Knowledge Assessment Worksh

Summary & Report Update

Originally Presented at SPG, Phoenix

Sept. 21, 2005

Presented Again for the TWG

November 30, 2005
Objectives of Knowledge Assessm

1. Evaluate uncertainties about the effects of manag

actions on key resources in CRE.

2. Develop strategic science questions that would n

addressed to reduce uncertainties.

3. Identify modelling, research, monitoring and exp

designs required to answer the science questions

4. Identify actions that are understood well enough 

treated as management actions if appropriate. 
Definitions of Uncertainty

Very Certain Certain Uncertain V

Prediction 

Direction and magnitude of response Direction only Direction only Cann

Supported by Data from Colorado River Ecosystem 

Peer-reviewed, likely involving a model. Little debate on interpretation of predictions 

Peer-reviewed results, no model 

Limited data without peer-review and likely debatable inference 

No or 

Data from Other Reference Systems 

Validated prediction in other system that is considered a good model for CRE 

Validated prediction in other system that is a weaker model for CRE 

Weaker prediction fromother system that is a weak model for CRE 

No or 

in othsystemode

General Theory / Conventional Wisdom Very Strong Good Moderate Low Probability that Predicted Direction is Correct 90-100% 70-90% 50-70% <50% 
Physical Resource Matrix

Performance Measure 

Increase in 

GCD Release 

Water 

Temperature

Overall 

Effect of 

Increased 

Fluctuations 

Relative to 

MLFFA 

Reduce 

Variation 

in 

Monthly 

Volume 

BHBF 

with 

adequate 

sand 

supply 

BHBF 

without 

adequate 

sand 

supply 

HMF with 

adequate 

sand 

supply 

HMF 

without 

adequat

sand 

supply 

Fine- Sediment above 25 kcfs + - + + 0/+ Fine-Sediment between 8 and 25 kcfs + - + + - 0/+ - Fine-Sediment below 8 kcfs + - + + - - - Mainstem Water Temperature + - + - - - - Nearshore Water Temperature + - + - - - - 
Physical Resources Science Quest

1. Is there a “Flow-Only” (non sediment augmentation) opera

will restore and maintain sandbar habitats over decadal tim

2. Is there an optimal strategy for BHBF implementation to m

tributary inputs on an annual to inter-annual time scale? 

3. What are the short-term responses of sandbars to BHBFs? 4. What is the rate of change in eddy storage (erosion) during 

intervals between BHBFs?

5. How does the grain-size distribution of the deposits affect 

stability? Main channel turbidity?

6. What are the effects of ramping rates on sediment transpor

sandbar stability?
Performance Measure 

Increase in 

GCD Release 

Water 

Temperature

Overall 

Effect of 

Increased 

Fluctuations 

Relative to 

MLFFA 

Reduce 

Variation 

in 

Monthly 

Volume 

BHBF 

with 

adequate 

sand 

supply 

BHBF 

without 

adequate 

sand 

supply 

HMF with 

adequate 

sand 

supply 

HMF 

without 

adequat

sand 

supply 

Hydro Power LoadFollowing Capacity - + - - - - - Hydro Power Replacement Costs - + - - - - - 

Power Matrix
Power Science Questions

1. What are the hydropower replacements costs of the MLFF 

(annually, since 1996)?

2. What are the projected costs associated with the various alt

flow regimes being discussed for future experimental sciendefined in the next phase experimental design)?
Highlights from Fish Matrix

Performance Measure Species

Increase 

in GCD 

Release 

Water Temp.

Overall 

Effect of 

Increased 

Fluctuations 

Relative to 

MLFFA

BHBF 

with 

adequate 

sand 

supply

Sustaine

Low 

Steady 

Flow 

(summe

fall)

Y

O

Y

/Juvenile 

nearshore rearing HBC + - +

FMS + - +

Invasive Fish Species Coldwater + - NA + 

Warmwater +- +

Adult Population HBC

FMS + +
Performance 

Measure

Location and/or Species

Increase 

in GCD 

Release 

Water 

Temp.

