U.S. Department of the Interior

U.S. Geological Survey

Circular 1383–G

U.S. Geological Survey Water Science Strategy—

Observing, Understanding, Predicting, and 

Delivering Water Science to the Nation
Cover. Clockwise left to right: 

 USGS hydrographer measuring discharge with a flowtracker at San Carlos River near Peridot, Arizona, Nov. 2010. Photograph 

 by Norbert R. Duet, U.S. Geological Survey (USGS). 

 Solomon Gulch at top of Falls near Valdez, Alaska, Oct. 2010. Minor flood stage from Solomon Lake spill. Photograph by 

 Jeffery M. Wiles, USGS. 

 USGS hydrographer measuring streamflow with Acoustic Doppler Current Profiler (ADCP), West Fork Cedar River near 

 Finchford, Iowa, June 2008. Photograph by Don M. Becker, USGS. 

 Molly Wood, USGS, making comparison ADCP measurements with Chilean and University of Idaho scientists on the Rio Murta 

 in Chilean Patagonia, Jan. 2011. 

 USGS hydrographer sampling in Grand Teton National Park, Wyoming, Oct. 2006. Photograph by Melanie L. Clark, USGS. 

 The Blue Marble. Image by NASA Goddard Space Flight Center.

Background. Lake Josephine, Glacier National Park, Montana, Aug. 2005. Photograph by G. Lynn Wingard, USGS. 
U.S. Geological Survey Water Science 

Strategy—Observing, Understanding, 

Predicting, and Delivering Water Science 

to the Nation

By Eric J. Evenson, Randall C. Orndorff, Charles D. Blome, John Karl Böhlke, Paul

K. Hershberger, Victoria E. Langenheim, Gregory J. McCabe, Scott E. Morlock, 

Howard W. Reeves, James P. Verdin, Holly S. Weyers, and Tamara M. Wood

Circular 1383–G

U.S. Department of the Interior

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

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

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

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Suggested citation:

Evenson, E.J., Orndorff, R.C., Blome, C.D., Böhlke, J.K., Hershberger, P.K., Langenheim, V.E., McCabe, G.J., Morlock, 

S.E., Reeves, H.W., Verdin, J.P., Weyers, H.S., and Wood, T.M., 2013, U.S. Geological Survey water science 

strategy—Observing, understanding, predicting, and delivering water science to the Nation: U.S. Geological 

Survey Circular 1383–G, 49 p.

ISBN 978-1-4113-3543-1
iii

Foreword

In 2007, the U.S. Geological Survey (USGS) published a Bureau Science Strategy Facing Tomorrow’s 

Challenges—U.S. Geological Survey Science in the Decade 2007–2017. It provided a view of the future, 

establishing science goals that reflected the USGS’s fundamental mission in areas of societal impact such 

as energy and minerals, climate and land use change, ecosystems, natural hazards, environmental health, 

and water. Intended to inform long-term program planning, the strategy emphasizes how USGS science 

can make substantial contributions to the well-being of the Nation and the world. 

In 2010, I realigned the USGS management and budget structure, changing it from a structure associated 

with scientific disciplines—Geography, Geology, Biology and Hydrology—to an issue-based organization 

along the lines of the Science Strategy. My aim was to align our management structure with our mission, our science priorities, our metrics for success, and our budget. An added benefit was that the USGS 

immediately appeared relevant to more Americans, and it became easier for those outside the agency to 

navigate our organizational structure to find where within the USGS they would find the solution to their 

problem. External partners rarely approached us with a problem in “geology,” but they might need help 

with an issue in climate change or energy research. 

The new organization is focused on seven science mission areas:

• Climate and Land Use Change

• Core Science Systems

• Ecosystems

• Energy and Minerals

• Environmental Health

• Natural Hazards

• Water

The scope of each of these new mission areas is broader than the science directions outlined in the USGS 

Science Strategy and together cover the scope of USGS science activities. 

In 2010, I also commissioned seven Science Strategy Planning Teams (SSPTs) to draft science strategies 

for each USGS mission area. Although the existing Bureau Science Strategy could be a starting point for 

this exercise, the SSPTs had to go well beyond the scope of the existing document. What is of value and 

enduring from the work of the programs that existed under the former science disciplines needed to be 

reframed and reinterpreted under the new organization of the science mission areas. In addition, new 

opportunities for research directions have emerged in the five years since the Bureau Science Strategy 

was drafted, and exciting possibilities for cooperating and collaborating in new ways are enabled by the 

new mission focus of the organization.

Scientists from across the Bureau were selected for these SSPTs for their experience in strategic planning, broad range of experience and expertise, and knowledge of stakeholder needs and relationships. 

Each SSPT was charged with developing a long-term (10-year) science strategy that encompasses the 

portfolio of USGS science in the respective mission area. Each science strategy will reinforce others 

because scientific knowledge inherently has significance to multiple issues. Leadership of the USGS and 

the Department of the Interior will use the science vision and priorities developed in these strategies 

for program guidance, implementation planning, accountability reporting, and resource allocation. These 

strategies will guide science and technology investment and workforce and human capital strategies. 

They will inform our partners regarding opportunities for communication, collaboration, and coordination.

The USGS has taken a significant step toward demonstrating that we are ready to collaborate on the most 

pressing natural science issues of our day and the future. I believe a leadership aligned to support these 

issue-based science directions and equipped with the guidance provided in these new science strategies 

in the capable hands of our scientists will create a new era for USGS of which we can all be proud.

Marcia McNutt 

 Director
iv

About This Report

The Water Science Strategy expands on the U.S. Geological Survey (USGS) Science Strategy, 

“Facing Tomorrow’s Challenges—U.S. Geological Survey Science in the Decade 2007–2017” 

(U.S. Geological Survey, 2007), which developed seven integrated science Mission Areas. This 

water strategy builds on the strengths of water science in the USGS and links to other science 

disciplines and Mission Areas of the Bureau and our many partners outside of the USGS. In 

addition, it recognizes that “in the coming decades of the 21st century the United States faces 

serious and complex water problems. Constraints on availability of water—quantity and quality—will impact what we do and where we do it as a society. To face these problems the Nation 

will need more, new, and improved water science, information and tools to manage and adapt 

to these constraints” (National Research Council, 2009). This report is addressed primarily to 

policymakers who will determine the future resources with which the USGS has to conduct its 

work, so that they will be apprised of the technical and societal issues that the Bureau will face 

in the future.

The USGS Science Strategy, “Facing Tomorrow’s Challenges—U.S. Geological Survey Science in 

the Decade 2007–2017” (U.S. Geological Survey, 2007) included a science direction on “A Water 

Census of the United States—Quantifying, Forecasting, and Securing Freshwater for America’s 

Future.” The Water Census is to inform the public and decisionmakers about (1) the status of 

freshwater resources and how they are changing; (2) water use for human, environmental, and 

wildlife needs; (3) freshwater availability related to natural storage and movement; (4) means 

of identifying water sources not commonly thought to be a resource; and (5) forecasts of likely 

outcomes of water availability and quality. Six specific strategic actions were put forth in the 

Science Strategy to address the aspects of a water census. The “U.S. Geological Survey Water 

Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the 

Nation,” takes the fairly broad strategic actions of the Water Census and develops the steps and 

actions to move the USGS forward to a strategic focus.
v

The Water Mission Area is one of seven science areas that will lead to integrated science 

across the various USGS disciplines to address societal earth science needs. A Water Science 

Strategy Planning Team (SSPT) was charged with developing a long-term (10-year) strategic 

science plan for the USGS Water Mission Area and the programs that support it. This Science 

Strategy looks at the issues facing society and develops a strategy that observes, understands, 

predicts, and delivers water science by taking into account the water science and core capabilities of the USGS; the document also looks forward over the next 5 to 10 years toward building 

new capabilities, tools, and delivery systems to meet the Nation’s water-resource needs. This 

Science Strategy serves as a guiding document for USGS leadership in science planning and 

execution and will be used as a basis for budget initiatives and national and regional guidance. 

Through observing components of the water cycle, we can better quantify the water resource 

in terms of abundance and quality. Understanding the water cycle leads to development of 

better tools for assessing all aspects of the water resource, from water availability, to flooding, to degradation of surface waters and groundwater. Predicting modifications of the water 

cycle from factors such as human effects on watersheds and climate variability is important 

for decisionmaking to ensure the sustainability and resilience of communities and ecosystems. 

Finally, USGS science related to observing, understanding, and predicting components of the 

water cycle must be delivered to managers, policymakers, and the public in understandable and 

relevant ways to be an effective force in managing the water resource. 

The goals, objectives, and strategic actions presented in this report are a result of many meetings and forums with stakeholders and input from USGS scientists and staff, along with discussions with collaborators and partners of water science outside the Bureau. This information was

considered in forming the Priority Actions discussed in the section by that name of this report. 

“Priority Actions” attempts to take the crosscutting objectives and strategic actions in the 

section entitled “Water Science Goals and Objectives” and integrate them into science for the 

future to meet water needs of the 21st century. The Water SSPT recognized that water needs 

include sustaining ecosystems along with human uses. Competing uses of water including 

human consumption, industry, agriculture, and ecosystems are exacerbated by the challenges 

we face with population growth, energy demands, climate variability, and other factors. The 

science needed to address these issues requires a diverse workforce with expertise in hydrology, geology, physics, chemistry, and biology.
vi

Contents

Foreword ........................................................................................................................................................iii

About This Report .........................................................................................................................................iv

Executive Summary.......................................................................................................................................1

Introduction.....................................................................................................................................................3

Vision for Water Science in the USGS ..............................................................................................3

Societal Issues and Water Science ..................................................................................................3

Core Capabilities: Strengths, Partnerships, and Science Integration—

What We Do Now that is Important and Needs to Continue....................................................7

Priority Actions.............................................................................................................................................11

Improve Integrated Science Planning for Water ..........................................................................11

Expand and Enhance Water-Resource Monitoring Networks....................................................11

Characterize the Water Cycle Through Development of State-of-the-Art 3-D/4-D 

Hydrogeologic Framework Models at Multiple Scales ..................................................12

Clarify the Linkage Between Human Water Use (Engineered Hydrology) and the 

Water Cycle (Natural Hydrology)........................................................................................15

Advance Ecological Flow Science ..................................................................................................15

Provide Flood-Inundation Science and Information.....................................................................16

Develop Rapid Deployment Teams for Water-Related Emergencies.........................................16

Conduct Integrated Watershed Assessment, Research, and Modeling...................................17

Deliver Water Data and Analyses to the Nation............................................................................17

Water Science Goals and Objectives.......................................................................................................18

Goal 1: Provide Society the Information It Needs Regarding the Amount and Quality 

of Water in All Components of the Water Cycle at High Temporal and Spatial 

Resolution, Nationwide ........................................................................................................18

Objective 1: Advancement of Hydrologic Monitoring Networks and Techniques..........23

Objective 2: Advancement of Monitoring Networks and Techniques for Determining 

Water Quality ................................................................................................................24

Objective 3: Assessment of Water Resources and their Suitability to Meet Human and 

Ecosystem Needs.........................................................................................................25

Goal 2: Advance Understanding of Processes that Determine Water Availability..................25

Objective 1: Comprehensive Understanding of Geological Controls of Water 

Availability, and Improved Integration of Geologic and Hydrologic 

Multidimensional Models ...........................................................................................26

Objective 2: Comprehensive Understanding of the Effects of Climate Variation on 

Water Availability at Multiple Spatial and Temporal Scales.................................28

Objective 3: Comprehensive Understanding of the Interactions Among Aquatic 

Ecosystems, Hydrology, and Hydrochemistry .........................................................28

Objective 4: Comprehensive Understanding of Human Interactions with Water 

Availability .....................................................................................................................28
vii

Goal 3: Predict Changes in the Quantity and Quality of Water Resources in Response 

to Changing Climate, Population, Land Use, and Management Scenarios.................32

Objective 1: Development and Application of Models To Predict Potential Effects 

of Changes in Population, Land Use, Climate, and Management Practices

Upon Future Water Availability Considering Human and Ecological Needs......32

Objective 2: Prediction of the Availability of Alternative (Impaired) Water

Resources, and the Effects of Using These Water Sources on the 

Environment ..................................................................................................................33

Goal 4: Anticipate and Respond to Water-Related Emergencies and Conflicts ......................34

Objective 1: Identification of Current and Future Threats to Communities from

Water-Related Hazards...............................................................................................34

Objective 2: Development and Deployment of Observational Systems for

Identifying and Tracking Hydrologic Hazards, Making Operational

Decisions During Extreme Hydrologic Events, and Providing Data for

Recovery........................................................................................................................35

Objective 3: Through an Understanding of the Conditions Leading to Water

Shortages that Result in Conflicts, Provide Assistance to Communities 

in Finding Science-Based Solutions When Conflicts Occur.................................35

Objective 4: Providing Tools that Allow Managers to Detect and Respond to

Emergencies Related to Water-Quality Degradation of All Kinds—

Natural, Accidental, and Intentional.........................................................................36

Goal 5: Deliver Timely Hydrologic Data, Analyses, and Decision-Support Tools

Seamlessly Across the Nation to Support Water-Resource Decisions.......................38

Objective: Development of New, Integrated Information Dissemination in Formats

Appropriate for the 21st Century to Aid Scientists and Decisionmakers ...........38

Communicating Science to Society: Inform—Involve—Educate .......................................................41

Local Communication and Outreach ...............................................................................................41

Social Media........................................................................................................................................41

Integrating Resources .......................................................................................................................41

Crosscutting Science with Other USGS Mission Areas........................................................................42

Climate and Land Use Change..........................................................................................................42

Core Science Systems.......................................................................................................................42

Ecosystems..........................................................................................................................................43

Energy and Minerals ..........................................................................................................................44

Environmental Health Science .........................................................................................................44

Natural Hazards ..................................................................................................................................45

Acknowledgments.......................................................................................................................................46

References Cited..........................................................................................................................................47
viii

Figures

1. Graph showing Colorado River Basin water supply, 1914–2007...........................................4

2. Graph showing trends in population and freshwater withdrawals by source,

1950–2005 .......................................................................................................................................4

3. Diagram showing time scales of various geologic, climatic, and human events..............9

4. Graph and photograph showing vertical distribution of ages and lead

concentrations in a sediment core from the bottom of an impounded lake.....................10

5. Example of a super gage is White River at Hazleton, Indiana ............................................13

6. Schematic showing boundary extents of a basin-fill aquifer and the aquifer’s

confining layer containing impermeable bedrock ................................................................14

7. Photograph showing Bonneville Dam, the first of 14 dams in place on the Columbia

River main stem, between Oregon and Washington ............................................................15

8. Diagram showing the water cycle...........................................................................................20

9. Plot of dissolved oxygen concentration data at Oswego diversion dam and

photograph of Oswego diversion dam on the Tualatin River near West Linn, Oregon...22

10. Graph showing nuclear magnetic resonance, gamma, and electromagnetic

conductivity logs from a borehole completed in sand and gravel on Cape Cod,

Massachusetts............................................................................................................................27

11. Cross section showing surficial aquifer on the Delmarva Peninsula, Delaware,

Maryland, and Virginia; map view and cross section of simulated traveltimes of

groundwater from recharge to discharge in a watershed in New Jersey; and 

diagram showing natural attenuation processes that can occur when organic 

contaminants come into contact with oxygenated compounds in the aquifer, 

causing microbially mediated reactions that transform the contaminants into 

other chemicals that are less harmful ....................................................................................31

12. Example of flood inundation map.............................................................................................35

13. Photograph of a tributary of the Kalamazoo River near Marshall, Michigan, July

2010, and flood-inundation map for a 15-mile reach of the Kalamazoo River from

Marshall to Battle Creek, Michigan, July 2010 ......................................................................37

14. Screenshot showing real-time data collected from the U.S. Geological Survey

streamgage on the Potomac River at Point of Rocks, Md. (1410000002), and

photograph of the streamgage.................................................................................................39

Tables

1. Links of priority actions to goals and strategic actions .......................................................12

2. List of goals and strategic actions...........................................................................................19
ix

Highlights

The Water Budget...................................................................................................................5

Geochronology/Paleohydrology—Interpreting the Past as Key to the Future ..........10

Real-Time Data and the “Super Gage” .............................................................................13

Geologic Complexities..........................................................................................................14

Use of Continuous Water-Quality Monitors for Real-Time Regulatory 

Decisionmaking—The Tualatin River Success Story........................................22

Trends in Hydrogeophysics.................................................................................................27

Land Use and Contaminant Hydrogeology and Geochemistry .....................................30

Prediction in Earth Science ................................................................................................33

Kalamazoo River Oil Spill and Flood ..................................................................................37

USGS WaterAlert..................................................................................................................39
x

Abbreviations

ACWI Advisory Committee on Water Information

AHPS Advanced Hydrologic Prediction Service

CUAHSI Consortium of Universities for the Advancement of Hydrologic Science

EM electromagnetic conductivity

EMI electromagnetic induction conductivity

FEMA Federal Emergency Management Agency

FIMI Federal-Inundation Mapping Initiative

IDA Instantaneous Data Archive

InSAR Interferometric Synthetic Aperture Radar

IWRSS Integrated Water Resources Science and Services

NADP National Atmospheric Deposition Program

NASA National Aeronautics and Space Administration

NAWQA National Water Quality Assessment

NCGMP National Cooperative Geologic Mapping Program

NGO nongovernmental organization

NHD National Hydrography Dataset

NIDIS National Integrated Drought Information System

NMR nuclear magnetic resonance

NOAA National Oceanic and Atmospheric Administration

NWC National Water Center

NWIS National Water Information System 

NWS National Weather Service

SSPT Science Strategy Planning Team

TMDL Total Maximum Daily Load

USACE U.S. Army Corp of Engineers

USDA U.S. Department of Agriculture

USEPA U.S. Environmental Protection Agency

USGS U.S. Geological Survey

WSC Water Science Center

WestFAST Western States Federal Agency Support Team

WSWC Western States Water Council
U.S. Geological Survey Water Science Strategy—

Observing, Understanding, Predicting, and Delivering 

Water Science to the Nation

By Eric J. Evenson,Randall C. Orndorff, Charles D. Blome, John Karl Böhlke, Paul K. Hershberger, Victoria E. 

Langenheim, Gregory J. McCabe, Scott E. Morlock, Howard W. Reeves, James P. Verdin, Holly S. Weyers, 

and Tamara M. Wood

Executive Summary

This report expands the Water Science Strategy that 

began with the USGS Science Strategy, “Facing Tomorrow’s 

Challenges—U.S. Geological Survey Science in the Decade 

2007–2017” (U.S. Geological Survey, 2007). This report 

looks at the relevant issues facing society and develops a 

strategy built around observing, understanding, predicting, and 

delivering water science for the next 5 to 10 years by building new capabilities, tools, and delivery systems to meet the 

Nation’s water-resource needs. This report begins by presenting the vision of water science for the USGS and the societal 

issues that are influenced by, and in turn influence, the water 

resources of our Nation. The essence of the Water Science 

Strategy is built on the concept of “water availability,” defined 

as spatial and temporal distribution of water quantity and 

quality, as related to human and ecosystem needs, as affected 

by human and natural influences. The report also describes the 

core capabilities of the USGS in water science—the strengths, 

partnerships, and science integrity that the USGS has built 

over its 134-year history.

Nine priority actions are presented in the report, which 

combine and elevate the numerous specific strategic actions 

listed throughout the report. Priority actions were developed as 

a means of providing the audience of this report with a list for 

focused attention, even if resources and time limit the ability 

of managers to address all of the strategic actions in the report. 

Priority actions focus on the following:

• Improve integrated science planning for water.

• Expand and enhance water-resource monitoring networks.

• Characterize the water cycle through development of 

state-of-the-art 3-D/4-D hydrogeologic framework 

models at multiple scales.

• Clarify the linkage between human water use 

(engineered hydrology) and the water cycle (natural 

hydrology).

• Advance ecological flow science.

• Provide flood-inundation science and information.

• Develop rapid deployment teams for water-related 

emergencies.

• Conduct integrated watershed assessment, research, 

and modeling.

• Deliver water data and analyses to the Nation.

