Development of a Method for Recommending ...

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Virginia Water Resources Research Center Virginia Polytechnic Institute and State University

Bulletin 152

Development of a Method for Recommending Instream Flows for Fishes in the Upper James River, Virginia

Paul M. Leonard, Donald J. Orth and Christopher J. Goudreau

VWRRC OFFICe; coPy DO NOT R5MOVE

& Bulletin 152

June 1986

Development of a Method for Recommending Instream Flows for Fishes in the Upper James River, Virginia

Paul M. Leonard

Donald J. Orth

Christopher J Goudreau

Department of Fisheries and Wildlife Sciences

Virginia Polytechnic Institute and State University

Project G938-02 VPI-VWRRC-BULL 152

5C

Virginia Water Resources Research Center

Virginia Polytechnic Institute and State University

Blacksburg. 1986

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r

This publication was supported in part by funds provided by the

U.S. Department of the Interior, Washington, D.C.

as authorized under the Water Resources Research Act of 1984, P.L. 98-242.

Contents of this publication do not necessarily reflect

the views and policies of the

United States Department of the Interior, nor does mention

of trade names or commercial products constitute their

endorsement or recommendation for use

by the United States Government.

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ii

List of Figures

.v

List of Tables

vii

Acknowledgments

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Abstract

xi

Introduction

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Additional copies of this publication, while the supply lasts,

may be obtained from the Virginia Water Resources Rese~rc~ Center.

Single copies are provided free to persons and organizations

within Virginia. For those out-of-state, the charge is $6 a copy

if payment accompanies the order, or $8 a copy if billing is to follow.

TABLE OF CONTENTS

Project Scope and Objectives

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Literature Review I. Background II. Office Methods III. Field Methods . IV. Comparison of Methods

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Study Area Description I. James River II. Site Selection Process III. Site Description IV. Biological Description

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Methods I. Temperature II. Habitat Measurements III. Development of Habitat Suitability Criteria A. General . B. Selection of Target Species C. Microhabitat Data Collection D. Habitat Suitability Curve Development IV. Physical Habitat Modeling A. General . B. Data Collection C. Hydraulic Simulation D. Selecting Appropriate Models .. E. Model Calibration and Quality Diagnostics F. Calculation of Weighted Usabte Areas . V. Flow Recommendations " . . . . . . . . . . . . . VI. Relations Between Flow Recommendations Criteria and

Hydrologic Statististics .

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Results . I. Temperature . II. Habitat Suitability Criteria A. Habitat Availability and Coverage B. Curve Quality Evaluation C. Microhabitat Suitability III. Physical Habitat Modeling A. Hydraulic Simulation B. Habitat Simulation . . IV. Flow Recommendations . V. Relations Between Flow Recommendations and

Hydrologic Statistics . VI. Comparisons of Flow Recommendations A. Montana Method . B. Aquatic Base Flow (ABF) Method . . C. Wetted Perimeter . D. Flow Recommendations and Water Availability

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LIST OF FIGURES

1. Map of Virginia, Showing the Location of Study Area in

the Upper James River Basin

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. . . 45

2. Tributary Map of the Upper James River Basin, Showing Major

Tributaries, Candidate Stream Segment Boundaries, Stream Gauging

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Points, and Study Site Locations

3. Gradient Profiles of the Major Tributaries of the Upper James

River Basin with Physiographic Provinces Indicated

. . 48

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4. Example of Optimization Procedure Used to Identify the Discharge

Which Maximizes Habitat for Most Critically Limited Lifestage . . 50

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5. Mean Weekly Temperatures and Temperature Range for Three

Discussion . I. Temperature . II. Habitat Suitability Criteria and Physical Habitat Modeling III. Flow Recommendations . IV. Proposed Office Method for the Upper James River Basin

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Summary and Conclusions

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Figures

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Tables

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Appendices

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Tributaries in the Upper James River Basin

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6. Depth, Velocity, Substrate, and Cover Suitability Curves for Four

Species/Lifestages, Each Representing One of the Four Major

Habitat Guilds: Black Jumprock - Riffle, Smallmouth Bass - Run,

Rock Bass - Pool, and Northern Hog Sucker - Stream Margin . 54

39

7. Relations Between Weighted Usable Area and Discharge (Habitat

Response Curves) for the Four Types of Habitat Versus Flow

Responses Observed

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8. Habitat Optimization Curves for Dunlap Creek for Each

Bibliography

of Four Biologically Defined Seasons

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9. Relations Between Recommended Flows and Stream Size for Each

of the Five Habitat Maintenance Objectives

. 58

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LIST OF TABLES

1. Montana Method for Prescribing Instream Flow Regimens for Fish,

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Wildlife, Recreation, and Related Environmental Resources

2. Physical Characteristics, Boundaries, and Stream Gauging Locations

for Candidate River Segments Considered for This Study 66

3. Physical Characteristics and Hydrologic Statistics of the Four

Study Sites in the James River Basin

. 70

4. Frequency of Occurrence, Frequency of Occurrence as > 1 Percent

of Sample, and Percent of All Fish Collected for Fish Species

at 13 Sites in the James River Basin

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5. Four Most Abundant Fish Species at 13 Upper James River Basin

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Sampling Stations 6. Substrate and Cover Classifications for Microhabitat

Measurements .

. . . 76

7. Target Species Selected for Development of Habitat Suitability

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Criteria and Size Ranges of Each Lifestage

8. Physical Parameters and Number of Habitat Measurements Collected

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at Underwater Observation Sites

9. Phenology Chart for Stream Flow Requirements of Target

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Species and Lifestages

10. Percentage of Days in Each Month for Which Temperatures Equaled

or Exceeded 29°, 30°, and 31 ° C. at Flows Less Than

. . . . 80

or Equal to Specified Flows

11. Summary of Microhabitat Availability Measurements Made

at Snorkeling Observation Sites on Craig and Dunlap Creeks

. 81

12. Number of Microhabitat Measurements, Habitat Guilds, and Curve

Type for Nine Target Species

. . . . . . . . . . . . . . . . ..

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13. Hydraulic Simulation Summary Statistics: Range of Flow Simulated

(Percent of Average Discharge) and Percent Extrapolation

as a Percentage of the Nearest Calibrated (Measured) Flow

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ACKNOWLEDGMENTS

14. Species and Lifestages Exhibiting the Four General Types of Habitat Response Curves and Their Maximum Habitat Flow Range .

.. 84

15. Discharges Recommended to Provide the Optimum Combination of Habitats and Suboptimum Habitat Maintenance with Corresponding Percentages of the Maximum Habitat (WUA) Possible for Individual Species/Lifestages

' . . . 86

16. Flows Required to Provide Percentages of Maximum Habitat Values for Selected Species

17. Hydrologic Statistics and Corresponding Normalized Values for the Four Study Streams 18. Habitat Simulation Flow Recommendations Expressed as a Percentage of Average Discharge .

19. Comparison of Flow Recommendations Using Two Office Methods, Single Transect Field Method, and Habitat Simulation

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We appreciate the cooperation of the following agencies which provided data, aerial photographs, and suggestions during the course of this study: Virginia Water Control Board, U.S, Geological Survey, U.S. Army Corps of Engineers, and the Virginia Commission of Game and Inland Fisheries. Additional financial support for the project was provided by the Department of Fisheries and Wildlife Sciences, Virginia Polytechnic Institute and State University. We thank Thomas W.;.~hnson, Margaret S. Hrezo, and William R. Walker for their advice and continued administrative support. Robert J. Graham and V. Randall Tinsley assisted with field data collection and Jan Doran and Lisa Brumback typed the manuscript. Special acknowledgment is also made to Robert T. Milhous and Ken D. Bovee for advice on hydraulic simulation techniques, and to the following who generously gave their time to critically review the manuscript: Ken D. Bovee, Marshall Flug, John P. Hartigan, Robert T. Milhous, and Michael J. Sale. We thank Lois Cummings for style editing and typesetting the manuscript and for production of the bulletin.

