Memorandum

To: Technical Work Group members 

From: Desired Future Conditions Ad Hoc Group 

cc: TWG alternates and interested persons 

Date: November 20, 2007 

Re: Recommendation with regard to Desired Future Conditions 

RECOMMENDATION

The Desired Future Conditions Ad Hoc Group (DFCAHG) is pleased to make the following 

recommendations to the Technical Work Group (TWG): 

 That the TWG forward the attached four sets of targets for Humpback chub and sediment to 

AMWG (see Attachments 1, 2, 3, and 4, starting on page 3), and advise AMWG that TWG has 

found all four sets to be scientifically and technically credible. 

 That the TWG recommend to the AMWG that the TWG be charged with developing a range of 

options for targets for the remaining resources in the AMP Strategic Plan. 

BACKGROUND

The DFCAHG met for three days (November 6, 7, and 13) in a workshop to assist the TWG to fulfill 

the charge from the Bureau of Reclamation (see Attachment 5, page 17). Note that the charge 

asks that the TWG recommend “a range of options” for targets of Management Objectives from 

approved AMP strategic plan, and that the TWG first focus on Humpback chub and sediment. The 

charge also requests that TWG address short-term (10-year) and long-term targets; the Ad Hoc 

Group agreed that the timeframe for the 10-year targets is assumed to begin in 2008. 

the 

The DFCAHG considered certain excerpts of the AMP strategic plan (see Attachment 6, page 18),

so that it could ensure that the targets were consistent with the plan, per the charge. The DFCAHG 

also reminded itself of the approved Management Objectives for those two resources (see 

Attachment 7, page 20). The DFCAHG notes that the principles from the AMP strategic plan,

included in Attachment 6, apply to the attached targets. 

The DFCAHG spent many hours planning for the workshop in order to ensure that it would be 

productive. Part of its deliberations prior to the workshop included developing a purpose and 

decision rule (see Attachment 8, page 25). The DFCAHG agreed to operate somewhat differently

from the usual TWG operations, as follows: 

 It agreed to operate by consensus, not by majority vote; and 

 It agreed that its task was to determine whether the rationale used to develop targets was 

scientifically and technically credible, rather than to choose among targets; leaving the latter 

task up to the AMWG as a policy decision. 
Memorandum to TWG from the DFCAHG Page 2 of 26 

November 20, 2007 

All Ad Hoc Group members were invited to submit targets for consideration. Two sets of targets

were proposed by Ad Hoc Group members: one from the National Park Service, and one from 

Western Area Power Administration. The workshop attendees thoroughly discussed the proposed 

targets, raised questions, and identified unspoken assumptions. Both proposers (NPS and Western) 

made numerous changes to their proposed targets as their thinking was advanced by discussion of the 

group. Finally, and in accordance with the “purpose and decision rule” document (Attachment 8, 

page 25), all four sets of targets that are attached as Attachments 1-4 (starting on page 3) were

determined, by consensus, to met the standard of scientific and technical credibility. There is not 

consensus, however, that all targets meet all applicable law. 

The DFCAHG recommends that the TWG use the same process of determining scientific and 

technical credibility, and forward to AMWG all targets that meet that standard. 

Because the operating procedures of the AMWG and TWG require that TWG work only on tasks 

given it by the AMWG, the DFCAHG further recommends to the TWG that it recommend to the 

AMWG that the TWG be charged with developing ranges of targets for the remaining resources in 

the AMP Strategic Plan. It will be important to develop targets for other resources to support the 

targets developed for Humpback chub and sediment. 
Memorandum to TWG from the DFCAHG Page 3 of 26 

November 20, 2007 

Attachment 1: Sediment Targets 

These targets were originally proposed by Western Area Power Administration, and were determined 

by consensus to be scientifically and technically credible by the Desired Future Conditions AHG. 

Short- and Long-Term Target

To slow or reverse the rate of decline of fine sediment deposits at all stages described in Management 

Objectives 8.1-8.5 over the next ten years and beyond, throughout the CRE, as measured by the number, 

volume, and areal extent of beaches and backwaters. 