The body of the report is presented as a hierarchal set of 

5 goals, 14 objectives, and 27 strategic actions that the USGS 

should undertake to advance water science over the next ten 

years. The goals deal with the following:

1. Providing society the information it needs regarding 

the amount and quality of water in all components of 

the water cycle at high temporal and spatial resolution, 

nationwide;

2. Advancing our understanding of processes that determine 

water availability; 

3. Predicting changes in the quantity and quality of water 

resources in response to changing climate, population, 

land use, and management scenarios;

4. Anticipating and responding to water-related emergencies 

and conflicts; and 

5. Delivering timely hydrologic data, analyses, and decisionsupport tools seamlessly across the Nation to support 

water-resource decisions.
2 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

Scientific information produced on water resources would 

not be valuable if it were not communicated to society in a 

fashion that can inform decisions and actions. Therefore, the 

section following the goals describes how the USGS should 

inform, involve, and educate society about the science it produces. This section includes discussions on local outreach and 

the use of social media for effective communication.

This report concludes with a section devoted to the crosscutting science issues of the Water Mission Area with the other 

USGS Mission Areas: Climate and Land Use Change, Core 

Science Systems, Ecosystems, Energy and Minerals, Environmental Health Science, and Natural Hazards. No single Mission Area stands alone—all must work together and integrate 

their actions to fulfill the USGS science mission for the future. 

This final section identifies the important linkages that must be 

realized and maintained for this integration to occur.

USGS hydrologic technician at Many Glacier, Montana, with StreamPro 

Acoustic Doppler Current Profiler (ADCP) unit, September 2010. 

Photograph by D.A. Bischoff, USGS.
Introduction 3

Introduction

Vision for Water Science in the USGS

The USGS will provide unbiased knowledge of the 

Nation’s water resources to support human well-being, healthy 

ecosystems, economic prosperity, and anticipate and help 

resolve impending water-resource conflicts and emergencies.

The USGS Water Mission Area, through integrated 

activities with other USGS Mission Areas and partners, will 

serve society through water-resource monitoring, assessment, 

modeling, and research to provide tools that managers and 

policymakers can use for the following:

• Preserving the quality and quantity of the Nation’s 

water resource, which is critical to the survival of our 

society, the support of our economy, and the health of 

our environment;

• Balancing water quantity and quality in relation to 

potential conflicting uses among human consumption, 

industrial use and electric power production, agricultural use, mineral and energy extraction, and ecosystem needs; 

• Understanding, predicting, and mitigating water-related 

hazards such as floods, droughts, and contamination 

events, as well as understanding the effects of climate 

variability on the water resource, to foster more sustainable and resilient communities and ecosystems; and

• Quantifying the vulnerability of human populations 

and ecosystems to water shortages, surpluses, and 

degradation of water quality.

To manage water resources and to meet human and 

environmental needs, it is necessary to understand the effects 

of water quantity, timing, and quality on these systems. The 

USGS is in a position to provide data, understanding, and prediction tools regarding the responses of human water-resource 

management systems and ecosystems to hydrologic variability 

and change.

Societal Issues and Water Science

Water is essential to life on our planet and is the most 

widely used natural resource. Our own species cannot go more 

than 36 hours without water before our lives are endangered. 

Water is essential to every biological function of life. Water 

provides energy, food, habitat, hygiene, recreation, transportation, waste assimilation, and more. 

Water availability, defined.—Spatial and temporal distribution of water quantity and quality, as related to human and 

ecosystem needs, as affected by human and natural influences.

The foundation for this science strategy is based on 

the fundamental importance (or value) of water availability in its broadest sense. Water availability, as defined here, 

encompasses aspects of water supplies (quantity and quality) 

and water needs. Water supplies are governed by a complex 

system of natural and human-induced processes, ranging in 

scope from local to global. Many of the processes affecting 

water supplies have changed in the past, and will continue to 

change in the future, on various time scales. Water needs are 

diverse, and they are increasingly in conflict. Water is a critical commodity for human consumption, agriculture, energy, 

and industry. Water is a fundamental requirement for ecosystem health, biodiversity, and resilience, and it has important 

recreational and aesthetic values. In many areas of the world, 

one or more of these aspects of water availability is under 

stress. Yet, the diversity of values associated with water availability makes it difficult to assess, predict, and manage water 

resources effectively. Improvements are needed in the characterization and understanding of water quantity and water 

quality if we are to maintain our society and quality of life. 

Water supplies are not evenly distributed across the 

landscape. At all scales ranging from small subwatersheds to 

the Nation as a whole, water storage, movement, and quality 

are heterogeneous. Similarly, water needs are highly variable spatially and temporally. It is increasingly the case that 

water needs and water supplies are not well matched. For 

example, electric power plants, community water systems, 

and cities occupy relatively small areas in comparison to the 

catchment areas that ultimately supply the water they need. 

In many localities, water needs are being met by depleting 

resources that took an extended period of time to accumulate 

(for example, groundwater in aquifers recharged over hundreds of years). Even in some large areas of the United States, 

such as the Colorado River Basin, consumptive water use and 

losses now equal or exceed water supply (fig. 1). Therefore, it 

is essential to understand the spatial and temporal interactions 

between water supplies and needs at all scales.

Competition over water has involved conflicts over differing human uses and human uses versus ecosystem values 

throughout time. It is an unavoidable outcome of growing populations and increasing demands. Important issues regarding 

water availability include understanding and quantifying the 

vulnerability of human populations and ecosystems to water 

shortages and surpluses. Water-quality concerns include toxic 

chemicals, pathogens, excess nutrients and sediments, salinity, 

and oxygen depletion. As society has developed, questions 

about the quantity and quality of water have evolved from 

simple to complex issues in need of investigation and answers. 

As the population in the United States has increased, pressures 

on water supplies have increased. Of interest, water withdrawals in the United States increased steadily until 1980 and then 

declined and leveled off, indicating that some critical choices 

were made about water use in the last 30 years (fig. 2). 

Water can also present itself as a hazard to society in the 

form of droughts, floods, and debris flows. Scarcity or overabundance of water causes some of society’s most dangerous, 
4 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

Figure 1. Colorado River Basin water supply, 1914–2007 (Bureau of Reclamation, 2011).

Figure 2. Trends in population and freshwater withdrawals by source, 1950–2005 (Kenny and others, 2009).

Population, in millions

0

50

100

150

200

250

300

350

400

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

0

50

100

150

200

250

350

300

Withdrawals, in billion gallons per day

Trends in population and freshwater withdrawals, by source

Groundwater

EXPLANATION

Surface water

Total

Population

0

5

10

15

20

25

30

19141917192019231926192919321935193819411944194719501953195619591962196519681971197419771980198319861989199219951998200120042007

Water supply, in millions of acre-feet

Annual basin water supply

EXPLANATION

Annual basin water use
Highlight

Introduction 5

costly, and damaging situations to human life and property. 

Droughts and floods rank first and second, respectively, as 

the most costly natural hazards we face (Bryant, 2005). It is 

of vital importance for our Nation to understand, predict, and 

mitigate these hazardous situations, and the science of hydrology is critical to undertaking this endeavor. These situations 

prompt questions related to the magnitude and frequency of 

extreme events, the landscapes and property that are at risk, 

and the ability of water to assimilate the wastes and chemicals 

accidentally or intentionally introduced into it.

To fully understand the importance of our Nation’s water 

resources, society must assess a multitude of water-resource 

issues, ask the pertinent questions, and find the critical 

answers that will address our concerns. Broadly, the first set 

of societal questions relate to the need to observe the water 

resource.

• Where does our water come from?

• How much water do we have?

• How much water do we use?

• Is our water supply safe for people, industries, and 

ecosystems?

• What are the trends in our supplies of and demand for 

water?

• Do we have adequate information to make waterresource decisions?

Next, society moves to questions about our level of 

understanding and ability to predict the resource.

• How much water does our society need for the future, 

and is that amount sustainable?

• How can we protect our water supply, both quantity 

and quality, for the future?

• What can the past tell us about the future of water 

availability? Can human effects be clearly distinguished from natural variability? Can critical thresholds or “tipping points” be recognized or predicted? 

• What new tools will be needed to improve assessment, 

understanding, and prediction of water availability in 

the future?

• Do we understand the processes near hydrologic 

boundaries or interfaces (for example, groundwater/

surface water, sediment/water, freshwater/seawater, 

and shallow/deep flow systems)? 

• What are potential benefits and limitations of increased 

reliance on “unconventional” water resources (for 

example, deep saline groundwater; brackish coastal 

waters; enhanced water storage, recovery, and reuse)?

• How can contamination of groundwater and surface 

water be prevented or mitigated? 

The Water Budget

Water budgets are a means of evaluating how much 

water is available in each “compartment” of the 

water cycle and whether the uses of that water are 

sustainable over time.

“A water budget simply states that the rate of change 

on water stored in an area, such as a watershed, is 

balanced by the rate at which water flows into and 

out of the area” (Healy and others, 2007).

By quantifying the various compartments of a watershed’s water budget, hydrologists take the first steps 

in assessing water availability. One form of the waterbudget equation is

P + Qsw

in + Qgwin + Qswhumanin + Qgwhumanin = 

ET + ∆Ssw + ∆Ssnow + ∆Sgw + Qgw

out + RO + Qbf + 

Qswhumanout + Qgwhumanout

where 

P is precipitation, 

Qsw

in is surface-water flow into the 

watershed, 

Qgw

in is groundwater flow into the 

watershed, 

Qswhumanin is water returned by humans to 

surface water, 

Qgwhumanin is water returned by humans to 

groundwater, 

ET is evapotranspiration, 

∆Ssw is change in surface-water storage, 

∆Ssnow is change in snow and ice storage, 

∆Sgw is change in groundwater storage, 

Qgw

out is groundwater flow out of the 

watershed, 

RO is surface runoff, 

Qbf is base flow out of the watershed, 

Qswhumanout are water withdrawals by humans 

from surface water, and 

Qgwhumanout are water withdrawals by humans 

from groundwater. 

By measuring or estimating the amount of water for 

each of these terms over time for watersheds across 

the Nation, hydrologists can provide users with the 

capability to calculate water budgets for their areas 

of interest. The water-budget equation can become 

as detailed as the user requires if general terms in 

the equation are separated into component parts 

representing processes within the watershed. For 

example, in this equation, surface-water flow out of 

the basin has been separated into the components of 

streamflow: runoff and base flow.
6 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

• How can water-related hazards be prevented or mitigated? 

• What principles should guide optimization of water 

availability for multiple uses (that is, drinking water, 

ecosystems, agriculture/energy/industry), and how 

should water management adapt to changing conditions?

Streamgage 03479000 Watauga River near 

Sugar Grove, North Carolina, December 8, 2010. 

Photograph by John A. Mazurek, USGS.
Core Capabilities: Strengths, Partnerships, and Science Integration 7

Core Capabilities: Strengths, Partnerships, and Science Integration—

What We Do Now that is Important and Needs to Continue

The Water Science Strategy is based on four guiding principles: observe, understand, predict, and deliver. Integrated 

observations of the entire water cycle are the cornerstone for 

water-availability science in terms of quantity and quality. 

Understanding the water cycle is a hallmark of the unbiased 

science that the USGS is known for. The science we produce 

is applied to societal relevance by predicting changes to water 

availability in response to events such as sea-level rise and climate and land-use change, and informing society during water 

conflicts and emergencies such as floods, droughts, and waterquality degradation. To sustain the resource and contribute to 

safety in society, water data and science must be delivered to 

the public and other scientists. These guiding principles are 

reflected throughout this strategy and the development of its 

goals, objectives, and strategic actions.

The USGS is the premier water-monitoring and science 

Bureau within the Federal Government. The USGS works 

within the Water Mission Area through a variety of programs 

that serve to observe, understand, and predict components of 

the water cycle, which are the guiding principles of this report. 

The guiding principles are critical to societal issues involving 

water resources. Core capabilities include the following:

• Observe.—The USGS operates and maintains national 

hydrologic monitoring networks consisting of more 

than 8,000 streamgages, 1,900 continuous waterquality monitoring stations, and 250 precipitation 

monitoring stations, and monitors 20,000 groundwater 

observation wells. USGS programs that support these 

networks include the Water Cooperative Program, 

National Streamflow Information Program, National 

Stream Quality Accounting Network, as well as others. 

Nationwide assessments and discontinuous monitoring 

of water storage, movement, and quality are conducted periodically by various USGS programs. The 

USGS also maintains the Nation’s only comprehensive 

program for estimating water use. The USGS operates 

a system of state-of-the-art water-quality laboratories 

for aqueous chemistry, isotope hydrology, microbiology, and sediment. The USGS laboratory capabilities 

include the National Water Quality Laboratory, producing more than 30,000 analyses per year. USGS laboratories have pioneered efforts to establish protocols for 

the collection and analysis of constituents that occur at 

very low concentrations. The USGS Hydrologic Instrumentation Facility provides hydrologic instrumentation, hardware, and software to support water-resource 

science. Support also is provided through development, 

testing, evaluation, repair, calibration, and quality control of hydrologic instrumentation. The USGS is the 

steward of Landsat—the world’s longest continuously 

acquired collection of space-based moderate-resolution 

land remote-sensing data. Nearly four decades of 

imagery provide a unique resource for water-resource 

understanding and research. Landsat images are also 

invaluable for rapid response to water-related emergencies. In addition, the use of extensometers coupled 

with satellite radar (InSAR) imagery is a technique 

used by the USGS to characterize and model aquifer 

system compaction and land subsidence. Furthermore, 

the USGS has an institutional commitment to make the 

data collected by the Bureau available to the public, 

including Internet access through the Web pages of the 

National Water Information System.

• Understand.—The USGS carries out numerous scientific investigations designed to improve understanding 

of processes affecting water availability that can lead 

to more informed decisions by water managers dealing 

with national, regional, and local water-resource issues. 

Many such investigations are carried out through the 

USGS network of Water Science Centers and through 

a variety of programs such as the Water Cooperative 

Program, the Groundwater Resources Program, the 

National Water-Quality Assessment Program, and the 

Toxic Substances Hydrology Program. The USGS also 

maintains a strong research presence in water-resource 

science through its National Research Program. The 

USGS conducts intensive research and develops new 

tools and concepts for use by the scientific community 

at large. USGS research adds value to monitoring and 

assessment activities, provides unbiased interpretations 

of specific water-resources issues, and advances general knowledge of hydrologic principles. An important 

feature of USGS research is the synergy of local studies, national surveys and syntheses, laboratory experiments, and method-development activities that are 

dispersed among its varied programs. USGS scientists 

also contribute expertise and maintain proficiency by 

interacting externally with academia, industry, and 

other government agencies.

• Predict.—The USGS provides data, information, and 

tools that are useful to predicting long- and short-term 

changes within the water cycle. Historical data from 

hydrologic networks, combined with other tools such 

as paleohydrology, can provide information on trends 

such as the effect of climate change on timing of 

seasonal streamflow in rivers—an important consideration for flood control and water supply. The USGS 

produces, maintains, and freely distributes numerous 

computer programs that are used for research and 

predictions in hydrology and geochemistry. Examples 

include SPARROW, a model that computes delivery of 
8 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

water-quality constituents in rivers and streams, based 

on watershed characteristics; MODFLOW, considered 

the international standard for simulating and predicting 

groundwater conditions and groundwater/surface-water 

interactions; PHREEQC, one of the most popular 

codes used for modeling chemical reactions and movement in groundwater; and GSFLOW, a rapidly developing integrated tool for understanding and predicting 

transient stream responses to precipitation and complex 

watershed processes, and many other codes.

• Deliver.—The USGS is known for long-term storage 

and delivery of real-time and historical hydrologic 

data. The USGS National Water Information System 

(NWIS) database includes millions of data entries for 

surface water, groundwater, and water quality that are 

easily accessible through the World Wide Web. USGS 

real-time water data are served more than 20 million 

times per month. The USGS also delivers numerous 

scientific reports and journal articles on our Nation’s 

water resources every year; these publications are 

the product of a stringent peer review system and are 

almost without exception publicly available through 

multiple outlets, including the Internet.

The USGS is distinguished for its proficiency in the following: 

• Measurements of streamflow.

• Flow statistics.

• Flood monitoring and post-flood data recovery.

• Flood-frequency analysis.

• Measurement and understanding of groundwater at 

local and regional scales.

• Understanding geologic framework controls on 

groundwater.

• Development of computer models of water, sediment, 

and chemical transport.

• Understanding aquifer-system compaction and land 

subsidence.

• Age-dating of water and sediments.

• Chemical and isotopic tracer techniques in hydrologic 

and biogeochemical investigations.

• Water-quality sampling and analysis.

• Relating water quality to causative factors.

• Development of water-quality statistical models.

• Field methods, data collection, and preservation of 

hydrologic information.

• Water-use estimation.

• Development of water-information databases.

• Training the next generation of water scientists and 

technicians.

Along with this proficiency, however, is acknowledgment 

of the uncertainty in water science. Scientists struggle with 

uncertainty in terms of how to adequately assess it; how to 

understand uncertainty; how to control it; and how to effectively communicate the uncertainty of the science with science 

information products. Understanding uncertainty in water 

science is essential for resource managers and others who use 

water data and information in decision making. Uncertainty 

is an inherent factor in hydrologic data collection, estimation 

techniques, and simulation modeling. Errors associated with 

measurement techniques arise from the inability to accurately 

measure specific aspects of the hydrologic system, such as 

streamflow, the water level in a well, or soil properties that 

control evapotranspiration and runoff. Uncertainty arises from 

the inadequacy of data collection networks to fully characterize natural spatial and temporal variability associated with 

hydrology, geology, climate, and land use. Uncertainty also is 

present in simulation models because it is impossible to thoroughly reproduce a natural hydrologic system in a model.

An additional USGS objective is to reduce uncertainty 

in the highest priority water data and information. Improvements in the spatial and temporal coverage of data collection 

networks, the techniques for measuring flows, and improved 

estimation techniques with data layers that account for more 

of the factors that influence variability will lead to reduced 

uncertainty in the information provided to the public. Additionally, the USGS will make a strategic effort in the future to 

estimate or quantify uncertainty associated with its information products.

USGS strengths that benefit the Water Mission Area and 

underscore the above four guiding principles include national 

quality-assurance standards and policies; the long-term retention of hydrologic data, reports, and other products; and the 

unbiased science that underlies every mission activity of the 

Bureau. Two other major strengths of the USGS are a business 

model that supports a high level of partnering with other agencies, academia, and the private sector; and a diverse workforce 

of scientists and physical-science technicians from multiple 

disciplines that allows the Bureau to bring an integrated scientific approach to water-resource problems. 

USGS water science starts within Water Science Centers, 

located in every State and in Puerto Rico. These Water Science 

Centers build important relationships with State and local 

agencies that are vital to the management of water resources in 

the United States. These Water Science Centers are supported 

by a regional and national structure that includes offices dedicated to the development of models, methods, tools, databases, 

and quality-assurance measures to support the Water Science 

Centers and maintain consistency in USGS work. Many of 

the national priorities of the USGS Water Mission Area are 

carried out through the network of Water Science Centers. 

Another hallmark of the USGS is the nationwide consistency 

that it brings to water data collection, analysis, and interpretation. This consistency allows the valid comparison of data 
Core Capabilities: Strengths, Partnerships, and Science Integration 9

Figure 3. Time scales of various geologic, climatic, and human events.

across many locations and at multiple scales. Water science 

is furthered by the USGS National Research Program, which 

advances the science of hydrology to keep the USGS on the 

cutting edge. Finally, collaboration and joint project investigations with other USGS Mission Areas lend strength to USGS 

integrated science. The USGS is a multidisciplinary scientific 

Bureau: disciplines represented within the Bureau include 

hydrology, engineering, geology, geography, ecology/biology, 

meteorology, and social sciences. With a workforce of more 

than 8,000 employees with diverse backgrounds, education, 

and experience, the USGS can bring an integrated approach 

to the Nation’s water-resource issues. The interdisciplinary 

nature of the USGS workforce and organizational structure 

brings strength to its capability. Critical to understanding and 

optimizing water availability is knowledge about how geology, climate, and humans interact with the water cycle at all 

time scales (fig. 3). An important component of such research 

is analysis of former conditions (historical and pre-historical) 

for insights about modern processes and trends. A few 

examples of where the USGS has worked effectively to help 

answer interdisciplinary questions include research into how 

climate affects water movement and storage, how geology 

affects movement of water and persistence of contaminants, 

how streamflow affects aquatic and riparian ecosystems, and 

how energy and mineral-resource development affect water 

resources, among many other questions. 

