A Practical Framework for 

River-Quality Assessment 

By David A. Rickert and Walter G. Hines 

RIVER-QUALITY ASSESSMENT OF THE WlllAMETTE RIVER BASIN, OREGON 

G E 0 l 0 G I CAl 5 U R V E Y CIRCUlAR 715-A 

1975 
First printing 1975 

Second printing 1980 

United States Department of the Interior 

Geological Survey 

V. E. McKelvey, Director 

Library of Congress Cataloging in Publication Data 

Rickert, David A. 1940-

A practical framework for river-quality assessment. (River-quality assessment of the Willamette 

River Basin, Oregon) 

(Geological Survey Circular 715-A) 

Bibliography: p. A16-A17. 

Supt. of Docs. No.: I 19.4/2:715-A 

1. Water quality management. I. Hines, Walter G., joint author. II. Title. III. Series. IV. Series: 

United States Geological Survey Circular 715-A. 

QE75.C5 no. 715-A [TD365) 557.3'08s [333.9'162] 75-619203 

Free on application to the U.S. Geological Survey, Notional Center, Reston, Va. 22092 
FOREWORD 

The American public has identified the enhancement and protection of river 

quality as an important national goal, and recent laws have given this commitment considerable force. As a consequence, a considerable investment has been 

made in the past few years to improve the quality of the Nation's rivers. Further 

improvements will require substantial expenditures and the consumption of 

large amounts of energy. For these reasons, it is important that alternative 

plans for river-quality management be scientifically assessed in terms of their 

relative ability to produce environmental benefits. To aid this endeavor, this 

circular series presents a case history of an intensive river-quality assessment 

in the Willamette River basin, Oregon. 

The series examines approaches to and results of critical aspects of riverquality assessment. The first several circulars describe approaches for providing 

technically sound, timely information for river-basin planning and management. Specific topics include practical approaches to mathematical modeling, 

analysis of river hydrology, analysis of earth resources-river quality relations, 

and development of data-collection programs for assessing specific problems. 

TI?-e later circulars describe the application of approaches to existing or potential 

river-quality problems in the Willamette River basin. Specific topics include 

maintenance of high-level dissolved oxygen in the river, effects of reservoir 

release patterns on downstream river quality, algal growth potential, distribution of toxic metals, and the significance of erosion potential to proposed future 

land and water uses. 

Each circular is the product of a study devoted to developing resource information for general use. The circulars are written to be informative and useful to 

informed laymen, resource planners, and resource scientists. This design stems 

from the recognition that the ultimate success of river-quality assessment 

depends on the clarity and utility of approaches and results as well as their basic 

scientific validity. 

Individual circulars will be published in an alphabetical sequence in the 

Geological Survey Circular 715 series entitled uRiver-Quality Assessement of 

the Willamette River Basin, Oregon." 

J.S. Cragwall, Jr. 

C hie{ Hydrologist 

III 
Cover: WillameHe River as it winds through Portland, Oregon. Photograph talcen by 

Hugh Aclcroyd. 
CONTENTS 

Page Page 

Foreword ------------------------------------------- III Elements of river-quality assessment- Continued 

Abstract _______________________ ----------- ______ ---- A1 Analysis of river hydrology________________________ 6 

Introduction---- _________________ --------------------- 1 Selection of assessment methods _ _ ______ _________ __ 7 

River-quality assessment__________________________ 1 Identification, collection, and collation of required 

data ------------------------------------------ 10 

Data analysis, method formulation, and the testing of 

Background _ _ _ _ _ _ _ ___ _ _ ____ _ _ __ __ _ _ ___ _ _ ___ _ _ _ __ _ _ _ __ 2 

Interrelation of river-quality assessment and river-basin 

planning ------------------------------------------ 3 

Communication: A key factor in interdisciplinary assesspredictive capability---------------------------- 12 

ment and planning --------------------------------

Elements ofriver-quality assessment ------------------

Overview ---------------------------------------- Delineation of river-quality problems ________ -----. 

Forecasting impacts of planning alternatives ______ 12 

4 Communication of results ------------------------ 13 

5 Program evaluation ------------------------------ 16 

5 Summary and discussion------------------------------ 16 

5 References cited-------------------------------------- 17 

ILLUSTRATIONS 

Page 

FIGURE 1. Schematic showing the interrelation of river-quality assessment and river-basin planning ___________________ A3 

2. Diagram representing the Willamette River, Oreg., showing distinctive hydrologic reaches and elevation profile 8 

3. Diagram showing relative difficulty of applied modeling__________________________________________________ 9 

4. Schematic showing the interrelation of data analysis, method formulation, and the testing of predictive capability 13 

5. Graph showing relation between dissolved oxygen and summer-condition discharge for Willamette River, Oreg., 

at river mile 6 ------------------------------------------------------------------------------------ 14 

6. Schematic showing the process of assessing the impacts of land-use activity on erosion and river quality ____ 15 

TABLE 

Page 

TABLE 1. Selected physical characteristics ofthe main stem Willamette River -------------------------------------- A7 

CONVERSION FACTORS 

Multiply English units By To obtain SI units 

Feet (ft) ------------------------------------------- 0.3048 ___________________________ Metres (m) 

Miles (mi) ----------------------------------------- 1.609 ___________________________ Kilometres (km) 

Cubic feet per second (ft3 /s) ------------------------- 28.32 ___________________________ Litres per second (l/s) 

.02832 Cubic metres per second (m3/s) 

Feet per mile (ftlmi) ------------------------------- .1894 ___________________________ Metres per kilometre (m/k.m) 

v 

A PRACTICAL FRAMEWORK FOR RIVER-QUALITY ASSESSMENT 

By David A. Rickert and Walter G. Hines 

ABSTRACT 

The U.S. Geological Survey is now (1975) conducting an 

intensive river-quality assessment of the Willamette River basin, Oregon. The objectives are (1) to define a practicai 

framework for conducting comprehensive river-quality assessments; (2) to determine the kinds and amounts of data 

required to adequately assess various types of river-quality 

problems; (3) to develop and document methods for evaluating 

basin-development alternatives in terms of potential impacts 

on river quality; and (4) to apply the framework, data, and 

methods to assess the existing or potential river-quality problems of the Willamette River basin. 

This paper describes the results of the first objective. The 

defined framework involves a seven-step iterative process 

which includes: (1) determination, in conjunction with resource 

planners and managers, of existing and potential river-quality 

problems; (2) analysis of river hydrology; (3) selection and development of applicable assessment methods; {4) identification, 

collection, and collation of required data; (5) analysis of data 

and formulation of assessment methods to provide predictive 

capability; (6) forecasting the impacts of planning alternatives 

on each problem; and (7) effective communication of results to 

the planning and management community, including the general public. 

The seven steps provide a rational framework for organizing 

and executing technically sound assessments of river-quality 

problems and planning alternatives. All steps and ideas are 

tempered by a goal of providing technically sound, adequate, 

and timely information for decisionmaking. The framework 

stresses communication and is designed to be a joint venture, 

from beginning to end, including scientists, planners, and resource managers. The design stems from the recognition that 

the ultimate success of each assessment depends on the clarity 

and utility of results as well as on their basic scientific validity. 

INTRODUCTION 

Today there is an urgent need for comprehensive 

resource assessment in most river basins of the 

United States. In response to this need, many 

planning groups have prepared reports that project future demands for water supply, waste-water 

treatment, and other services, and suggest possible alternatives for meeting the demands. Implicit 

Al 

in these reports is the acceptance of economic and 

population growth, but in a manner consistent 

with some desired level of land and river quality. 