Overall 

Effect of 

Increased 

Fluctuations 

Relative to 

MLFFA

Reduce 

Variation 

in Monthly 

Volume

BHBF 

with 

adequate 

sand 

supply

BHBF 

without 

adequate 

sand 

supply

HMF with 

adequate 

sand 

supply

HMF 

without 

adequate 

sand 

supply

Sustained 

Low 

Steady 

Flow 

(summerfall)

High 

Sustained 

Flow 

(pondingspring)

Mechanical 

Removal of 

Coldwater 

Exotics 

(Mainstem 

and Trib)

Mechanical 

Removal of 

Warmwater 

Exotics

Supplemenfrom Hatch

Food base Glen + + -

Grand - -+

Mainstem spawning & incubation HBC + + ++

FMS +- + ++RBT-Glen - + ++RBT-Marble

YOY/Juvenile nearshore rearing HBC + - + - -+ + +

FMS + - + - -+ + +RBT-Glen + - +- - - -++RBT-Marble - +- - - -++

Invasive Fish Species Coldwater +- + -

Warmwater +- + -

Disease

Asian Fish Tapeworm +

Whirling Disease +

Adult Population HBC 

FMS + +RBT #s - Glen +- +RBT Size - Glen ++ +RBT #sMarble - +-

Angling Opportunity and Quality Glen + - +------
Food Base/Fish Matrix

Performance Measure

Location and/or Species

Increase 

in GCD 

Release 

Water 

Temp.

Overall 

Effect of 

Increased 

Fluctuations 

Relative to 

MLFFA

Reduce 

Variation 

in 

Monthly 

Volume

BHBF 

with 

adequate 

sand 

supply

BHBF 

without 

adequate 

sand 

supply

HMF 

with 

adequate 

sand 

supply

HMF 

without 

adequate 

sand 

supply

Sustained 

Low 

Steady 

Flow 

(summerfall)

High 

Sustained 

Flow 

(pondingspring)

Food base Glen + + -

Grand - -

Mainstem spawning & incubation HBC + + 

FMS +- + RBT-Glen - + ++RBT-Marble

YOY/Juvenile nearshore rearing HBC + - + - -+ 

FMS + - + - -+ RBT-Glen + - + --- - + +RBT-Marble - + --- - + +
Food Base/Fish Matrix (con’t

Performance Measure

Location or Species

Increase 

in GCD 

Release 

Water 

Temp.

Overall 

Effect of 

Increased 

Fluctuations 

Relative to 

MLFFA

Reduce 

Variation 

in 

Monthly 

Volume

BHBF 

with 

adequate 

sand 

supply

BHBF 

without 

adequate 

sand 

supply

HMF 

with 

adequate 

sand 

supply

HMF 

without 

adequate 

sand 

supply

Sustained 

Low 

Steady 

Flow 

(summerfall)

High 

Sustained 

Flow 

(pondingspring)

Invasive Fish Species Coldwater +- + 

Warmwater +- + 

Disease

Asian Fish Tapeworm

+

Whirling Disease

+

Adult Population HBC

FMS + +

RBT #s - Glen +- +RBT Size - Glen ++ +RBT #s- Marble - +

Angling

Opportunity and Quality Glen + - + --- - - -
Food Base/Fish Matrix (con’t

Performance Measure

Location or Species

Supplementation from Hatchery

Translocation of HBC

Food base Glen

Grand

Mainstem spawning & incubation HBC

FMSRBT-GlenRBT-Marble

YOY/Juvenile nearshore rearing HBC

FMSRBT-GlenRBT-Marble

Performance Measure

Location or Species

Supplementfrom Hatch

Invasive Fish Species Coldwater

Warmwater

Disease

Asian TapewormWhirling Disease

Adult Population HBC

FMSRBT #s - GlenRBT Size - GlenRBT #s- Marble

Angling

Opportunity and Quality Glen
Food Base Science Questions

1. What are the important pathways, and the rate of flux alon

that link lower trophic levels with fish?

2. How is invertebrate flux affected by water quality (e.g., tem

nutrient concentrations, turbidity) and dam operations? 

3. Are trends in the abundance of fish populations, or indicato

fish such as growth, condition, and body composition (e.g.correlated with patterns in invertebrate flux? 
Native Fish Science Question

1. What ultimately limits native fish populations:

• production of young fish from tributaries• spawning and incubation in the mainstem• survival of YoY and juvenile stages in the mainstem• growth and maturation in the adult population as influenced 

conditions?

2. What is the relative importance of increased water temperature

stability, food availability, and predators on the survival of earl

native fish?

3. How important are backwaters and vegetated shoreline habitats 

growth and survival of YoY and juvenile native fish?

4. Do the potential benefits of improved rearing habitat outweigh 

impacts owing to increases in non-native fish abundance or dise
Rainbow Trout (Glen Canyon

Science Questions

1. To what extent is the adult population of rainbow trout contro

survival rates during incubation and YoY/juvenile rearing sta

changes in growth and maturation in the adult population infegg deposition?

2. To what extent is the size of rainbow trout in Glen Canyon co

density and food availability?

3. Does increased water temperature result in the occurrence of 

disease in rainbow trout and if so, what affect will this have opopulation size and adult growth and condition?