An additional key strength of the USGS is its development of partnerships in the conduct of its water science. 

Landslide

Tidal cycle

Volcanic eruption

Flood Erosion/sedimentation

Sea level change

Tectonics

Daily cycle

Precipitation, runoff

Snowmelt

Wildfire

Seasonal cycle

El Niño

Drought

Glaciation/deglaciation

Dam break, reservoir release

Water impoundment, diversion

Agriculture, industry, urbanization

Geology

Climate

Contaminant release, spill

Hour Day Week Month Year Decade Century Millenium Billion

years

Million

years

Human
Highlight

Emissions to air

Sediment

record

0 50

Lead in sediment, in parts 

per million

100

2000

1980

1960

1940

1920

1900

10 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

Through the Cooperative Water Program, the USGS partners 

with more than 1,800 State, Tribal, county, local, regional, and 

watershed agencies in accomplishing its mission. Key Federal 

partners include Bureau of Reclamation, U.S. Fish and Wildlife Service, National Park Service, Bureau of Land Management, Bureau of Indian Affairs, U.S. Department of Defense 

(including U.S. Army Corps of Engineers), U.S. Environmental Protection Agency (USEPA), National Oceanic and 

Atmospheric Administration (NOAA) and National Weather 

Service, U.S. Department of Agriculture (USDA), National 

Atmospheric and Space Administration (NASA), National 

Geospatial Intelligence Agency, National Science Foundation, 

and U.S. Department of Energy. USGS scientists also work 

with numerous academic institutions, providing training and 

collaboration for faculty and students. Without these partnerships, the Water mission of the USGS could not be fulfilled. 

The USGS is always seeking opportunities to strengthen and 

expand its network of partners. To this end, the USGS will 

increase its role in the future in interagency collaborative work 

through institutions such as the Advisory Committee on Water 

Geochronology/Paleohydrology—Interpreting the Past as Key to the Future

Information about the past can provide insights about 

events and processes that may affect the future. USGS 

scientists use a variety of techniques for determining ages 

of groundwater, rocks, and sediments (geochronology) 

that can be used to reconstruct the past, where historical 

records are absent or incomplete, on time scales ranging 

from months to millions of years. Ages of such materials 

are estimated from laboratory measurements of radioactive 

isotopes and other environmental tracers—including both 

natural and artificial constituents—and by examining the 

fossil record. 

Concentrations of natural radioactive carbon-14 in flooddeposited sediments can be used to determine recurrence 

intervals of catastrophic floods or debris flows on time 

scales of thousands of years, thus providing important 

information about hazards that may not be available from 

historical records (paleohydrology). Carbon-14 content of 

dissolved carbon can be used to determine where aquifers 

contain groundwater that recharged thousands of years 

ago and where modern recharge is limited. 

Similarly, ages of stratified sediments in lakes, reservoirs, 

and estuaries can be used to determine sedimentation 

rates, document climate change effects on water levels and 

nutrients, and reconstruct past changes in concentrations 

of sediment-bound constituents such as toxic metals and 

organic contaminants. For example, figure 4 shows the vertical distribution of ages and lead concentrations in a sediment core from the bottom of an impounded lake (Callender 

and Van Metre, 1997). Changes in lead concentrations of 

sediments that accumulated on the lake floor during the 

20th century were related to the history of lead emissions to 

the atmosphere, which decreased abruptly after lead reduction in gasoline in the 1970s. Sediment ages were estimated 

from the distribution of radioactive cesium-137. Lead emissions are in relative units (scale not shown). Applications of 

geochronologic techniques commonly reflect team efforts 

involving specialized laboratories, multidisciplinary field 

investigations, and computer simulation capabilities.

Figure 4. Vertical distribution of ages and lead concentrations 

in a sediment core from the bottom of an impounded lake

(Callender and Van Metre, 1997).

Information (ACWI), the Integrated Water Resources Science 

and Services (IWRSS) consortium, and the National Integrated 

Drought Information System (NIDIS). The USGS Water Mission Area brings hydrologic understanding to questions that 

logically intersect with the missions of these partner agencies. 

A good example of how partnership could be strengthened 

around mutual interests in the future is an opportunity to 

work with the USDA to integrate studies of agriculture and 

water availability. USDA expertise, models, and data for crop 

systems, soils, and drainage could be coordinated with USGS 

expertise in groundwater and surface-water movement and 

quality to yield important insights for best management practices relating to water use and water quality. Similarly, collaborative work with NOAA could result in integrated studies 

of climate, precipitation, and watershed processes, with each 

agency providing strength in its areas of expertise. Collaboration with NASA could further improve understanding of earth 

and hydrologic processes through remote sensing and spatial 

imagery. Collaborative work with USEPA could improve 

understanding of linkages between contaminant distributions, 
Priority Actions 11

hydrogeologic processes, and human and ecosystem effects. 

Partnership opportunities extend well beyond Federal agencies to academia and nongovernmental organizations (NGOs). 

USGS does, and should in the future, look to these prospects 

for mutual advancement of hydrologic science. The USGS 

through the National Cooperative Geologic Mapping Program (NCGMP) STATEMAP component partners with State 

geological surveys to provide geologic maps and frameworks important for identification and characterization of the 

Nation’s aquifers. NCGMP had determined that most geologic 

maps in the United States are related to groundwater issues 

(Orndorff and others, 2008). In the recent past the USGS has 

advanced the area of environmental flow science through a 

liaison position with the Nature Conservancy. The USGS has 

worked to advance access to hydrologic information through 

joint opportunities with the Consortium of Universities for the 

Advancement of Hydrologic Science (CUAHSI). The USGS 

is also a partner in the Western States Federal Agency Support Team (WestFAST). WestFAST is a collaboration between 

11 Federal agencies with water management responsibilities 

in the West. WestFAST was established to support the Western 

States Water Council (WSWC), and the Western Governors 

Association in coordinating Federal efforts regarding water 

resources. The USGS views WestFAST as a prime model of 

partnerships in action and should be replicated in other venues. 

The USGS also benefits from being informed, involved, and 

educated by other agencies and organizations on the science, 

monitoring, tools, and strategies they are developing. The 

USGS sees these and similar collaborative efforts as vital to 

successful water-resources science endeavors and important 

for the future of the Nation’s water availability. 

Priority Actions

This report details the strategic science directions for 

the Water Mission Area. The section entitled “Water Science 

Goals and Objectives” specifically outlines the strategic 

actions. In “Water Science Goals and Objectives,” five goals 

of the Water Science Strategy speak to emerging issues identified by the USGS and major stakeholders. Priority Actions 

provides a short discussion emphasizing the highest priority 

actions that incorporate multiple goals, expanding on them, 

and in places integrating them with the work of the other 

Mission Areas (table 1). Priority actions were developed as a 

means of providing the audience of this report with a list for 

focused attention, even if resources and time limit the ability 

of managers to address all of the strategic actions in the report. 

Priority actions aggregate virtually all of the 27 strategic 

actions into eight areas where future changes could have the 

greatest impact. The first priority action, “Improve integrated 

science planning for water,” influences all strategic actions and 

requires no additional resources to implement, only a change 

in planning philosophy. For this reason, it is not included in 

table 1 with the other eight priority actions.

Improve Integrated Science Planning for Water

Understanding the hydrology of the United States 

requires a multitude of scientific disciplines, working in 

concert, to produce the water-resource information that our 

society needs. To work effectively requires the integration of 

expertise and knowledge, along with deliberate and careful 

planning. The USGS can and should take a leadership role in 

this kind of integrated science planning for water resources. 

The USGS should renew the way it plans and implements 

water science by recognizing that program integration entails 

joint planning, joint funding, and coordinated program execution toward a common goal. The USGS and science branches 

within other agencies need to plan together so that we and 

other agencies can execute programs in concert and generate 

products collaboratively. The USGS should look for opportunities where its Water programs can intersect and build 

synergy with other science programs. The USGS can do more 

science and make better use of its resources if it improves the 

integration of its water-science planning and execution where 

these opportunities exist.

The Water Census provides the USGS with the opportunity to integrate our efforts on groundwater, surface water, 

water quality, biology, ecology, geography, remote sensing, 

geology, and climate variability to answer key questions about 

water availability. This opportunity extends well outside of 

the USGS to other Federal, State, regional, and local agencies who have complimentary programs and goals. The USGS 

should lead the way and demonstrate how science disciplines 

plan together for deliberate outcomes in water-availability 

science that are achieved through coordinated program 

implementation.

Expand and Enhance Water-Resource 

Monitoring Networks

Monitoring networks that generate hydrologic data are 

the foundation of any understanding of the Nation’s hydrologic systems; they provide information that is critical for 

defining, using, and managing our water resources. The USGS 

has a real-time network of more than 8,000 streamgages 

that monitor stage and streamflow; 1,400 wells that monitor 

groundwater levels in real time; and more than 1,900 locations 

where real-time water-quality parameters such as dissolved 

oxygen, pH, temperature, and specific conductance are monitored. However, the coverage of these networks (particularly 
12 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

groundwater and water quality) is neither funded consistently 

at the national level nor ideally distributed across the landscape; further, water quality and quantity information collected 

by other qualified resource partners is not currently included 

in USGS datasets. To assist the Nation with a better understanding of the quantity and quality of our surface-water and 

groundwater systems, it is the goal of the USGS to maximize 

our monitoring capabilities in the following ways:

• Design and develop a more nationally consistent, 

federally funded backbone network of surface-water, 

groundwater, and water-quality monitoring stations 

that is supplemented by the use of qualified records 

collected and furnished by local, State, or other 

Federal agencies.—This concept has been explored 

and embraced by the Subcommittee on Ground Water 

under the Advisory Committee on Water Information 

(ACWI) as part of its National Ground Water Monitoring Network design and should be expanded to include 

surface-water and water-quality monitoring stations as 

well. The design of these networks must be linked to 

allow the capacity to monitor changes in the combined 

hydrologic system. 

• Capitalize on existing streamgage infrastructure to 

install “super gages” that integrate many types of 

monitoring sensors and thus record and transmit many 

kinds of data parameters at key monitoring locations.—Examples can include meteorological data, 

chemical data related to water quality, and physical 

data such as water temperature, water velocity, and 

suspended-sediment data measured through optical 

or hydroacoustic surrogates. Super-gage locations 

should be targeted to provide real-time data specifically designed to improve understanding of watershed processes and to address specific water-resource 

issues such as climate and land-use effects, waterrelated human health issues, floods and droughts, or 

hazardous-substance spills.

• Consider customer requirements for hydrologic monitoring data to ensure that USGS hydrologic monitoring 

networks meet multiple Bureau mission requirements 

and serve as broad a base of user needs as possible.—Examples can include working with NOAA 

and State and local emergency management to ensure 

streamgage data meet flood forecasting and warning 

requirements, and considering the data needs of large 

water consumers when examining groundwater observation well network optimization. 

Characterize the Water Cycle Through 

Development of State-of-the-Art 3-D/4-D 

Hydrogeologic Framework Models at Multiple 

Scales

Characterizing and predicting water availability at the 

spatial and temporal scales needed to understand and manage water resources require the integration of hydrologic and 

earth science data with state-of-the-art geologic, geophysical, 

and geochemical models. Geological information mapped 

at the surface must be projected into the subsurface (3-D) to 

Table 1. Links of priority actions to goals and strategic actions.

Priority Action. Expand and enhance water-resource monitoring 

networks

Goal 1, Strategic Actions 1, 2, 5, 7

Goal 4, Strategic Action 20

Priority Action. Characterize the water cycle through development 

of state-of-the-art 3-D/4-D hydrogeologic framework models at 

multiple scales

Goal 1, Strategic Action 4

Goal 2, Strategic Action 9

Goal 3, Strategic Actions 13, 16, 18

Goal 4, Strategic Actions 19, 22

Goal 5, Strategic Action 25

Priority Action. Clarify the linkage between human water use 

(engineered hydrology) and the water cycle (natural hydrology) 

Goal 1, Strategic Actions 2, 3, 6, 8

Goal 2, Strategic Actions 10, 11, 12, 13

Goal 3, Strategic Actions 14, 15, 16, 17, 18

Goal 4, Strategic Actions 22, 23, 24

Goal 5, Strategic Actions 25, 26, 27

Priority Action. Advance ecological flow science

Goal 1, Strategic Action 1

Goal 2, Strategic Actions 11, 13

Goal 3, Strategic Action 14

Goal 5, Strategic Actions 25, 26, 27

Priority Action. Provide flood-inundation science and information

Goal 1, Strategic Actions 1, 2, 3, 4

Goal 4, Strategic Actions 19, 20, 21, 22

Goal 5, Strategic Actions 26, 27

Priority Action. Develop rapid deployment teams for water-related 

emergencies

Goal 1, Strategic Actions 1, 2, 3

Goal 4, Strategic Actions 20, 21, 22, 23, 24

Goal 5, Strategic Action 27

Priority Action. Conduct integrated watershed assessment, 

research, and modeling

See Goals 1-4

Priority Action. Deliver water data and analyses to the Nation

Goal 4, Strategic Action 19

Goal 5, Strategic Actions 25, 26, 27
Highlight

Figure 5. Example of a super gage is White River at Hazleton, Indiana (U.S. Geological Survey 

streamgage 03374100).

Priority Actions 13

Real-Time Data and the “Super Gage”

The USGS operates and maintains national hydrologic monitoring networks consisting of more than 8,000 streamgages 

that typically provide water stage data and volumetric streamflow data. Often, other parameters are monitored 

at streamgage sites, such as water temperature, precipitation, and water quality. The physical infrastructure of a 

streamgage and the data recording and telemetry instrumentation it contains makes the streamgage an ideal platform 

for measuring and transmitting a variety of parameters—simultaneously, in real time—to examine unique trends in 

water resources in a critical resource area such as agricultural and urban land-use effects, water-related human health 

issues, floods and droughts, or hazardous-substance spills. The USGS has developed the “super gage” concept to 

describe such streamgages. 

An example of a super gage is White River at Hazleton, Indiana (USGS streamgage 03374100). This is a large-river site 

with a drainage area of 11,305 square miles of primarily agricultural land. Parameters collected at this streamgage are 

the following:

• Physical water parameters: stage, streamflow, water velocity, 

water temperature, 

and suspended sediment (using measurements of turbidity as a 

surrogate).

• Water-quality parameters: dissolved 

oxygen, 

specific conductance, 

pH, and nitrate.

The USGS and partner 

agencies will use these data 

to assess environmental 

impacts of agricultural and 

other land-use practices 

through a better understanding of short-term, long-term, 

and seasonal trends and 

through more accurate 

water-quality modeling. 

determine the features (such as faults or fine-grained layers 

that are impermeable) that influence groundwater storage, 

flow, and quality. These features (the geologic framework) 

need to be translated into hydrogeologic properties that may 

vary with time (4-D). 

The Merriam-Webster online dictionary defines “dimension” as a measure in one of three or four coordinates 

determining a position in space and time. Two dimensional 

(2-D) space in modeling is represented with a simple geometric shape with length and width (x and y dimensions, 

respectively), whereas three dimensions or 3-D includes the 

representation of depth (z dimension). Unlike 2-D space, the 

use of 3-D incorporates volume and depth. Modeling of fourdimensional space includes the factor of time (t dimension) or 

motion to a 3-D object, entity, or unit. For example, instead 

of characterizing the static subsurface geology of an aquifer 

system, 4-D geologic modeling can provide a better understanding of how the rock properties (including water/rock 

interactions, fluid saturation, and geochemistry) can change 

over time.
Highlight

Map view of depth 

to basement

200 meter (m) contours

(O to -2400 m)

Gravel

Sand and gravel

Sandstone and gravel

Sand

Sandstone

Sand and clay

Sandstone and clay

Clay, sand and gravel

Clay, sand and trace gravel

Clay and gravel

Clay and trace gravel

Clay and sand

Clay and sandstone

Clay

Clay, sand and limestone

Clay, sand, and/or gravel and shells

Conglomerate

Basalt

Ash and/or tuff

Undifferentiated basement

Vertical cross sections

through solid 3-D model

Wells, colored

by lithology

Depth to basement

surface

View is to the northeast

Vertical exaggeration x5

3-D Subsurface lithology model; Santa Rosa to Sebastopol

14 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

Geologic Complexities

Figure 6. Boundary extents of a basin-fill aquifer and the aquifer’s confining layer containing impermeable bedrock (Sweetkind 

and others, 2010).

Water, and its movement through the water cycle to the land surface and subsurface, is dependent on the interplay of 

geologic and hydrologic frameworks through time. This interaction also affects both water quantity and quality. The geologic frameworks of both surface-water and groundwater systems can be quite diverse, ranging from streams, lakes, and 

aquifers that are surrounded by surficial deposits to those dominated by fractured bedrock and even volcanic deposits. 

Faulting and fracturing, dissolution in carbonate rocks, alteration, and thermal history also can affect the physical properties of surficial- and bedrock-dominated groundwater systems. 

Using geology as a template, a hydrogeologic framework forms a foundation for the modeling of hydrologic properties that 

control flow direction, storage, and quality. For example, in the Santa Rosa Plain in northern California, geologic drillhole 

data and geophysical gravity modeling have provided the boundary extents of a basin-fill aquifer and the aquifer’s confining 

layer containing impermeable bedrock (Sweetkind and others, 2010; fig. 6). Three-dimensional modeling and drillhole data 

also can be used to determine the hydraulic permeability of an aquifer and reveal how permeability can abruptly change 

across the basin. 

Hydrogeologic models demonstrate the importance of integrating geologic, geospatial, and hydrologic data and using 

improved methods for modeling the data across multiple scales.
Priority Actions 15

The spatial domain of the hydrogeologic framework 

models will need to extend from near the ground surface (for 

example, models for characterizing surface-water/groundwater interactions) to the bottom of deep aquifers (for example, 

regional flow models for characterizing brackish waters). 

The models will integrate the natural variability of physical, 

chemical, and hydrologic properties at all spatial and temporal 

scales. This integration also must involve the use of multidirectional approaches and interdisciplinary feedback to answer 

complex questions such as, “How do earth science systems 

affect water movement and chemical transport?” Emerging 

societal issues will demand a better understanding and assessment of the changing hydrogeologic and biogeochemical conditions commonly associated with stressed or marginal-water 

aquifers. Characterizing the depth of freshwater circulation in 

gas shale exploration or contamination issues associated with 

concealed faults resulting from hydrofracking or CO2 sequestration are two societally relevant examples.

The assignment of hydrologic properties to geologic 

framework models also will promote the development of new 

tools, techniques, and concepts, given the challenge of modeling the subsurface with properties where few direct observations are available. Integration of 3-D framework and property 

models may include the discretization of temporal data into 

4-D subsurface grids for predicting real-time flow-pathway, 

storage-capacity, and water-quality data. This interdisciplinary integration provides a means of testing and enhancing our 

understanding and knowledge of the hydrogeologic processes 

controlling the water cycle. Discretization of framework- and 

property-model data also can be incorporated into studies only 

marginally related to water availability and quality, such as 

studies of the various effects of mineralization and maturation 

on oil and gas resources.

Clarify the Linkage Between Human Water Use 

(Engineered Hydrology) and the Water Cycle 

(Natural Hydrology)

The USGS is the premier water-use science Bureau in the 

Nation; however, the Bureau has yet to realize its full potential 

for collecting, analyzing, integrating, and reporting water-use 

information. An extensive analysis of the water-use program in 

the USGS and potential improvements for the future was published by the National Research Council as “Estimating Water 

Use in the United States: A New Paradigm for the National 

Water-Use Information Program” (Committee on USGS Water 

Resources Research, 2002). 

