Temperature Control Device Workshop

January 22-24, 2001

Saguaro Lake Ranch

Mesa, Arizona

Summary of Results
Organizations Represented

• GCMRC

• Fish and Wildlife Svc

• Bureau of Reclamation

• EPA

• National Park Service

• USGS

• AGFD

• Utah DNR

• Arizona State Univ.

• Utah State Univ.

• Colorado State Univ.

• Northern Arizona Univ.

• Argonne National Lab.

• SWCA

• Ecometrics

• Reservoir Environ. Mgmt.

• Stevens Consulting
REQUESTED INFORMATION

• Summary of variables being measured,

• Frequency and intensity of measurements,

• Methods of analysis,

• Ability to detect change in those variables,

• Recommendations for additions or changes 

to assess effects of a TCD.
Presentations

• GCDAMP Background: Dennis Kubly and Barry Gold 

(AMP and TCD), Barb Ralston (AMP Science Program)

• Modeling: Josh Korman (Conceptual Model), Amy Cutler 

(CEQUAL-W2), Dave Harpman (Flow Routing)

• Empirical: Susan Hueftle (Lake Powell-Colorado River 

Water Quality), Joe Shannon (Algae-Invertebrates), 

Wayne Gustaveson (Lake Powell Fisheries), Bill Persons 

(Lees Ferry Trout), Rich Valdez (Mainstream NativeNonnative Fish ), Lew Coggins (Little Colorado River 

Native-Nonnative Fish), Larry Stevens (Riparian)
Types of Monitoring

• Core monitoring to measure status and 

trends of high priority resources; highly 

standardized, few changes once established

• Effects monitoring to measure conditions 

before and after management actions are 

taken; more flexible, event driven, set up to 

accommodate particular actions
Monitoring & Management Actions

• Water temperature is modified as a consequence 

of modifying hydrology: consider them together in 

planning

• Researchers need more lead time for design and 

implementation; water managers need to work 

more closely with researchers
Riparian Monitoring

• Water Quality & Hydrogeology—Flows, GIS 

network, local velocities, system-wide air temp 

and relative humidity (10 Tw sites)

• Establish meterological instrument stations to 

measure and model nearshore climate

• After third year of TCD measure 

dendrochronology of Tamarix and Salix exigua

• Secondary productivity of important insects

• Diet analysis of herps as surrogate for riparian 

birds
Recreation Monitoring

• Questionnaire to river runners 2 yrs before 

TCD and during operation re: occurrence of 

bacterial infections, sickness, injuries 

during swimming

• Involve Center for Disease Control in 

monitoring for Shigella and other 

pathogens?
Core Monitoring Physicochemical

Nutrients (P, 

N, TOC), 

hydroacoustic 

survey

Conductivity,

DO, pH, 

chlorophyll

Water 

Temperature

Forebay

Uplink Continuous Monthly

Continuous

Nutrients (P, 

N, TOC)

Conductivity,

DO, pH, 

chlorophyll

Water 

Temperature, 

Flow

Downstream 

(3 stations)

Nutrients (P, 

N, TOC), 

plankton, 

eggs

Conductivity,

DO, pH, 

chlorophyll

Water 

Temperature, 

Discharge

Dam
Core Monitoring

Algae & Invertebrates

• Present sampling design is biased

• Change to randomized approach and clearly define 

the sampling universe; EPA ORD-EMAP 

approach, GIS-based

• Two index periods—spring and fall

• Three major habitats—cobble bars, backwaters, 

and tributaries

• 30-50 samples in each stratum

• Integrate physical habitat, water quality, lower 

trophic, and fish sampling
Core Reservoir

Fish Monitoring

• Shad population measurement indicative of 

all elements of Lake Powell fishery

• Sample with midwater trawls and tow nets

• Some hydroacoustic work done; may be 

useful tool in forebay for measuring 

potential for entrainment with TCD
Core Fish Monitoring - LCR

Nov (2-3 weeks)

Oct (1-2 weeks)

June (2-3 weeks)

Suite of demographic parameters

• > 100 mm TL pit tag

• intensive mark-recapture

• hoop net, trammel catch rates

• stock synthesis models

• native fish emphasis

May (1-2 weeks)

Trips Purpose
Core Fish Monitoring - Mainstem

Nonnative electrofishing, predator 

collections

Sep

Mark-recapture LCR area (HBC, 

FM, BH), 

June-July

Lees Ferry, native fish on spawning 

bars, trammel nets

Mid-May

May Systemwide survey LF-DC

Early April Systemwide survey LF-DC

Mark-recapture HBC, FM, BH 

aggregations in tributaries

Spike flow camps Kanab, Havasu

March-April

Trips Purpose
Lee’s Ferry Trout Fishery

Frequency of Sampling

• Electroshocking:

– 1984-1990 Inconsistent

– 1991-1996 15 sites 3x / year 2000 sec/site

– 1997-2000 9 sites 3x / year 2000 sec/site

– 2001 - ? 9 + 27 sites 4x / year 500 sec/site

• Creel:

– 1965-1970 Inconsistent

– 1977-2000 Monthly estimates (12d/month)

– 2001 - ?