4. Do rainbow trout migrate from Glen to Marble and eastern G

Canyons? If yes to former, then to what extent do Glen Canyimmigrants support the population in Marble and eastern GraCanyons?
Rainbow Trout (Marble and Easter

Science Questions

1. Does a decrease in the abundance of rainbow trout in Marble 

Grand Canyons result in an improvement in the recruitment r

juvenile humpback chub to the adult population?

2. Will a limited number of years of mechanical removal of rain

in Marble and eastern Grand Canyons result in a long-term d

abundance, or will re-colonization require that mechanical re

ongoing management action?
Lees Ferry Angling Science Ques

1. Assuming a trade-off between trout density and size, what is 

preferred combination for fishing guides?

2. What GCD flow constraints (ramping rates, daily flow range

maximize fishing opportunities and catchability?
Riparian Habitat Matrix

Performance Measure

Location and/or Species

Increase 

in GCD 

Release 

Water 

Temp.

Overall 

Effect of 

Increased 

Fluctuations 

Relative to 

MLFFA

Reduce 

Variation 

in 

Monthly 

Volume

BHBF 

with 

adequate 

sand 

supply

BHBF 

without 

adequate 

sand 

supply

HMF 

with 

adequate 

sand 

supply

HMF 

without 

adequate 

sand 

supply

Sustained 

Low 

Steady 

Flow 

(summerfall)

High 

Sustained 

Flow 

(pondingspring)

Fluctuation zone <25 kcfs

Glen & Grand Canyon + + 0/+ 0/+ 0/+ - +

Lower Riparian 25-45 kcfs + + 0/+ 0/+ 0/+ 0/- 0/+Upper riparian zone 45-60 cfs> 60 kcfs
Riparian Habitat Science Quest

1. How do processes occurring at a variety of spatial scales (i.e., populat

community to landscape scales) interface to influence riparian habitat?

2. What is the nature and timing of terrestrial—aquatic linkages, and wh

influence on the recipient habitat?

3. How do terrestrial habitat and cultural resources interface?4. How do flows affect productivity and decomposition rates of riparian 5. How do warmer releases affect viability and productivity of native/non

vegetation?

6. To what extent and in what respects can BHBF’s (magnitude and freq

reduction of exotic species?

7. How could monthly volumes be changed to beneficially affect riparian 
Recreation Matrix

Performance Measure

Location and/or Species

Increase 

in GCD 

Release 

Water 

Temp.

Overall 

Effect of 

Increased 

Fluctuations 

Relative to 

MLFFA

Reduce 

Variation 

in 

Monthly 

Volume

BHBF 

with 

adequate 

sand 

supply

BHBF 

without 

adequate 

sand 

supply

HMF 

with 

adequate 

sand 

supply

HMF 

without 

adequate 

sand 

supply

Sustained 

Low 

Steady 

Flow 

(summerfall)

High 

Sustained 

Flow 

(pondingspring)

Campsites (available campable area)

+ -

++ +-

Access to attraction sites - +Rafting navigability + + 0/- 0/+qw and human health - + +++ - +safety

+ + -

Recreational experience + - 0/- +
Recreation Science Questions

1. How do dam controlled flows affect visitors’ recreational experiences

the optimal flows for maintaining a high quality recreational experienc

2. What are the drivers for recreational experience in the CRE, and how 

flows relative to other drivers in shaping recreational experience outco

3. How do varying flows positively or negatively affect campsite attribut

important to visitor experience?

4. What are the minimum size, quantity, distribution and quality of camp

goals for visitor experience?

5. Can changes in quality of recreational experience be quantified for sin

opportunities (e.g., white water rafting, angling, camping) vs. multi-opexperiences (e.g. white water rafting with overnight camping)?
Recreation Science Questions (Co

6. How can safety & navigability be reliably measured relative to flows? 7. How do varying flows positively or negatively affect visitor safety, he

navigability of the rapids?

8. How do varying flows positively or negatively affect group encounter 

competition, and other social parameters that are known to be importavisitor experience?
Historic Properties Matrix

Performance Measure

Location and/or Species

Increase 

in GCD 

Release 

Water 

Temp.