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ABSTRACT Reliable methods are urgently needed for recommending minimum instream "flows to protect aquatic life. For statewide or basinwide planning purposes simple methods which require little or no field investigations are required. We applied the instream flow incremental methodology (IFIM) on four streams in the Upper James River Basin using nine target fish species in the analyses. Flows which optimize habitat for these target species were identified for four seasons. Flow recommendations were also developed using IFIM for meeting lower habitat-maintenance objectives. The recommended 'flows for a given habitat­ maintenance objective increased with increased stream size but the rate of increase was not constant; lower proportions of average discharge were required to maintain optimum habitat as stream size increased. Equations are presented for applying these results to develop flow recommendations for other streams in the Upper James River Basin based on the average discharge. Key Words: James River, Instream Flow, Stream Flows, Smallmouth Bass, Micropterusdolomieui, Water Resources, Habitat Preferences, Minimum Flows

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INTRODUCTION

Free-flowing streams represent one of our nation's most important and valuable natural resources. The functional roles and beneficial uses of water within the stream channel are collectively termed instream values. These values include fish and wildlife population maintenance, aesthetic and recreational activities, navigation, hydropower, waste assimilation and ecosystem maintenance (e.g., estuarine salinity balance, riparian zone maintenance) [Bayha, 1978]. Although the value of offstream uses of water (irrigation, industrial and domestic water supply, cooling) have long been recognized, until recently instream values have been largely ignored. The decline in quality and extent of 'free-flowing stream systems is rapid and in direct proportion to development of water for offstream uses [Stalnaker, 1979]. The increasing demand for water to support population growth and expanding economic development coincides with rapidly increasing use of rivers and streams for recreational and aesthetic purposes. To resolve the potential water-use conflicts and allocate water for offstream uses, we must first identify the instream flow needed to maintain the integrity of our streams and instream values at acceptable levels. Conflicts between instream and offstream uses of water are predicted to become more acute as a result of the estimated 27 percent increase in consumptive water use nationwide by the year 2000 [United States Water Resources Council (USWRC), 1978]. Withdrawal of water from the stream, however, constitutes only one category of stream flow impacts. Stream regulation associated with flood control and hydroelectric power generation modifies the timing, magnitude, and duration of stream flows. The negative impacts of such flow alterations have been identified [Corning, 1969; Ward and Stanford, 1979; Hildebrand, 1980; Walberg et al., 1981; Brooker, 1981; Cushman, 1985] but not quantified. Significant conflicts between instream and offstream water uses first developed in the western United States, where water supplies are scarce and great demands are being placed on offstream uses. As of 1975, the total use of water (consumplive plus instream uses) exceeded the total available average stream flow for river basins in thirteen western states by an average of 67 percent [Bayha, 1978; USWRC, 1978]. Considering the same situation in dry years, few river basins escaped such deficits. Encroachment of out-of-stream water use on optimum instream conditions is occurring throughout most of the west. Although Virginia is generally considered to be a water-abundant state, disparities in seasonal and geographic patterns of water availability and population distribution have created localized water supply shortages [Cox and Walker, 1979]. These shortages are especially acute in the populous northern

and southeastern sections of the state. Examination of recent water supply problems and controversies highlight the magnitude of this problem. In a report to the Virginia State Water Study Commission, Cox et al. [1981] provided an assessment of water use and availability for 27 hydrologic planning areas (HPA) in Virginia. Comparisons of projected water needs through the year 2000 with minimum instream flow (ISF) standards indicated that consumptive use violates ISF standards in three HPAs under low flow conditions [Cox et aI., 1981]. The overall assessment indicates that problems of stream flow allocation are limited and basin-specific. However, the potential for local stream flow availability problems within HPAs is much higher [Cox et aI., 1981]. The ISF standard used in the Cox et al. study was the 10 percent of average annual flow criteria of Tennant [1976]; such flows lead to degradation of aquatic and riparian habitat, stress on fish and invertebrate populations and reduced recreational and aesthetic conditions [Tennant, 1976]. Re-evaluation with a more appro­ priate ISF standarq may indicate more pervasive stream flow allocation conflicts. Other highly visible examples of actual and potential water conflicts in Virginia emphasize increasing demands on limited water resources: proposed with­ drawal of water from Lake Gaston by Virginia Beach [Walker and Bridgeman, 1985]; municipal water supply impoundment for the City of Roanoke and; water needs for the coal slurry pipeline [Cox, 1983]. Alternatives for alleviating local water supply problems, such as small impoundments and interbasin transfer, often only redistribute the problem. Impacts associated with these options include negative effects on aquatic organisms [Spence and Hynes, 1971 a, 1971 b; Lehmkuhl, 1972; Ward and Stanford, 1979], losses of valuable fisheries [Smith, 1979], and associated reductions in recreational opportunities and expenditures. As demand for water continues to increase, more states are developing compre­ hensive water management plans to determine how best to allocate the limited supplies. Protection of instream values must be a fundamental component of any such plan [Trihey, 1979]. Virginia water resource management agencies are charged under state law to estimate, for each major river and stream, the minimum instream flow necessary to maintain water quality and avoid permanent damage to aquatic life. However, lack of proven methods for developing instream flow recommendations in eastern states hampers such efforts. Because of the large number of streams in Virginia and money­ manpower constraints of water management agencies, methods developed and used in Virginia must be simple, require little or no field investigation, and be completed in a short time.

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PROJECT SCOPE AND OBJECTIVES The purpose of this document is to provide a tool to water resource managers for recommending suitable instream flow regimes for protection of fish habitat in smallmouth bass (Micropterus dolomieui) streams in the Upper James River Basin. Our approach was to develop a simple method for making instream flow recommendations that can be formulated on the basis of stream hydrologic parameters. A wide range of stream sizes were investigated so that the results can be applied to other streams in the basin. The proposed method uses only stream size related hydrologic data for making streamflow recommendations, but is soundly based on the analysis of the habitat preferences of warmwater fish species and hydraul ic-habitat simulation of streams using the instream flow incremental methodology (lFIM). This habitat-based approach quantifies the amount of "potential" fish habitat at various discharges as the basis for flow recommendations. Several existing instream flow methods are also considered and evaluated for use in Virginia and their flow recommendations for the study streams compared. In deriving a range of possible flow recommendations, optimization techniques were used to integrate the habitat versus flow response of the various target species. Flows which provide the best combination of habitat availability were identified for each season. With the optimum flow defined, flow regimes providing various percentages of that optimum were considered relative to flows normally available in the streams. The results of this study provide a method for recommending flows based on a range of possible fish habitat-maintenance objectives. Establishment of final instream 'Flow standards must be made based on the objectives of resource management agencies and adjusted for political and social considerations. Water quality is an important component in developing instream flow recom­ mendations, but was not integrated into the design of this study. Where water quality is currently or potentially unsatisfactory, approaches other than those outlined in this report are warranted (Le. water quality modeling). The proposed method should be tested in and used as a model for other regions of Virginia, but should not be applied outside the Upper James River Basin without validation.