• Snorkel:

– 1998-2000 Exploratory

– 2001 - ? 36 sites 4x / year to evaluate, calibrate
Status and Trend Variables

Lee’s Ferry Fishery

• Electrofishing:

– Date, time, RM station, effort (seconds)

– Species, length, weight, PIT tag info (growth, 

movement), sex, maturity

– Wild/hatchery origin (coded wire tags)

• Creel:

– Angler catch/hour

– Angler use (angler hours/month)

– Satisfaction 

• Snorkel Surveys:

– Fish density/calibration efforts
Lee’s Ferry Trout

Methods of Analysis

• Descriptive statistics for status and trends--Catch 

per unit effort (CPUE), Kn (relative condition), 

proportional stock density, length frequency 

distribution; 

• Stock Synthesis Models--Age structured dynamic 

population model; calculate Walford/von 

Bertallanfy growth curves from mark/recapture.
Lee’s Ferry Trout

Change Detection

• Power analysis and evaluation of electrofishing

protocol--Preliminary results suggest that current 

protocol (1991-2000) was capable of detecting 

moderate variations in trout relative density and 

condition over both short (1-2 yr.) and long-term (5+ 

year) time scales;

• Results also indicate that detectable magnitudes of 

change vary considerably with fish size;

• Increases in number of sample sites and frequency of 

sampling should increase ability to detect short term 

change.
Temporal Indicators of Change

Recruitment,

2nd population,

Down- and 

delisting of T&E

Sustained range 

expansion, 

Growth, Disease/ 

parasites, Pop 

estimates

Catch rates, Range, 

Reprod success, Growth, 

SBE numbers, New 

colonists

Fish

MIB Community 

Composition

PB Community 

Composition

PB & MIB Biomass

New colonists

Lower 

Trophic

Water temp

System metabolism

Allochthonous input 

(reservoir)

C:N SI Ratios

Physicochemical

Early (~Yr 1) Mid (~Yr 2-5) Late (~Yr 6-20)

Recruitment,

2nd population,

Down- and 

delisting of T&E

Sustained range 

expansion, 

Growth, Disease/ 

parasites, Pop 

estimates

Catch rates, Range, 

Reprod success, Growth, 

SBE numbers, New 

colonists

Fish

MIB Community 

Composition

PB Community 

Composition

PB & MIB Biomass

New colonists

Lower 

Trophic

Water temp

System metabolism

Allochthonous input 

(reservoir)

C:N SI Ratios

Physicochemical

Early Mid Late (~Yr 6-20)
Requested Information

• Summary of variables being measured, 

• Frequency and intensity of measurements,

• Methods of analysis, 

• Ability to detect change in those variables,

• Recommendations for changes or additions to assess

effects of a TCD.
Change Detection

• Our ability to detect significant change depends on 

five interacting factors (Valdez):

• <Sample Size

• <Variability

• <Level of Significance

• <Power (probability of detecting a difference 

when one exists)

• <Minimum Detectable Effect
Null Hypothesis True Alternative Hypothesis True

Reject Null Hypothesis Type I Error

"

Probability of Rejecting Ho

when Ho is true

 Correct Decision

(1 - $)

Probability of Rejecting Ho

when Ha is True

Fail to Reject Null Hypothesis Correct Decision

(1- ")

Probability of Not Rejecting Ho

when Ho is True

Type II Error

$

Probability of Failing to Reject 

Ho when Ha is True

Types of Statistical Error
Potential Glen Canyon Dam Releases

0

10000

20000

30000

40000

50000

60000

J F M A M J J A S O N D

Month

Flow (cfs x 1000)

MLFF

BHBF/HMF

Exp Fish Flows

?

? ?

? ? ?

? ? = Timing, 

Duration, and 

Magnitude of 

Flows
Predam-Postdam and Potential TCD Release Water 

Temperatures

0

5

10

15

20

25

30

J F M A M J J A S O N D

Month

Water Temperature ( C)

Predam

Postdam

Increment 1

Increment 2

Increment 3

Increment 4
Probability of Future Lake Powell Elevation Exceedances in July

0

0.2

0.4

0.6

0.8

1

20022004200620082010201220142016201820202022202420262028203020322034203620382040204220442046204820502052

Year

Probability of Occurrence

3610'

3638'

3670'
POTENTIAL MONITORING SCHEDULES

0

1

2

3

4

5

6

1 2 3 4 5 6 7 8 9 10 11 12

Month

Levels