Overall 

Effect of 

Increased 

Fluctuations 

Relative to 

MLFFA

Reduce 

Variation 

in 

Monthly 

Volume

BHBF 

with 

adequate 

sand 

supply

BHBF 

without 

adequate 

sand 

supply

HMF 

with 

adequate 

sand 

supply

HMF 

without 

adequate 

sand 

supply

Sustained 

Low 

Steady 

Flow 

(summerfall)

High 

Sustained 

Flow 

(pondingspring)

 Conservation> 45 kcfs stage arch. sites + - + 0/+ 0/+ -

Conservation <45 kcfs + - + 0/+ - Conservation> 45 kcfs stage TCPs Conservation <45 kcfs 
Cultural Resource Questions

1. Do dam controlled flows affect (increase or decrease) rates of erosion 

growth at arch sites and Traditional Cultural Property (TCP) sites, and 

2. If dam controlled flows are contributing to (influencing rates of) arch 

what are the optimal flows for minimizing future impacts to historic p

3. How do flows impact the sedimentary matrix of the higher terrace dep

kinds of important historical/legacy information about the CRE ecosydue to ongoing erosion of these older Holocene sedimentary deposits?

4. How effective are check dams in slowing rates of erosion at archaeolo

the long term?

5. What are the TCPs in the CRE, and where are they located? 
Cultural Resource Questions (Co

6. How can tribal values/data/analyses be appropriately incorporated into 

science-driven adaptive management process in order to evaluate the e

operations and management actions on TCPs?

7. Are dam controlled flows affecting TCPs and other tribally-valued res

CRE, and if so, in what respects are they being affected, and are those considered positive or negative by the tribes who value these resource
KAW Draft Report Update

- Comments solicited from workshoparticipants in September- Ecometric Research & GCMRC currently revising draft report in resto comments- Report is to be finalized by winter 2005-06
Approaches to Resolve Scienc

Questions (Native Fish)

• Almost all questions require manipulations of flow 

temperature from GCD and long-term data.

• Try approach for native fish as it is very important 

AMP goal.

• First step is to make a relatively long-term decision 

which strategies will be evaluated (next 5 yrs).

• After that, can look at smaller-scale manipulations 

not confound main treatments.
Hatchery 

(juvenile production)

Decrease monthly volumes in summer

DecreaseIncrease TCD Translocation

Mechanical removal

Maintain Natural pattern(MLFFA)

Non-Flow Options

Water Temperature

Daily Flow Fluctuations

Treatments for Native Fish Restorati
Chub, sand Power, Ripari

storage, recreation, cultural

Benefits to Resources# of Treatments 3-4 1-2 2-3

MR & Translocation

MR & Translocation

MR & Translocation

Non-Flow

Confounded ichub response

Least confounded but little learning about GCD if reservoir fills

Maximum but confounded (does RPA work?)

Learning

Natural basin hydrology/ increased watremovals

Natural basin hydrology/ increased water removals

TCD or stabilize monthly volumes

Water Temperature

Maintain Increase(MLFFA)

Daily DecreaseFluctuations

Stay-The- Power

Course

Golden Sink

Major Experimental Options to Resolve Uncert

in HBC Fish Response to GCD Operation
Stay-TheCourse

+’ve Chub

WaterWarms

BuilQ flu

null Chub Stead

TCD

Water Doesn’t Warm

+’ve Chubnull Chub

MPoStan

Stay-The-Course Experimental Sequen
Golden Sink

+’ve Chubnull Chub hatchery

TCD + higher Q fl

Golden Sink Experimental Sequen
Power 

Flows

+’ve Chub

WaterWarms

BuilQ flu

null Chub MLF

highe

Water Doesn’t Warm

+’ve Chubnull Chub

H

MTC

Power Flows Experimental Sequence
Food Base/Fish Matrix 

(Flow Flux Response)

Performance Measure

Location or Species

Overall Effect 

of Increased 

Fluctuations 

Relative to 

MLFFA

Increase 

Upramp 

Rate

Increase 

Downramp 

Rate

Increase 

and/or 

Lengthen 

Maximum 

Daily Flow

Increase 

Daily 

Variation in 

Flow

Decrease 

Minimum 

Daily Flow

Supplemefrom Hatc

Food base Glen

Grand - --

Mainstem spawning & incubation HBC

FMS - -

RBT-Glen - - --RBT-Marble - --

YOY/Juvenile nearshore rearing HBC - -+

FMS - -+RBT-Glen - -RBT-Marble - -
Food Base/Fish Matrix 

(Flow Flux Response, con’t)

Performance Measure

Location or Species

Overall Effect 

of Increased 

Fluctuations 

Relative to 

MLFFA

Increase 

Upramp 

Rate

Increase 

Downramp 

Rate

Increase 

and/or 

Lengthen 

Maximum 

Daily Flow

Increase 

Daily 

Variation in 

Flow

Decrease 

Minimum 

Daily Flow

Supplemefrom Hatc

Invasive Fish Species Coldwater - -+

Warmwater - -+

Disease

Asian TapewormWhirling Disease

Adult Population HBC

FMSRBT #s - Glen - --RBT Size - Glen + ++RBT #s- Marble - --

Angling

Opportunity and Quality Glen - - - --