Bases, Assumptions, and Current Data

a. The purposes of Grand Canyon sediment, as approved by AMWG in 2002, are for “enough sediment 

to achieve the biological, recreational, and cultural goals. Given limited sediment inputs, we need to 

retain enough sediment in the system to achieve ecosystem patterns in these goals. For the biological 

goals, the purposes are habitat and nutrient storage. For the cultural goal, the purposes are enhancing 

plant habitat and preserving historical properties. For recreational goals, the purposes are camping 

beaches and trout spawning habitat.” 

b. We assume that backwaters are beneficial for native fish. 

c. If we slow the decline of sediment in RM 1-87, we assume that the decline will be slowed throughout 

the Colorado River ecosystem. 

d. The focus of evaluation for mass balance will be on RM 1-87 due to the fact that we have the best 

data for this reach. 

e. In the recent past, we have been in a decline of 2% to 3% annually of total sediment in River Miles 1 

through 87. (This has been validated by GCMRC.) 

f. Given the current and near-future sediment, precipitation, and hydrology, we assume that a rough 

approximation of future sediment loss in the system will be 2-3% per year, with MLFF and no 

BHBFs. 

g. If we add certain management “tools,” e.g., BHBFs and HMFs, to be done a certain number of times 

per year or decade, we assume that we can reduce the decline. 

h. The relationship of sediment balance and number of backwaters is unknown and should be 

monitored and tested during this period. 

The method described herein is proposed for the development of targets for the Sediment MOs. There 

are two large steps and several smaller, intermediate steps as follows: 

Step One – Determine long-term average sediment level that is sustainable given natural variables and 

application of management tools. Experiment with and/or model and document effects of potential 

management “tools” on sediment conservation. Each “tool” would be examined for its utility in sediment 

conservation, impact on other resources, impact on other “tools” and cost and legal parameters. The list 

of potential “tools” includes the five parameters of normal operations (upramps, downramps, minimums, 

maximums, and daily ranges), BHBFs, HMFs, and others. 

After documentation of the natural variables (i.e. sediment inflow, precipitation and hydrology), apply 

various management tools in a modeling exercise to derive an optimum sediment mass that can be 

sustained and, when the management tools are applied, does no/insignificant long-term harm to key 

resources identified in the GCD EIS. 
Memorandum to TWG from the DFCAHG Page 4 of 26 

November 20, 2007 

Evaluation 

Two evaluation methods: 

1. Mass Balance as calculated in RM 1-87 – measuring loss of sediment. 

2. Evaluation of number, volume, and areal extent of beaches and backwaters. 

In order to evaluate the efficacy of this course of action, perform the following three steps to determine 

what the sediment balance trajectory would have been with no action. 

a. Document/model long-term average sediment inflow between Lees Ferry and the Grand Canyon 

Gage. (NOTE: This work may be done sufficiently to complete Step One.) 

b. Document/model long-term upgradient precipitation in this reach. NOTE: This work may be done 

sufficiently to complete Step One. 

c. Document/model GCD releases over the long-term, to include potential influences of climate 

change. NOTE: This work may be done sufficiently to complete Step One. 

Step Two – In order to further quantify the long-term target, we will determine the number and size of 

camping beaches in critical reaches (Marble Canyon, Upper Granite, and Muav Canyon) and the area of 

backwater habitat that can be supported by Step One. 

Translate the optimum sediment mass produced in Step One into an estimate of: 

• The numbers and size of camping beaches in critical reaches. 

• The area and number of backwater habitat. 

Step Two provides the basis for maintaining the optimum sand volume. Once we know what sand 

volume we can reasonably produce (Step One), we translate that into numbers and sizes of beaches, grainsize and distribution (draft DFCs) and into backwater habitat area. Although the beaches and habitat 

produced may not be as many or of the size and area that all parties would prefer, they are a sustainable, 

scientifically based target. We could also determine the non-operational steps available to enhance the 

utility of shoreline areas for camping if there is less beach sand (e.g., vegetation removal from camping 

beach areas, sleeping cots for greater camping flexibility) and other non-flow actions that can benefit 

HBC. 
Memorandum to TWG from the DFCAHG Page 5 of 26 

November 20, 2007 

Attachment 2: Sediment Targets 

These targets were originally proposed by National Park Service, and were determined by consensus 

to be scientifically and technically credible by the Desired Future Conditions AHG. 