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LITERATURE REVIEW: INSTREAM FLOW METHODS

I. Background During the past two decades, numerous methods have been developed to identify instream flow needs for fishery resources [see reviews by Stalnaker and Arnette, 1976; Wesche and Rechard, 1980; Loar and Sale, 1981]. These methods differ in their use of hydrologic records, hydraulic simulation tech­ niques, the degree to which they incorporate the habitat needs of aquatic organisms and in the type of flow recommendation they yield. Consequently, their data requirements, costs, level of complexity, and degree of resolution vary greatly. Basically, two types of flow recommendations exist; threshold and incremental (dynamic). The majority of methods developed to date yield threshold recom­ mendations [Annear and Conder, 1984]. These are single-flow recommen­ dations, limited in their ability to incorporate biological or hydrological infor­ mation, and incapable of evaluating the effects of alternative flows. Methods yielding incremental recommendations are capable of addressing the need for seasonally adjusted flows based on species habitat requirements for a continuum of possible stream flows and management alternatives. Selection of an instream flow method is dictated in part by the degree of resolution needed to fulfill specific planning or management objectives. Often only preliminary or reconnaissance-grade flow recommendations are needed (low priority cases, early stages of water project planning, etc.), and some of the more simple office methods are applicable. When seasonally adjusted flow needs based on a range of potential objectives (e.g. water allocation, fisheries maintenance flows) are required, the more complex field methods must be used. Instream flow methods have evolved along two lines: office and field methods. The characteristics of these methods and their applicability in Virginia are discussed in detail in the following sections. II. Office Methods

Most office methods can be called "discharge methods" because decisions concerning instream flow needs are based only on historical flow records [Loar and Sale, 1981]. These require low time and financial input but do not provide information for assessing flow· habitat trade-offs. The basic assumption common to these methods is that aquatic biological resources present in a stream are a function of past discharges. Flow management then is directed at conserving those past conditions [Loar and

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Sale, 1981]. Of these methods the preferred approaches are those based on flow duration data because they provide the most realistic representation of natural stream flow variability [Stal naker and Arnette, 1976], an important determinant of riverine fish community structure [Horwitz, 1978]. Two existing office methods are sometimes used in Virginia, the Montana method [Tennant, 1976] and the aquatic base flow (ABF) method [United States Fish and Wildlife Service, 1981]. The Montana method [Tennant 1976], the most widely used of the office methods is based on field studies of eleven streams in Montana, Wyoming, and Nebraska. The results suggested that the condition of the aquatic habitat is similar for those streams when carrying the same percentage of the average flow. General flow recommendation guidelines (Table 1) were developed by Tennant [1976]: 10 percent of the average discharge (AD) is the minimum instantaneous 'flow needed to sustain short-term survival habitat; 30 percent AD maintains good quality habitat for aquatic life; optimum habitat occurs at 60-100 percent AD; and 200 percent AD provides sufficient flushing flows. The Montana method must be modified for different low flow season if applied in Virginia. The aquatic base flow (ABF) method, used by the United States Fish and Wildlife Service in the New England area, uses a combination of median flow and constant watershed yield statistics to formulate minimum flow recommendations [USFWS, 1981]. This method uses the August median monthly flow (MMF) as the minimum instantaneous recommended flow for all periods of the year. It is applicable only to unregulated streams exceeding 50 sq. mi. drainage area with good historical flow records. (~ 25 years and ± 10 percent accuracy of gauge). For streams not meeting these criteria, a constant yield factor (0.5 cfs/sq. mi.) is used to estimate actual flow conditions. Seasonal recommendations for spawning and incubation periods are estimated as 100 percent MMF for that period. In Virginia ABF for ungauged sites can be estimated as 0.26 cis/sq. mi. or should be base~ on MMF for September [Jean Gregory, SWCB, pers. comm.]. The office methods developed to date must be tested to determine the level of habitat protection provided before they can be applied with confidence in Virginia. Differences in the minimum flow recommendations of these and other methods proposed for use in eastern states [Robinson, 1969; Chiang and Johnson, 1976] reflect the lack of general consensus of office methods as to what flows satisfy the needs of the aquatic environment. The Montana method has been criticized due to failure to account for regional differences in hydrology and stream channel geometry [Stalnaker and Arnette, 1975; Nehring, 1979; Annear and Conder, 1984]. As a result, it could yield recommended flows not normally available or unprecedented low flows [Nehring, 1979; Hilgert, 1982]. This could be especially problematic in Virginia, a geologically diverse state. Most investigators reviewing or comparing instream flow methods concur that field methods are superior [Nehring, 1979; Wesche and Rechard, 1980; Loar

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and Sale, 1981; Hilgert, 1982]; therefore, field methods should be used if time, resources, and significance of water use conflicts warrant them.

III. Field Methods Field methods have been developed for analyzing habitat-flow relationships in different geographic regions and for various fish species. While the intensity of fieldwork required differs, the basic data collection tool, the cross-channel transect, is the same [Wesche and Rechard, 1980]. Most field methods develop a response relationship between a parameter descriptive of habitat condition and stream flow [Loar and Sale, 1981]. This can range from a single parameter such as wetted perimeter, to a composite of several fish microhabitat parameters such as weighted usable area [Bovee and Milhous, 1978]. Site-specific hydraulic and stream channel measurements are collected along transects across a stream channel and are used to describe the aquatic habitat. In most cases, habitat conditions at unmeasured flows are estimated by hydraulic simulation techniques covering the range of complexity from simplified staff-gauge analysis [Loar and Sale, 1981 ]tostate-of-the-art computer hydraulic models[Milhouset aI., 1984]. The resulting flow recommendations are made on the basis of actual habitat conditions rather than on stream flow statistics. The bulk of the field methods proposed to date were developed in western states for coldwater streams. Many are specifically designed to address spawning, incubation, or passage habitat requirements of salmonids and have little applicabilityto Virginia streams. Others evaluate general habitat conditions and could be applied in eastern streams where the habitat requirements of indigenous fish species were known. In differentiating the various field methods the most important component is how the data is used to arrive at the final flow recommendations. That is, what decision criteria are used and what assumptions are implicit in their use. To illustrate this point, general examples will be examined. Several field methods use or incorporate wetted perimeter (distance of wetted stream bottom) as a decision variable [Collings, 1972; Rose and Johnson, 1976; Nelson, 1980]. It is assumed that a direct relationship exists between wetted perimeter and fish habitat or area fC'r benthic insect production. The instream flow recommendation is made at the inflection point of the wetted perimeter versus discharge curve belowwhich further reduction offlowyields an increased rate of habitat loss. The major drawback of wetted perimeter methods are that inflection points are identified subjectively (Annear and Conder, 1984]. Lack of clearly defined inflection or multiple inflection points and complex channels cause further complications. As a result, recommendations can vary between investigators.

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Some field methods can be grouped by their use of the concept of habitat retention. In these methods transect measurements of hydraulic parameters and, in some cases, subjective habitat quality evaluations are used to "quantify" the general habitat [Chrostowski, 1972; Dunham and Collotzi, 1975; Silvey, 1976; Nehring, 1979]. The amount of habitat satisfying certain criteria or relative to a reference habitat value are calculated for a range of flows. Stream flow recommendations are made at flows where two or more criteria are met or the minimum acceptable habitat retention value is reached for the appropriate stream size and habitat type. The major assumption here is that the defined flow is as adequate for the rest of the stream as it is for the specified segment or habitat type [Annear and Conder, 1984]. Generally considered to be the most advanced and comprehensive of the field methodologies available is the U. S. Fish and Wildlife Service's instream flow incremental methodology (IFIM) [Stalnaker, 1979; Wesche and Rechard, 1980; Loar and Sale, 1981; Bovee, 1982]. This methodology combines detailed hydraulic simulations with multiple transect data and species-specific habitat su itabiIity fu nctions. The decision variable of th is methodology, weighted usable area (WUA) as a function of discharge, used alone or in conjunction with streamflow records, provides a great capacity for evaluating various management objectives and impacts from agricultural, municipal, or other water development projects.

the models investigated [Nehring, 1979; Prewitt and Carlson, 1979; Nelson, 1980; Loar and Sale, 1981; Hilgert, 1982; Orth and Maughan, 1982; Annear and Conder, 1984]. Often the results of several different methods will yield reasonably similar recommendations. [Nehring, 1979; Prewitt and Carlson, 1979; Orth and Maughan, 1982]. This can be especially true when using different hydraulic simulation techniques with identical required flow criteria [Nehring, 1979]. Annear and Conder [1984] reported that the Montana method and two habitat retention methods were least biased and wetted perimeter methods and IFIM were biased relative to the mean of all recommendations. However, while some methods may yield similar or more consistent estimates, this is not equated with accuracy or model capability. Methods yielding variable recommendations for different stream types or sizes may be more biologically accurate than methods found to have consistent tendencies [Annear and Conder, 1984]. Most comparative studies concur that methods that generate single-flow recommendations are inadequate, inflexible, and promote the incorrect assumption that only flows below some minimum are detrimental to aquatic life. Any instream flow method for fisheries should be based on biological data, defensible, and capable of evaluating various management objectives.