A planning report is not an end in itself, but 

merely a step in the resource-management process. The actual decisions are usually made by 

elected or appointed officials with assistance from 

resource scientists and planners. 

Virtually all forms of growth and development 

exert some impact on river quality. Achie.vement 

of desirable river quality at acceptable cost requires that management decisions be based on 

sound impact assessments, not on arbitrary assumptions. Thus, the vital link between resourcedevelopment plans and management decisions is 

scientific assessment to predict the probable impacts of each planning alternative. At present, 

river-quality assessment is the Achilles' heel of 

the overall process. The difficulty in appraising 

impacts results from (1) the absence of a rational 

framework for structuring such work, (2) the lack, 

poor development, and misapplication of assessment methods, and (3) the scarcity of reliable data. 

To bridge the gap between planning and decisionmaking, this paper presents a practical 

framework for conducting river-quality assessments. Subsequent papers will focus on the design 

of data programs and the application of methods 

for assessing specific river-quality problems. 

RIVER-QUALITY ASSESSMENT 

River quality is the physical, chemical, and 

biological character of a river with regard to its 

suitability for a specified purpose. A river may be 

of good quality for one purpose, and bad for 

another, depending on its characteristics and the 

criteria by which quality is judged. 

The characteristics and criteria for judging 
quality are based on scientific knowledge and 

popular perceptions. Popular perceptions, in turn, 

depend primarily on environmental, economic, 

and demographic conditions. As these conditions 

change, perceived purposes and suitabilities of 

rivers change, and the resource decisionmaker is 

often left without adequate scientific information 

to evaluate alternatives. 

The concept of river-quality assessment was developed to fill this information vacuum. The goal of 

river-quality assessment is to provide sound technical information that is appropriate and adequate 

for resource decisionmaking. The approach is to 

define the major environmental and cultural controls of those characteristics of a river that dethe Non-Federal Committee on Water Data for 

Public Use. This committee was created recognizing that the non-Federal sector both uses and acquires a major part of the Nation's water data. The 

committee includes 26 representatives of wateroriented organizations: among these are national, 

State, and regional organizations, professional 

and technical societies, and the academic community. The major function of the committee is to 

advise the Geological Survey on existing, future, 

and emergency needs for water-resource data. 

Several years ago, the Non-Federal Committee 

voiced concern at the lack of suitable information 

for adequate river-basin planning. The concern 

resulted from the lack of reliable data to address 

cisionmakers perceive as being most important to problems that, because of public consciousness and 

resource planning and management. These pending legislation, demanded immediate ascharacteristics can be ( 1) existing conditions sessment. These problems included (1) definition 

widely perceived as problems or (2) parameters , of the existing quality of the Nation's rivers; (2) 

sensitive to growth and development which must analysis of quality trends, especially as to whether 

be managed to maintain ~~desirable quality." In the pollution-control programs were actually improvcontext of planning, both represent river-quality ing river quality; (3) determination of whether 

problems. advanced waste treatment was desirable or necesTo enable decisionmakers to evaluate alterna- sary on a national, State, or river-basin scale; ( 4) 

tives, river-quality assessments must provide in- definition. of the interrelations of land use and 

formation on the potential impacts of land and river quality; and (5) assessment of reservoir operwater development. Provision of such information ation and flow regulation on river quality. 

requires that important problems are analyzed in In 1971, Wolman (1971) reviewed these andreterms of cause and effect. Other analytical ap- lated problems in the context of data-collection 

proaches have been used to study river quality (for programs. He concluded that designs of past and 

example, trends and indices), but only an approach existing water-data programs were unsuited to 

based on definition of cause-effect relationships provide information for assessing these problems 

can provide an ability to predict impacts of plan- or for defining meaningful measures of river qualning alternatives. ity. Wolman further noted, as had the Advisory 

BACKGROUND 

Historically, many Federal agencies collected 

water-quality data, resulting in duplication of effort and significant diff~rences in data standards. 

In 1964, in an attempt to correct these problems, 

the Bureau ofthe Budget (Executive Office ofthe 

President, 1964) issued Circular A-67 designating 

the Department of the Interior as the lead agency 

in coordinating Federal activities in water-data 

acquisition. Responsibility for execution of the 

functions was assigned by the Department specifically to the U.S. Geological Survey. 

Circular A-67 prescribed creation of Federal 

and non-Federal committees to assist the Geological Survey in coordinating designated functions. 

The non-Federal committee was officially named 

A2 

Committee, that little interpretive use was being 

made of the data that did exist. 

In 1971, the Non-Federal Advisory Committee 

formally recommended that the Geological Survey 

conduct an interdisciplinary river-quality study. 

The recommended objectives were (1) to define a 

practical framework for conducting comprehensive river-quality assessments; (2) to determine 

the kinds and amounts of data required to 

adequately assess various types of river-quality 

problems; (3) to develop and document methods for 

assessing planning alternatives in terms of potential impacts on river quality; and (4) to apply the 

framework, data, and methods to assess the critical river-quality problems of a major river basin. 

The Geological Survey responded to the Committee's recommendation by starting in January 
DEVELOPMENT OF 

PUBLIC POLICY 

AND 

LONG-RANGE GOALS 

// 

DESCRIPTION ---o OF 

OPPORTUNITIES 

AND PROBLEMS 

2 

AND 

IDENTIFICATION 

DESCRIPTION 

r 

OF NEEDS 

EVALUATION OF 

EXISTING 

INFORMATION 

r.;:--------, 

1

2 ANALYSIS OF I L _:I~E:_ HYDRO~OGY- J 

5 

FORMULATION OF 

ALTERNATIVE 

PLANS FOR 

GROWTH AND 

DEVELOPMENT 

6 

PLANNING 

AND 

~----------~~MANAGEMENT 

DECISIONS 

~.---- --- r: ___ ] ____ , 

1

1 1 

3 

sELEcTioN oF 1

1 

r ----------, I DELINEATION OF I ASSESSMENT METHODS l5 1 

r:------.., 

1

6 FORECASTING I I IMPACTS OF I. • I PLANNING I 

I RIVER-QUALITY I I I DATA ANALYSIS, 

PROBLEMS • J I METHOD FORMULATION, '--+1 ALTERNATIVES ON I RIVER QUALITY I I I ----J---- ND THE TESTING OF 

L ______ j I A PREDICTIVE I '4--- - ---!-----+! CAPABILITY I L._ __ r __ _JJ 

I IDENTIFICATION ._ ________ J 

I COLLECTION, AND I 

17 ___ --, 

I COLLATION OF I 

I REQUIRED DATA I 

I COMMUNICATION 

I OF RESULTS I 

L---------.J '--------~ 

FIGURE I.-Interrelation of river-quality assessment and river-basin planning. 

1973 a prototype river-quality assessment study in 

the Willamette River basin, Oregon. The Willamette River basin was selected for several 

reasons. First, there is an excellent base of 

background data, particularly on hydrology. Second, the social and political attitudes in Oregon 

reflect a keen interest in environmental quality. 