Short-Term Targets (10 years) 

1. Rebuild and stabilize sandbars, campsites, and backwater habitats to 40-45,000 cfs levels, moving 

toward 1983-1985 post flood values (abundance, grain size, and distribution including volume and 

areal extent). 

2. Achieve a positive mass balance of fine sediment throughout the CRE. 

Assumptions – Short-Term Targets 

a. Under low water conditions, dam operations (including BHBFs up to 40-45,000 cfs) can be used to 

achieve targets. 

b. Sediment supplies will be adequate to sustain and enhance shoreline habitats and protect and enhance 

camping beaches and other deposits. 

c. By meeting the target, we will also make sand available for aeolian transport to upper benches to 

enhance native riparian community function and protect cultural sites. 

d. Management actions other than dam operations may be used to reach the targets. 

Long-Term Targets (more than 10 years) 

1. Conserve sediment throughout the system to enhance near shore habitat and restore riparian 

function. 

o‘Restore’ ecosystem function (elements and values TBD) that recognize specific influences on the 

ecosystem, such as existence of the dam and non-natives, to the extent possible through 

conservation of sediment. 

oProtect and maintain OHW zone/terrace deposits and vegetation. 

o Maintain a neutral mass balance in the mainstem after achievement of 1983-85 sediment deposits. 

oCRE cultural resources continue to be protected through sediment Aeolian transport and enhanced 

native riparian community function. 

2. Rebuild and stabilize sandbars, campsites, and backwater habitats to 1983-1985 post flood values 

(abundance, grain size, and distribution including volume and areal extent) as hydrologic and safety 

conditions and operational constraints permit (e.g., 60,000-93,000 cfs releases assuming water 

availability). 

Assumptions – Long-Term Targets 

a. Assumes higher water volume availability which permits discharges greater than power plant and jet 

tube capacity. 

b. Enough sediment will accumulate in the system to provide sufficient sediment to achieve targets. 

c. Despite historical losses of sediment in the system, the dam can be operated to meet the targets. 

d. Management actions other than dam operations may be used to reach the targets. 

Process 

Over the 10-year period beginning in 2008, determine if the short-term assumptions are valid. 

NOTE: Not everyone agrees with the assumption that these targets can be met with existing 

sediment inputs and operational “tools.”
Memorandum to TWG from the DFCAHG Page 6 of 26 

November 20, 2007 

Attachment 3: Humpback chub Targets 

These targets were originally proposed by National Park Service, and were determined by consensus 

to be scientifically and technically credible by the Desired Future Conditions AHG. 

Short-Term Targets (10 years) 

1. The Grand Canyon population is maintained as a core over a 5-year period, starting with the first 

point estimate acceptable to the Fish and Wildlife Service, such that the trend in adult (age 4+ years) 

humpback chub estimates does not decline significantly. 

2. HBC population estimate is at least 6,500 adult fish, age 4+ years, and a positive trend is maintained 

from 2008 onwards as determined by ASMR; thus, progress towards the long-term target is being 

made. 

3. Mean estimated recruitment of age-3 years (150–199 mm TL) naturally produced fish equals or 

exceeds mean annual adult mortality. 

4. All aggregations in the mainstem outside the LCR as defined in Valdez and Ryel (1995) have been 

maintained or restored to 1993 levels, and at least one viable spawning aggregation outside the LCR in 

the mainstem of at least 500 adult (age 4+ years) fish has been established so that the historic range is 

partially restored. 

5. Develop at least one spawning aggregation in a tributary. 

6. Prepare, adopt, and implement an emergency response/contingency plan, e.g., for the two Cameron 

bridges spanning the LCR, to protect HBC populations from hazardous material spills that could 

result in catastrophic loss of population. 

7. Assess other emerging threats and develop a contingency plan to address them. 

8. Implement the other highest priority projects listed within the HBC Comprehensive Plan that are 

achievable within 10 years. 

9. Implement requirements of Biological Opinions, as necessary. 

Long-Term Targets (more than 10 years) 

1. HBC population estimate is at least 10,000 adult fish, age 4+ years, as determined by ASMR. 

2. All threats criteria for this recovery unit have been met or eliminated. 

3. The Fish and Wildlife Service has issued a non-jeopardy, non-adverse modification Biological 

Opinion on the operation of Glen Canyon Dam. 