The USGS should aggressively implement the National 

Research Council recommendations and take definitive action 

to integrate water use with its information on the rest of the 

water cycle through actions that include integrating water-use 

databases; using modeling and statistical designs in wateruse estimation; improving the geospatial information on 

site-specific water-use features; revitalizing consumptive-use 

estimation; quantifying and locating interbasin transfers; and 

linking water-use information with water budgets, watershed 

and aquifer analyses, and StreamSTATS. StreamSTATS is a 

web-based geographic information system that allows users to 

easily obtain streamflow statistics, drainage-basin characteristics, and other information for user-selected sites on streams. 

These data also should be linked to assessments of marginal 

resources, water-quality criteria for different uses, treatment 

options, and factors affecting conservation and reuse.

Advance Ecological Flow Science

Ecological, or environmental, flows are defined as 

the quantity, timing, and quality of water flows required to 

sustain freshwater and estuarine ecosystems and the human 

livelihoods and well-being that depend on these ecosystems. 

These water flows broadly include streamflows and the variation of water levels in lakes, streams, and wetlands because 

the variation in water levels, not solely volumetric flows, 

are recognized to play an important ecological role (fig. 7). 

Ecological flow science incorporates several of the strategic 

actions within the Water Mission Area strategic plan and may 

serve as a powerful integrating theme for work within the 

Water Mission Area and between the Water and Ecosystems 

Mission Areas. The quantification of ecological flows is built 

on observed streamflow records across diverse settings, from 

Figure 7. Bonneville Dam, the first of 14 dams in place on the 

Columbia River main stem, between Oregon and Washington. 

Dams provide flood control, power generation, and water 

supplies for irrigation and human consumption; however, they 

dramatically alter ecological flows and impact native floral and 

faunal assemblages. For example, the dams on the Columbia River 

represent barriers for the migration of threatened and endangered 

salmonids. The U.S. Geological Survey is involved in integrated 

biological, hydrological, and geological studies to understand 

the recovery of ecological systems after the removal of derelict 

hydroelectric facilities, including two dams on the Elwah River in 

Washington State.
16 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

a range of stream sizes, for a sufficient length of time. Understanding flow processes, processes controlling water quality, 

and interrelations between water flow, water quality, and ecology is required to develop stream-ecosystem relations and to 

determine relevant flow attributes that can be used to classify 

streams into types. Predictive modeling to extend streamflow 

records to ungaged locations and to estimate the interaction of 

future water withdrawals, land-use or climate variability, or 

other changes in condition is required to inform management 

decisions seeking sustainable ecological flows. The suite of 

core capabilities required for this work will need to be developed within the USGS, as will new techniques and methods to 

effectively provide this information and analysis to the Nation.

Provide Flood-Inundation Science and 

Information

Floods are the leading cause of natural-disaster losses 

in the United States. A powerful tool for flood response and 

mitigation is digital geospatial flood-inundation mapping 

that shows floodwater extent and depth on the land surface. 

The USGS has been developing a national flood-inundation 

program (http://water.usgs.gov/osw/flood_inundation/).The 

USGS, working with NOAA, the U.S. Army Corps of Engineers, Federal Emergency Management Agency (FEMA), 

other Federal, State, and local government agencies, universities, and the private sector, should continue development of a 

science-based flood-inundation mapping program that would 

include the following:

• Static flood-inundation map libraries, linked to USGS 

streamgages and National Weather Service (NWS) 

flood-forecast points, consisting of a set of flood 

extent and depth maps developed for predetermined 

stream stage intervals and served through the World 

Wide Web. Development of these libraries will require 

collection, processing, and dissemination of land use, 

elevation, and bathymetric data (LiDAR is a particularly important source of these data); development and 

application of 1-D and 2-D inundation models; streamflow data collection; and ongoing map maintenance. 

LiDAR data, in particular, will be needed to provide 

the best possible products and will require leveraging 

the use of existing and planned LiDAR datasets from 

within the USGS and from partner organizations.

• Development of state-of-the art dynamic, real-time 

flood-inundation applications to meet a host of partner 

and cooperator needs, from flood response and mitigation to dam- and levee-breach simulations. These 

applications involve a higher level of science and 

technologies than static maps, and the USGS can make 

substantial advances in this area.

• Development of a core science team of personnel from 

the USGS and other Federal and local partner agencies 

tasked with the development of flood-inundation tools 

that fulfill multiple Bureau missions and thus provide 

the most benefit to the Nation’s communities and citizens at risk from floods.

Develop Rapid Deployment Teams for WaterRelated Emergencies

The USGS should develop “rapid-deployment teams” and 

accompanying response plans that would ensure the Bureau 

properly responds to water-related emergencies and waterrelated conflicts. These multidisciplinary teams would draw 

expertise from USGS headquarters and science centers and 

would maintain a suite of scientific hardware and software to 

provide partner agencies with information during emergencies. 

The teams would activate and operate according to detailed 

response plans. Each plan would include information on the 

following:

• The monitoring of USGS real-time data and other 

resources to identify potential events that would 

require activation of a team. (This would include plans 

that would provide USGS staffing and resources to 

monitor conditions around the clock, all year.)

• Coordination with other relevant agencies such as 

NWS River Forecast Centers and FEMA Emergency 

Operation Centers on event monitoring and team 

activation. 

• Criteria for triggering team activation.

• Personnel—including team expertise, size, structure, 

and organization.

• Scientific instrumentation and equipment, including vehicles (for example, boats, trucks, all-terrain 

vehicles, aircraft).

• Remote-sensing needs (for example, tasking acquisitions by satellites and aircraft).
Priority Actions 17

• Research priorities to mobilize the appropriate USGS 

research scientists to study the specific hazard and hazard impacts, with the goal of improving understanding 

and providing better planning, response, and recovery 

for future events by using science-guided principles.

This action builds upon USGS successes responding to 

major riverine flood events by installing “rapid-deployment” 

real-time streamgages in critical ungaged areas and by installing temporary submersible water-level sensors ahead of major 

hurricanes to record storm-surge flooding. Rapid-deployment 

team activities would best be coordinated through a multiagency effort. A potential location for such multiagency coordination is the Integrated Water Resource Science and Services 

(IWRSS) National Water Center (NWC) at the University of 

Alabama, Tuscaloosa. The NWC is intended to provide the 

USGS, NWS, and U.S. Army Corps of Engineers (USACE) an 

operations center for water analysis, forecasting, and decision 

support (Interstate Council on Water Policy, 2011).

Conduct Integrated Watershed Assessment, 

Research, and Modeling

To fully comprehend the water cycle, water availability, 

human and ecosystem responses, and management options, 

it will be important to incorporate a wide variety of information in a watershed context. A stepwise approach to such 

integration could include synthesis of available information 

for selected watersheds. Large-watershed syntheses would 

be aimed at highlighting key interactions between physical, 

chemical, geological, and biological processes in the context 

of natural and human influences, and identifying important 

gaps in data or understanding. This information would provide 

guidance for targeted studies to be carried out in a stable 

framework of small to large watershed research sites with 

multidisciplinary objectives. A long-range goal of such studies would be to have integrated models for predicting water 

availability and optimizing water management at the scale of 

large watersheds, or river basins. Progress toward this goal 

could include development and application of increasingly 

comprehensive statistical and numerical models for understanding monitoring data, such as real-time water-quality data 

at streamgages, and ecosystem responses to short-term climate 

and land-use stressors. Near-term products could include summary reports linking current data and factors affecting water 

availability in one or more watersheds that represent important 

water issues. 

Deliver Water Data and Analyses to the Nation

To accomplish the priority actions, the USGS must 

develop integrated information systems and means for disseminating information appropriate for 21st-century technology. Science information has value, and this value is best 

realized when its quality is apparent and it is easy to access. 

Priority actions such as flood-inundation mapping and 

response to water-related emergencies will best be served 

with real-time information and use of World Wide Web and 

smart-phone applications. Water-related databases also can 

be integrated with other sciences to better understand water 

interactions with socioeconomic factors, ecosystems, human 

uses, agriculture, and industry. One area in which the USGS 

can take the lead is employing map interfaces for geospatial 

searches, a means that will predominantly be used by the 

public to locate information. For example, water information 

related to groundwater needs to be displayed to users in four 

dimensions for the hydrogeologic frameworks and the flow 

models. The USGS must build and promote the systems that 

can adequately serve and communicate this information. By 

setting up clearinghouses of information and models, scientists 

can find and apply the best information in understanding realworld issues. In turn, these models can be used for decision 

support throughout society.

Facing page: USGS hydrographers respond to 

the flood of June 11, 2008, in Cedar Rapids, Iowa. 

Photographs by Don Becker, USGS. 

Right: High school students participate in World 

Water Monitoring Day, Onondaga Creek, New York, 

October 7, 2010. Photograph by Scott Grover, USGS.
18 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

Water Science Goals and Objectives

The five goals of this Water Science Strategy speak to 

issues expected to emerge in the next 5 to 10 years and the scientific research and outcomes needed to address them. These 

issues were identified by the USGS through input from USGS 

employees and from major stakeholders. Each goal frames 

major societal water-resources questions relevant to the goal 

and then provides objectives to answer those questions; and 

for each objective, specific strategic actions are provided. The 

goals support the guiding principles of the Water Mission Area 

Science Strategy—observe, understand, predict, and deliver—

and are developed with integration of the other USGS science 

Mission Areas through their links to the water cycle (fig. 8). 

Each goal was developed with the understanding that spatial 

concepts from local to national scales, variation of time scales 

from daily to decadal to historical to geologic time, recognition of trends in data, world-class laboratories and monitoring 

networks, degrees of uncertainty, and development of new 

techniques and delivery of information are important. It is recognized through these goals that unbiased science outcomes 

are developed from keen observation and monitoring of complex systems and understanding those systems. The important 

scientific outcomes can then be applied to predicting changes 

in the water cycle into the future and informing during water 

emergencies and conflicts. The five science goals build upon 

existing USGS core capabilities and strengths and follow 

the four actions of observing, understanding, predicting, and 

delivering. Goal 1 is based mainly on integrated observations of the entire water cycle, looking at water availability in 

terms of quantity and quality. These observations follow onto 

the understanding of the water cycle of Goal 2, the excellent 

unbiased science that the USGS is known for. The science we 

produce is applied to societal relevance in Goals 3 and 4 by 

predicting changes to water availability in the water cycle in 

response to events such as sea-level rise, land-use change, and 

climate change, which may require alternative resources, and 

by anticipating water conflicts and emergencies such as floods, 

droughts, and declining water quality. To sustain the relevance 

of the USGS and contribute to safety in society, water data 

and science must be delivered to the public and other scientists; Goal 5 looks at current and emerging technologies to 

effectively deliver our science through integrated databases 

with other geoscience disciplines, interoperable models and 

decision-support tools, and social media.

The goals presented in this report are interconnected. 

For example, delivering information and science outcomes 

discussed in Goal 5 ties to all of the other goals. Data from 

Goal 1 need to be made available for all to use. The science 

generated in Goal 2, as well as the trends in data and conclusions on predicting future water availability and hazards in 

Goals 2, 3 and 4, also need to take advantage of emerging 

technology to be delivered to society. Table 2 lists the strategic 

actions for each goal so the reader can follow the flow of goals 

and the specific action for each.

Goal 1: Provide Society the Information It Needs 

Regarding the Amount and Quality of Water 

in All Components of the Water Cycle at High 

Temporal and Spatial Resolution, Nationwide

To answer society’s basic questions about water availability, we need detailed observations of the Nation’s water 

cycle. Assessing water availability involves understanding 

the storage and movement of water through the cycle, and 

this understanding can be achieved only through a robust 

system of observation networks and basic assessment tools 

that allow users to quantify each component of the cycle and 

assess trends in those components through time. Monitoring networks also are used to support models that estimate 

parameters for unmonitored areas and time periods. Society’s 

questions about water availability include the following:

• Where does our water come from?

• How much water do we have?

• How much water do we use?

• Is our water supply safe for people, industries, and 

ecosystems?

• What are the trends in our supplies of and demand for 

water?

• Do we have adequate information to make waterresource decisions?

The availability of water is defined not only by quantity 

but also by quality. Many naturally occurring and humansynthesized substances limit the suitability of water for one or 

more important uses if they occur at high enough concentrations. For example, the U.S. Environmental Protection Agency 

(2009) estimates that more than one-third of U.S. streams 

and rivers are impaired or polluted. Changes in the quality of 

groundwater, which is the source of drinking water for 130 

million Americans and 40 percent of U.S. irrigation water 

(Hutson and others, 2004), have been documented in every 

State; thus, it is critical to national water security that a commitment be made to establish and maintain a national network 

to measure the occurrence (concentration) of these substances 

in our water—consistently, and over the long term.

The design and establishment of water-monitoring networks can serve many purposes. Streamgages monitor flow 

that is useful for water supply, water quality, flood assessment, 

flood warning, watershed function analyses, and many other 

functions. Sometimes the design of a monitoring network is 

targeted at a specific aspect of the water cycle, such as the 

way the National Atmospheric Deposition Program (NADP) 

is targeted at monitoring the precipitation chemistry across 

the landscape. Another example of a targeted network is the 

USGS Hydrologic Benchmark Network, which monitors 
Water Science Goals and Objectives 19

Table 2. List of goals and strategic actions.

Goal 1: Provide society the information it needs regarding the amount and quality of water in all components of the water cycle at high 

temporal and spatial resolution, nationwide

Objective 1: Advancement of hydrologic monitoring networks and techniques

Strategic Actions 1, 2, 3, 4

Objective 2: Advancement of monitoring networks and techniques for determining water-quality 

Strategic Actions 5, 6, 7

Objective 3: Assessment of water resources and their suitability to meet human and ecosystem needs

Strategic Action 8

Goal 2: Advance understanding of processes that determine water availability

Objective 1: Comprehensive understanding of geological controls of water availability, and improved integration of geologic and hydrologic 

multidimensional models

Strategic Action 9

Objective 2: Comprehensive understanding of the effects of climate variation on water availability at multiple spatial and temporal scales

Strategic Action 10

Objective 3: Comprehensive understanding of the interactions among aquatic ecosystems, hydrology, and hydrochemistry

Strategic Action 11

Objective 4: Comprehensive understanding of human interactions with water availability

Strategic Action 12, 13

Goal 3: Predict changes in the quantity and quality of water resources in response to changing climate, population, land-use, and 

management scenarios

Objective 1: Development and application of models to predict the potential effects of changes in population, land-use, climate, and management practices upon future water availability considering human and ecological needs

Strategic Actions 14, 15, 16, 17

Objective 2: Prediction of the availability of alternative (impaired) water resources, and the effects of using these water sources on the 

environment

Strategic Action 18

Goal 4: Anticipate and respond to water-related emergencies and conflicts

Objective 1: Identification of current and future threats to communities from water-related hazards

Strategic Actions 19, 20

Objective 2: Development and deployment of observational systems for identifying and tracking hydrologic hazards, making operational 

decisions during extreme hydrologic events, and providing data for recovery

Strategic Action 21

Objective 3: Through an understanding of the conditions leading to water shortages that result in conflicts, provide assistance to communities in finding science-based solutions when conflicts occur

Strategic Actions 22, 23

Objective 4: Providing tools that allow managers to detect and respond to emergencies related to water-quality degradation of all kinds—

natural, accidental, and intentional

Strategic Action 24

Goal 5: Deliver timely hydrologic data, analyses, and decision-support tools seamlessly across the Nation to support water-resource 

decisions

Objective: Development of new, integrated information dissemination in formats appropriate for the 21st century to aid scientists and decisionmakers

Strategic Actions 25, 26, 27

flows and stream-water quality in small, relatively undisturbed 

watersheds. This discussion is provided to draw attention to 

the need to consider the role of broad, national monitoring 

designs, as well as designs targeted at specific aspects of water 

resources. The network design should be suited to the answers 

being sought from the resulting information (Hirsch and 

others, 2006).
20 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation Water Science Goals and Objectives 21

Agricultural

Surface water pumpage

Watershed

Mine drainage

Watershed boundary

Agricultural

 pumpage

Snow melt

Intermittent streams

Dry lake

Gas

production

well

Agricultural

 pumpage

Surface water pumpage

Landfill

Wetlands

Recreational

 pumpage

Saltwater

intrusion

Saline groundwater

Agricultural

Sinkhole

Figure 8. The water cycle.
Highlight

05-25-2008

06-14-2008

07-04-2008

07-24-2008

08-13-2008

09-02-2008

09-22-2008

10-12-2008

3

4

5

6

7

8

9

10

11

12

13

14

Dissolved oxygen, in milligrams per liter

EXPLANATION

Hourly data

No supersaturation

7-day mean

7-day mean minimum

30-day mean

A Saturation

22 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

Use of Continuous Water-Quality Monitors for Real-Time Regulatory Decisionmaking—

The Tualatin River Success Story

Figure 9. A, Plot of dissolved oxygen concentration data at 

Oswego diversion dam (U.S. Geological Survey streamgage 

14207200; http://or.water.usgs.gov/tualatin/monitors/oswegodam_

do_30.html) and computed statistics that are used by managers 

to compare the water quality in the Tualatin River to the State of 

Oregon standard in real time. B, Photograph of Oswego diversion 

dam on the Tualatin River near West Linn, Oregon.

The Tualatin River water-quality monitors are an excellent 

example of how continuous water-quality monitors can be 

used for real-time regulatory management. Several Total 

Maximum Daily Loads (TMDLs) have been written for the 

Tualatin River, including one for ammonia. When this TMDL 

was revised in 2001, the wastewater discharger (Clean 

Water Services of Washington County, Oregon) was given 

the flexibility to discharge different ammonia loads depending on the capacity of the river to assimilate those loads. 

This flexibility is exercised in real time with the use of 

continuous water-quality monitors operated by the USGS. 

Figure 9 shows a plot of the various dissolved oxygen 

parameters that are monitored or calculated for this purpose and the diversion dam at which one of the monitors 

is located. Two such monitors are located approximately 

1.5 days traveltime downstream from large advanced 

wastewater treatment facilities. When the real-time dissolved oxygen monitors in the river indicate that the river 

has no extra assimilative capacity (dissolved oxygen 

concentration statistics are less than the State of Oregon 

minimum standard), then the treatment facilities are held to 

their most strict TMDL limits for ammonia. However, when 

the river has “extra” assimilative capacity—that is, when 

readings from the real-time instream dissolved oxygen 

monitors indicate oxygen levels are above the standard by 

a certain amount—then Clean Water Services has the flexibility to discharge ammonia loads that are higher than their 

strictest TMDL limits. In this way, the water-quality monitors 

are used for real-time continuous feedback regarding the 

water-quality status of the river and are used for real-time 

management and regulatory decisionmaking.

Streamgage 05117500 located along the Souris 

River above Minot, North Dakota, June 24, 2011. 

Photograph by Brent Hanson, USGS.
Water Science Goals and Objectives 23

Objective 1: Advancement of Hydrologic 

Monitoring Networks and Techniques

Understanding water budgets and the water cycle is 

dependent on the accurate measurement of volumes within 

each compartment and the rate at which water moves between 

compartments. Routine measurement of these quantities typically is accomplished through networks of monitoring stations 

that measure the compartments and transfer rates of the water 

cycle such as groundwater storage; surface-water flow and 

storage (including lake levels, snowpacks and icepacks); precipitation; evapotranspiration; water use by humans for drinking, irrigation, energy, and other needs; and water returned to 

the cycle through wastewater streams. Additionally, techniques 

have been developed to augment networks and estimate components of the cycle that are difficult to measure, such as the 

transfer between surface water and groundwater. In addition to 

the demands placed on water supplies by humans, ecosystems 

have water needs that must be met if they are to be sustained, 

and quantification of those needs is required to complete an 

understanding of the water budget. 

The USGS already operates networks that measure 

components of the water cycle. The USGS network of active 

streamgages includes more than 3,000 sites that have records 

of 30 years or more (http://waterwatch.usgs.gov). The USGS 

network of active groundwater-level network sites is composed of more than 20,000 wells that are sampled yearly or 

more frequently (http://groundwaterwatch.usgs.gov/). These 

networks provide a starting point, but improvements in spatial 

coverage, an expansion to more components of the water 

cycle, and the commitment to long-term records is required 

to meet the Nation’s needs for these types of data. The USGS 

also collects and aggregates information on water withdrawals 

(http://water.usgs.gov/watuse/). This information needs to be 

expanded to include information on conveyances, consumptive uses, and return flows.