This suggested that the people and agencies would 

welcome the study and that results would be used 

at the State and local levels. Third, a river-basin 

management plan already existed, as did several 

studies of land-use projections (Willamette Basin 

Task Force, 1969). Thus, the study could evaluate 

existing planning alternatives to provide a realistic test of assessment approaches. Fourth, the Willamette is the largest river in the Nation on which 

all major point-source discharges presently receive secondary waste-water treatment (Oregon 

Department of Environmental Quality, 1970). The 

quality now is above the stringent State standards, and the river is considered a national success 

story (Gleeson, 1972). Thus, the· study could include appraisal of the factors to which past imA3 

provement is attributed, in addition to evaluating 

the factors that must be managed to maintain or 

improve the quality. 

INTERRELATION OF 

RIVER-QUALITY ASSESSMENT 

AND RIVER-BASIN PLANNING 

Figure 1 illustrates an idealized integration of 

river-quality assessment into river-basin planning. The planning components (across the top) 

are outlined by solid lines to symbolize a more or 

less standard process, whereas the assessment 

components are portrayed in dashed lines to represent an undeveloped potential. 

River-basin planning usually begins with the 

development of public policies and long-range 

goals (step 1). In this r~ase, the process normally 

continues with identification and description of 

resource needs (step 2), followed by description of 

opportunities and problems (step 3), and evaluation of existing information (step 4). In some basins, the process begins with step 2, and long-range 

policies are eventually generated by feedback from 
steps 2, 3, and 4. Regardless of the actual order of 

the first four steps, step 5 is formulation of alternative plans for river-basin development (planning 

alternatives). Customarily, basin plans are considered complete at this point, and decisionmakers 

then choose among alternatives without knowledge of their probable impacts on river quality. 

Ideally, river-quality assessment should be built 

into the planning process in a step-by-step progression. The assessment approach of the Willamette River Quality Study includes seven steps 

(fig. 1 ), beginning with delineation of existing and 

potential river-quality problems (step 1). The approach continues with analysis of river hydrology 

(step 2), which is followed by selection of suitable 

assessment methods (step 3). These two steps lead 

to and form a feedback circuit with step 4, which is 

identification, collection, and collation of required 

data. The fifth step is analysis of data and formulation of assessment methods to provide predictive 

capability. Step 6 focuses on using the predictive 

tool to forecast the impacts of planning alternatives on delineated (step 1) river-quality problems. 

Most alternatives derive from existing river-basin 

plans (step 5, River-basin planning), but viable 

alternatives are added that existing plans fail to 

consider. Finally, assessment results are communicated in concise, nontechnical formats to 

decisionmakers, the public, and the scientific 

community (step 7). 

For maximum efficiency, the six steps of planning (fig. 1) and the seven steps of assessment 

could ultimately be integrated into one iterative 

network. Thus, following a period of initial organization, information would flow freely between 

each of the 13 steps. For simplicity of presentation, 

feedback loops are omitted in figure 1, and only the 

major points of integration are noted between the 

planning and assessment processes. 

To place figure 1 in perspective, it must be noted 

that river quality is one of many factors that decisionmakers consider in choosing among alternative plans. River quality is a single component of 

the natural-resource system, which, in turn, is 

only one aspect of the socioeconomic-politicalenvironmental structure of river-basin management. In many basins, demographic and economic 

uncertainties (for example, population growth, industrial development, interest rates, costs) may be 

greater than river-quality uncertainties. However, such a situation increases the need for assessment, because a sound understanding of river 

quality provides a starting point for systematic 

evaluation of socioeconomic and political options. 

COMMUNICATION: A KEY FACTOR IN 

INTERDISCIPLINARY ASSESSMENT 

AND PLANNING 

Useful assessment of complex river-quality 

problems requires development of a mutual understanding between the resource scientist and 

planner. The scientist needs to assess critical problems in the context of a planner's requirements, 

and the planner needs to appreciate the meaning 

and implication of the scientist's results. Each 

must appreciate how the other thinks and this 

requires free and continuing communication. 

Unfortunately, effective communication is presently an exception rather than the rule. Most environmental assessments tend to be unilateral efforts by resource scientists. Efforts at cooperative 

ventures are mostly perfunctory. Attempts at 

communication are usually relegated to a few 

meetings to set up a study and a concluding meeting at which the scientist dumps voluminous, 

jargon-ridden reports into the laps of bewildered 

planners. 

Mutual understanding between resource scientists and planners is most easily attained by conducting resource assessments as joint ventures 

from beginning to end. The effective approach begins with joint delineation of pub1ic policies, longrange goals, and appraisal of problems; continues 

with exploration of study methods; proceeds with 

joint evaluation of planning assumptions and an 

examination of alternatives to be tested; and ends 

with an iterative process of evaluation, discussion, 

and use of results. 

As noted, the goal is to evolve beyond the mere 

communication of ideas to a state of mutual understanding and trust. This goal requires growth on 

both sides. The scientist must understand the 

planner's information needs, his legal, monetary, 

and time constraints, and the level of his ability to 

comprehend scientific information. The planner 

must understand that present scientific knowledge often limits the scientist's ability to deliver 

quantitative resource assessments and that each 

assessment method has inherent strengths and 

weaknesses. Both need to realize that valid data 

and sound analyses, rather than complex analytical methods, are the foundation of reliable resource assessment. 

A4 
ELEMENTS OF 

RIVER-QUALITY ASSESSMENT 

An understanding of the planner's needs is essential for the resource scientist to achieve 

efficient formulation of assessments and effective 

communication of results. However, the ultimate 

success of resource assessments is still basically 

dependent on the scientist's ability to produce 

practical and technically sound information. 

The task of developing practical, scientifically 

valid assessments can be viewed as a stepwise 

cyclic process, which, if structured around flexible 

criteria, can yield increasingly useful information. 

The steps of the process are basically the same as 

those outlined for river-quality assessment (fig. 1), 

with the addition of steps to include preplanning 

(overview) and postevaluation criteria. These additional steps serve to create the cyclic nature that, 

hopefully, can ensure that each successive study 

can build and improve upon the last. 

OVERVIEW 

The foremost considerations for river-quality 

assessment are: 

1. Results must be scientifically valid and limitations on use need to be carefully 

explained. 

2. Results must be practical. 

3. Results must be available by the time important planning decisions need to be made. 

The first overview consideration will be discussed under the topic of methods. It should be 

noted at this point, however, that comprehensive 

assessments often require use of several methods 

and that each method has inherent limitations for 

projecting potential impacts of development alternatives. Some assessments will be quantitative, 

others qualitative. (Functional definitions of qualitative and quantitative are presented in HSelection of Assessment Methods.") All can be helpful to 

the planner provided the limitations of use are 

carefully explained. 

The utility of assessments depends on the practicality of results. Understanding the planner's 

needs will greatly aid the scientist in formating 

practical approaches to produce practical results. 

Scientists should understand a variety of assessment methods from which they can choose the 

most appropriate for specific situations. For example, mathematical modeling is often best for assessing certain river-quality problems. However, 

with improper application, or without a strong 

data base, models can easily produce less practical 

results than those possible from less glamorous 

methods. 

Assessments need to be accomplished within the 

time frame of planning needs because results are 

virtually useless if major decisions have already 

been made. The ideal is to begin studies far enough 

in advance of the decision timetable to provide 

opportunity for in-depth assessment. Where this is 

impossible, there are two options: (1) conduct 

short, preliminary studies to shed some light on 

the situation and then carefully explain the predictive limitations, or (2) insist on the time needed 

to develop adequate information. The choice will 

be made by the decisionmaker and dictated by the 

importance of the pending decision, socioeconomic 

and political pressures, and how badly the information is needed to adequately evaluate alternatives. 