4. HBC population and distribution will meet or exceed short-term targets based on further evaluation 

of the CRE habitat and carrying capacity of the river and perennial tributaries. 

5. A spawning aggregation of at least 1,667 adult (age 4+ years) fish has been established in the 

mainstem. 

6. Spawning aggregations in at least three tributaries have been developed. 

7. Implement the remaining projects listed within the HBC Comprehensive Plan. 

8. Implement requirements of Biological Opinions, as necessary. 

Assumptions and Rationale

a. If there were a lower basin recovery implementation program, and the actions listed in the recovery 

goals were implemented, it would assist in reaching the long-term targets. 

b. Meeting the delisting criteria and issuance of a non-jeopardy opinion will contribute to meeting NPS’ 

and other agencies’ management responsibilities. 

c. The HBC monitoring program will be maintained and enhanced to support evaluation of progress 

toward targets. 
Memorandum to TWG from the DFCAHG Page 7 of 26 

November 20, 2007 

d. Establishment of in-situ refuges and translocation of HBC, and other actions, will meet NPS 

management policies regarding restoring historic range. 

e. The long-term target of 10,000 fish as determined by ASMR will not include fish in the maintstem 

spawning aggregations or tributaries other than the LCR. 

f. The HBC Comprehensive Plan will be finalized and implemented, and will include in-situ refuges and 

translocations, and address hazardous material spills. 

g. The 10-year short-term target period will begin in 2008. 

h. With regard to Short-Term Target #4, the current population numbers of the mainstem aggregations 

are unknown. The assumption is that the target is achievable in the timeframe noted. If the target is 

not achievable in the short-term, it would become a long-term goal. 

 

NOTE: Not everyone agrees with these assumptions. 
Memorandum to TWG from the DFCAHG Page 8 of 26 

November 20, 2007 

Attachment 4: Humpback chub Targets 

These targets were originally proposed by Western Area Power Administration, and were determined 

by consensus to be scientifically and technically credible by the Desired Future Conditions AHG. 

Grand Canyon recovery unit and core population (includes the LCR) 

The Grand Canyon recovery unit of humpback chub (HBC) has recovered as described in the 

2002 Recovery Goals. Recovery actions necessary to meet recovery goals have been 

implemented and threats have been removed or eliminated to ensure the long term survival of the 

recovery unit. 

Short-Term Targets (10 years) 

1. The Grand Canyon core population (recovery unit), trend in adult (age 4+ years) is stable or 

increasing (no significant decline) for a 5 year time period. 

2. Each population estimate within that 5-year time period exceeds the average population estimates of 

years 2002-2006 (about 5,500), and as determined by ASMR (or other acceptable assessment method). 

3. Mean estimated recruitment of age-3 years (150–199 mm TL) naturally produced fish equals or 

exceeds mean annual adult mortality (approximately 24%). 

4. Fish condition can be monitored as a signal of potential changes in recruitment or survival of adults, 

but there should not be a numerical value establish for a target for fish condition. Poor condition 

may signal future declines, but may not signal specific outcomes. 

5. Prepare, adopt, and implement an emergency response/contingency plan, e.g., for the two Cameron 

bridges spanning the LCR, to protect HBC populations from hazardous material spills that could 

result in catastrophic loss of population. 

6. Assess other emerging threats and develop a contingency plan to address them. 

Long-Term Targets (more than 10 years) 

1. The Grand Canyon core population (recovery unit), trend in adult (age 4+ years) does not decline 

significantly for 8 years in a row from the average population estimates of years 2002-2006 (about 

5,500). 

2. Management measures are in place which ensure a high likelihood of continued population stability. 

3. Mean estimated recruitment of age-3 years (150–199 mm TL) naturally produced fish equals or 

exceeds mean annual adult mortality (approximately 24%). 