Some important assumptions of the instream flow incremental methodology (IFIM) have yet to be adequately tested in warmwater streams [Orth and Maughan, 1982; Mathur et aI., 1985]. The most fundamental assumption is that of a positive linear relationship between weighted usable area and fish biomass. Orth and Maughan [1982] reported significant correlations between WUA and standing stock only for some species and seasons investigated. However, Wesche [1976] found a high correlation between standing crop (r=O.85) and biomass (r=0.9) and weighted usable area for brown trout (Sa/mo trutta). Nelson and Bovee [1984] found similar results for rock bass (Amb/op/ites rupestris) and concluded that IFIM habitat simulation can be effective in identifying flows at which physical habitat may be limiting to one or more life stages of a species. Recent studies by Loar et al. [1985] also support the validity ofthe WUA-biomass assumption when minimum habitat values calculated for the entire period that a given Iifestage is present are used. While some criticism of this methodology remains [Mathur et al. 1985], evidence to date supports the validity and utility of the incremental habitat simulation approach.

IV. Comparison of Methods Some recent studies have addressed the issue of which method is best suited for a particular situation and provided comparisons of the final recommendations of

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STUDY AREA DESCRIPTION I. James River The James River Basin is the largest river system in Virginia, comprising over 25 percent of the total area of the state (Figure 1). From its origins in the Appalachian Mountains in the western part of the state, it bisects four major physiographic provinces as it flows to its mouth in the Chesapeake Bay. Geologic characteristics, predominant land and water uses, and stream characteristics differ in each of these regions. The James River Basin upstream of Lynchburg is the focus of this study. The drainage area of the upper basin as defined here is 3259 square miles [U.S.G.S. gauge 02.0255.00 at Holcombs Rock] lies primarily within the Valley and Ridge physiographic provinces. A summary of drainage area and flow statistics for several major gauges in the upper basin are presented in Table 2. The streams and rivers of the region are physically diverse. In the Ridge and Valley province, trellis drainage patterns predominate. Small high gradient streams, often intermittent, join lower gradient larger tributaries in valleys. Larger streams have relatively high base flow due to large storage of ground­ water. Both small and large streams are characterized by meandering, slow moving sections and fast moving riffles and rapids. Pool-riffle ratios vary from 30:70 in smaller streams to 70:30 in larger rivers [Raleigh et aI., 1974]. Cobble and gravel sub~trates predominate. Land uses in the upper basin include forest, agriculture, and urban-industrial development. However, the majority of the area is forested (Jefferson and George Washington national forests), and relatively little development or environmental degradation has occurred. Overall, population density is relatively low except in the areas around the cities of Covington, Lexington and Buena Vista. The major water uses in the upper basin include municipal and industrial water supply, recreation, and waste assimilation. The only major dam on the upper basin is Gathright Dam on the Jackson River, designed primarilyforflood control. Several low-head dams exist in the upper basin, but no major hydro­ power sites are planned in the near future. II. Site Selection Process Streams in the Upper James River Basin were divided into segments exhibiting similar channel characteristics and flow regime as outlined by Bovee [1982] and Trihey and Wegner [1983]. Stream segment boundaries were identified at abrupt changes in channel pattern, structure, or gradient, and at confluences

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with major tributaries (Figure 2). Segmentation was done using United States Geological Survey(U.S.G.S.) 7.5 minute topographic maps and gradient profiles developed from them (Figure 3). Aerial photographs aided in identifying channel structure changes. Stream segments within the preferred gradient range of smallmouth bass [Trautman, 1981; Edwards et aI., 1983]andwithincloseproximitytoa U.S.G.S. gauge having a long period of record were considered as candidates for the study (Table 2). Study sites were selected from within the homogenous stream segments using the representative reach concept [Bovee 1982; Trihey and Wegner 1983] to be representative of the microhabitat characteristics of that segment. Final criteria for selection of study sites included: (1 )field inspection to verify that study sites accurately represented stream segments; (2) landowner permission; and (3) all-season boat access. These sites were then used for the study of microhabitat conditions.

III. Site Description The four study sites selected represent distinct stream sizes; stream order ranges from three to five, drainage area ranges from 164 to 1373 square miles, and mean daily discharge ranges from 166to 1603 cubic feet per second (Table 3). The seasonal pattern of discharge is very similar among the four study sites (Table 3). Mean channel width, and percentage of run/pool and pool habitat exhibit consistent increases with stream size (Table 3).

IV. Biological Description Fish sampling was conducted at sites throughout the Upper James River Basin by Raleigh et al. [1974]. We summarized their data for 13 main stem and larger tributary sites with gradients less than 25 feet/mile to characterize the fish species composition and relative abundance in our study streams (Table 4). Fish assemblages in the Upper James were similar to other smallmouth bass streams reported by Funk [1975]. A total of 46 species were collected but four species, usually cyprinids and centrarchids, typically comprised the majority (50-72 percent) of individuals at a site (Tables 4 and 5). The most abundant cyprinids were bluehead chub, common shiner, rosefin shiner, bull chub, and stoneroller. The most abundant centrarch ids were redbreast sunfish, rock bass, and smallmouth bass. The most common species in other families represented were: white sucker, black jumprock and northern hog sucker (Catostomidae); mottled sculpin (Cottidae); chain pickerel (Esocidae); margined madtom (Icta­ luridae); and fantail darter and Roanoke darter (Percidae).

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METHODS I. Temperature Temperature is one of the most important environmental parameters which affects the biota of an aquatic system [Macan, 1961; Hubbs, 1972; Stauffer et aI., 1976]. An important question in this study is whether historical temperatures entered unsatisfactory ranges during warm months at naturally occurring low flows. To determine if temperature must be considered as a factor in developing flow recommendations in this region of Virginia, temperature versus flow relations were evaluated using daily temperature and discharge data for James River at Buchanan for the period April 1968 through September 1983 [USGS, 1984]. The potential for temperature problems is greatest at the larger James River sites because they are more exposed to direct solar insolation, exhibit slower heat loss, and contributions of cooler groundwater are less. Comparison of temperature-flow relationships with the thermal tolerances and preferred optimum temperatures requirements of resident warmwater fish species [Horning and Pearson, 1973; McFarlane et aI., 1976; Stauffer et aI., 1976; Christie, 1981; McCrimmon and Robbins, 1981] should identify flow levels at which temperature could become a problem. Similarities in the acute temperature preferences among species within a family [Mathur et aI., 1983] suggests that examination of a few representative species should be sufficient. Based on the results of these studies, it was decided that temperatures equal to and above 29 0 C would be stressful to some fish species. Temperature versus discharge frequency tables for each month were then examined to gain some general information on the discharges related to the high temperature periods. Regression analysis was used to investigate the relationship between daily temperature and discharge values for each month and all months combined. Since highest stream temperatures during summer are most often associated with extended periods of warm weather and low discharges, additional lag variables, mean water temperature and mean discharge during the previous 7 and 14 days were calculated and used as regressor variables. All data were 10910 transformed. Various candidate simple and multiple linear regression models were tested in order to identify those providing a good fit to the data and predictive capability. Temperature data from continuous monitoring thermographs placed in the Maury River and Craig Creek sites and the Cowpasture River during the study period were also examined.