The duration of study is a compromise between 

taking enough time to do an appropriate level of 

scientific assessment and so much time. that results become irrelevant to the decisionmaking 

process. From experience in the Willamette River 

basin, it appears that 2% to 3 years may be a 

reasonable period for assessment of immediate 

problems. The beginning of a study needs to be 

timed to provide a reasonable period for planning 

prior to initiation of fieldwork. A 2%- to 3-year 

study time permits 2 years of fieldwork and hence 

the opportunity to recheck critical time periods (of 

annual cycles) for specific problems. Longer 

studies begin to lose their usefulness to the planning process. Specific critical problems may be 

studied over longer periods, but the bulk of the 

initial assessments should be completed. Reappraisals can then be made under reduced time 

pressures, while full-scale updates can be 

scheduled on a periodic basis. 

DELINEATION OF RIVER-QUALITY PROBLEMS 

Delineation of problems is the first technical 

step of river-quality assessment. Adequate delineation requires exhaustive review of reports and 

interviews with knowledgeable individuals until 

all significant aspects have been evaluated. The 

success of assessment depends on how well the 

relevant problems are initially defined in relation 

to development plans and other important 

socioeconomic, political, and environmental factors. 

A5 
Although the delineation of problems is done in 

coordination with basin planners, the scientist 

needs to remain sensitive to the potential for problems that planners are not aware of and which 

previous studies did not appraise. To date, most 

planning studies have focused on the classical inriver paran1eters of dissolved oxygen, <DO), temperature, and indicator bacteria. Fewer assessments have been made of the factors which control 

algal growth in rivers of"the distribution and effects of hazardous materials. Even less work has 

been done on delineating the relationships of 

land-use activities and erosion to subsequent river 

quality. Today, however, there is awakening recognition that planning for maintenance or improvement of river quality needs to be based on 

comprehensive, integrated assessment ofland and 

water resources. Land-use activity controls not 

only the amount of wastes which reach rivers from 

municipal and industrial outfalls, but also the 

kinds and amounts of wastes which enter directly 

in storm runoff. In places, the materials in storm 

runoff may cause undesirable algal growth, metal 

and pesticide toxicity, and sediment problems. The 

situation is now such that either land use and 

storm runoff are considered, or else the ultimate 

result will be land-imposed constraints on river 

quality (Howells, 1971 ). 

Once the full range of river-quality problems is 

delineated, the scientist and planner can collaborate in developing problem priorities. These 

priorities, together with planning decision deadlines, provide the basis for deciding which problems need immediate attention and which can be 

studied over longer periods of time. 

ANALYSIS OF RIVER HYDROLOGY 

River hydrology exercises a dominant control 

over river quality. Hydrologic characteristics determine the physical dynamics of rivers, which, in 

turn, control the pattern and extent of chemical 

and biological processes. Because of this control, 

analysis of river hydrology is a prerequisite to 

selecting a method or identifying the data needed 

to assess a river-quality problem. Only through 

such analysis can we determine the inherent 

(background) variability in river quality that results from natural variations in hydrology. Once 

this is known, the impacts of man on the basin can 

be examined independently of natural variations. 

River hydrology is a complex interrelation of 

climate, geology, topography, vegetation, and 

A6 

man's activities such as land and water use. As 

described by Brown and Jackson (1973, 1975), 

these basic basin features also control certain land 

processes that directly affect river quality. 

Pollution problems arising from discharge of 

municipal and industrial effluents are a major 

consideration of river-quality planning. Study of 

such problems focuses largely on the quantification of in-river processes, and hence, on the hydrologic factors of flow, water temperature, and 

channel morphology. 

Flow characteristics, along with water temperatures, govern many physical, chemical, and biological river processes. In conjunction with channel 

morphology and temperature, flow determines the 

reaches where specific water-quality problems are 

most likely to occur. Furthermore, seasonal flow 

variability, especially extreme events such as 

droughts and floods, is in1portant in defining the 

magnitude, duration, and recurrence probability 

ofmany river-quality problems. Fortunately, most 

large rivers in the United States have fairly longterm, continuous-flow records that can be used to 

analyze both natural and regulated variabilities. 

Computer packages for statistical analysis of flow 

data are in common use by the Geological Survey 

and other agencies. 

Water-temperature patterns are a major control 

of river quality because of their influence on 

biological activity. Patterns vary seasonally and 

in many basins correlate directly with air temperature. However, anomalous patterns can result 

from manmade influences such as impoundments 

and thermal discharges. 

Many river-quality problems are manifested 

during high-temperature, high-insolation periods 

when biological activity is at a maximum. Water 

temperature records are available for many basins 

and can be analyzed to determine the optilnum 

period for collecting data on biologically controlled 

problems such as DO depletion by carbonaceous 

wastes, nitrification, and excessive algal growth. 

In basins without sufficient records, seasonal 

water-temperature variations can be closely estimated from analysis of air-temperature data 

(Velz, 1970; Collings, 1973). Moreover, where the 

problem warrants, it is possible to compute 

equilibrium water temperature from data on air 

temperature, relative humidity, wind velocity, 

and solar radiation (Velz, 1970). 

Three aspects of channel morphology-bed 

slope, cross-sectional geon1etry, and the nature of 
bed materials--are especially pertinent to river-

'1uality behavior. Bed slope, together with flow 

volume, defines the rate of energy dissipation 

along the course of a river. Bed slope thus partly 

governs mixing phenomena, transport of materials, 

time of travel, and processes such as reaeration. 

Width and depth are the primary characteristics 

of cross-sectional geometry. These characteristics 

partly control the same important processes as bed 

slope. Moreover, in conjunction with the nature of 

bed materials, width and depth control the 

surface-to-volume ratio of river reaches, and thus 

define the availability of surfaces for biological 

growth. Information on cross-sectional geometry 

of most large rivers is available from the U.S. 

Army Corps of Engineers, the National Oceanic 

and Atmospheric Administration, the Geological 

Survey, or local agencies responsible for controlling river navigation. Where adequate data are 

lacking, inexpensive echo-sounding equipment 

can be used to characterize the geometry in a relatively short time. Width and depth characteristics 

vary with discharge and must be adjusted to each 

flow regime. 

The nature of bed materials determines to a 

large extent the types of biological communities 

that inhabit different river reaches. For example, 

different groups of organisms thrive in mud, sand, 

and gravel. Bed-material characteristics areprimarily determined by geology, topography, and 

man's activities. General information on the bed. 

materials is available for many rivers from reports 

of State agencies, intrastate river-basin commissions, the Army Corps of Engineers, and the 

Geological Survey. 

An example of the types of pertinent physical 

inforn1ation commonly available for United States 

rivers is illustrated in figure 2 and table 1. These 

data were available from existing records and 

reports on the Willamette River. The data were 

compiled into their presented form as a basis for 

selecting sampling reaches and stations for 

assessment of DO depletion and potential algal 

problems. 

SELECTION OF ASSESSMENT METHODS 

River quality encompasses all the processes on 

land, in air, and water, and the actions of society 

that affect the health of rivers. With this broad 

perspective, a wide spectrum of interpretive 

methods is needed to conduct comprehensive assessments. 

Four types of methods are being used in the 

Willamette study: 

1. Information matrices for planning the study 

(see Rickert and others, 1973), and for relating assessment results to planning alternatives. 

2. Mathematical models for assessing problem 

variables that can be quantitatively modeled. 

3. Interpretive maps for relating land-use activity to environmental impacts. 

4. Descriptive methods for assessing problems 

that presently cannot be modeled, mapped, 

or addressed through matrices. 