4. All threats criteria for this recovery unit have been met or eliminated. 

Assumptions and Rationale 

a. The 2002 Recovery Goals are currently undergoing revision in response to a court order requiring 

that the Service include time and costs estimates to recovery as required by the ESA. This revision is 

unlikely to result in significant changes to these goals, and thus, they are reasonable goals to consider 

when developing these targets. 

b. Because the recovery goals (USFWS 2002) do not require a second spawning aggregation within the 

Grand Canyon recovery unit, it will not be required in any revised action which will undergo reconsultation in the LTEP. 

c. Fish condition indices have been proposed as a method for determining health of populations and 

their likelihood of recovery. Although MO 2.3 describes fish condition as an important factor, it may 

be difficult or impossible to a) develop quantitative targets that are reasonable indicators of population 
Memorandum to TWG from the DFCAHG Page 9 of 26 

November 20, 2007 

performance and b) collect the data necessary to evaluate and track fish condition. In the past few 

years the program has stopped or reduced collection of some fish condition data (e.g. weights) due to 

the excessive handling required and the potential adverse impacts on the fish from sampling. This 

MO is helpful in its current form without quantitative targets as fish condition data should be used 

whenever available to help support other evaluations, but may have little utility on its own and may 

actually harm fish if additional data was collected in order to evaluate progress toward condition 

targets. Likewise, although it is important to monitor trends in disease and parasite infection, we 

know too little about the effects of most of these conditions to develop meaningful targets. Rather, 

trends in these conditions may provide more general information that would be helpful to the 

program in understanding potential changes in demographics due to changes in condition/disease 

rates. 

d. The goal of the recovery criteria is to establish stable populations above the 2,100 MVP guideline and 

that the Grand Canyon population should not decline significantly from credible estimates in the time 

frame from 2002-2006. It is assumed if this population was stable from an average population 

estimate from 2002-2006 (about 5000 adults), that this would meet the demographic criteria in the 

2002 Recovery Goals (subject to modification in the revised goals). 

e. Viability – a population of 5,800 – 7,300 adults should have a 99% persistence probability over 40 

generations (based on assumptions in Reed et al. 2003). The 2,100 value for adults in the recovery 

plan provides a guide for a minimum value for a viable population, which is somewhat risk-prone and 

based primarily in genetics, and it assumes limited population variability over a very short (1 year) time 

period. 

f. All adult HBC found downstream of Glen Canyon Dam within the recovery unit designation would 

be considered toward the demographic goal. 

g. The 2002 Recovery Goals require management actions to remove threats to the recovery of the 

Grand Canyon recovery unit. Many of these management actions are likely to be outside of the scope 

of the AMP, but may be important in reaching the recovery goals. The AMWG recommended that a 

recovery implementation program be developed in order to begin to address these needs. If there 

were a lower basin recovery implementation program, it would assist in reaching the targets, especially 

for efforts deemed “out” of the AMP. 

h. Meeting the delisting criteria for the lower recovery unit of HBC and issuance of a non-jeopardy 

opinion will also meet NPS management responsibilities. 

NOTE: Not everyone agrees with these assumptions. 

Discussion and Background 

Humpback chub status and trends below Glen Canyon Dam 

The following text was taken from USGS (2007; page 15): 

“The participants were informed that the current population of adult humpback chub (age-4+) is 

less than 50% of what it was as late as 1990, according to the most recent capture and modeling 

information (Coggins and others, 2006a). This conclusion assumes that the initial 1989 

population estimate was accurate. Since 2000, however, the number of adult fish stabilized at a 

new, lower level, which is estimated at 5,000 (Melis and others, 2006). The recent stabilization of 

the adult population could reflect the loss of humpback chub that resided primarily in the 

mainstem since the late 1980s and the inability of mainstem habitat to support successful 

recruitment. The current population of 5,000 adults may represent the capacity of the Little 
Memorandum to TWG from the DFCAHG Page 10 of 26 

November 20, 2007 

Colorado River. These population changes may or may not reflect a response of the population 

to changes in river conditions or actions taken under the auspices of the GCDAMP. 

The participants also reviewed available information regarding the recruitment abundance of 

humpback chub younger than 4 years old. This segment of the population seems to have reached 

a modern low in 1991. However, numbers of young humpback chub increased steadily during 

the 1990s, returning to approximately late 1980s levels, by 2001, the most recent year for which 

these data are available (U.S. Geological Survey, unpub. data).” 

