
The fourth task will be to apply the linked models,
embedded in a global climate model, to project
possible future climate and water resources conditions
in Illinois.
Products. Assessments will be made of the risks
and possible consequences of future climate
change on water resources in Illinois. Resulting
data sets will be disseminated in reports and made
available via the Internet.
Outcome. Policy makers and water supply
planners will be able to use the new data on
possible future water resources conditions in Illinois
to conduct risk assessments, to evaluate alternative
policies and strategies, and to make far-sighted
decisions.
4.iii. Assessment of Climate Change
Model Projections
Issue. Climate models are complex mathematical
computer programs that scientists use to project
possible climate changes due to natural and
human factors. Research groups around the world
are improving these models. However, large
model-to-model differences in future projections
of precipitation and temperature for Illinois
reflect scientists incomplete understanding and
model simplifications of the global climate system.
It is important to evaluate model differences and
to assess the credibility of new model projections,
since the climate and water resources of the 21st
Century could be significantly different from
those of the 20th Century.
Activities. Projections of Illinois’ climates
produced by different models will be assessed
and their implications for Illinois water resources
evaluated.
Products. Reports on a range of possible future
climate conditions will be provided, along with
assessments of the uncertainties of these
projections. Explanations will be provided why
models using essentially the same drivers—
emissions associated with natural processes and
population and economic growth—produce
different climate projections.
Outcome. Governments and private industry
will be able to use these projections, with
interpretations and uncertainty estimates, as
guidance for risk assessment in water resources
planning and management. The information and
knowledge gained also will provide valuable
guidance for the regional climate modeling
activity to decide which models to use for more
detailed assessments of water resources.
19
•5•
Reporting of Water Use
Water supply planning requires comprehensive
and detailed information on water withdrawals,
uses, transfers, and returns. Assessment of water
availability is fundamental, but it is equally
essential that the demands on that resource be
quantitatively and geographically identified. Water
withdrawal information is necessary to develop
water budgets, calculate adjustments to streamflow
records, monitor trends in water demand, as input
to develop and calibrate hydrologic models, and
resolve conflicts.
5.i. Reporting and Analysis of Water
Withdrawal, Use, Transfer, and Return
Issue. The ISWS has a long-standing program of
water withdrawal data collection, analysis, and
reporting for surface waters and groundwater.
However, more comprehensive, detailed, and
precise data collection, analysis, and reporting are
required for self-supplied users, trend analysis,
integration and analysis of water returns, and
accounting of water transfers.
Activities. Building on existing data, expertise, and
resources, ISWS will a) coordinate work with other
governmental organizations to collect, archive, and
disseminate water data; b) expand current data
collection activities to increase annual reporting
return rates to approach 100 percent for major users;
c) assimilate water withdrawal, use, transfer, and return
data; d) develop a coordinated, Internet-based database;
e) expand and refine data quality control and quality
Fresh Water Withdrawals 1995 (MGD)
Domestic and Public Supply
Self-Supplied Industries
Livestock and Irrigation
Thermoelectric Power
Total
1450
422
2
17,100
18,974
500
183
234
11
928
1949
606
236
17,100
18,891
Surface
Water
Ground
Water Total
Source: USGS Circular 1200
Freshwater withdrawals in millions of gallons per day (mgd)
from surface water and groundwater, 1995.
Electric power generation is the major use of water in Illinois.
20
assurance for the data; f) analyze consumption,
returns, and inter-basin transfers; and g) provide water
use data to communities and engineers engaged in
facility design and watershed and water supply
planning.
Products. Databases and reports on surface water
and groundwater withdrawals, transfers, uses, and
returns will be disseminated and made available
on the Internet.
Outcomes. Fuller accounting of water
withdrawals, uses, transfers, and returns will enable
water supply planners and managers to develop
water budgets, calculate adjustments to streamflow
records, monitor trends in water demand, prioritize
water withdrawals, calibrate hydrologic models,
and resolve conflicts. As a result, the state’s water
resources can be used more wisely.
•6•
Comprehensive Water Supply
Planning and Management
Water use in Illinois is largely unregulated and
controlled by a market economy. Surface water and
groundwater resources are usually studied and
managed separately, yet there are many opportunities
for the conjunctive use of these resources. To date,
there is little conservation or reuse of water in Illinois,
but many opportunities for doing so exist. The above
studies will provide large quantities of quality-assured
data that must be assembled, synthesized, analyzed, and
made easily available to other agencies and the general
public for appropriate use.
6.i. Decision Support
Issue. The management of water resources in
Illinois is complicated by the spatial and temporal
Data
Collection
Data Analysis
and Interpretation
Data
Management
Planning
Outcome: Water Management
Decision support for comprehensive water resources planning and management.
21
variability of water resources, climatic uncertainty,
groundwater/surface water interactions, a diversity
of constituent interests, social and economic
considerations, and legal constraints. Wise and
optimal use of water supplies requires evaluating
options for and the consequences of water
management policies and strategies, which can
come only from accurate, unbiased data
interpreted and analyzed for water resources
planners. Comprehensive water supply planning
at the regional and local scales can increase
efficiencies, lower costs, and ensure the future
availability of adequate supplies of clean water
at a reasonable cost.
Activities. Three major activities are identified.