The predictive capability of these methods 

ranges from qualitative to quantitative. Quantitative assessments imply a sound numerical prediction of a future condition and are obtained through 

mathematical modeling. For example, a wellverified DO model (method 2) is being used to predict future DO concentrations of the Willamette 

River at selected sites under specified conditions of 

pollutionalloading, temperature, and flow. 

Qualitative assessments imply a general 

knowledge of the manner in which environmental 

and cultural factors 1nay combine to affect future 

conditions. Numerical predictions are not made. 

For example, a qualitative descriptive assessTABLE I.-Selected physical characteristics of the main stem Willamette River, Oreg. 

[Characteristics refer to summer low-flow conditions of 6l< 103ft 3/s at Salem] 

Read1 

Tidal 

Length 

I mil 

Reach ( 1) 26.5 

Newberg 

Pool (2) 25.5 

Upstream 

Reach (3) 135 

Approximate 

bed slope Bed material 

!ft/mi) 

Intermixed clay, sand, 

<0.1 and gravel. 

Intermixed clay, sand, and 

. 12 gravel with some cobbles . 

2.8 Mostly cobbles and gravel. 

1Cakulated by volume displacement method usmg channel cross-sectwnal data 2Cakulated from dye study conducted by U.S. Geologieal Survey !Harris, 196Hl. 

A7 

Representative Approximate midchannel Velocity traveltime 

water depth tmiihrl in reach 

tftl thrsl 

40 10.11 240 

25 I .27 94 

7 2 2.0 68 
26.5 mi (43 km) 

2 25.5 mi (41 km) 

\ 

5 187 mi (301 km) 

( 3 135 m1 (217 km) 

{ 

\ 

0 30 MILES 

I 1 1 I 1, 

0 50 KM 

A 

FEET METRES 

~ 500' ~;:~:~~~~~~~~~~~~~~~~~~~---S-H_A_l_l_O_W_F_A_S_T~~~~~~~~~~: ~ :~ ~ ~~: 160 

100'~r-r-r-r-t-t-t-t-t-t-t-t-t-t-t-~f=f=r=~r-r-r-r-r-r-l-.-.-~r-~ 40 SEA I SEA 

LEVEL 150 100 50 0 LEVEL 

DISTANCE, IN RIVER MILES ABOVE MOUTH 

300 200 100 0 

DISTANCE, IN RIVER KILOMETRES ABOVE MOUTH 

B 

FIGURE 2.-Diagram representing the Willamette River, Oreg. A, Distinctive hydrologic reaches. B, Elevation profile. 

ment (method 4) is being made of the Willamette 

River to determine whether algal problems are 

likely to develop from increases in algal-nutrient 

concentrations, changes in river hydrology (flow, 

mixing, temperature), neither, or both. 

Semiquantitative assessments combine various 

elements of the quantitative and the qualitative. 

For example, a combination of interpretive maps 

and information matrices (methods 1 and 3> is 

being used for the Willamette River basin to relate 

terrain, land-use activity, and erosional-depositional features. The matrices qualitatively summarize an array of quantitative data to provi~ 

estimates of the relative severity of erosionaldepositional impacts associated with different activities in different parts of the basin. 

The objective of assessment is to provide information that is sound, appropriate, and adequate 

for planning needs. The ideal would be to possess 

the scientific capability to quantify through 

AB 
mathematical modeling all processes and variables that give rise to river-quality problems. At 

present, however, many complex processes such as 

those appearing in the mid and upper parts of the 

triangle in figure 3 are difficult, if not impossible, 

to model in a practical, applied sense. (See Hines 

and others, 1975; Rickert and Hines, 1975.) This 

stems primarily from the fact that appropriate assumptions and accurate model parameters are 

difficult to develop because knowledge of these 

processes is presently very limited. Moreover, this 

poor state of knowledge makes it difficult to design 

data programs for elucidating the processes at 

reasonable cost. 

Thus, at present, mathematical modeling is not 

realistically applicable to practical assessment of 

all river-quality problems. Comprehensive studies 

require several methods and, often, the most ap:. 

propriate for a specific problem will be qualitative. 

Generally, the less quantitative the method, the 

less predictive are the results. Nevertheless, qu~litative assessments are very valuable to decisionmakers, often providing critical information that 

cannot be obtained by other methods. The primary 

task of the scientist, then, is to select a method that 

fits the context of the problem, the basin complexity, the desired degree of detail, and the urgency 

with which the results are needed. 

For complex, poorly understood problems, the 

scientist would best serve the planner by selecting 

a qualitative method for a timely preliminary assessment. The scientist can then provide a careful 

delineation of needs for conducting further work to 

upgrade assessments to more quantitative levels. 

Through this approach, the planner will have 

some information quickly, will know the limitations he must exercise in its use, and can suggest 

rational interim solutions while awaiting subsequent assessments. 

Qualitative methods are often the most reasonable approach for assessing the impacts ofland-use 

activity on land and river quality. For example, in 

the case of erosion problems related to land development, there is excellent general understanding of the basic processes and the kinds of data 

required to conduct in-depth assessments. Thus, a 

quantitative modeling approach might seem possible. However, the usual drawback to such a 

quantitative approach is an inability to obtain 

data in sufficient detail. Faced with analyzing' the 

erosion potential of a large drainage basin, the 

resource scientist will usually be unable to find or 

A9 

EROSION 

EUTROPHICATION 

~ 

~ (<' 

"YIP 

~ Q 

0 TOXICITY RELATIONSHIPS 0 

~ ~ ~ 17 

~"?" f----------------\ ~ 

.# ALGAL GROWTH : METAL TRANSPORT ~ iP 

NUTRIENT AND PESTICIDE TRANSPORT 

INDICATOR BACTERIA : SEDIMENT TRANSPORT 

DISSOLVED SOLIDS 

FIGURE 3.-Diagram showing relative difficulty of applied 

modeling. 

collect enough data in a reasonable time to allow 

use of a quantitative method. Given the current 

availability of data, the most appropriate approach will usually be a qualitative met:Qod that 

interrelates land-use activity, erosion potential, 

and potential impacts on river quality. 

An important consideration in selection of 

methods is that limitations on the use of results 

must be carefully explained. For example, in mapping assessments, limitations are often inherent 

in, and sometimes obscured by, the scale at which 

information is presented. A qualitative mapping 

assessment (or any qualitative result), if misapplied or overapplied, can create havoc in the 

resource-management process. The resource scientist needs to accept the challenge that expert 

explanation of the limitations of a qualitative assessment is equal in importance to the assessment 

itself. 

In theory, sound quantitative assessments are 

more definitive than qualitative assessments. The 

fact is, however, that most river-quality processes 

are so complex the scientist is never entirely sure 

of the reliability of supposedly quantitative results. For example, in formulating a DO model, the 

scientist can collect statistically reliable data on 

biochemical oxygen demand (BOD), DO, and flow. 

However, if photosynthesis or benthic demands 

affect the DO regime, the scientist may be unable 

to define these effects in statistically reliable 

terms. Thus, even with sound assessments using 

!!quantitative" methods, the scientist must take 
care to explain the uses and limitations of results. 

The resource scientist should be constantly 

aware that all usable assessment methods, no 

matter how qualitative or quantitative, are based 

upon the scientific principles. Given today's emphasis on modeling, computers, and equipment, 

this is critical to remember; otherwise, assessment 

studies can easily become ~~method oriented" 

rather than ~~problem oriented" (Platt, 1964). 