13

II. Habitat Measurements Many factors potentially affect habitat quality and quantity and the response of fish species or populations to changes in habitat [Terrell et aI., 1982]. The IFIM focuses on variables most directly affected by changes in stream flow: water depth, velocity, substrate, cover, and temperature. Morphological [Keast and Webb, 1966; Gatz, 1979], ecological [Mendelson, 1975; Gorman and Karr, 1979; Shirvel and Dungey, 1983], and behavioral [Hartman, 1965; Gee, 1974; Moyle and Li 1979] evidence suggests that many stream fishes are closely associated with specific microhabitats defined by these variables. Methods used to measure water depth and velocity and to evaluate substrate composition and cover types present were identical for development of habitat suitability criteria and physical habitat modeling. At each point of interest in the stream, depth (nearest 0.1 feet) was measured with a wading rod or sounding cable, current velocity (0.01 feet/second) was measured at 0.6 of the depth from the water surface with a pygmy current meter, and dominant-subdominant substrate and cover types within a three-foot radius were classified according to a modified Wentworth scale [Bovee and Cochnauer, 1977] and a cover type description, respectively (Table 6), and given numerical codes.

III. Development of Habitat Suitability Criteria A. General The biological component of stream habitat simulation is represented by fish species habitat suitability criteria. These criteria are used to translate predicted changes in the physical stream environment into predicted changes in usability of a stream area by a species or lifestage of concern. Habitat suitability curves define the tolerated and optimum ranges of selected habitat variables for each species. To develop these curves, optimum ranges of habitat values are assigned preference values equal to one and least preferred or unsuitable ranges are assigned values near zero. Bovee and Cochnauer [1977] describe methods for developing habitat suitability curves; frequency analysis of habitat variables measured at individual fish locations was the preferred method and was used in this study. There are two general classes of habitat evaluation criteria: (1) utilization curves, and (2) preference curves. Habitat utilization curves are derived solely from measurements of physical habitat variables at sites where organisms were located or from general descriptions of fish habitat use. Habitat preference curves represent utilization data corrected for bias due to unequal habitat

availability [Baldridge and Amos 1981; Johnson 1980; Orth and Maughan 1982]. The validity of habitat suitability curves is based on several assumptions which are discussed in detail by Bovee and Cochnauer [1977], Smith et al. [1979], Orth and Maughan [1982], and Orth et al. [1982]. B. Selection of Target Species Development of stream flow recommendations from habitat simulations are highly dependent upon the fish species selected and the accuracy and reliability of their habitat suitability curves. Flow recommendations affect, and therefore must be made for, the entire fish assemblage. Our approach is designed to select target species representative of the major trophic and habitat guilds that comprise the fish assemblage of typical small mouth bass streams. The assumption is that adequate protection of habitat for target species will also protect the others. Target species were selected from a list of candidate species using the following criteria. First, the species should be a desired gamefish or perform some key role in the aquatic community. For example, rock bass and small mouth bass are desirable and economically important gamefish and, as top predators, regulate the abundance of other species. Abundant nongame, forage species are important in energy transfer between trophic levels. Second, the species should be common in most streams that support small mouth bass and be representative of other species which utilize common resources. Representatives of dominant taxonomic groups found in smallmouth streams are minnows, suckers, and sunfish [Funk, 1975]. Abundant species [Raleigh et aI., 1974] were selected considering both feeding and habitat guilds [Minckley, 1963; Starrett, 1950; Schlosser, 1982]. Finally, there should be adequate habitat suitability criteria available or the data should be readily collectable during the study. We divided our efforts equally between developing curves for species with little or no available habitat suitability information and evaluating/verifying curves developed in other regions. Nine target species (Table 7) were selected from among the candidate species. C. Microhabitat Data Collection Collection of species microhabitat data was performed during three separate periods. The earliest collection period (15 May 1984; 15.5° C) was specifically for spawning northern hog suckers at the Little River, Virginia. Fish were located and captured at spawning sites using boat-mounted electrofishing gear. Flow reduction on this regulated stream following collection of microhabitat utilization data precluded collection of habitat availability data. The second habitat use data collection period (May-August 1984; 19.5-27.5° C) 15

14

•

includ~s observations at th~ M~ury R.iver study site made concurrently with collection of data for hydraulic simulations. With the exception of some small­ mou~h b~ss nests located by snorkeling, nests or individuals of the following specles/llfestages were located from a boat shore or by wad' . db f ' ' , l n g . re reast sun Ish spawmng, rock bass spawning, chub spawning, and northern hog sucker young-of-year (YOY). The thir~ period i.ncludes microhabitat use data collected only by underwater observation. Hablta.t availability data was collected concurrently. These data we~e collected dunn~ late summer and early fall with water temperatures typical of low water penods (Table 8). Consequently, preference curves developed re~resent s~mmer and early fall habitat use. Underwater observation (snor­ keling) was JUdge~ to ~e the least biased method to locate undisturbed fish for the selected combination ~f target species and the wide range of habitats to be sampled [Northcote and Wilke, 1963; Goldstein, 1978; Sale and Douglas 1981' Hel!man, ~ 984]. Craig an~ Dunlap Creeks were selected for sampling b~caus~ their consistent water clanty and small size allowed full coverage of the stream by two observers. Visua I observations of fish locations were made between 1000 and 1500 h .. . ours ( fir h op Ima Ig t cond~tlons) In a fu II range of habitats. Water visibil ity was measured and rec?rded and In all cases well exceeded minimum standards suggested for snorkeling obs~rvations [Hickman and Saylor, 1984]. Fish were located as divers ~oved SI~~ly In an upstream direction. Undisturbed fish were observed for a tlm.e .sufflclent to. determi~e and record species/lifestage (size class) (Table 7), act~vlty, focal pOInt of microhabitat use, and type of cover being utilized A welghte~, numbered I?catio~-marker was placed to identify that point. U~on completion of snorkeling, microhabitat variables and marker number were recorded at each location-marker. To qu~ntify .habitat availability, we established a grid of possible random

sampling POints over the area of stream observed. A measuring tape was

extended t~e lengt~ of the study site with perpendicular transects every three

feet and microhabitat sampling points every three feet along each transect.

Transects were selected at r~ndom until the number of sampling points equaled

or exceeded the number of fish habitat utilization measurements (Table 7).

D. Habitat Suitability Curve Development !he continuous microhabitat variables, depth and velocity, were divided into Intervals. Fr~uency of utilization and availability measurements in each of the dept~, velocl~, substrate, and cover categories were tabulated for each site by sP~cles and IIfestage. For preference curves the relative use of each category of vanable was calculated as the percent utilization divided by percent availability 16

in its respective interval. Relative use values for a variable were normalized by dividing each relative use value by the maximum relative use. This yielded a preference value ranging from one (most preferred) to near zero (least preferred). The resulting preference values were evaluated and used to draw habitat preference curves as follows. The range of intervals with the highest preference values were assumed to represent the optimum range of that variable for a species/lifestage. We attempted to avoid bias due to high preference values based on very few fish observations «3) or locally low habitat availability by not considering such values. Locally low availability was defined as categories with abnormally low availability relative to adjacent categories. At this point in the curve development process we had three unique estimates of the microhabitat preference values of each species, one for each study site (two for species not found in Dunlap Creek). One curve was constructed from the estimates by redefining the optimum range to include the previously defined optimum ranges for all sites. The forum for finalizing the habitat suitability curves combined curves developed from our data, curves obtained from the literature and other sources, and the professional judgements of the biologists involved in snorkeling surveys. In most cases differences between curves could be attributed to differences in curve type (utilization versus preference), available habitat, or sampling gear. Some dissimilarities implied real differences in preference. The final curve form was a result of iterative examination and adjustments based on the available data and judgement of the biologists until a consensus was reached. IV. Physical Habitat Modeling

A. General The physical habitat simulation (PHABSIM) system is a collection of computer programs developed to simulate physical habitat in a stream in relation to flow regime. Various elements of fish behavior and open channel hydraulics are simulated and the result combined to describe the effect of changes in streamflow on fish habitat conditions. The three most important major system components are the hydraulic programs (physical component), species suitability criteria data base (biological component) and the habitat program, which combines these two components to calculate the amount of habitat available at various flows.