Thus, the population appears to have stabilized since about 2000 (see Figure 1 below), with good 

recruitment observed at the LCR. Recent unpublished data suggests that the population may have actually 

increased significantly from the low point at about 2000. This cannot be confirmed with published 

materials, but these peer reviewed publications are expected to be available before the completion of the 

draft EIS for the LTEP. 

ESA Recovery Goals 

The Humpback Chub Recovery Goals (USFWS 2002) established by the U.S. Fish and Wildlife Service 

(Service) group all of the humpback chub populations within the Colorado River below Glen Canyon 

Dam as one recovery unit (Lower Basin) and populations above Glen Canyon Dam as a second recovery 

unit (Upper Basin). As a recovery unit, the Service indicated under the ESA that the viability of the Lower 

Basin (Grand Canyon) is necessary to the long-term viability of the entire species, and if the Lower Basin 

was lost, would substantially increase the likelihood of extinction for the species as a whole. The Service 

also defined the Grand Canyon as a “core population” for purposes of the recovery criteria, which is 

supported by spawning within the Little Colorado River (LCR). 

The USFWS (2002) describes the following populations: 

“Six self-sustaining populations of humpback chub are known to exist. Each of these populations 

consists of a discrete reproducing group of fish, with independent stock-recruitment dynamics, 

and is geographically separated from other populations. Five of the populations occur in the 

upper basin recovery unit: (1) Black Rocks, Colorado River, Colorado; (2) Westwater Canyon, 

Colorado River, Utah; (3) Yampa Canyon, Yampa River, Colorado; (4) Desolation/Gray 

Canyons, Green River, Utah; and (5) Cataract Canyon, Colorado River, Utah (Figure 1; Appendix 

A; Valdez and Clemmer 1982; U.S. Fish and Wildlife Service 1990a). The only population in the 

lower basin recovery unit occurs in the mainstem Colorado River in Marble and Grand Canyons 

and the Little Colorado River (LCR).” 

The Recovery Goals argue that a stable population greater than 2,100 adults, within the Grand Canyon 

core population, would be a viable recovery unit if all of the threats were removed (i.e., threats criteria). 

Given the recent stabilization of the Grand Canyon population at numbers above the 2002 Recovery 

Goals (see Figure 1 below from USGS fact sheet 2006-3109), it is possible that no further increase in 

population size may be required under the ESA in order to meet the demographic recovery criteria for 

this recovery unit (assuming the revised goals are similar to the 2002 goals). The recovery goals are 

currently undergoing revision in response to a court order requiring that the Service include time and costs 

estimates to recovery as required by the ESA. This revision is unlikely to result in significant changes to 

these goals. The Court found that the challenge to the recovery goals themselves had no merit (see 

January 18, 2006 Order at page 9, lines 9-15): 
Memorandum to TWG from the DFCAHG Page 11 of 26 

November 20, 2007 

“Accordingly, we conclude that no cause of action arises under 16 U.S.C. §1540(g)(1)(C) for the 

failure to provide for the conservation and survival of the humpback chub, in contrast to the 

development and implementation of a plan to conserve them. We therefore grant defendants' 

motion for summary judgment on this claim (doc. 49). And because this claim is no longer 

before us, we grant defendants' motion to strike the declarations submitted by plaintiffs (doc. 52), 

which are only relevant to plaintiffs' challenges to the substance of the Recovery Goals.” 

The recovery goals provide a rational argument for lumping observed populations within the Grand 

Canyon as one population/recovery unit: “recent studies (Douglas and Marsh 1996; Valdez and Ryel 

1995, 1997) show that humpback chub aggregations in the mainstem Colorado River in Marble and 

Grand Canyons are largely supported by reproduction and recruitment from the LCR, and hence, fish in 

these two systems are treated collectively as one Grand Canyon population.” (USFWS 2002) This 

statement is further supported by recent findings from Douglas and Douglas (2007), which indicate no 

significant genetic differentiation in populations within the Grand Canyon recovery unit (the exception 

may be the 30-mile population which may exhibit some differentiation from the LCR population to 

include variation common in the upper river). 