IDENTIFICATION, COLLECTION, AND COLLATION 

OF REQUIRED DATA 

Valid data are the basis of sound resource assessment. The kinds and amounts of data required 

to assess a river-quality problem depend primarily 

on the complexity of the river process, the size of 

the study area, and the method chosen for assessment. 

Qualitative methods of assessment generally 

require less data than do quantitative methods, 

and also may permit greater utilization of existing 

data. For example, experienced investigators have 

developed qualitative maps of erosion potential 

from existing data on climate, slope, geology-soils, 

runoff, and erosional-feature locations (Brown and 

Jackson, 1973, 1975). 

Likewise, a qualitative reach-to-reach analysis 

of DO variations can often be made from existing 

data collected by State and Federal agencies for 

water-quality monitoring and pollution-control 

surveillance. In contrast, data collected for such 

purposes are usually poorly suited for calibration 

and verification of an applied DO model. This lack 

of suitability stems from several factors (Hines 

and others, 1975): 

1. Correlative data on hydrology and especially 

waste discharges are seldom determined. 

As a result, most monitoring and surveillance data indicate effects rather than give 

insight into causes. A river-quality model 

can be structure imitating and predictive 

only if cause-effect relationships are quantitatively established. 

2. Monitoring programs usually collect limited 

grab samples at widely dispersed sites under a variety of conditions. Such data rarely 

provide quantitative knowledge of reachto-reach, cross-sectional, and daily variations. This is particularly true for a nonconservative, dynamic variable such as 

DO. 

3. The relation between riverflow and time of 

travel is seldom known or is overlooked in 

the planning of monitoring programs. 

Therefore, results obtained from individual 

sites represent a synoptic picture of the 

river only if samples are collected during a 

long-term, steady-state flow condition and 

at the same time of day. This is rarely the 

case. 

4. The inherent sampling and analysis errors for 

river-quality variables are relatively large. 

Consequently, to develp an applied riverquality model, a number of sample sets are 

necessary to define a range of error as an 

index of inherent variability. 

The tendency today is to conduct river-quality 

assessments solely on the basis of existing data. 

This approach is mostly ineffective, because existing data are seldom adequate to support intensive 

assessment of multiple problems. In fact, existing 

data are deemed insufficient even to determine 

whether the Nation's water quality is generally 

getting better or worse (McKelvey, 1974). 

Standard water-quality monitoring networks 

will never provide all the data needed to conduct 

intensive river-quality assessments. It is unfeasible to design a network to include enough 

parameters at enough sites at suitable sampling 

frequencies so that all potential problems can be 

adequately assessed. Even if such a network were 

theoretically possible, the cost would be prohibitive. Thus, each new study will be faced with collecting information to fit specific needs not covered 

by existing data. Collection of good data requires 

money, but the cost should be weighed against the 

possible cost of poor planning decisions that might 

result from inadequate assessments or arbitrary 

conclusions. The pertinent question is not what· 

the data will cost, but what an unsound planning 

decision will do to river quality and eventually cost 

the taxpayer. 

To obtain appropriate data to assess specified 

problems, a four-step approach is being used in the 

Willamette study: 

1. Identify the types of data required to assess 

each problem. 

2. Collate and analyze pertinent existing data. 

Where these data appear insufficient to assess the problem adequately, proceed to 

step 3. 

3. Design a reconnaissance study to determine: 

a. The major factors that actually affect the 

river-quality problem in question. 

A10 
b. The anticipated range of values for each 

factor. 

c. The amount of data needed to analyze 

each cause-effect relationship. 

4. On the basis of steps 1 through 3, design and 

conduct a field and laboratory datacollection program at an intensity appropriate to adequately assess the problem. 

In the Willamette study, certain problems are 

being assessed entirely through the use of existing 

data (step 2). For example, existing streamflow 

records have provided a sound basis for the 

mathematical modeling of reservoir releases and 

the flow aspects of DO depletion. In addition, exist- · 

ing data are sufficient for qualitative analysis of 

climate, slope, geology, and soils as a basis for 

mapping basinwide erosion potential. 

Step 2 (collation and analysis of existing data) 

plays a vital role in data programs, even for those 

cases in which new data must be collected: For 

example, existing data were analyzed for study of 

DO depletion in the Willamette River. Although 

the records were not suitable for providing a reliable analysis of cause-effect relationships, the 

data did indicate (1) the general magnitude of DO 

depletion (up to 40 percent depletion of DO saturation), (2) the affected reaches of the river (the lower 

80 miles, 129 km), (3) the yearly period of most 

severe DO depletion (July-August), and (4) the 

fact that summer flow was effectively steady state 

and greatly augmented by reservoir releases. This 

information provided the background for a 

reconnaissance-level study. 

The reconnaissance-level study (step 3) was 

made to determine (1) river mixing and flow patterns, (2) waste-loading characteristics, (3) the 

presence or absence of benthic oxygen-demanding 

deposits, and (4) expected ranges of model parameter values. Results of the survey indicated that 

several major changes had occurred since 1951 and 

1960 when Velz (1951, 1961) studied the DO regime of the Willamette: BOD loadings were much 

lower and more uniform because ofbasin-wide secondary treatment; river deoxygenation rates were 

much lower; large benthic deposits were absent 

except in Portland Harbor; and detention time and 

river-channel geometry, and thus reaeration 

rates, had been affected by dredging. One important condition remained unchanged: the river was 

still well mixed in most reaches. 

Such findings indicated that a simpler model 

configuration could be used than was originally 

anticipated. The results also provided the basis for 

design and implementation of an efficient datacollection program for model calibration and verification (Rickert and Hines, 1975). 

Collection of valid data requires time in addition 

to money. The time element is of prime importance 

in all types of river-quality assessments, but especially for quantitative methods such as mathematical modeling. An inverse relationship exists between the complexity of a river-quality process 

and the ability to produce sound modeling assessments within a given timespan. For many rivers, 

where sufficient and valid hydrologic data are available, practical, reliable flow models can be 

calibrated and verified within a year. Possible exceptions would include extremely large basins, 

small rivers having no past streamflow records, 

complex estuarine systems, and basins experiencing prolonged periods of marked extremes such as 

drought. 

In sharp contrast, data for few if any rivers are 

adequate to permit formulation of an applied DO 

model. In cases where only a specific period of the 

year needs to be modeled, sufficient data may be 

collected in 1 year to calibrate and verify a model. 

In systems that are hydraulically complex, or 

where assessments are needed over large variations of flow, 2 to 3 years of data collection may be 

needed to produce a reliable DO model. 

For highly variable parameters such as indicator bacteria, considerably more time and larger 

amounts of data may be required to produce a 

reliable and practical model. 

Even farther up on the data-requirement scale 

(fig. 3) is the process of eutrophication. Certain 

critical subprocesses such as nutrient transport 

and algal-growth dynamics are so poorly understood that programs for collecting definitive data 

are difficult to design. In fact, the great difficulty of 

collecting sound data on sinks and sources of nutrients and on environmental controllers of algal 

growth makes it questionable whether eutrophication can presently be modeled in a practical 

applied sense (McGauhey, 197 4). Several attempts 

have been made at modeling eutrophication, and 

perhaps the best practical study to date (Jaworski 

and others, 1971) was based on more than 5 years 

of specialized data collection. 

Somewhat equivalent to the difficulty of modeling eutrophication are the problems inherent in 

the mathematical modeling of sediment yield. 