17

log10 (discharge) data for each transect and 10 . data for each vertical. Edge cell vel 'f g10(veloclty) versus log10(discharge) equation and were calibrated by adjUS~~ les were calculated using Manning's results from an IFG4 simulation ~nts to cell roughness values. Accurate relationships being log-linear over t~re fl ependant u~on: (I) stage-discharge distribution within the channel' . ~ ow range of Interest; and, (2) velocity IS simi ar over the flow range of interest.

Data Collection Jr collection of field data required for PHABSIM models followed the pro­ dures outlined by Bovee [1982] and Trihey and Wegner [1983] needed for ~scribing channel structure and stream flow parameters. Within each study te, six to eight transects were established at hydraulic controls and over major 3bitat types. Transect ends were permanently marked by headstakes using mcrete reinforcing bar (rebar). A permanent benchmark was established and iven an arbitrary elevation. Headstake elevations relative to the benchmark ,ere measured with a level and a surveying rod to the nearest 0.03 feet. listance and bearing between headstakes were recorded for headstake ~Iocation and making scale drawings. Streambed elevations were measured nd substrate type classified at 32-79 fixed intervals along each transect. At ~ast one complete water surface elevation summary was made at each site luring steady flow as required for the water surface profile (WSP) hydraulic nodel [Bovee and Milhous, 1978]. Depth and velocity were measured at >reviously established intervals along transects and water surface elevations Nere measured for at least 3 different stream flows. An attempt was made to l1easure hydraulic parameters at equally spaced flow intervals spanning one

D. Selecting Appropriate Models Upon completion of data collection, a ro r" '" were selected using the followin ~~ p la~e hydraulic simulation techniques transect at all sites were: g gnostic parameters. Evaluated at each i

,

i i

1. log10 (stage) versus log10 (dischar ) I . calibration flows' ge pots and reSidual error at 2. plots of velocity distributions at all -Flows' 3. cell roughness (Manning's n) I ' . . hydraulic radius; and va ues and their relationship to cell

'.

Ii

i

j

4. residual errors and slope values at cal"b . versus log10 (discharge) regressions. I ration flows for log10 (velocity)

1,1

Ii 'It

,

'

1\ \

i I

'

1

.

order of magnitude. C. Hydraulic Simulation

Where non-linearity or excessive residual err . relationship suggested that the IFG4 od ~r In the. stage-discharge m el was inappropriate for predicting stage, WSP was used.

I':

The type of hydraulic simulation technique appropriate for a given situation depends on the degree of resolution required, the characteristics of the stream, and the assumptions and limitations inherent in the hydraulic models [Bovee and M iIhous, 1978]. Several techniques are available for prediction of the stage discharge and velocity distribution-discharge relationships. These techniques can be used separately or in conjunction to obtain an accurate simulation under various conditions. The WSP program, an open channel flow model, is an analytical approach that utilizes the Manning and Bernoulli equations [Chow, 1959] to predict stage and cell velocities based on a single set of field measurements. This model is appropriate only under conditions of uniform or gradually varied flow. Channel roughness and energy slope must be assumed constant at all flows unless multiple calibration measurements sets are collected [Bovee and Milhous, 1978]. The WSP model was calibrated by iterative adjustments of channel and cell roughness values until stages and mean cell velocities match those measured in the field. The IFG4 model is a more accurate empirical technique, requiring field measurements from at least three widely spaced discharges. The IFG4 model was calibrated by fitting linear regression equations for the log10 (stage) versus

18

\; ii

l. '~;."

>,

'i

I

1)"1

f

\ \

'

I:

Where substantial shifts in velocity distributions . at different flows were detected the regression approach (I FG4) f l ' . .' .. or ve oCltles was not . velOCities measured at any calibr f fl appropriate. In thiS case distribution in that discharge ran:el~~ o~ were ~ore representative of velocity flows to be simulated were divid d ~n t at predicted by re~ression. Therefore, velocities measured at the close: c~~~~~~nges, each being represented by Simulated separately using stages cal I d n flow. Each range of flows was predicted using Manning's equation ~~I~te USIn~ IFG4 or WSP and velocities measured velocities. This procedure' t bradt~? .uslng the corresponding set of IS erme Single-velocity IFG4" simulation.

E. Model Calibration and Quality Diagnostics

I

I'

When the appropriate model or combination of were calibrated and the quality of sim I f 0 models was selected, the models t~ make final corrections and ad' u: Ions evaluated. The objective here was Simulation, and define the range off~uS ments, e~aluate the reliability of the be expected. The IFG4 model has se~ws ov~r whlc~ accurate simulations could WSP is subjective. eral diagnostic features but evaluation of In this study the WSP model was used only for prediction of water surface

19

&

elevations for portions of Dunlap Creek and Maury River. For this purpose, the WSP model is considered to be calibrated when close (0.01 - 0.03 feet) agreement between predicted and observed water surface is obtained. To increase the accuracy of WSP simulations we developed roughness modi'fiers and placed bounds on roughness values to avoid exceeding values expected at that site [Robert T. Milhous, Cooperative Instream Flow Group, pers. comm.]. At all sites we used either combinations ofWSP and IFG4 orthe "single-velocity IFG-4" simulations because shifts in velocity distributions at different flows or nonlinearity of stage-discharge relationships occurred. Therefore, the standard si mulation diagnostics from IFG4 (velocity prediction errors, velocity adj ustment factors, see Milhous et al. [1984] are not available. We used velocity adjustment factors obtained with the standard IFG4 model to provide a conservative estimate ofthe simulation range and quality, assuming that any modifications to simulations result in a more accurate representation of microhabitat in the stream. F. Calculation of Weighted Usable Area In the third phase of PHABSIM, the biological information for target species is incorporated. The utility of each cell for a life stage of a species is evaluated by the application of microhabitat suitability criteria. The HABITAT program calculates the amount of physical habitat weighted by its suitability for each target species. For each cell (i) a composite weighting factor Si for suitability was obtained as follows:

SFSv x Sd x S9 X Sc where:

Sv =suitability for the velocity in cell i

Sd = suitability for the depth in cell i

S9 = suitability for the substrate in cell i

Sc = suitability for the cover in cell i

Suitability weighting factors are obtained from the habitat suitability curves for target species. The estimate of the amount of usable habitat is called weighted usable area (WUA): n

WUA=ISiAi i = 1 Where Ai is the area of cell i and n is the number of cells in the stream reach. This computation is repeated for each discharge of interest resulting in a WUA versus discharge relationship for each target species and Iifestage. The effect of various stream flow regimes can then be assessed based on estimated changes in available habitat.