Viability 

Implicit in the ESA definitions of threatened and endangered and in the principles of conservation 

biology is the need to consider genetics, demographics, population redundancy, and threats (as identified 

by the listing factors in the ESA). The ESA is mandated to recover species to the point that they are “not 

likely” to be in danger of extinction for the foreseeable future throughout all or a significant portion of 

their range. The “not likely” standard represents a minimum threshold of risk, and that recovery should 

also involve maintenance of multiple widespread populations that are independently viable because it is 

less likely that future singular threats will endanger widely separated multiple populations than a single 

population with the same abundance. Viable populations have sufficient numbers of individuals to 

counter the effects of deleterious gene mutations as a result of inbreeding, and to counter the effects of 

deaths exceeding births and recruitment failure for periods of time. Thus, the conservation biology 

principle of redundancy is satisfied by the required multiple genetically and demographically viable, selfsustaining populations. Furthermore, the principle of resiliency is satisfied with sufficiently large 

populations to persist through normal population variations, as well as through unexpected catastrophic 

events. A set of guidelines for viable populations is provided in USFWS (2002, page 9). 

Population size is a major determinant of extinction risk. Reed et al. (2003) undertook a population 

viability analysis (PVA) of 102 vertebrate species to determine what a reasonable range of population sizes 

might be. The mean and median of these estimates was 7316 and 5816 adults. Interestingly, they did not 

find any correlation between taxa, latitude, or trophic level. They did however find a relationship between 

population size and study period. The greater the study period, the greater variation was observed, and 

thus the larger population size needed to buffer that variability over the long term. Without a PVA 

specific to this species, the estimates from Reed et al. (2003) may provide a method to evaluate the 

likelihood of extinction while considering long term population fluctuations due to environmental 

stochasticity, and other factors as described. 

Rationale 

Step 1: M.O. 2.2. The first critical question is whether two spawning populations are needed or just one 

(as required by the 1994 Biological Opinion). Our assessment is that only one spawning population is 
Memorandum to TWG from the DFCAHG Page 12 of 26 

November 20, 2007 

necessary to recover the Grand Canyon recovery unit and meet the requirements of the ESA. As 

described above, the Grand Canyon recovery unit is but one of five self-sustaining populations within the 

species designation. Thus, five populations already exist and offer a substantial buffer against extinction 

(see USFWS 2002 at section 3.1.3). Adding a sixth self-sustaining population (second within the Grand 

Canyon) may offer some marginal increase in the viability, but would likely be susceptible to similar 

threats to the LCR aggregation below Glen Canyon Dam. 

The RPA from the 1994 Biological Opinion requires two spawning aggregations of humpback chub in 

the Grand Canyon recovery unit, while the remanded 2002 recovery goals did not require this additional 

spawning aggregation. This has created a legal grey area that has not been resolved. This could have been 

resolved through reconsultation after the 2002 Recovery Goals were released. 

In order to jeopardize under section 7, an action must be shown to jeopardize the continued survival and 

recovery of a species. An RPA is a substitute action presented in a jeopardy opinion, and is defined as 

those activities required to avoid the condition which resulted in jeopardy. Thus, an RPA cannot require 

actions beyond which would result in recovery of the species, or in this case the recovery unit. Looking at 

it differently, if the humpback chub population has met the demographic criteria in the recovery goals and 

the threats have also been satisfactorily ameliorated, then any reconsultation would be unlikely to reach a 

jeopardy conclusion. Because this population appears to have met the demographic criteria from the 

2002 Recovery Goals, consultation should be (and is expected to be) reinitiated on the LTEP EIS 

preferred alternative. BOR is not bound to submit an alternative that conforms to a 13 year old biological 

opinion. In fact, that would ignore 13 years of science and learning, and would also ignore the recovery 

goals. Reconsultation allows an action agency to propose alternatives which avoid jeopardy in a manner 

different from a previously issued RPA. In order to conclude jeopardy on the two population issue, 

USFWS would have to argue that the action jeopardizes the recovery of HBC in the lower recovery unit 

by not allowing for the establishment of two populations of the one population that is required for 

recovery. On the face of it, it presents a logic problem. This is not to say that a jeopardy determination is 

not possible, only that one cannot argue for a second population solely based on the 1994 RPA. 