Conceptually, the various subprocesses can be 

All 
modeled. As explained by Bennett (1974), the 

present lack of practical models stems from the 

difficulty of collecting enough reliable data for 

calibration and verification. Many years of 

specialized data collection would be needed to produce a sound and practical sediment-yield model. 

DATA ANALYSIS, METHOD FORMULATION, 

AND THE TESTING OF PREDICTIVE CAPABILITY 

After collection of the initial data, the assessment-.pr-oceeds with a step (fig. 4) that begins with 

(1) analysis of the data, (2) incorporation of 

analyzed data in the selected assessment method, 

and (3) testing of the data-method package to determine its predictive capability. If the predictive 

capability is less than adequate, as measured 

against predetermined criteria, the assessment 

method is reformulated or additional data are collected. The process then recycles. Once the datamethod package is deemed suitable for projecting 

impacts, it is ready for application to planning. 

This procedure, as noted in figure 1 (River quality 

assessment, step 5) and as outlined in figure 4, is 

referred to as data analysis, method formulation, 

and the testing of predictive capability. 

This procedure can be illustrated by considering 

the process of mathematical modeling. First, an 

initial set of data is analyzed and interpreted. 

Next, the data are used to formulate and calibrate 

the model (incorporation of data and method). Following this, model outputs (predicted values) are 

compared to a second set of values; this is verification. If the fit is poor, new data must be collected to 

recalibrate the model or the model reformulated 

until outputs can adequately reproduce observed 

conditions. Only when the model is adequately 

verified is it ready for use in-resource planning. 

Development of other data-assessment method 

packages goes through the same procedure, regardless of whether the predictive capability is 

qualitative or quantitative. The important points 

of this procedure are first, that the data must be 

carefully analyzed prior to incorporation with the 

method, and second, that the data-method package 

must be tested, and, if necessary, adjusted before 

impact assessment can begin. There is a tendency 

in some resource assessments to skip or give short 

shrift to these two highly important points. Consideration of figure 4 should help to emphasize 

their essential role in the overall procedure. 

FORECASTING IMPACTS OF 

PLANNING ALTERNATIVES 

The goal of river-quality assessment is to use 

predictive tools to provide decisionmakers with 

the best attainable insight to the impact of planning alternatives on delineated problems. Nearly 

all land and water development affects river quality, but the physical and cultural complexity of 

most river basins precludes assessment of each 

and every impact. An approach for dealing with 

this problem is to screen the full spectrum of planning proposals as to possible impacts on the most 

important problems. 

This approach can narrow a myriad of possibilities to a workable program. Because most of 

the selection depends on judgment rather than 

hard fact, the process should be a joint venture 

between the resource scientist and planner. The 

scientist can provide information and knowledge 

on river quality and the possible impacts of water 

and land development. The planner can provide 

insight as to how, when, and where basin development will occur under anticipated social, 

economic, and political stimuli. The joint venture 

can assure that all proposals with large impact 

potential are included and proposals with little or 

no impact potential are excluded. 

During selection of alternatives for assessment, 

the resource scientist and planner should resist 

the temptation to focus only on those forms that 

are presently Hin vogue." For basin planning, the 

complete spectrum of alternatives stretches from 

zero growth to uncontrolled growth and development. For approaches to resource development and 

protection, the spectrum stretches from those having well-documented statutory regulations and 

funding mechanisms to innovative approaches for 

which the legal and funding aspects are not yet 

established. 

Assessments might indicate that previously untried alternatives are reasonable from the 

standpoint of river quality. If so, the planners and 

decisionmakers can later determine the legal and 

financial advisability of each new alternative. 

Ideas, funding mechanisms, and laws can be 

changed when there is sound reason to do so. 

River-quality assessment is a never-ending 

process, and even the most comprehensive studies 

are likely to become outdated. The resource scientist can respond to this problem in three ways: (1) 

A12 
REFORMULATION OR 

COLLECTION OF 

ADDITIONAL DATA 

FAILURE 

SUCCESS 

APPLICATION 

TO lNG 

TESTING TO 

DETERMINE 

PREDICTIVE 

CAPABILITY 

DATA 

ANALYSIS 

INCORPORATION OF 

ANALYZED DATA 

INTO ASSESSMENT 

METHOD 

FIGURE 4.-lnterrelation of data analysis, method formulation, and the testing of predictive capability. 

frequently assess newly developed alternatives 

through use of existing methods; (2) develop programs to improve the data and knowledge base for 

future assessments; and (3) periodically, perhaps 

every 5 to 10 years, conduct a full-scale reassessment that incorporates new scientific data, new 

planning information, and new assessment 

technology. The three-element process is important, because badly outdated assessments might 

be more detrimental to decisionmaking than complete lack of environmental knowledge. 

COMMUNICATION OF RESULTS 

The resource scientist should carefully design 

reports so results can be easily and quickly understood. Reports need to be written in nontechnical 

A13 
DISCHARGE, IN CUBIC METRES PER SECOND, AT SALEM GAGE 

100 150 200 

z 

0 

1-

<{ 

0:: 

::> 

1-

<{ 

Cl) 

1-

z 

w 

u 

0:: 

w 

0.. 40 

z 

z 

w 

C) 

>-

X 

0 

a 

w 20 > _j 

0 

Cl) 

Cl) 

a 

DISCHARGE, IN CUBIC FEET PER SECOND, AT SALEM GAGE 

FIGURE 5.-Relation between dissolved oxygen and summer-condition discharge for Willamette River at river mile 6. 

language and style, with emphasis on graphical 

reporting of results. 

Techniques for graphically expressing results 

vary with the nature of the problem and the 

method of assessment. For modeling assessments, 

a useful technique for presenting results is the 

control-curve concept described by Velz (1970). For 

example, figure 5 illustrates predicted relationships between percentage DO saturation and discharge at various reductions of average (in 1950) 

BOD loading. Each curve was computed from 

Velz's (1951) DO model. The curves are useroriented and permit assessment of three factors on 

one graph. Such curves provide assessment flexibility and enable the user to simultaneously 

evaluate numerous planning and managementalternatives. 

Two approaches for presenting integrated earth 

resource-water resource assessments are multiple-factor maps and information matrices. Steps 

1 and 2 of figure 6 portray the development of an 

erosional province map for the Willamette River 

basin. The inputs to the map are an up-to-date 

photomosaic base; high-altitude, false-color, infrared photography; and composite overlays of 

selected earth- and water-resource factors. The 

components are integrated to provide a product 

that relates natural terrain properties and landuse activity to the type, number, and extent of 

erosional features. 

Step 3 of figure 6 illustrates a matrix for converting information from the erosional province map 

into a format useful to resource planners. The matrix lists erosional provinces as columns and 

land-use activities as rows. The erosional provinces are numerically ranked in order of their 

potential to erode, whereas the land-use activities 

are ranked in their order of land-surface disrupA14 
BASIN 

PHOTOMOSAIC 

COLOR-IR 

PHOTOGRAPHY 

DESCRIPTION OF 

LAND USERIVER QUALITY 

RELATIONSHIPS 

CD EROSIONAL 

PROVINCE 

MAP 

EROSIONAL PROVINCES 

CD 

FIGURE 6.-Process of assessing the impacts of land-use activity on erosion and river quality. 

A15 
tion. The matrix body records the product of the 

ranks from each column and row. The magnitudes 

of these products indicate the relative seriousness 

of erosional problems likely to develp under the 

various combinations of erosional provinces and 

land-use activities. 