A concept that should be further used in network design 

and operation is the development of a Federal core backbone 

network of stations and measurements supplemented by the 

use of records collected by and furnished by other agencies. 

This concept has been explored and embraced by the Subcommittee on Ground Water under the Advisory Committee on 

Water Information (ACWI) as part of their National Ground 

Water Monitoring Network design. It is strongly recommended that this concept be evaluated for all other hydrologic 

networks operated by the USGS to see where networks may be 

strengthened and extended through this type of design and the 

incorporation of qualified records furnished by other agencies. 

More can be read about the work of the Subcommittee on 

Ground Water and their work on the National Ground Water 

Monitoring Network design at http://acwi.gov/sogw/pubs/tr/

index.html or in their publication “A National Framework for 

Ground-Water Monitoring in the United States” (Advisory 

Committee on Water Information, 2009).

In addition to monitoring networks, society demands 

hydrologic information at spatial and temporal scales that far 

exceed the capabilities of all water-resource agencies to provide direct measurements. These information needs can be fulfilled only through a robust capability to estimate parameters 

for unmonitored areas and time periods. Techniques should 

be developed to improve our ability to estimate hydrologic 

parameters where and when measurements cannot be made. 

These techniques include, but are not limited to, modeling the 

use of remote-sensing information. Remote-sensing data such 

as land use, land cover, elevation, evapotranspiration, snow 

cover, precipitation, vegetation indices, energy budget, gravity, 

and thermal infrared information should be fully integrated 

with monitoring information and models to extend understanding of the hydrologic systems and draw further relations 

between these data and hydrologic responses. A key requirement for hydrologic analysis of surface-water-network information is the National Hydrologic Dataset (NHD) maintained 

by the USGS, which allows spatial orientation of upstream and 

downstream features within a watershed context.

Strategic Action 1.—Maintain and enhance existing 

national networks that accurately measure, analyze, and report 

information about each of the compartments of the water 

cycle. Improve and expand networks and techniques to reduce 

uncertainty about the resource to an acceptable level and to 

expand our capability to estimate the resource in ungaged or 

unmeasured areas.

Strategic Action 2.—Seek ways to expand the Nation’s 

understanding of the hydrologic resource not only through 

its own monitoring networks but also through optimizing the 

use of hydrologic data collected by and through other public 

agencies. Work through the Advisory Committee on Water 

Information (ACWI), as has been done through the National 

Ground Water Monitoring Network, to establish a systematic 

approach for the utilization of records furnished by others for 

all major quantity compartments of the water cycle.

Strategic Action 3.—Devote expanded resources to the 

integration of remote-sensing products into hydrologic modeling analyses for parameter estimation, forcing, and verification 

of modeled states and fluxes. Establish closer links between 

USGS hydrologists and remote-sensing experts, as well as 

with other agencies that collect, analyze, and use remotely 

sensed information for modeling.

Strategic Action 4.—Direct resources to defining a set of 

hydrologic parameters that can be researched in the paleorecord and developed into a time series of data for the purpose 

of deep-time trend analysis. At a minimum, this would include 

flood flows and recurrence; drought recurrence; changes in 

storage in lakes, wetlands, snow, and icefields; and changes in 

groundwater storage.
24 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

Objective 2: Advancement of Monitoring 

Networks and Techniques for Determining Water 

Quality

The USGS should leverage its core capabilities and 

maintain and enhance its infrastructure of monitoring sites so 

as to determine the distribution of basic water-quality characteristics in the Nation’s surface waters and groundwaters, 

as well as naturally derived and human-derived contaminants 

that have the potential to limit the use of water for drinking 

or limit its ability to support ecosystems. In conjunction with 

this effort, the USGS should determine the variability of these 

characteristics and contaminants on time scales from daily 

to seasonal to decadal. The USGS WaterQualityWatch Web 

site (http://waterwatch.usgs.gov/wqwatch/) provides a user 

interface to more than 1,600 active, real-time, continuous 

water-quality records and demonstrates the potential for these 

networks; however, major improvements in spatial coverage, 

the number of water-quality characteristics measured, data 

delivery, and commitment to long-term records is required to 

meet the Nation’s needs for these types of data. 

With regard to surface-water networks and use of current 

technology, several important water-quality parameters can 

be measured reliably by automated sensors (primarily, but 

not limited to, temperature, pH, dissolved oxygen, specific 

conductance, nitrate, dissolved organic carbon, and turbidity). 

Several other important contaminants that cannot be measured 

directly with automated sensors can, nonetheless, be estimated 

with these sensors by using the sensor data as surrogates and 

deriving quantitative relations between sensor data and the 

contaminant of interest; for example, sediment concentration 

can be estimated from turbidity data (Rasmussen and others, 

2009). The USGS National Real-Time Water Quality Web 

site (http://nrtwq.usgs.gov/) provides a user interface to sites 

where the surrogate approach is used to provide real-time, 

continuous, computed concentrations for sediment, nutrients, 

bacteria, and other constituents. Other contaminants that 

can limit the uses of water cannot be measured or estimated 

by means of automated sensor technology; to measure the 

concentration of these contaminants in water, a site must be 

visited and a physical sample collected and sent to a laboratory 

for analysis (http://waterdata.usgs.gov/nwis/). The suite of 

measurements included in a surface-water contaminant observation network will be site dependent, but potential contaminants include nutrients, trace elements, microbes, pesticides 

and other synthetic organic compounds, pharmaceuticals and 

personal care products, and algal toxins. Subnetworks should 

be defined based on measured parameters and techniques. 

For example, because temperature can be measured relatively 

cost effectively, the temperature network will likely contain 

the most sites, with many sites on smaller streams where the 

temperature response to climate variability has great effect on 

ecosystems. Continuous measurements of temperature, pH, 

specific conductance, and dissolved oxygen can be collected 

efficiently at many streamgage sites, on rivers small to large. 

The site-specific techniques for development of sediment 

surrogate models probably limit those measurements to fewer 

sites on larger rivers. The collection of discrete measurements 

is relatively expensive, so fewer sites, chosen for their national 

significance, will make up the contaminant network. Because 

technologies and techniques constantly change, the network 

will need ongoing updating and improvement to remain vital. 

Therefore, a function of maintaining the network should be the 

development, assessment, and—as appropriate—incorporation 

of new sensors, new laboratory methods, and new analytical 

techniques.

As stated previously, techniques should be developed 

to improve our ability to estimate and interpolate hydrologic 

parameters where and when measurements cannot be made. 

An example of a model that does this type of interpolation 

is the USGS SPARROW model (Preston and others, 2009; 

2011), which has been used to predict amounts of nutrients 

and sediments in stream reaches at the scale of small catchments throughout entire major river basins. Examples of 

remotely sensed data as applied to spatial interpolation include 

the use of satellite imagery to estimate chlorophyll concentrations in surface-water bodies and the use of infrared imagery 

to estimate temperature. It is important to recognize, however, that all models and uses of remotely sensed data rely on 

observation and research for the quantitative descriptions of 

the sources and processes that affect water quality; ultimately, 

all models and application of remotely sensed data need to 

be validated with measurements made on the ground. Thus, 

an ongoing, comprehensive monitoring network, as well as 

research aimed at quantitatively describing the processes that 

affect water-quality characteristics, are critical to defining and 

increasing the accuracy of water-quality predictions made with 

these types of models and data applications.

Similar to the surface-water-quality network, a groundwater-quality network needs to be more fully developed, and 

a function of maintaining the network should be the development, assessment and—as appropriate—incorporation of 

new sensors, new laboratory methods, and new analytical 

techniques. A vision for this network was provided by ACWI 

Subcommittee on Ground Water (Advisory Committee on 

Water Information, 2009), that calls for monitoring wells in 

places where the groundwater is not disturbed by pumping or 

land use and sites where development has affected groundwater. Additionally, the ACWI calls for coverage in shallow 

groundwater—where surface development is most likely to 

affect quality—and deep aquifers that are tapped for public 

supply. The suite of measurements included in a groundwatercontaminant observation network will be site dependent, but 

the quality of shallow groundwater can be affected by nutrient 

contamination, chloride or bromide because of saltwater intrusion in coastal areas, pesticides and other synthetic organic 

compounds, and trace elements. In deep aquifers, naturally 

occurring contaminants such as major ions, radionuclides, and 

trace elements can affect the suitability of the water for some 

uses. 
Water Science Goals and Objectives 25

Strategic Action 5.—Commit to long-term data collection at a core set of nationally important surface-water-quality 

sites that would constitute a national surface-water-quality 

observation network, incorporating all available measurement 

techniques, including the use of automated sensors, the use 

of surrogates, the use of discrete measurements, in addition 

to coordinating with the hydrologic networks of Strategic 

Action 1. 

Strategic Action 6.—Develop robust water-quality spatial 

modeling tools and make use of remotely sensed information 

to interpolate data from the national observation networks to 

high spatial resolution. 

Strategic Action 7.—Commit to long-term data collection 

at a core set of nationally important groundwater-quality sites 

that would constitute a national groundwater-quality observation network. Design the network to measure the quality of the 

Nation’s principal and regionally important aquifers, coordinating with the hydrologic networks of Strategic Action 1. To 

the extent possible, take advantage of the existing infrastructure provided by the network of USGS groundwater-level sites 

where data collection has been ongoing.

Objective 3: Assessment of Water Resources 

and their Suitability to Meet Human and 

Ecosystem Needs

A vital aspect of any resource evaluation should include 

monitoring and assessment. The earlier objectives within this 

goal statement have been devoted to monitoring activities. 

This objective is focused on assessment of data and other 

information. The design of the various hydrologic networks 

described above must be linked to allow the capability to 

monitor changes in the combined hydrologic system. Assessment of hydrologic information generally takes the following 

direct forms: analysis of trends, comparison of data between 

areas of differing hydrologic stress, analysis of the uncertainty 

associated with measurements, and integration of hydrologic 

data with information that describes or explains hydrologic 

functions. Descriptive information can include land cover, 

land use, geology, ecology, species distributions, climate, population and other socioeconomic information, and water use. 

Emphasized here is the need to assemble and integrate information that helps the USGS describe the hydrology and the 

factors that influence it or are, in turn, influenced. The USGS 

should work with agencies, organizations, and academia at 

various levels to bring such data into an interactive system that 

facilitates robust assessment of hydrologic information.

Strategic Action 8.—Working through USGS resources 

and in collaboration with others, expand USGS capabilities to 

assemble, integrate, and serve information that assists in the 

assessment of hydrologic data, with the intent of improving 

the ability to detect trends, draw comparisons between differing hydrologic settings, lessen uncertainty, and improve the 

description of hydrologic functions.

Goal 2: Advance Understanding of Processes 

that Determine Water Availability

Management of water resources for multiple purposes 

will be improved by increased understanding of processes 

affecting water movement, storage, quality, and use, through 

a combination of new tools, concepts, and discoveries. New 

insights about such processes will be gained by spatial and 

temporal studies at a wide range of scales, from nationalglobal syntheses to local, intensive investigations (including 

experiments and theoretical models). To accomplish these 

tasks, the USGS will balance and integrate complementary 

approaches to water science, such as monitoring, assessment, 

statistical models, deterministic simulations, field and laboratory experiments, and fundamental research on concepts and 

methods. 

Knowledge about interactions of geology, climate, 

humans, and ecosystems with the water cycle is critical to 

understanding and optimizing water availability. Most efforts 

to predict or manage water resources require a clear understanding of how water availability has already been affected 

by human activities and what are the underlying causes of 

stress on the various components of the water cycle. Interdisciplinary approaches and studies are needed to address these 

important issues. A few examples include (1) how climate 

affects water movement and storage, (2) how agriculture, 

energy, and mineral resource development affect (and depend 

upon) water resources, (3) how streamflow affects aquatic, 

riparian, and coastal ecosystems, and (4) how geology affects 

contaminant transport and attenuation. Both water and energy 

have important national-security implications, and ensuring 

our water and energy supplies will require USGS-wide multidisciplinary scientific and technical expertise and approaches. 

An essential component of future research on water availability will involve application of innovative technologies to 

generate new types of data and large datasets. Some examples 

of water-related research tools for which the USGS is known 

and should continue to develop include (1) chemical and 

isotopic techniques for geochronologic and process-related 

research in geology, hydrology, and biology; (2) geophysical and geochemical characterization of aquifer properties; 

(3) remote sensing to quantify terrestrial water balance and 

ecosystem change; (4) computer simulation of groundwater 

flow and chemical transport; and (5) statistical models of 

water-quality variation in relation to hydrology and land use. 

New insights will be obtained from these approaches through 

new data acquisition and database management tools along 

with the integration of data and research across disciplines. 

Selected questions that address research to improve understanding include the following:

• What principles should guide optimization of water 

availability for multiple uses (that is, drinking water, 

ecosystems, agriculture/energy/industry), and how 

should water management adapt to changing conditions?
26 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

• What can the past tell us about the future of water 

availability? 

• Can human effects be clearly distinguished from natural variability? 

• Can critical thresholds or “tipping points” be recognized or predicted? 

• What special processes must be considered near hydrologic boundaries or interfaces (for example, air/water, 

sediment/water, groundwater/surface water, saltwater/freshwater, impounded/flowing waters, or local/

regional groundwater-flow systems)?

• How can groundwater and surface-water contamination 

be prevented or mitigated? 

• What new tools will be needed to improve assessment, 

understanding, and prediction of water availability in 

the future?

Objective 1: Comprehensive Understanding of 

Geological Controls of Water Availability, and 

Improved Integration of Geologic and Hydrologic 

Multidimensional Models

Water movement, storage, and quality are intimately 

related to surface and subsurface geology and geochemistry. 

Movement of water and solutes through watersheds from 

the land surface through soils, bedrock, aquifers, and stream 

corridors depends on the interplay of geologic framework 

properties and hydrologic conditions through time. Water/rock 

reactions affect water quality naturally and control the occurrence and persistence of artificial contaminants. Conversely, 

research on hydraulic, geochemical, and isotopic properties 

can provide critical insights about flow paths, traveltimes, 

and water/rock interactions. Although general principles of 

geological controls of water movement and water quality 

are largely understood, modeling and prediction of flow and 

transport remain difficult because they require the incorporation of geological and hydrological data at multiple scales and 

resolutions. 

Improvements are needed to characterize complex systems and to integrate physical and chemical geological properties with flow and transport data and simulations. Construction 

of new hydrogeological frameworks for modeling geologicalproperty data and their effects on water movement and quality 

in 3-D and 4-D (changing with time) requires integration of 

new and existing geologic-map data with subsurface geophysical, geochemical, and associated rock-property data (Gundersen and others, 2011; Jacobsen and others, 2011). Improved 

geophysical imaging of the subsurface is needed to provide 

information on critical interfaces that control water availability, such as fault structures, geologic contacts, and boundaries 

between fresh and saline waters. Examples of needed geologic 

studies include ascertaining (1) hydraulic properties affecting 

groundwater flow at multiple scales in complex (heterogeneous) geologic settings, such as fractured crystalline rocks, 

karst and epikarst, confining units, fault zones, volcanic rocks, 

stream corridors and floodplains, sub-estuarine formations, 

and permafrost; (2) geochemical and mineralogic properties 

affecting water/rock interactions, microbial communities, 

and biogeochemistry (for example, redox conditions); and 

(3) distribution and sources of salinity and natural contaminants, such as arsenic, heavy metals, and radioactive elements. 

Achieving this objective also will require more advanced 

mathematical and statistical spatial analysis tools to accurately 

predict and model the natural variability inherent in geological 

systems.

Strategic Action 9.—Produce new 3-D and 4-D hydrogeological framework models and property databases that are integrated with flow and transport models and data to effectively 

trace water movement and water-quality changes in complex 

systems under varying hydrologic conditions.

Flow from a storm event fills up a buried karst feature along the 

dry riverbed near Bartow, Florida, June 12, 2006. Photograph by 

Patty Metz, USGS.
Highlight

Silt layer identified in drilling log

Total

0 Percent 0.5

Mobile

0 Percent 0.5

Bound

0 Percent 0.5

Mean Relaxation Time NMR Determined Water Content 

0 1 Ralaxation Time Distribution

0 33

EMI Conductivity

0 mS/m 20

Gamma

0 API units 200

50

60

70

80

90

Depth below land surface in meters

 Log10 (seconds) 

NMR Data 

Water Science Goals and Objectives 27

Trends in Hydrogeophysics

Figure 10. Nuclear magnetic 

resonance (NMR), gamma, and 

electromagnetic conductivity 

(EM) logs from a borehole 

completed in sand and gravel 

on Cape Cod, Massachusetts

(Johnson and others, 2011). 

The NMR data, which measure 

how hydrogen nuclei spin in 

response to a magnetic field 

and can determine how much 

and where water is stored 

in porous media, indicate 

decreased total water and 

increased proportion of 

bound water in silt zones 

identified by the gamma and 

electromagnetic induction 

conductivity (EMI) traces and 

drilling logs, as indicated by the 

shaded boxes.

Current trends in relation to hydrogeophysics and water science focus on three main areas: properties, processes, and 

scale. 

Properties.—In the past, geophysical characterization provided direct insight into geologic structure and properties but 

only indirect insight into hydrologic properties. Today (2012), there is a trend toward direct measurement of hydrologic 

parameters by use of geophysical tools. The prime example of this trend is the emerging interest in nuclear magnetic resonance (NMR) methods (for example, magnetic resonance sounding and borehole NMR; see fig. 10). At this time, the USGS 

is an “early adopter” of these methods, which involve use of a surface unit and a borehole system. These methods provide 

estimates of saturation, total porosity, and permeability. In the case of the borehole tool, one can also extract mobile/immobile pore fractions important for understanding and modeling hydrologic behavior (for example, rate-limited mass transfer). 

Processes.—Application of geophysical methods in time-lapse mode to monitor hydrologic processes is a productive area 

at the intersection of geophysics and water science. Permanent resistivity arrays are being used to monitor engineered 

remediation (for example, biostimulation) in 4-D, and resistivity/induced polarization (IP) and distributed temperature systems are being used to monitor tracer tests, natural processes (for example, hyporheic exchange, groundwater discharge 

to coastal bays and estuaries, unsaturated zone dynamics), and aquifer-management operations (for example, aquifer 

storage and recovery).

Scale.—There is a trend toward multiscale characterization and monitoring, facilitated by the advent of mobile measurement platforms. Towed seismic land streamers are used for multichannel analysis of surface waves, refraction, and even 

some reflection surveys, and towed multifrequency electromagnetic and shallow electrical resistance tomography/ground 

penetrating radar systems provide broad-scale geoelectrical information at the study scale (for more than depths of about 

20–30 meters). The transfer to civilian Federal agencies of military unmanned aviation technology developed since 9/11 

has the potential to revolutionize our ability to acquire multisensor data in support of a wide range of science needs. It is 

expected that the application of unmanned aerial vehicle systems will soon have a transformative effect on USGS science.
28 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

Objective 2: Comprehensive Understanding 

of the Effects of Climate Variation on Water 

Availability at Multiple Spatial and Temporal 

Scales

Water availability is affected by weather and climate 

variation over a wide range of time scales, including seasonal 

and glacial-interglacial cycles. Such variations can affect precipitation, evapotranspiration, streamflows and chemical loads, 

terrestrial weathering and erosion rates, aquatic life cycles, 

sea level and coastal aquifer salinities, and so forth. Watershed responses to short-term climate variability can obscure 

underlying trends related to longer-term changes in climate, 

land use, and management actions, thus affecting management 

decisions and monitoring plans. Watershed responses to longterm climate trends may be superseded locally by effects of 

land use or other human activities some of which may, in turn, 

be driven by human responses to climate issues. It is an important challenge to distinguish long-term trends from shortterm variability. Descriptions and predictions of water-cycle 

processes and probabilities of extreme events must account for 

short-term variability that is superimposed on various types of 

longer-term nonstationarity (systematic changes that may or 

may not continue in the same way as in the past). 