20

V. Flow Recommendations Flow recommendations were developed for four seasons: (1) winter non­ spawning, December-March; (2) early spawning, April-May; (2) late spawning June-July; (4) fall non-spawning, August-November. These periods were biologically defined based on species life history and presence of various lifestages (Table 9). For example, the early spawning period includes juvenile and adults of all species, all spawning lifestages except redbreast sunfish, and excludes all young-of-year (YOY) lifestages which are not yet present (Table 9). When defining the optimum flow, the flow requirements of all species/lifestages were integrated as follows. The WUA versus flow data for all species were combined into matrix format, columns representing each species present during that season and rows representing stream discharges to be considered. The elements of the table are the percent of the maximum attainable WUA value at that site for each species at each specified stream flow (i.e. normalized habitat values). The minimum of these percentage values is calculated for each discharge (row). The optimum flow is equal to the discharge (row) with the greatest minimum percentage. Illustrated graphically, the optimum flow occurs at the peak of the curve of the minimum percentage of the maximum habitat versus discharge plot (optimization curve) (Figure 4). This "optimum flow" value is interpreted as providing the best possible combination of habitat availability for all species considered. Although all species appear to receive equal weighting in this optimization scheme, the species/lifestage for which habitat is most limited is the determinant. Since the stream flow to be recommended at a site must depend on the objectives of management agencies, we developed flow recommendations for the following range of potential objectives: 1) optimize habitat for indigenous fishes; 2) maintain habitat at 80 percent of the optimum WUA value; 3) maintain habitat at 60 percent of optimum; 4) maintain habitat at 40 percent of optimum; and 5) maintain habitat at 20 percent of optimum. VI. Relations Between Flow Recommendations Criteria and Hydrologic Statistics The relationship between recommended flows (optimum, 80 percent, 60 percent, 40 percent) and average discharge was plotted for all seasons. Simple linear regression analysis was used to relate log-tra nsformed recommended flows and log-transformed average discharge for each season. The slopes of these regressions for the four habitat-maintenance flows were similar; therefore, an

21

average slope was calculated and fixed in all subsequent analyses. Analysis of covariance was used to determine if the relationships for a given objective varied among seasons.

RESULTS I. Temperature Water temperatures in the James River near Buchanan reached or exceeded the 29° C level only 38 days (2.3 percent) during June, July, August and early September for the period of record analyzed (16 years) (Appendix A). The majority of these days occurred in July (24) and August (13). A consistent trend of increasing percentage of days equal to or exceeding 29° C at lower flows was found for the July data (Table 10). This relationship was less apparent for June data and not present in August. For all months combined, simple linear regression of temperature with discharge variables (0, 07, 014) yielded some significant relationships (p < 0.05), but the best model explained less than 30 percent of the observed temperature variability. Analysis by month revealed similar results, the maximum variability explained being 39 percent for June (logeT =3.769 - 0.089 x 10geO). Significant relationships were found between temperature and temperature lag variable for all months combined (T7, p..-"-- / .......

_- , / - ...... _..

-.....---

/ / '~ , / /

'I

, Y\

I

,

,

"

--

I \ II I\.,/

1 I

,

o

, I \. I

,\ I/----­

350

-HABITAT OPTIMIZATION CURVE

--------SPECIES WUA CURVE

Example of Optimization Procedure Used to Identify

the Discharge which Maximizes Habitat

for Most Critically Limited Lifestage

FIGURE 4

-

~

30

28

26

MAURY

24

22

20

18

16

14

12

10

30

28

26

G 24

~ w 22

a:: ~

FIGURE 5

Mean Weekly Temperatures and Temperature Range (Vertical Bars) for Three Tributaries in the Upper James River Basin.

20

~ 18

~ 16

~ 14

.... 12

10

30

28

26

COWPASTURE

24

22

20

18

16

14

12

10

iii

, , ,

,

i

,

,

,

,

,

»

,

12 34 12 3412 34 1 234 12 34

MAY

52

JUNE

JULY

AUGUST

SEPTEMBER

53

--

E$-!

(J'1 (J'1

--~------

«

~

(J'1

*.-1% of sample

Rock bass (31), Redbreast sunfish (18), Rosefin shiner (8), Torrent suckers (5), t·1ottl ed scul pi n (5) Bluehead chub (42), Redbreast sunfish (17), r.largined madtom (8), Rock bass (5) Smallmouth bass (19), Redbreast sunfish (19), Rock bass (18), Bluehead chub (14) Common shiner (21), Redbreast sunfish (18), Bull chub (16), Bluehead chub (9) Bluntnose minnow (18), Redbreast sunfish (16), Spottail shiner (13), Mimic shiner (7) Rosefin shiner (24), Rock bass (15), Bluehead chub (11), Rosyface shiner (7) Stoneroller (29), Fallfish (23), Bluehead chub (7), Longnose dace (7) Mottled sculpin (32), Rock bass (16), Cutlips minnow (13), Bluehead cub (10) Mottled sculpin (19), Stoneroller (17), Rock bass (10), Conwon shiner (9) r·iottled sculpin (16), Common shiner (13), Stoneroller (11), Bluehead chub (10) Bluehead chub (23), Mottled sculpin (18), Rock bass (15), Roughhead shiner (5) Redbreast sunfish (37), Bluehead chub (14), Carp (10), Bull chub (8) Swallowtail shiner (23), Bull chub (19), Redbreast sunfish (11), Common shiner (8)

Four Most Abundant Species and % of Sample

5

6

2

2

1

1

1ar Apr May J un J ul Aug Sep Oct

'illiiJ" '""e;.,,, ..

38 38 38 38 38 38 38 38 38 38 38 38

= 384

~'i~'~'~""w.",

313 400 388 456 330 201 84 69 63 66 87 146

Craig Creek (AD 115 115 115 115 115 115 38 38 38 38 38 38

CFS) 154 154 154 154 154 154 77 77 77 77 77 77

63 63 63 456 330 201 84 63 63 63 63 63

en

om

Z C

m

~ ~

)It

60 60 60 60 60 60 60 60 60 60 60 60

TABLE 19 continued

100 100 100 140 140 160 160 100 100 100 100 100

87 87 87 63 63 55 55 70 70 70 70 87 49 62

49 49

62 62 62 45 45 31 31 49

45 45 45 31 31 23 23 32 32 32 32 45

22 22 22 19 19 7 7 20 20 20 20 22

U'1

co

11m

[iii r:fVIjt1~>;,c,-,,,,-

20.0 20.5 21.0 21.5 22.0 22.5 23.0 23.5 24.0 24.5 25.0 25.5 26.0 26.5 27.0 27.5 28.0 28.5 29.0 29.5 30.0 30.5 31.0

12.0 12.5 13.0 13.5 14.0 14.5 15.0 15.5 16.0 16.5 17.0 17.5 18.0 18.5 19.0 19.5

Telnperature

-

--

18.298 21.277 31.277 37.021 48.511 54.894 64.255 67.660 76.383 80.213 85.745 89.787 94.468 96.170 97.660 98.511 99.574 99.787 100.000

3.885 7.566 10.429 14.928 20.450 30.675 34.356 44.581 53.170 63.804 74.438 83.436 88. 753 92.843 95.092 97.546 98.364 99.387 99.591 100.000

3.681

2.454

0.613 1.022 1.431

7.739 8.147 10.183 10.998 14.053 16.497 20.163 24.847 35.031 40.733 51.935 59.674 65.580 70.265 79.022 84.521 92.464 97.352 99.389 100.000

1.222 1.629 2.444 2.851 3.870 4.888 5.092 5.499 5.906

0.851 1.702 3.191 3.830 4.043 6.170 8.085 11.064 13.191

-

0.407

0.204

August (491)

0.815 1.018 0.204

July (489)

0.213 0.426 0.638

June (470)

r',1onth

19.502 21.162 25.726 29.046 33.195 36.929 45.643 50.622 61.826 67.635 78.838 83.817 88.797 95.021 97.095 97.925 99.170 100.000

10.788 12.448

5.394 5.809 6.224

4.564

3.320 4.149

-

2.075

(241 )

Early September

APPENDIX A Cumulative Frequency (Percent) Distribution of Temperatures Occurring

in Summer Months in the James River at Buchanan (USGS, 02.0195.000)

for Period April 1968 through September 1983. Number of Days

Analyzed in Each Month Indicated in Parentheses

III

~

APPENDIX B-1

Mean Daily Discharges (cfs) by Month and Chance of Exceedence for Dunlap Creek

Near Covington (0.20130.00). Period of Record: 10/1928 to 9/1981 and 10/1982 to 9/1983.