PROGRAM EVALUATION 

All scientific programs need to be evaluated to 

determine strengths and weaknesses and to develop criteria for the future. In river-quality assessment, program evaluation provides the 

framework for improvement of methods and 

knowledge. The evaluation, like the assessment 

itself, should be a joint effort between scientists 

and planners. Each party needs to evaluate the 

overall program, but responsibility for duties can 

be divided. For example, all parties should consider the following: 

1. Were they able to communicate freely and effectively with each other? If not, how can 

the communication process be improved? 

2. What river-quality problems, if any, need 

further attention to upgrade the working 

knowledge? 

3. How often should a detailed comprehensive 

assessment be made of river quality? 

The resource scientist should address the following questions: 

1. Was the existing data base adequate for conducting the assessment? If not, what improvements could be made in Federal, 

State, and local programs to provide the 

data required for future assessments? 

2. Were the assessment methods adequate for 

the task? What kinds of new methods · 

should be developed for future use? 

The planners, first alone and then with the resource scientist, should consider these questions: 

1. Do the assessments provide the right kind of 

information? If not, what improvements 

could be made? 

2. Were results reported in an easily understandable, easy-to-use form? If not, how 

could understandability and utility be improved? 

These questions are only a framework of the 

kinds of questions that need to be evaluated, discussed, and rediscussed to provide a basis for future efforts. To paraphrase Bella and Overton 

(1972), the quality of the questions we ask now, 

and seek answers to, will determine the quality of 

tomorrow's available information. 

SUMMARY AND DISCUSSION 

Nearly all forms of growth and development 

exert some impact on river quality. Thus, to 

achieve desirable river quality at acceptable cost, 

it is imperative that planning decisions be based 

on sound impact assessments rather than on arbitrary assumptions. 

Comprehensive resource assessments require a 

rational framework for proceeding with scientific 

analysis. The Willamette study was undertaken to 

define such a framework and, also, to develop practical methods and to determine the data requirements for assessing several of the Nation's most 

prominent river-quality problems. 

The procedural framework described in this circular provides only a starting point for assessment 

of river quality. Rivers and their basins are 

dynamic, and the processes and problems within 

them result from the interaction of complex 

natural variables with man's activities and alterations. The dominant problems are usually so complex that desk-top analyses have little likelihood 

of success. Moreover, each river is an entity unto 

itself and must be studied as such. A resource 

scientist must visit and examine a river basin in 

detail to adequately understand the environmental conditions, the problems, and the data needs. 

Each new assessment will require modifications 

of existing methods, and, in some cases, development of new methods. Each intensive study will 

also require the collection of new data. In addition 

to the technical factors, the resource scientist 

needs to build a relationship of mutual understanding with the basin planners and decisionmakers. 

The resource scientist must ask and answer 

many questions to conduct a successful riverquality assessment. Perhaps the three most important questions need to be asked at the beginning of each study: 

1. Have the relevant problems been delineated? 

2. What types of data programs are needed to 

provide a technically sound assessment? 

3. How much time is needed to provide information that is adequate for decisionmaking? 

The ultimate success of a resource assessment is 

largely determined by its initial formulation. 

Careful answers to these questions, together with 

thoroughly defined objectives, will provide a sound 

start to each new assessment. 

A16 
REFERENCES CITED 

Bella, D. A., and Overton, W. S., 1972, Environmental planning 

and ecological possibilities: Am. Soc. of Civil Engineers, 

Jour. Sanitary Eng. Div., v. 98, no. SA3, Proc. Paper 8994, 

p. 579-592. 

Bennett, J. P., 1974, Concepts of mathematical modeling of 

sediment yield: Water Resources Research, v. 10, no. 3, 

p. 485-492. 

Brown, W. M., III, and Jackson, L. E., Jr., 1973, Preliminary 

map of erosional and depositional provinces and descriptions of sediment-transport processes in the south and 

central San Francisco Bay region, California: U.S. Geol. 

Survey Misc. Field Studies Map MF-515. 

---1975, Sediment source and deposition sites and erosional 

and depositional provinces, Marin and Sonoma Counties, 

California: U.S. Geol. Survey Misc. Field Studies Map 

MF-625. 

Collings, M. R., 1973, Generalization of stream-temperature 

data in Washington: U.S. Geol. Survey Water-Supply 

Paper 2029-B, 45 p. 

Executive Office of the President, 1964, Coordination of Federal activities in the acquisition of certain water data: Bur. 

ofthe Budget Circ. A-67. 

Gleeson, G. W., 1972, The return of a river, the Willamette 

River, Oregon: Advisory Comm. on Environmental Sci. 

and Technology and Water Resources Inst., Oregon State 

Univ., Corvallis, 103 p. 

Harris, D. D., 1968, Travel rates of water for selected streams in 

the Willamette River basin, Oregon: U.S. Geol. Survey 

Hydrol. lnv. Atlas HA-273. 

Hines, W. G., Rickert, D. A., McKenzie, S. W., and Bennett, J. 

P., 1975, Formulation and use of practical models for 

river-quality assessment: U.S. Geol. Survey Circ. 715--B, 

p. B1-B13. 

Howells, D. H., 1971, Land use function in water quality management: Water Resources Bull., v. 7, no. 4, p. 162-170. 

Jaworski, N. T., Lear, D. W., Jr., and Villa, Orterio, Jr., 1971, 

Nutrient management in the Potomac estuary: Environmental Protection Agency, Water Quality Office, Tech. 

Rept. 45, 61 p. 

McGauhey, P. H., 1974, Synopsis ofworkshop on modeling the 

eutrophication process, in Middlebrooks, E. J., Falkenborg, D. H., and Maloney, T. E., eds., Modeling the eutrophication process: Ann Arbor Sci., 228 p. 

McKelvey, V. E., 1974, Water quality-is it getting better or 

worse?: Paper presented before the Seventh Internat. Water Quality Symposium, Washington, D.C., April23, 1974. 

Oregon Department of Environmental Quality, 1970, Water 

quality control in Oregon: Oregon Dept. Environmental 

Quality, 28 p. 

Platt, J. R., 1964, Strong inference: Science, v. 146, no. 3642, 

p. 347-353. 

Rickert, D. A., and Hines. W. G., 1975, Methods and data 

requirements for river-quality assessment: Water Resources Bull. (in pressl. 

Rickert, D. A., Schneider, W. J., and Spieker, A.M., 1973, A 

procedure for assessing water resources for urban planning: Water Resources Bull., v. 9, no. 4, p. 768-792. 

Velz, C. J., 1951, Report on natural purification capacities, 

Willamette River: Natl. Council for Stream Improvement 

of the Pulp, Paper, and Paperboard Industries, Inc., School 

of Public Health, Michigan Univ., Ann Arbor, 80 p. 

---1961, Supplementary report on lower Willamette River 

waste assimilation capacity: Natl. Council for Stream Improvement of Pulp, Paper, and Paperboard Industries, Inc., 

School of Public Health, Michigan Univ., Ann Arbor, 28 p. 

---1970, Applied stream sanitation: New York, John Wiley 

and Sons, Inc., 619 p. 

Willamette Basin Task Force, 1969, Main report, Willamette 

Basin Comprehensive Study: Pacific Northwest River 

Basins Comm. Rept., 155 p. 

Wolman, M. G., 1971, The nation's rivers: Science, v. 174, no. 

4112, p. 905--918. 

!:} U. S. GOVERNMENT PRINTING OFFICE: 197 5-0-690-036/10 A 17