Understanding of past hydrological responses to climate 

change can improve our ability to distinguish between natural 

and human influences on water availability, especially when 

combined with improved understanding of water use and 

other human effects. Combined with improved trend analysis 

and simulation tools, information about the past can be used 

to improve water-availability projections and assessments of 

potential management options for the future. Trends from the 

past cannot be projected confidently into the future without 

accounting for the complex processes that link causes and 

effects. Whereas many factors are incorporated into sophisticated climate models that may be used to predict hydrologic 

responses at global to regional scales, further research on past 

conditions including historical and geological time scales 

will play a critical role in improving those models through 

improvements in understanding of processes, model testing, 

and calibration. Relatively short-term climatic variations and 

responses are evaluated using historical data such as streamflow, snow cover, and groundwater and lake levels, including 

changes in the timing of seasonal patterns “hydrologic phenology”. Knowledge about longer-term hydrologic changes such 

as past lake levels, stream flood heights and frequencies, and 

groundwater recharge rates (“paleohydrology”) will require 

observations derived from geology, geomorphology, paleontology, and various techniques for dating groundwater and 

sediment. 

Strategic Action 10.—Use data and studies of hydrological variability on historic and prehistoric (geologic) time 

scales, along with data and models of human effects on watersheds, to improve understanding and anticipation of climate 

effects on water availability.

Objective 3: Comprehensive Understanding of 

the Interactions Among Aquatic Ecosystems, 

Hydrology, and Hydrochemistry

Sustainable aquatic ecosystems depend on suitable hydrological and hydrochemical conditions. Conversely, healthy 

ecosystems can help to maintain water availability. Important 

biological ecosystem components range from microbes to 

macrofauna and macroflora. Hydrological and hydrochemical changes in lakes, streams, and wetlands can alter physical 

habitats, complex life cycles, trophic interactions, nutrient supplies, and contaminant exposures. Coastal marine ecosystems 

are affected by changing inputs of freshwater and associated 

constituents from streams and groundwater. In turn, sustainable ecosystems can mitigate physical and chemical disturbances, such as floods and contaminant spills. Holistic science 

approaches are needed to (1) describe the natural variability 

of aquatic systems, (2) assess hydrodynamic and ecological 

conditions over a wide range of climatic conditions, (3) evaluate ecological responses resulting from adaptive management 

strategies for ecological flows, and (4) incorporate ecosystem 

approaches into whole-watershed management. 

An aquatic ecosystem is characterized by its hydrology, 

chemistry, geomorphology, hydroclimatology, and a suite of 

biological and socioeconomic parameters. To a large extent, 

water-ecosystem interactions involve rapidly changing conditions (for example, snowmelt, floods, daily and seasonal light 

and temperature changes, and solute and sediment fluxes 

during runoff events). Ecosystem responses to change may 

be nonlinear, exhibiting abrupt shifts at critical thresholds or 

tipping points. Improvements in understanding these complex 

systems therefore will require intensive measurements and 

integrative environmental models. 

Strategic Action 11.—Conduct integrated research 

relating water availability to sustainable aquatic ecosystems, 

including the timing of streamflow variations, hydrodynamics 

of groundwater/surface-water interactions, water quality and 

biogeochemistry, competing human demands, and relations to 

ecosystem structure and health.

Objective 4: Comprehensive Understanding of 

Human Interactions with Water Availability

Movement, storage, and quality of groundwater and 

surface water have been altered substantially by agriculture, 

urbanization, energy and mineral production, waste disposal, 

and other human activities. Although many of these activities 

and their effects are widely documented, it remains difficult 

to predict their actual effects across a range of geologic and 

climatic settings and time scales. Because detailed studies 

cannot be done everywhere, an improved understanding of 

interactions between land use and hydrogeology is needed 

to predict effects of human activities and to design appropriate monitoring strategies for detecting change; thus, it is 

important for the USGS to continue research on natural and 
Water Science Goals and Objectives 29

human-related processes affecting water quantity and quality, 

including the ability of natural systems to tolerate or remediate 

human impacts.

Large amounts of money and effort are spent annually 

to capture, store, and reuse water supplies, to prevent or clean 

up contaminants that threaten water availability (for example, 

excess nutrients, sediment, toxic metals, and synthetic organic 

compounds), and to restore impaired ecosystems. Strategies 

include agricultural best management practices, monitored 

natural attenuation, in situ remediation, stormwater retention, 

stream and wetland restoration, and dam removal, as well 

as conservation measures that include enhanced recharge, 

groundwater storage, recovery, and reuse. Yet, relatively little 

co-located effort is devoted to monitoring and studying the 

outcomes of these practices. Remediation models and strategies are relatively weak in relation to the hydrogeologic conditions that promote or impede intended outcomes. An improved 

understanding of the linkages between human actions, 

hydrogeological conditions, and ecosystem responses will lead 

to improved targeting and optimization of control efforts and 

a better use of adaptive management strategies. For example, 

the USGS can provide the science needed to guide decisions 

regarding unconventional fossil energy resources (coal-bed 

methane, tight gas sands, shale gas, and shale oil) through a 

variety of monitoring, modeling, and assessment studies that 

are natural extensions of activities described in this report. 

USGS expertise in hydrologic flow and 3-D/4-D geologic 

modeling to characterize the subsurface serves to answer society’s questions on these processes. Spatially and temporally 

targeted assessments, including water quality, can be used to 

monitor the effects of operations at drill sites.

Addressing this objective will require a combination of 

basic research on fundamental processes as well as collaborative studies of systems that have been targeted for different 

management actions. The USGS can add value not only by 

studying the effects of such actions but also through direct 

involvement in conservation and remediation technology 

development, including design and testing under real-world 

field conditions. Results of such efforts will yield insights 

into processes and controlling factors, and they can be used 

in adaptive management strategies. Collaborative possibilities 

exist with the USDA, the USEPA, regional and local agencies, 

nongovernmental organizations, international entities, and 

industry. 

Strategic Action 12.—Conduct monitoring, research, and 

modeling activities, in coordination with various water-related 

management actions, to improve understanding of benefits, 

limitations, and adaptive strategies. 

Comprehensive understanding of natural and artificial 

stressors and their effects on water availability can be used to 

design potential management strategies for protection and sustainability of water resources through regulatory or economic 

measures. However, management success ultimately will 

depend on less tangible or predictable socioeconomic factors, 

such as aesthetics, population growth and movement, competing priorities, values, and costs. Given some understanding of 

existing and impending water-availability issues and management options, how decisions will be made and implemented, 

and how different options will be accepted by society (for 

example, conservation, reuse, redistribution, and treatment) 

are questions to be answered. Although this is a complex subject with high uncertainty, it is critical that such considerations 

be incorporated with other principles of water availability in 

research aimed at identifying realistic solutions. 

Strategic Action 13.—Through internal and external collaboration, incorporate socioeconomic drivers such as competing uses, values, and costs into water-availability research, 

assessments, and models.

USGS test well 10 34h363 in the East River, 

Brunswick, Georgia, August 2007. The U.S. 

Geological Survey drilled this test well in 

the early 1970s and at the time it was on the 

edge of the marsh at Andrews Island. It is now 

only accessible by boat or canoe at high tide. 

Despite being surrounded by saltwater the 

artesian well flows very fresh water from the 

Upper Floridan Aquifer. Photograph by Alan 

Cressler, USGS.
Highlight

30 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

Land Use and Contaminant Hydrogeology and Geochemistry

Contaminants are introduced into groundwater and surface water by various processes, and the persistence of contaminants can be highly variable depending on the environment. USGS research includes studies to improve understanding of 

the sources, movement, and fate of contaminants in aquatic systems. This research includes development of new tools and 

methods, as well as local and regional process studies and computer models. 

“Point-source” contaminants typically come from small source areas such as oil spills, landfills, mine drainages, wastewater disposal sites, and unconventional fossil energy development site. Nonpoint-source contaminants are more widely 

distributed and may be related to specific land uses (for example, agricultural nutrients, pesticides), regional or global 

atmospheric emissions (for example, mercury), and the like. For example, figure 11A illustrates recharge of nitrate (orange 

colors) beneath agricultural fields and its movement along groundwater flow paths toward downgradient wells and a 

stream (Dubrovsky and others, 2010). 

Management options for preventing or minimizing the effects of nitrate on downgradient drinking-water sources and 

ecosystems will depend on the input history, groundwater flow paths and traveltimes, the rate of reaction of nitrate with 

aquifer material, and other factors. For example, streams are largely fed by groundwater discharge, which can deliver contaminants that entered the watershed at various times in the past. Figure 11B shows a map view of simulated traveltimes 

of groundwater from recharge to discharge in a watershed in New Jersey (Kauffman and others, 2001). Groundwater that 

recharges far from streams can spend decades or more in an aquifer before discharging; thus, contaminants introduced 

into the aquifer may take decades or more to be flushed from the system. The simulation-model parameters were constrained by groundwater ages estimated from concentrations of tritium and helium isotopes in wells. 

Another important consideration is the reactivity of the contaminant during its passage through the system. Interactions 

between a groundwater contaminant plume, surrounding uncontaminated groundwater, and solid aquifer materials can 

limit the progress of the plume through the aquifer, a process called natural attenuation. Figure 11C illustrates natural 

attenuation processes that can occur when organic contaminants come into contact with oxygenated compounds in the 

aquifer, causing microbially mediated reactions that transform the contaminants into other chemicals that are less harmful (Steefel and others, 2005). Understanding processes at the microscale is important for understanding and predicting 

contaminant migration at the aquifer or watershed scale. Simulating such processes at the watershed scale is a challenge. 

USGS studies in contaminant hydrology therefore integrate effects of land use, climate, geology, hydrology, geochemistry, microbiology, ecology, and water use to develop general principles and predictive tools for evaluating management 

options.

Yellowstone River near Custer, Montana, August 2011. 

Photograph by Peter R. Wright, USGS.
Organics

Calcite growth FeCO2

Clay

O2

O2

Denitrification

SO4

 reduction

Methanogenesis

Landfill

C

Fe reduction

Aerobic respiration

Qtz

Qtz

Qtz

Nitrate concentration, in 

milligrams per liter as nitrogen

<5

5–10

>10 

EXPLANATION

Unsaturated zone

Agricultural

Confining unit

Surficial aquifer

Urban

Groundwater age, in years 

since recharged

Publicsupply

well

0

25

50

75

100

Domestic

well Monitoring

well

Depth below land surface, in feet

5

10

15

Forest

Direction of 

groundwater 

flow

Water table

A Figure 11. A, Surficial aquifer on the Delmarva 

Peninsula, Delaware, Maryland, and Virginia. B, Map 

view and cross section of simulated traveltimes of 

groundwater from recharge to discharge in a watershed 

in New Jersey (Kauffman and others, 2001). C, Natural 

attenuation processes that can occur when organic 

contaminants come into contact with oxygenated 

compounds in the aquifer, causing microbially mediated 

reactions that transform the contaminants into other 

chemicals that are less harmful (Steefel and others, 

2005). 

0 50 100 150 200 250

Travel time, in years

EXPLANATION

Stream

39°30'

39°45'

75 °15'

75° 

A'

0 2 4 6 8 10 12 14 15.7

-200

200

-100

0

100

Altitude, in feet above or below

sea level 

Distance, in miles

A A'

Confining unit

Pumped wells

Confining unit

Stream cell Stream cells

VERTICAL SCALE GREATLY EXAGGERATED

A

B

Water Science Goals and Objectives 31

Land Use and Contaminant Hydrogeology and Geochemistry—Continued

Highlight
32 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

Goal 3: Predict Changes in the Quantity and 

Quality of Water Resources in Response to 

Changing Climate, Population, Land Use, and 

Management Scenarios

The role of prediction in the USGS is to (1) generate 

understanding of earth processes by developing and testing 

hypotheses and (2) provide information to decisionmakers and 

the public to help “minimize loss of life and property, manage 

our natural resources, and protect and enhance our quality of 

life” (Larson, 2009). Prediction does not necessarily imply a 

precise forecast of the future, but can involve examination of 

potential future scenarios and ranges of options. Prediction is 

inextricably tied to the observing, understanding, and delivering goals outlined in this document. Predictions are developed 

from understanding and are based on field observations, in 

turn, predictions are used to help develop understanding and 

to guide sampling and monitoring location and frequency. 

Prediction relies on mathematical or physical models that capture the essential elements of the water-resources system. The 

USGS plays a role in all aspects of model development. USGS 

scientists formulate conceptual and mathematical models 

describing various aspects of water-resources systems, develop 

methods to solve or approximate mathematical models, devise 

physical and numerical experiments, apply models to predict 

system response on a range of spatial scales from local to 

global, analyze results from predictive models, and communicate results within the scientific community and to the public.

In addition to the major societal questions raised in 

the introduction, prediction also addresses the following 

questions:

• What future water-resources conditions and issues 

should we anticipate based on our understanding 

of hydrologic principles, water-related trends, and 

expected changes in human activities, climate, and 

ecosystem condition?

• How can we best manage water resources in the 

context of identified trends and expected future conditions?

• What alternative water sources may be available to 

meet future human, industrial, and ecological needs?

Objective 1: Development and Application 

of Models To Predict Potential Effects of 

Changes in Population, Land Use, Climate, and 

Management Practices Upon Future Water 

Availability Considering Human and Ecological 

Needs

Quantifying one aspect of a resource a single time 

does not provide enough information regarding the effects 

of changing conditions on water resources to enable good 

management decisions (see, for example, Bredehoeft, 2002). 

The USGS will continue to develop and apply laboratory 

experiments and mathematical (deterministic, statistical) models to quantify all aspects of water availability and account 

for changing conditions. Substantial progress in developing 

accurate predictions about water availability will be aided by 

focused effort on integrated models that combine different 

parts of the water cycle that traditionally have been modeled 

separately. These integrated models allow for more comprehensive study of the factors controlling water availability and 

improved prediction by including coupled and often nonlinear processes. Use of integrated models acknowledges the 

observed relations between different parts of the hydrologic 

system (see, for example, Winter and others, 1998).

Integrated modeling is also important for relating water 

quantity and movement with water quality and ecosystem 

health. For example, prediction models may be developed to 

include the geomorphic effects of land use and management 

on infiltration, runoff, and sediment transport, which have 

direct implications for water quality and aquatic life in areas 

subject to urbanization, agriculture, grazing, forestry practices, 

and water-retention projects. Such models should include 

aspects of geology, climate, hydrology, biology, and human 

factors. Important challenges to modeling such complex 

coupled systems include the verification of model results and 

incorporation of data from diverse sources, which will require 

coordinated efforts in research and database management. 

Strategic Action 14.—Develop and apply predictive models for coupled systems integrating geology, hydrology, water 

quality, and ecosystems, including potential effects of nonlinear behavior and feedback.

On a national scale, regional assessments and prediction 

models are important to the understanding of water availability 

and, ultimately, the effective management of water resources. 

Local-scale processes also are important in understanding, 

for example, groundwater/surface-water interaction under 

changing flow conditions, groundwater pumping leading to 

undesirable lowering of groundwater levels, and the interaction of water-quality characteristics and processes, especially 

in locations affected by point- or nonpoint-source contamination. In addition, responses to changing conditions can occur 

over a range of time scales from hours or less to millennia and 

more, thus, studies spanning a full range of spatial and temporal scales are needed to quantify water availability and to 

predict future water availability. Moreover, methods to bridge 

relevant scales are needed to predict how local processes influence regional water availability and how regional settings may 

influence local hydrologic response.

Strategic Action 15.—Develop and apply 3-D and 4-D 

(transient) hydrologic prediction models at a range of spatial 

scales (local to regional) and temporal scales (short to long 

timeframes), including methods to bridge these scales. 

Predictive models are inherently uncertain, and mathematical and statistical techniques continue to be developed to estimate this uncertainty (Hill and Tiedeman, 2007; 

Beven, 2009). Estimating and communicating uncertainty 
Highlight

Water Science Goals and Objectives 33

to decisionmakers and other users of the information from 

predictive models will improve decisionmaking and lead 

to questions that can ultimately improve understanding of 

the underlying physical, chemical, or biological processes. 

Performing post-audits of past model predictions can identify 

areas for improvement and lead to better predictions in the 

future.

Strategic Action 16.—Develop and apply improved methods to estimate uncertainty in model simulations, and routinely 

assess and communicate model uncertainty to end users.

Anticipation of potential future conflicts over water 

resources requires improved predictions of future water 

demands. These predictions require understanding of the 

relations between future demands and population, land use, 

and climate change, as well as improved understanding of the 

social-science factors influencing water use. Improved wateruse data and complementary water-use science (Committee 

on USGS Water Resources Research, 2002) would allow the 

USGS to more accurately and effectively predict future water 

availability under different scenarios and provide needed 

information on which to base sound decisions.

Strategic Action 17.—Work with partners to develop 

improved methods for prediction of future water-use demand 

and develop strategies to track, validate, and update water-use 

predictions through time.

Objective 2: Prediction of the Availability of 

Alternative (Impaired) Water Resources, and the 

Effects of Using These Water Sources on the 

Environment

For areas experiencing water conflicts or shortages, 

alternative sources such as saline water, contaminated water, 

or water reclamation and reuse, may serve as additional water 

resources. Alternative (impaired) water resources may be 

used for purposes that do not require high-quality water, or 

they may be treated to improve their quality to acceptable 

levels. For example, wastewater and runoff from paved areas 

is captured in Las Vegas, Nevada, and either used directly 

for appropriate needs or processed and returned to the main 

surface-water reservoir for use by the city (Fishman, 2011). 

El Paso, Texas, another water-stressed city, is using the largest 

desalinization plant in the world to desalinate brackish groundwater to help meet water demand (El Paso Water Utility, 

2011). Availability of alternative water resources depends, in 

part, on the chemical composition of the water, which determines how the water can be used and what technology and 

expense will be required to treat it. Exploitation of alternative sources also may have consequences. For example, the 

desalinization process produces brines that must be disposed 

of, and water reuse has been associated with water-quality 

impacts (for example, Rosen and others, 2011). To quantify 

the potential water availability from alternative sources, their 

distribution and composition must be assessed and understood, 

and the effects of using such sources should be predicted. The 

rerouting of water and the potentially complex interactions 

between water withdrawals, return flows, brine disposal, and 

water reuse must be predicted to understand the hydrology of 

systems reliant on water reuse and alternative water sources.

Strategic Action 18.—Develop and apply methods to 

quantify the potential for expanded future use of alternative 

water sources (saline water, marginal water, and reused water, 

among others).

Prediction in Earth Science

Prediction has been an aim of earth science since 

its inception and was clearly identified as important 

for both developing understanding and anticipating 

system behavior. In discussing the role of prediction 

in earth science, Kleinhans and others (2010) note, 

“In his System of the Earth, James Hutton 

(1785), one of the founding fathers of earth 

science, proposed ‘to examine the appearances of the earth, in order to be informed 

of operations which have been transacted 

in time past. It is thus that, from principles 

of natural philosophy, we may arrive at 

some knowledge of the order and system in 

the economy of this globe, and may form a 

rational opinion with regard to the course 

of nature, or to events which are in time to 

happen.’”

Drought conditions on the Blacks Fork near Little America, 

Wyoming, September 2007. Photograph by Jerrod Wheeler, 

USGS.
34 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

Goal 4: Anticipate and Respond to WaterRelated Emergencies and Conflicts

Water-related emergencies and conflicts exact a costly 

toll on the Nation. Water-related emergencies are commonly 

caused by extreme events, such as floods and droughts, and 

can exacerbate underlying conflicts stemming from water 

competition. Managers and policymakers need science-based 

information and tools to anticipate and respond to waterrelated emergencies and conflicts. In doing so, the vulnerability of communities and ecosystems to extreme hydrologic 

events can be reduced. From the introduction to this document, the relevant major societal questions are as follows:

• How much water does our society need for the future, 

and is that amount sustainable?

• How can we protect our water supply, both quantity 

and quality, for the future?

• What can the past tell us about the future of water 

availability? Can human effects be clearly distinguished from natural variability? Can critical thresholds or “tipping points” be recognized or predicted? 

• What new tools will be needed to improve assessment, 

understanding, and prediction of water availability in 

the future?