Percent exceedence

..JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

90

25

35

66

101

67

33

17

16

12

14

18

21

80

59

67

94

113

74

38

20

18

14

16

21

22

70

73

86

114

128

82

47

23

20

17

18

25

26

60

105

106

136

147

96

61

27

22

18

21

30

32

50

121

152

162

172

125

76

32

25

21

24

34

40

40

144

202

186

213

158

96

39

29

23

27

43

56

30

199

250

297

265

201

134

46

38

28

35

62

74

20

279

407

431

369

318

200

58

52

34

51

112

103

10

510

724

800

660

563

322

92

96

48

84

199

148

-=-_II~~;'--'--

,

-~---

APPENDIX B-2

Mean Daily Discharges (cfs) by Month and Chance of Exceedence for Craig Creek

at Parr (0.2.0180.00). Period of Redord: 4/1925 to 9/1983.

co -...I

Percent exceedence

..JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

90

64

92

150

241

164

88

47

41

34

37

50

52

80

154

171

230

289

191

108

57

51

39

43

58

71

70

194

227

288

328

216

132

66

57

49

48

66

94

60

258

308

338

384

270

156

74

61

52

56

79

117

50

313

400

388

456

330

201

84

69

63

66

87

146

40

397

543

480

557

415

263

102

78

83

78

112

204

30

514

664

617

703

512

363

130

96

99

104

152

297

20

703

897

880

955

708

499

165

143

125

156

333

382

10

1290

1503

1488

1553

1213

795

249

288

286

350

636

712

1

287 362 492 582 782

260 324 386 500 600 837 1470 2057

80 70 60 50 40 30 20 10

CD CD

526 1013 1293 1780 2143 2583 3245 4492

90 80 70 60 50 40 30 20

7720

JAN

10

2410

1540 2270

1550

1240

876

704

604

482

436

291

MAR

2833

1807

1240

964

800

677

603

487

409

APR

1580

1080

844

700

582

520

462

358

265

MAY

2020

1103

705

504

404

321

276

235

193

JUN

382

304

268

236

193

173

148

120

103

JUL

379

268

206

178

148

129

119

101

90

AUG

434

291

236

164

132

117

102

86

72

SEP

533

322

237

191

151

126

113

98

81

OCT

9065

5482

4050

3116

2600

1995

2230

1287

777

FEB

8910

5832

3900

3100

2690

2264

1930

1540

1213

MAR

9072

6052

4192

3442

2877

2520

2195

1797

1507

APR

6682

3915

3057

2528

2080

1810

1530

1340

1150

HAY

4725

3348

2312

1850

1440

1180

1055

890

730

JUN

1905

1380

1110

901

749

617

562

527

450

JUL

1910

1260

913

705

609

555

484

449

373

AUG

1428

914

738

641

552

483

407

366

310

SEP

2138

1115

780

624

529

467

439

388

319

OCT

APPENDIX B-4

Mean Daily Discharge (cfs) by Month and Chance of Exceedence for James River

at Buchanan (02.0195.00). Period of Record: 10/1982 to 9/1983.

Percent exceedence

r" i~,~''''''''

194

135

90

1120

FEB

JAN

Percent exceedence

3175

1700

954

820

663

537

480

434

377

NOV

915

493

341

272

186

150

124

113

104

NOV

APPENDIX Mean Daily Discharge (cfs) by Month and Chance of Exceedence for the Maury River near Buena Vista (02.0240.00). Period of Record: 10/1938 to 9/1981 and 10/1982 to 9/1983.

4690

2632

1900

1487

1083

816

615

467

402

DEC

1047

694

467

336

272

232

182

145

109

DEC

-

0

--

8

3880 5767

2965 4260 5962

2510 3367 6030

1967 2805 5035

20 10

30 4727

2900

2040

1688

1355

1210

3293

2053

1585

1180

944

785

671

567

433

JUN

1080

818

668

558

445

389

350

318

280

JUL

1337

768

523

429

376

338

305

277

245

AUG

902

500

2253

1197

HV

P

Northern Hog Sucker (Spawning) Depth 0.00 0.00 4.66 0.11 Velocity 0.00 0.00 2.03 0.63 Substrate 1 0.00 7 0.00 Cover 1 1. 00 Northern Hog Sucker (YoUDft of Year) Depth O. 0 0.00 100 0.00 Velocitl 0.00 1. 00 Substra e 1 0.10 7 0.20 Cover 1 1. 00 Northern Hog Sucker (Adult~

De~th 0.0

0.00 Ve ocity 0.00 0.00 3.94 0.00 Substrate 1 0.10 7 0.60 Cover 1 1. 00

Species/Life Stage

0.00 0.00 0.00 0.00 0.00 0.00 1. 00 0.88 1. 00

0.40 0.10 1. 00

0.00 0.00 0.00 O. 10 0.40 1. 00

0.34 0.69 2 8 3 0.28 O. 19 100 2 8 3

3 9 5

1. 11 0.79

3 9 5

1. 11

0.52

0.40 0.20 1. 00

0.96 0.96

0.00 1. 00 0.10 1. 00

1. 00

1. 36 1. 00 100 0.00 0.59 0.72 100 0.00 3 0.00 9 0.00 5 1. 00

4 10 6

1. 18 0.86

100 4 10 6

1.05

0.80 0.10 1. 00

0.99 1. 00

0.00 1. 00 0.40 1. 00

1. 00 1. 00

5 7

1. 00 1. 00

1. 00

7 1. 31 2.55

0.50

0.88

1. 00

1. 00

1. 00

0.47

P

5

1. 15

7

1. 00

1. 00

5

1. 02

2.89

HV

1. 00

0.00

0.90

O. 79 4 10 6

1. 00

2.17

Habitat Preference Coordinates P HV P HV P 0.26 5.35 0.25 2.54 2 8 3

HV

8

6

100 2.66

8

6

1. 38

8

6

1. 61

3.81

HV

1. 00

1. 00

1. 00 0.96

1.00

0.40

0.00

1. 00

1. 00

1. 00

0.23

P

2930

1693

1170 725

931

722

538

413

338

258

DEC

1270

544

392

548

444

338

303

274

242

NOV

665

421

340

297

276

241

208

OCT

348

318

284

260

231

209

SEP

APPENDIXC

Habitat Preference Coordinates for Target Species Lifestages Used in Habitat Simulations. Table Entries

Are Pairs of Habitat Values (HV) and Corresponding Preference Values (P).

Depth and Velocity Values Expressed in Feet and Feet per Second, Respectively.

Descriptions of Substrate and Cover Codes Are Usted in Table 6.

2850

2213

1993

1963

1640

40

1940

1650

1457

1327

50

1662

1443

1160

1027

60

982

1450

1165

951

813

70

831

1207

936

746

689

80

707

1018

702

414

343

90

MAY

APR

FEB MAR

JAN

Percent exceedence

APPENDIX 8-5 Mean Daily Discharge (cfs) by Month and Chance of Exceedence for the James River at Uck Run (02.0165.00). Period of Record: 4/1925 to 9/1981 and 10/1982 to 9/1983

-

0.00 1. 38 0.00 0.85 1 7 1

Cover Rock Bass (YOY) Depth Velocity Substrate Cover

0.00 1. 00 0.00 1.00 1. 00 0.016

0.00 0.00 100 1 7 1

De~th

Smallmoutb Bass Deytb Ve oCitI Substra e Cover

Ve ocitI Substra e Cover

O. 0 0.00 1 7 1

(Spawning~

1

0.0 0.00 1 7

0.00 1.00 0.00 1. 00 0.30

0.00 1. 00 0.10 0.10 1. 00

0.00 1. 00 1. 00 0.00 1. 00 1. 00 0.016 0.00 100 0.00 1.08 1 7 1

HV

Cover Redbreast Sunfish (Spawnin8)

Cover Rock Bass (Adult) Deyth Ve ocity Substrate

Rock Bass (Juvenile) Depth Velocity Substrate

Species/Life Stage

~"""",';"",:"'