1. Develop quality-assured databases, tables, graphics,
and maps related to water supply (climate, surface
water and groundwater), demand, withdrawal,
use, and interbasin transfer. These databases will
be compatible and constructed by geographical
(watersheds and aquifers) and political units.
2. Develop and maintain an accessible, comprehensive
Internet-based decision-support system that will
include:
a. Quality-assured databases;
b. Research results to address key social,
hydrologic, and economic uncertainties (e.g.,
the value of nonmarket use of water, the impact
of climate variations on aquifer recharge); and
c. Tested computer models for evaluating
alternative hydrologic and economic strategies
for the optimal conjunctive use of water
resources (e.g., cost minimization or net social
benefit maximization) and water conservation
and reuse.
3. Interact with local, state, and national water
resource planners to construct plausible
management scenarios and to translate data and
model results into actionable knowledge.
Provide training to regional and local officials
on water supply planning and management
under variable climatic conditions.
Products. These activities will organize data
products and information and disseminate these
as reports and as multimedia presentations,
including models, via the Internet. Methods for
analyzing the optimal conjunctive uses of surface
water and groundwater resources, together with
water conservation and reuse strategies, will be
made available in reports and via the Internet.
ISWS will train personnel in water supply
planning.
Outcomes. Comprehensive water supply
planning can lead to the optimal use of limited
resources for minimum financial and
environmental costs. Economic models
developed by these activities will provide a
rational basis for determining water
management strategies. Water resource planners
and managers will be able to use their training
and the new data to design and develop water
supply, treatment, and distribution projects.
Costs
Benefits
Evaluating the costs and benefits of water supply,
conservation, and reuse options.
CONTACTS AT THE ILLINOIS
STATE WATER SURVEY
Illinois State Water Survey
2204 Griffith Drive
Champaign, IL 61820-7495
(217) 244-5459
TDD: (217) 782-9175
Fax: (217) 333-6540
Web: http://www.sws.uiuc.edu
Office of the Chief
Chief: Derek Winstanley, (217) 244-5459
Financial & Human Resources: Joyce Changnon,
(217) 333-0448
Planning & Operations: Ronald Karr, (217) 333-8885
External Relations & QA/QC: Mark Peden, (217) 333-8325
Geographic Information Systems: Kingsley Allan,
(217) 333-0545
Library: Patricia Morse, (217) 333-4956
Water & Atmospheric Resources Monitoring: Bob Scott,
(217) 333-4966
Analytical Chemistry & Technology Unit
Head: Kent Smothers, (217) 333-6167
Internal Analytical Services/Public Service Laboratory:
Loretta Skowron, (217) 333-4977
Midwest Technology Assistance Center: Kent Smothers,
(217) 333-6167
Water Analyses: Brian Kaiser, (217) 333-9234
Atmospheric Environment Section
Head: Kenneth Kunkel, (217) 244-1488
Agricultural Meteorology: Steven Hollinger,
(217) 244-2939
Atmospheric Chemistry: Gary Stensland, (217) 244-2522
Climate Modeling: Xin-Zhong Liang, (217) 244-6864
Climate Studies: Stanley Changnon, (217) 244-0494
Cloud Physics: Harry Ochs, (217) 333-4964
Mesoscale Meteorology: David Kristovich, (217) 333-7399
Midwestern Climate Center: Steve Hilberg,
(217) 333-8495
State Climatologist: James Angel, (217) 333-0729
Groundwater Section
Interim Head: Derek Winstanley, (217) 244-5459
Groundwater Supplies: Allen Wehrmann, (217) 333-0493
Groundwater Quality: Walt Kelly, (217) 333-3729
Groundwater Information: Ken Hlinka, (217) 333-8431
Well Design and Rehabilitation: Bob Olson,
(217) 333-8700
Well Records: Susie Dodd-Casey, (217) 333-9043
National Atmospheric Deposition Program
Head & NADP Coordinator: Van Bowersox,
(217) 333-7873
Central Analytical Laboratory: Karen Harlin, (217) 244-6413
Toxics and Mercury Deposition: Clyde Sweet,
(217) 333-7191
Watershed Science Section
Head: Mike Demissie, (217) 333-4753
Erosion & Sedimentation: Mike Demissie, (217) 333-4753
Hydrologic Modeling: Deva Borah, (217) 244-8856
Illinois River Decision Support System: Melinda Tidrick,
(217) 244-7106
River Mechanics & Hydraulics: Nani Bhowmik,
(217) 333-6775
Sediment Quality: Mike Machesky, (217) 333-9322
Streamflow Assessment: Vern Knapp, (217) 333-4423
Surface Water Information: Bill Saylor, (217) 333-0447
Surface Water Supplies: Sally McConkey,
(217) 333-5482
Water Quality: Gary Peyton, (217) 333-5905
Watershed Monitoring: Laura Keefer, (217) 333-3468
Watershed Restoration: Don Roseboom, Peoria,
(309) 671-3196
Wetlands: Mike Demissie, (217) 333-4753
22
Starved Rock Lock and Dam on the Illinois River.
Illinois State Water Survey
2204 Griffith Drive
Champaign, IL 61820-7495
(217) 244-5459
TDD: (217) 782-9175
Fax: (217) 333-6540
Web: http://www.sws.uiuc.edu
Electronic Documents of Illinois