• What principles should guide optimization of water 

availability for multiple uses (that is, drinking water, 

ecosystems, agriculture/energy/industry) and how 

should water management adapt to changing conditions?

The foregoing are augmented by these questions:

• What are the potential water-related emergencies and 

conflicts that society may face in the next 10 years?

• What scientific information and data are needed to 

better anticipate and respond to the impacts of waterrelated emergencies on humans and ecosystems?

• What important hydrologic trends have implications 

for the occurrence of water-related emergencies, and 

what are their causes? 

• How can we use these identified trends to prepare for 

future water-related emergencies?

• What gaps in scientific understanding and data need 

to be filled to help water managers and policymakers 

reduce the vulnerability of communities and ecosystems to water-related emergencies and conflicts? 

• How can water-related hazards be prevented or mitigated? 

• How can we protect our water supply, both quantity 

and quality, for the future?

USGS scientists should use unanticipated events as 

research opportunities. We need to be prepared to exploit 

sudden extremes (floods, spills, dam failure or removal) or 

longer-term disturbances (biofuel expansion, water storage 

or diversion projects, remediation projects, CO2

 sequestration, natural gas exploitation) to gain new insights about basic 

processes. This should be in addition to emergency response 

actions aimed at minimizing danger or damage.

Objective 1: Identification of Current and Future 

Threats to Communities from Water-Related 

Hazards

To become more resilient to water-related hazards, communities need to identify their potential exposure to those 

hazards to devote appropriate resources to hazard planning, 

mitigation, response, and recovery. The USGS can provide 

resources and tools that identify current and future hydrological hazards to communities, including riverine and coastal 

flooding, riverine and coastal erosion hazards, droughts, mud 

and debris flows, lahars, and dam and levee breaches (including intentional breaches through acts of terrorism). Those 

resources and tools should include the following:

• Studies of near-term and long-term trends in droughts 

and floods using historical hydrologic monitoringnetwork data and paleorecords, such as sediment cores 

in riverine slack-water areas, coastal areas, and lakes. 

Where possible, these studies should extrapolate trends 

to assist communities with hazard risk analysis.

• Studies to analyze floodplain dynamics, such as the 

effect of soil type on flood response, velocity distributions, and depth distributions.

• Pilot projects designed to examine the flood and 

drought response of geologically complex areas, such 

as karstic areas. These studies could be combined with 

water-quality monitoring to understand the potential 

pathways of toxins and impact of those toxins on water 

resources in these areas.

• Studies of causes and dynamics of debris flows in a 

variety of settings and lahars in volcano hazard areas.

• Studies of the processes associated with riverine and 

coastal erosion that would allow communities to identify areas of high potential erosion. 

• Studies of the impacts of sea-level rise on coastal communities and ecosystems.
Water Science Goals and Objectives 35

• Geospatial products, developed in collaboration with 

partners such as FEMA, that identify all potential 

hydrologic hazards areas that a community might 

be exposed to and that convey information that is 

understandable to users such as community planners, 

emergency managers, and first responders.

Strategic Action 19.—Develop scientific data, information, and analyses to help communities understand their exposure to extreme hydrologic events.

Objective 2: Development and Deployment 

of Observational Systems for Identifying 

and Tracking Hydrologic Hazards, Making 

Operational Decisions During Extreme 

Hydrologic Events, and Providing Data for 

Recovery

The USGS operates a large earth observation network 

that includes hydrologic monitoring stations used extensively 

to monitor extreme hydrologic events such as large floods. 

Building on its observational capabilities, the USGS should 

become a national leader in permanent and short-term hydrologic observation networks that provide (1) real-time data for 

emergency response during events such as floods and coastal 

storm surge and (2) data for science-based disaster recovery 

actions. This national observation networks program should 

develop new sensor and telemetry technologies to better monitor conditions that can lead to water-related emergencies and 

should lead to the installation of monitoring stations that can 

provide data for multiple hazards. 

Strategic Action 20.—Develop new sensor and telemetry 

technologies to better detect conditions that can lead to waterrelated emergencies, and install monitoring stations that can 

provide data for multiple hazards.

This national observation networks program should 

include the identification of data gaps in geographic coverage 

and observed parameters and installation of new observation 

stations and development of methods for synthesizing needed 

data in unobserved areas (such as developing streamflow 

statistics for streams that are not monitored by streamgages). 

Additionally, existing science-based tools should be enhanced 

and combined with new tools that use observation network 

data to assist communities with hazard planning, response, and 

recovery, such as 

• Flood-inundation mapping linked to USGS 

streamgages and National Weather Service (NWS) 

flood-forecast points, as detailed in the Priority Actions 

section of this report (fig. 12); 

• Alert/warning systems linked to USGS hydrologic 

observation networks (such as WaterAlert) that provide 

automated data and information alerts to users in 

response to observed conditions; 

• Science-based tools to assist the NWS in improving 

flash flood warnings and flood forecasts for small 

drainage basins; and

• Web-based tools based on hydrologic data from 

observation networks, such as the existing USGS 

WaterWatch and StreamSTATS programs, that provide 

hydrologic information usable for planning, response, 

recovery, and mitigation in regards to hydrologic 

hazards.

Strategic Action 21.—Develop new science-based tools 

and enhance existing tools, such as flood-inundation mapping, 

that use observation-network data to assist communities with 

hazard planning, response, and recovery.

Figure 12. Example of flood inundation map.

Objective 3: Through an Understanding of 

the Conditions Leading to Water Shortages 

that Result in Conflicts, Provide Assistance to 

Communities in Finding Science-Based Solutions 

When Conflicts Occur

Water shortages can be caused by drought, by damage to 

infrastructure from floods or geological hazards such as earthquakes, by impairment of the quality of water supplies, and 

by imbalances between groundwater recharge and pumping. 

Periods of water shortage leading to conflict can be characterized by antecedent hydrologic and climatic conditions, as well 

as spatial and temporal patterns of water use. Vulnerability of 

water-supply infrastructure to floods and geological hazards 

also can be identified in advance. Application of groundwaterflow models can identify conditions that lead to undesirable 

lowering of groundwater levels and groundwater withdrawals 

in excess of recharge (commonly referred to as “groundwater 
36 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

mining”), making it is possible for resource managers to 

develop science-based preparedness and response plans for 

water shortages, and thus avoid conflicts. Specifically, the 

USGS—through participation in multidisciplinary, multiagency activities like the National Integrated Drought Information System (NIDIS)—can assist Federal, State, Tribal, and 

local resource managers in developing drought preparedness 

and response plans that are well informed by USGS observations and analyses of hydroclimatic processes. These plans can 

provide a scientific basis for triggers and thresholds in drought 

plans that incorporate USGS surface-water, groundwater, and 

remote-sensing observations and can help identify threshold 

values of streamflow or groundwater levels below which water 

infrastructure will not function or ecosystems are damaged. 

Strategic Action 22.—Provide resources such as observations, analyses of hydroclimatic processes, and analyses of 

vulnerabilities in water-supply systems that allow resource 

managers to develop preparedness and response plans for 

water shortages because of imbalances between groundwater 

recharge and pumping, drought, and infrastructure damage 

from flooding or geological hazards.

The USGS can provide resources and expertise in water 

measurement and analyses to assist water providers and 

resource managers in making decisions during water shortages. For example, USGS Landsat imagery can be used to 

document historical and current rates of fallowing of cropland, 

a key impact of water shortage on irrigated agriculture in the 

West, to guide decisionmaking with respect to requests for 

local water transfers, county drought disaster designations, or 

State emergency proclamations. During extreme and prolonged water shortages, USGS expertise can help water providers and resource managers identify short-term sources of 

water supply and evaluate alternatives for water conservation.

Strategic Action 23.—Provide scientific expertise to assist 

water providers in making decisions regarding disaster/emergency declarations, water conservation, water transfers, alternative water supplies, and water conservation during extreme 

or prolonged water shortages.

Objective 4: Providing Tools that Allow Managers 

to Detect and Respond to Emergencies Related 

to Water-Quality Degradation of All Kinds—

Natural, Accidental, and Intentional

An emergency related to water-quality degradation 

could be natural, such as a toxic algal bloom; accidental, 

such as a large oil spill in a river; or intentional, such as the 

introduction of a known toxin into a public water supply (for 

example, acts of terrorism). The USGS should assist waterresource managers by developing research tools that provide 

an understanding of how water-quality degradation from all 

types of sources can affect water supplies. The USGS also 

should provide (1) enhanced hydrologic monitoring systems 

that allow managers to detect and provide alerts for intentionally or accidentally introduced hazardous substances in surface 

water and groundwater and (2) enhanced hazardous-substance 

spill-tracking tools, such as time-of-travel tools for spills in 

streams. Development of these types of tools will require an 

understanding of the occurrence and movement of substances 

that can adversely affect the water supply and the potential 

threat of those substances to human health and ecosystems.

Strategic Action 24.—Develop tools that provide an 

understanding of how water-quality degradation can affect 

water supplies and allow managers to detect and respond to 

emergencies involving water-quality degradation.

USGS Mississippi Water Science Center scientists collected 

a bulk sediment sample at Pascagoula Beach, Pascagoula, 

Mississippi, October 10, 2010, in response to the 2010 Deepwater 

Horizon oil spill in the Gulf of Mexico. Photograph by Shane 

Stocks, USGS.
Highlight

Water Science Goals and Objectives 37

Kalamazoo River Oil Spill and Flood

In July 2010 a crude oil pipeline ruptured, spilling more than 800,000 gallons of crude oil 

into Talmadge Creek, a tributary of the Kalamazoo River near Marshall, Michigan. The 

effects of the spill were exacerbated by high streamflows that moved the oil downstream 

quickly and distributed it out onto the flood plain (fig. 13). Digital flood-inundation maps 

for a 15-mile reach of the Kalamazoo River from Marshall to Battle Creek, Michigan, were 

created by the U.S. Geological Survey (USGS) in cooperation with the U.S. Environmental 

Protection Agency to help guide remediation efforts after the spill (fig. 13B). Streamflow 

data recorded at USGS streamgages in Marshall and Battle Creek, Michigan, were used 

in conjunction with field measurements of river channel geometry to develop a hydraulic 

model of the river. The model was used to construct flood-inundation maps for the stream 

conditions at the time of the oil spill and to estimate the extent of inundation of the floodplain with a 10-, 4-, 2-, 1- and 0.2-percent probability of occurrence. These maps assisted 

in identifying areas that were affected by oil, as well as areas that may be affected by 

future flood events (Hoard and others, 2011).

Figure 13. A, A tributary 

of the Kalamazoo River 

near Marshall, Michigan, 

July 2010. B, Floodinundation map for a 

15-mile reach of the 

Kalamazoo River from 

Marshall to Battle Creek, 

Michigan, July 2010.

Lake Michigan near 

Sheboygan, Wisconsin, 

July 2009. Photograph by 

Gael Kurath, USGS.
38 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

Goal 5: Deliver Timely Hydrologic Data, 

Analyses, and Decision-Support Tools 

Seamlessly Across the Nation to Support WaterResource Decisions

For each goal discussed in this report, scientific objectives and strategies have been proposed to meet the goal. 

These strategies consist of products and actions focusing on 

the specific scientific capabilities of the USGS to understand 

major components of the water cycle. This final goal supports the previous four by developing strategies to effectively 

deliver scientific information and data to those who would use 

it to answer the major questions for each goal. For delivery of 

timely data, scientific analyses and results, and decision-support tools, the concept of interoperability becomes extremely 

important. Interoperability means that tools and data can be 

shared easily within and outside of the USGS and that those 

tools and data are delivered in user-friendly formats that are 

as universal and broadbased as possible. By making technologies such as scientific databases, Web services, and data from 

earth observation networks interoperable within the USGS 

and with USGS partners, information can be conveyed much 

more efficiently to users. Another critical feature of delivery of 

USGS water-science data, analyses, and tools is that they must 

be understandable to the people who will use them to make 

important decisions in regards to water resources. The USGS 

must, therefore, include social scientists to ensure that science 

products and information are understood and used to solve the 

problems discussed so far.

The USGS will continue to develop comprehensive 

Web- and applications-based data delivery, models, and 

decision-support systems to advance approaches to communicate hydrologic science. By leading the Nation in delivering 

hydrologic data, the USGS can strengthen partnerships nationally and internationally.

The relevant questions are the following:

• What is the future of hydrologic data delivery?

• What products and delivery systems are needed to 

serve integrated data?

• How can the USGS take advantage of visualization 

techniques for science research and develop it for communication tools for decisionmakers, policymakers, 

and the public?

• What products and tools are needed to integrate USGS 

water science with our partner organizations?

Objective: Development of New, Integrated 

Information Dissemination in Formats 

Appropriate for the 21st Century to Aid Scientists 

and Decisionmakers

New integrated technologies need to be developed for 

dissemination of information, such as delivering data through 

the World Wide Web by way of real-time and smart-phone 

applications, expanded map-based search capabilities, integrated database warehouses, 3-D and 4-D visualization products, and dynamic model archives. This objective includes the 

development of interoperable decision-support systems that 

connect with earth observation networks across the disciplines.

The future of delivering timely and useful hydrologic 

data lies in using Web- and applications-based systems to 

support short-term decisions and long-term planning. Data 

[not just real-time data, but historical data contained in the 

Instantaneous Data Archive (IDA) and the National Water 

Information System (NWIS)] need to be integrated to maximize their usefulness in various science activities and need 

to be seamless across the Nation for consistency purposes. 

In the next 5 to 10 years, all databases related to hydrologic 

information from all science centers should have national 

search and display formats and be served from a single data 

warehouse. Users of USGS information need to be able to find 

the data they need rapidly and easily without intensive searching. Multiple search functions that anticipate the way users 

locate data should be available. For example, users should be 

able to retrieve USGS data spatially by searching a specific 

location or region on a map or image. In other instances, users 

may need to search on specific timeframes. We also may find 

that it is important to link hydrologic data from other Federal 

agencies, such as the U.S. Environmental Protection Agency, 

Department of Energy, National Oceanic and Atmospheric 

Administration, and environmental health agencies. In the 

short term, the USGS should work with these agencies to integrate our data, ensure cyber security, and define “ownership.” 

Strategic Action 25.—Ensure that a wide variety of 

hydrologic information is obtainable through map interfaces 

available on the Web that allow the user to geospatially search, 

locate, and link hydrologic parameters, access historical 

information and conduct trend analyses, and construct wateravailability analysis tools, such as water budgets.

Over the last decade, the use of conceptual, digital, analytical, and statistical models has increased to help scientists 

and others understand complex earth systems. Although these 

various models were developed for a specific purpose, they 

often have value into the future as integrated aspects of larger 
Highlight

A

B

Water Science Goals and Objectives 39

Figure 14. A, Screenshot showing real-time data collected 

from the U.S. Geological Survey streamgage on the Potomac 

River at Point of Rocks, Maryland (1410000002), and 

B, photograph of the streamgage.

models related to the water cycle. In an effort to maximize the use of these models, the USGS should construct a model “clearinghouse” where dynamic models 

can be built upon by others and archived for future use. 

The USGS Office of Groundwater within the Water Mission Area already supports groundwater model software 

and serves it publicly by way of the Web. A future model 

clearinghouse should include not only groundwater 

models but also surface-water and water-quality models. 

The USGS Science Strategy (U.S. Geological Survey, 

2007) calls for refinement of existing groundwater 

and watershed models and development of new ones. 

Models will be used to understand earth science systems 

interactions, to describe and calculate uncertainty, and 

to predict changes in the water cycle from short-term 

emergencies (that is, floods) to long-range effects (that 

is, climate change and droughts).

A variety of 3-D and 4-D visualization and interactive products and techniques will be needed to support 

integrated science, communicate science results to decisionmakers and policymakers, and educate the public on 

how the water cycle affects their lives and environment. 

Pilot projects in the USGS have shown that 3-D immersion technology can bring scientists of different disciplines together to better view, discuss, and understand 

integrated earth systems. The scientific results from the 

models can then be visualized to show decisionmakers 

and policymakers how the groundwater system works 

and how resource-management decisions can affect the 

aquifer, humans, and the natural environment over time. 

In addition, these visualizations can be used to educate 

the public by running simplified models over time to 

show how human activities can affect the environment.

Improvement will be needed in integration of 

databases related to water use that exist outside of 

the USGS, such as the use of modeling and statistical 

designs in water-use estimation; improving the geospatial information on site-specific water-use features; 

consumptive-use estimation; quantifying and locating 

interbasin transfers; and linking water-use information 

with water budgets, watershed and aquifer analyses, and 

StreamSTATS. 

Strategic Action 26.—Provide timely hydrologic 

data and develop dynamic integrated models and visualization products in formats appropriate for the 21st 

century that enhance water science, educate the public, 

and communicate to policymakers. 

In 2010, the USGS launched WaterAlert, a Webbased application that notifies subscribers by way 

USGS WaterAlert

The U.S. Geological Survey WaterAlert Service (http://

water.usgs.gov/wateralert) allows subscribers to 

receive updates at any of the sites where the USGS 

collects real-time water information (fig. 14A). Realtime data from USGS streamgages are transmitted 

by way of satellite or other telemetry to USGS offices 

at various intervals, usually once every 1 to 4 hours. 

Emergency transmissions—for example, during floods 

(fig. 14B)—may occur at more frequent intervals. The 

WaterAlert system sends notifications or updates to 

subscribers either daily or hourly by way of text message or email when the current conditions at a given 

site reach or surpass user-definable thresholds. The 

development and maintenance of the WaterAlert system is supported by the USGS and its partners, including numerous Federal, State, and local agencies.
40 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

Morning on the South Toe River 

near Celo, North Carolina (USGS 

streamgage 03463300), October 1, 

2009. Photograph by John A. 

Mazurek, USGS.

of email or text message when certain parameters (such as 

streamflow, gage height, groundwater level, water-quality 

parameters, or precipitation) measured by USGS real-time 

data-collection stations exceed user-definable thresholds. In 

addition, the USGS is launching FIMI (Flood-inundation 

Mapping Initiative), which is a map interface product that 

integrates USGS data and analysis with the National Weather 

Service forecasts and U.S. Army Corps of Engineers (USACE) 

operations to predict flood inundation at various locations 

around the country. USGS data also are used to support the 

National Weather Service AHPS (Advanced Hydrologic Prediction Service), as well as USACE river operations. Working 

with partner agencies such as FEMA, USACE, and NOAA, 

the USGS should develop geospatial tools that will help communities identify their vulnerabilities to multiple hazards that 

could cause water-related emergencies and conflicts in the 

next 10 years and beyond. Decision-support tools in development for applications in regional land-use management for 

water quality include a Web-based application of the SPARROW model for estimating nutrient export loads in streams 

and rivers based on watershed characteristics and loadings. 

Others could include stream transport models for predicting 

migration of chemical or biological hazards introduced into 

moving waters. Tools such as these could be developed in 

concert with risk-analysis tools so that communities can assess 

their risk from identified hazards. Furthermore, applications 

such as these should provide a community with information on 

vulnerability to hazards such as floods, droughts, earthquakes, 

high-hazard dams, hazardous-material spills, and degradation 

of the quality of water. Ideally, these tools should leverage 

existing resources such as FEMA’s RiskMAP program and the 

USGS Hazards Gateway and the Integrated Water Resources 

Science and Services (IWRSS) initiative. 

Strategic Action 27.—Develop decision-support systems 

to aid resource managers and policymakers.
Communicating Science to Society: Inform—Involve—Educate 41

USGS hydrologist is interviewed by media in downtown Minot, 

North Dakota, as the Souris River flooded during the summer of 

2011. Photograph by Dave Ozman, USGS.

Communicating Science to Society: Inform—Involve—Educate

Providing water data and information is and has always 

been a vital service to customers, stakeholders, partners, Tribal 

nations, academia, and the general public. Communicating the 

data and information in language and formats that are relevant 

to specific users is a challenge that our scientists and technicians have not shied away from, and many accessible datadelivery tools, methods, and approaches are available. 

Interpreting these streams of data into “common language” and explaining their meaning in appropriate contexts 

for greater understanding and application by the public serve 

to bring water science to the forefront of public discourse 

about water quality and availability. Informing the public also 

instills broader understanding of water as an essential resource 

for humans and other living species, for environmental health, 

and for economic prosperity, as well as a potential hazard by 

way of droughts, floods, icing, debris flow, and contaminant 

transport. 

Local Communication and Outreach

Communicating water-science information to the Department of the Interior and the Executive Branch, Congressional 

members and staffs, State governments, local resource managers, countless partners and stakeholders, the media, and private 

citizens is now and will continue to be a high priority within 

the Water Mission Area. An array of communication channels, methods, media, and technology will be used to convey 

water data and information to diverse audiences to ensure that 

reliable water data and information are timely, easily accessed, 

useful, and usable within and outside the USGS. 

USGS Water Science Centers (WSCs) are in an ideal 

position to communicate water-related news and information 

to local populations, the ones most receptive to what is going 

on in their local areas. Each WSC should have a full-time 

or part-time staff member dedicated to communication and 

outreach and working in conjunction with their respective 

Office of Communications and Publishing contacts. A robust 

water-science information system will become increasingly 

critical as the Nation steps up to challenges brought about by 

increased population and industrial demands; energy challenges; ecosystem impacts; health and safety threats from 

floods, drought, and contaminant transport; and other issues. 

Delivering local water science and technology information 

to the public through local news outlets can be important not 

only to increase the public’s understanding of water science 

but also to inform the public about the work the WSC performs on behalf of the State’s citizens. The need and value 

of water research and data gathering are most apparent and 

appreciated when understood within a familiar environment.

Social Media

In response to a 2009 Executive Order, use of social 

media in the U.S. Department of the Interior and the USGS 

has increased significantly and has proven to be a powerful 

tool for reaching wide and varied audiences. Many WSCs 

have begun to use social media to their advantage in communicating studies and findings in their respective States to 

educate and inform their local populations, particularly during 

water-hazard events. Social media appeal to citizens who are 

becoming more technically savvy and attuned to receiving 

immediate information, as well as to the scientist, partneragency official, academic, or resource manager interested in 

quantifiable, scientifically sound information. 

The USGS Office of Communications and Publishing’s 

protocols, based on the Department of the Interior Social 

Media Policy, will be applied, as appropriate, at local, State, 

and national levels. A comprehensive, well-defined strategy 

for social media, incorporating local, State, and national elements will be developed as part of a coordinated communication strategy addressing a variety of goals, audiences, and 

media for use by WSCs, technical offices, and Cooperative 

Water Programs to bring water-science information to the 

attention of users and the general public.

Integrating Resources

The Associate Director for Water, the Associate Director for Core Science Systems, and the Director of the Office 

of Communications and Publishing will maintain a practice 

of supporting comprehensive and evolutionary communication and data transmission planning and delivery. By leveraging and coordinating resources and expertise, as needed, the 

valuable and often life-saving data, information, and products 

of the Water Mission Area will continue to be available to 

employees, the Department of the Interior, Congress, stakeholders, cooperators and partners, the general public, and any 

entity to whom the information serves a vital purpose.
42 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

Crosscutting Science with Other USGS Mission Areas

The success of the USGS strategy of integrated science 

depends on deliberate interfaces between all Mission Areas. 

The following are recognized linkages between the Water 

Mission Area and the other Science Mission Areas within the 

USGS.

Climate and Land Use Change

To address 21st century water-resources issues, as well 

as to better understand and predict 21st century climate and 

land-use changes and their eventual impacts, the Climate and 

Land Use Change Strategic Plan incorporates water-resource 

linkages including dedicating one of its seven scientific goals 

to water, Goal 5. The water cycle and climate are intimately 

linked. USGS expertise and tools are well suited to understand 

and predict impacts of climate and land-use change on water 

resources, and contribute to integrated resource management 

to ensure available water for human activities and protection 

along with balancing ecosystem flows. The following crosscutting efforts must be well coordinated between the Climate 

and Land Use Change and Water Mission Areas of the USGS:

• The National Water (Availability) Census has recognized that its methods and findings will need to accommodate and address the potential influences of climate 

changes and variations in the 21st century in designing 

and interpreting its investigations and findings. Much 

of the Water Census plans are already focused on the 

historical and future roles that land-use changes play 

in determining water demands, water uses, and overall 

resource availability. Similarly, the Water Census will 

be the most up-to-date and complete available data and 

interpretive framework for assessing potential impacts 

of climate and land-use change.

• As the effects of land-use and climate changes become 

increasingly important to the Nation’s water resources, 

existing and planned monitoring networks that address 

a variety of water-resources management needs should 

be reevaluated where possible to ensure that they 

remain well suited and configured for their historical 

uses, as well as for (and in) the changing landscapes 

that they attempt to characterize. Where possible, additional monitoring may be required to detect and characterize climate-induced hydrologic and geochemical 

changes even more quickly and with greater precision 

than may be possible with some existing components 

of USGS monitoring programs. 

• Extreme hydrologic events, including floods and 

droughts, are expected to play critical roles in initiating and directing many expected landscape, hydrologic 

and biospheric responses to climate and land-use 

changes in the 21st century. Thus, the Climate and 

Land Use Change strategy calls for a national-scale 

assessment of the potential impacts of climate change 

on future probabilities of floods and droughts. Such an 

assessment will be successful only if the Climate and 

Land Use Change and Water Mission Areas coordinate 

closely on the underlying science and eventual assessment reports. 

• The Climate and Land Use Change strategy recommends a national assessment of historical and projected 

climate-change impacts on water quality. The National 

Water-Quality Assessment (NAWQA) Program, now 

entering into its third decade of observations and 

research, has produced many important products 

linking land uses and water quality across the Nation. 

Future NAWQA activities will continue to rely heavily 

on land-use science. Also, NAWQA may be expected 

to begin addressing the likely effects of climate 

changes on the Nation’s water quality. 

• The Water and Climate and Land Use strategies include 

actions for developing decision-support tools, data 

resources and models to understand resources and predict the future. With these two Mission Areas collaborating, the USGS can develop hydrologic projections 

and provide important information for scenario-based 

assessments for water-resource management and better 

understand model uncertainty. Integrated models of 

climate and land-use change and the water cycle can 

help in the understanding of streamflows, sediment 

transport, aquatic habitats, and ecosystems.

Core Science Systems

Use of a wide range of process simulation modeling tools 

is needed to achieve USGS goals for quantification, understanding, and prediction of water availability, emergencies, 

and conflicts. Such tools demand substantial data resources 

as inputs, often putting a large burden on researchers to find, 

access, and manage the diverse datasets they need to even 

begin an investigation. Communicating the results of these 

investigations can be equally challenging. The Core Science 

Systems Mission Area is well-positioned to provide valuable 

support and assistance with these problems in a partnership 

with the Water Mission Area. By building critical spatial data 

infrastructure, and facilitating the access, exploitation, and 

visualization of large earth science datasets, Core Science 

Systems can help increase the productivity of water-science 

researchers, including potential breakthroughs that would otherwise be impossible because of limited capacity for computation and data management.

Assessment of hydrologic information requires interdisciplinary science to integrate hydrologic data with information 
Crosscutting Science with Other USGS Mission Areas 43

that describes or explains the associated hydrologic processes 

through time. The descriptive information can include land 

cover, land use, water use, geology, ecology, biologic distributions, climate, population and other socioeconomic information. The Core Science Systems Mission Area can help 

the Water Mission Area to integrate information that helps 

describe the hydrology and the various factors that influence it. Core Science Systems provides much of the descriptive information, through its various geospatial databases, 

needed to undertake this level of analysis. The understanding 

of water availability requires specific knowledge of boundary conditions that includes the geologic, topographic, and 

biologic frameworks of a water system. Geologic mapping and 

3-D/4-D modeling of these systems provide critical information on surface and subsurface geologic properties, including 

the stratigraphy, fault structures, and associated rock properties, such as porosity and permeability. In addition, the Earth’s 

surface can be considered a boundary for water systems and 

the use of digital elevation models, LiDAR, topographic maps, 

and remote sensing provide interdisciplinary opportunities 

with Core Science Systems. This Mission Area is critical for 

hydrologic analysis as it is the primary developer and planner for foundational datasets, like the National Hydrography 

Dataset (NHD) and the National Groundwater Monitoring 

Network Dataset. Another area of collaboration for Core Science Systems and Water Mission Areas is in the integration 

and serving of data important to the public and decisionmakers. Core Science Systems and Water Mission Area science 

strategic plans emphasize the integration of observation 

networks, integration of databases, and the use of visualization 

techniques to understand earth processes. These two mission 

areas are capable of coordinating in the following ways:

• Understanding geologic controls on groundwater, surface water, and water quality; understanding geomorphic changes associated with land-use change; integrating the paleoclimatic record with hydrologic studies; 

and identifying the role geology plays in assessing and 

mitigating hydrologic risks (karst terrains, hydroseismicity, subsidence).

• Developing analytic, visualization and modeling techniques for water science and using them as a research 

and communication tool to address societal challenges.

• Collecting and maintaining high-quality data that span 

a wide range of spatial and temporal scales, followed 

by integrating the resulting databases for effective 

water science.

• Developing new technologies for organizing, understanding, characterizing, synthesizing, and delivering 

water information (for example, smart-phone applications) and improving Web-conferencing capabilities.

• Structuring effective information security, proprietary 

information, and privacy limitations for data acquisition and dissemination.

• Development of the NHD and similar water datasets 

and expanding their use in the understanding of the 

natural hydrology and the linkage of human water use 

to the natural system.

Ecosystems

The Water and Ecosystem Mission Areas have many 

crosscutting themes and have the potential for extensive multidisciplinary research. In particular, Goal 2 of the Ecosystem 

Science Strategy report, “Advance understanding of how drivers influence ecosystem change” requires data, understanding, 

and analysis regarding changes in hydrology that may drive 

changes in ecosystems. This goal integrates with the first three 

goals of the Water Mission Area: “Advance hydrologic monitoring networks and techniques,” “Advance understanding 

of processes that determine water availability,” and “Predict 

changes in the quantity and quality of water resources in 

response to changing climate, population, land use, and management scenarios.” In addition, major challenges identified 

by the Ecosystem Mission Area including developing tools, 

technologies, and capacities to inform decisionmaking also 

are shared with the Water Mission Area. Integrated work to 

address these challenges by both Mission Areas will produce 

powerful results that are relevant across the Bureau. 

Priority actions proposed by both Mission Areas highlight 

the crosscutting activities. The Water Mission Area report 

proposes “Advance ecological flow science” as a priority 

action and the Ecosystems Mission Area, within Strategic 

Priority 2—Promote the use of interdisciplinary ecosystem 

science—proposes a priority action to “evaluate ecological 

responses to hydrologic alteration.” The Water Mission Area 

also proposes the development of rapid deployment teams for 

water-related emergencies. This priority action corresponds 

well with the Ecosystems Mission Area proposed action to 

respond rapidly to environmental disasters with ecosystem 

science. These pairs of priority actions could be pursued in 

concert between the Mission Areas. This work would result in 

a more comprehensive understanding of the changes in water 

resources and needs in response to various drivers and the 

attendant impact of these changes on ecosystems, and would 

formalize the response of USGS to emergencies to provide 

needed science on which to base decisions. 

Other areas of research that would increase our understanding of the linkages between ecosystem science and water 

resources include the following:

• Science that examines the effects of water contamination and pollution on the functioning of ecosystems.

• Science that improves our understanding of adaptation 

strategies to assist in the conservation of plants and 

animals in ecosystems that experience change in water 

supplies in response to climate variability. 

• Science that supports the ability to restore and conserve 

aquatic ecosystems.
44 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

• Science to understand how drought, flood, and fire 

influence hydrology and ecosystem stability.

Energy and Minerals

Water is used in every stage of the lifecycle of energy 

and mineral resources (from discovery, extraction, production, 

and use, to recycling and disposal). A holistic understanding 

of the interaction of the hydrologic cycle with the lifecycle of 

energy and minerals is therefore required for a comprehensive assessment of water resources and energy and mineral 

resources. This fact is recognized by overlapping goals and 

strategic actions in reports of the Water Mission Area and 

the Energy and Minerals Mission Area. Energy and Minerals 

Goals of “Understand the environmental behavior of energy 

and mineral resources and their waste products” and “Understand the effects of energy and mineral development on natural 

resources” demand key data, analysis, and understanding that 

also are called for in the goals of the Water Mission Area. In 

particular, objectives in the Water Mission Area that overlap 

and tie into those in the Energy and Mineral Mission Area 

include “Assessment of water resources and their suitability 

to meet water-availability purposes for human use,” “Comprehensive understanding of human interactions with water availability,” and “Prediction of availability of alternative water 

sources, including saline, marginal water, and water reuse.” 

Opportunities for crosscutting activities also include 

basic research focused on processes that affect fluid pathways, 

and form a basis for understanding and forecasting the interactions between the hydrologic cycle and the lifecycle of energy 

and mineral resources. Three priority actions in the Water 

Mission Area— “development of 3-D/4-D hydrogeologic 

framework models at multiple scales,” “clarify the linkage 

between human water use and the hydrologic cycle (natural 

hydrology),” and “integrated watershed assessment, research, 

and modeling”—tie into three Energy and Minerals strategic actions, those being “develop 3D framework models to 

understand the fundamental processes of energy and mineral 

resources,” “investigate perturbations to natural landscapes,” 

and “provide information on development to large landscape 

conservation initiatives.” 

Other areas of research that link energy and minerals 

science with water science include:

• Understanding major geochemical cycles (for example, 

carbon and nitrogen). 

• Transferring insights between laboratory and fieldbased studies.

• Understanding the socioeconomic drivers for water-use 

trends.

• Predicting the consequences of major water stressors 

associated with the energy and minerals lifecycle such 

as mineral production (including mineral fuels), CO2

sequestration, biofuel production, and damming and 

undamming of surface water.

• Using the understanding the USGS has of future energy 

and mineral development to predict future stresses on 

water supplies. 

• Identifying the science intersections related to the 

water-energy-food nexus. 

• Synthesizing information on the kinds of hydrogeology (for example, karst) that may be at increased risk 

from unintended consequences of energy and mineral 

development, such as subsidence, hydroseismicity, and 

sinkhole formation.

Environmental Health Science

The distribution of natural and anthropogenic contaminants and pathogens in aquatic and terrestrial environments 

is tied to and often driven by the hydrologic cycle. Furthermore, understanding the role of the hydrologic cycle in these 

processes is critical to determining ecological and human 

exposure to these contaminants. Fundamental understanding 

of the natural and human factors that affect water quantity, 

movement, and quality is required to define various sources 

of contaminants and pathogens, to determine their persistence 

and fate in the environment, and to characterize environmental 

settings that may be more vulnerable to various environmental 

health concerns. Consideration of the many hydrologic factors that influence the health of the environment is important 

for determining the specific causes of adverse environmental health outcomes and identifying the best management 

alternatives. 

The Water and Environmental Health Mission Areas 

have many crosscutting linkages that provide the potential 

for multidisciplinary research. For example, Goal 1 of the 

Environmental Health Science Strategy report “Provide the 

science to identify, prioritize, and detect contaminants and 

pathogens of emerging environmental concern” is related to 

objectives from Goals 1, 2, and 4 of the Water Science Strategy report: “Advancement of hydrologic monitoring networks 

and techniques,” “Comprehensive understanding of human 

interactions with water availability,” “Identification of current 

and future threats to communities from water-related hazards,” and “Providing tools that allow managers to detect and 

respond to emergencies related to water-quality degradation 

of all kinds—natural, accidental, and intentional.” In addition, strategic actions related to transport, fate, and management of contaminants and pathogens in Goals 2 and 3 of the 

Environmental Health report have parallels throughout the 

Water report in monitoring, assessment, understanding, and 

prediction objectives. Responses to water-quality emergencies 

are featured in Goal 5 of the Environmental Health report and 

in Goal 4 of the Water report. Coordinated efforts to address 

these challenges by both Mission Areas will be essential for 

producing interdisciplinary and relevant results. 
Crosscutting Science with Other USGS Mission Areas 45

To achieve the most scientifically critical and relevant 

results, the Environmental Health Science Strategy will coordinate closely with the Water Science Strategy in the following 

ways:

• Participate in large quantity- and quality-assessment 

programs to make added use of national datasets in 

interpretations of environmental health issues. This 

could include understanding anthropogenic tracers that 

can be used for contaminant source-tracking and for 

hydrologic and sediment transport studies. 

• Develop new tools and methods to identify and address 

emerging environmental health concerns, including 

methods to measure emerging contaminants in the 

environment. Development could include analytical 

methods development for rare chemicals in water, 

sediment, and biota and could include approaches for 

multicomponent source tracking (environmental forensics). In addition, methods, data and models could be 

developed for detecting and responding to water-borne 

contaminant emergencies.

• Use newly developed tools and methods to make 

initial assessments of the relative priorities of various emerging contaminants with the intent to improve 

understanding of physical, chemical and biological 

processes affecting transport and fate of contaminants 

and pathogens in the hydrogeologic context.

• Make environmental health information available to 

the Water Mission Area in its implementation of systematic national monitoring and assessment activities. 

Such as coordination of monitoring activities for relating contaminant behavior with water quantity, movement and quality.

Natural Hazards

The Natural Hazards Science Strategy report describes 

broad science goals and strategic actions to help protect the 

safety, security, and economic well-being of the Nation. A 

number of the Natural Hazards Mission Area goals and actions 

are common with those of the Water Mission Area. Those 

science goals and actions that crosscut between the Natural 

Hazards and Water Mission Areas include the following:

• Conduct observations of natural hazards to improve 

fundamental understanding, assessments, warnings, 

and situational awareness, including the following:

• Expanding and enhancing monitoring networks 

(Water Mission Area Priority Action); for example, 

expanding the National Streamflow Information 

Program network of streamgages that are critical to 

flood observation and forecasting.

• Developing and deploying observation systems for 

detecting and tracking conditions leading to waterrelated emergencies, such as the rapid deployment of 

storm-surge sensors for hurricanes and tsunamis and 

rapid-deployment, noncontact water-stage sensors 

for riverine flooding.

• Advance and apply fundamental understanding of hazards to improve assessments, warnings, and situational 

awareness, including the following: 

• Studies of near-term and long-term trends in floods 

and droughts using monitoring network data and 

paleoflood studies to determine flood peaks in the 

pre-observational time period. 

• Studies of the processes associated with riverine and 

coastal erosion, and of the dynamics of debris flows 

in a variety of settings.

• Design projects to examine the flood response of 

geologically complex areas, including multidimensional models of flood processes.

• Monitor precipitation and streamflow in wildfire 

burn areas to provide warnings and scientific process 

understanding.

• Perform research to improve understanding of the 

effects of hazards on water quality.

• Assess hazards to inform decisions that minimize risk, 

including the following:

• Scientific data, information, and analyses to help 

communities understand their exposure to extreme 

hydrologic events, such as studies of the processes 

associated with riverine and coastal erosion and the 

causes and dynamics of debris flows. 

• Static flood-inundation map libraries and 

near-real-time dynamic flood-inundation mapping 

applications to meet a host of needs ranging from 

flood response and mitigation to dam- and leveebreak simulations (Water Mission Area Priority 

Action).

• Provide situational awareness to improve emergency 

response, inform the public, and minimize societal 

disruption, including the following:

• Development of new and enhancement of existing 

alert/warning systems linked to USGS hydrologic 

monitoring networks (such as WaterAlert) that provide automated data and information alerts to users 

in response to observed conditions.

• “Rapid deployment teams” consisting of USGS 

experts that would interface with local responders to 

ensure the Bureau responds properly to water-related 

emergencies and conflicts (Water Mission Area 

Priority Action).
46 USGS Water Science Strategy—Observing, Understanding, Predicting, and Delivering Water Science to the Nation

Acknowledgments

The authors would like to recognize the contributions 

of James R. Douglas for the preparation of the water cycle 

diagram (fig. 8) and Susan Wells for her input in communications. The report was improved by reviews from Mark T. 

Anderson and Francis H. Chapelle.

Cascades on Granite Creek, Wyoming, October 2006.

Photograph by Melanie L. Clark, USGS.
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