Step 2: Determine the genetic effective population size (Ne) needed for this population. Ne is the number 

of individuals contributing genes to the next generation (Wright 1931). An Ne of 50 adults avoids 

inbreeding depression in the short-term; an Ne of 500 is needed to avoid serious long-term genetic drift; 

an Ne of 1,000 or more provides a conservative estimate beyond which significant additional genetic 

variation is not expected (Allendorf and Ryman 2002). An Ne of 500 is commonly used for fishes 

(Waples 1990; Bartley et al. 1992; Allendorf et al. 1997; Rieman and Allendorf 2001). USFWS (2002) used 

an Ne of 500, and represents a reasonable choice for long-term conservation. 

Step 3: The next step is to determine what adult population size equates to an Ne of 500. This will be 

quite a bit larger than Ne because it is the number of adults contributing genes to the next generation. Due 

to various sex ratios, breeding cycles, and breeding types, N can be substantially higher depending upon 

the species. The ratio of Ne to N varies by species and with an overall average of about 0.30, which is the 

ratio reported for chinook salmon (McElhany et al. 2000) and other Pacific salmon species (Waples et al. 

1990a, 1990b). This overall average ratio for fishes of 0.30 was used by USFWS (2002) to determine the 

number of adult humpback chub needed to support an Ne of 500. Given the lack of data available for 

humpback chub, this is a reasonable value available in the literature. This equates to an adult population 

size (N) of 1,667. 
Memorandum to TWG from the DFCAHG Page 13 of 26 

November 20, 2007 

Step 4: Use a minimum viable population (MVP) approach; MVP is defined as a population that is 

sufficiently abundant and well adapted to its environment for long-term persistence without significant 

artificial demographic or genetic manipulations. Meffe and Carroll (1994) define an MVP as “the smallest 

isolated population size that has a specified percent chance of remaining extant for a specified period of 

time in the face of foreseeable demographic, genetic, and environmental stochasticities, plus natural 

catastrophes.” Thus, the concept is that a viable population would not approach Ne in the time frame 

considered. The following factors could be considered in increasing the population number to reach a 

target MVP: 

a. Demographic stochasticity (recruitment) 

b. Potential for human-related impacts 

c. Likelihood of sustained population declines 

d. Environmental stochasticity 

e. Other ecosystem related factors 

f. Risk – consider the likelihood that various “bad” things (above) may happen and how 

often/likely the population should be able to survive them. Under the ESA this is often 

expressed as the likelihood of reaching a certain low population size in X amount of years 

(i.e., 10% chance in 100 years). For this species, redundancy of viable populations provide 

a substantial buffer against risk. 

Examples of additions to the Ne value include the southern sea otter (potential for oil spills) and Steller sea 

lion (history of large declines due to a variety of threats). For humpback chub, USFWS (2002) reached a 

minimum viable population size of 2,100 adults. This was derived by adding 24% to the Ne of 1,667 to 

account for an estimate of the average annual mortality of adult humpback chub (1,667 x 1.24 = 2,067 or 

about 2,100, see USFWS 2002, Box 4; Valdez and Ryel 1995, 1997). An average annual adult mortality 

factor was added to buffer against an event that may result in recruitment failure for one year. 

However, the intent of the 2002 Recovery Criteria was to establish stable populations above the 2,100 

MVP guideline and that the Grand Canyon population should not decline significantly from credible 

estimates (presumably current). It is assumed if this population was stable from an average population 

estimate from 2002-2006 (about 5,500 adults), that this would meet the demographic criteria in the 2002 

Recovery Goals (subject to modification in the revised goals). A population of 5,800 – 7,300 adults should 

have a 99% persistence probability over 40 generations (based on assumptions in Reed et al. 2003). The 

2,100 value for adults in the recovery plan provides a guide for a minimum value for a viable population, 

which is somewhat risk-prone and based primarily in genetics, and it assumes limited population variability 

over a very short (1 year) time period. 

Discussion of the approach to achieve targets 

Based on the proposed targets and the 2002 Recovery Goals, the focus should be the continued 

stabilization (or increase) of humpback chub within the Grand Canyon. Substantial changes to the current 

operating regime at Glen Canyon Dam should be considered with caution as these changes may introduce 

new threats which might undermine the recent stabilization and recovery. It is possible that this 

population may continue to stabilize and may soon meet the demographic recovery criteria of the 2002 

Recovery Goals. At that point, the only obstacle between considering this recovery unit recovered would 

be positive evidence that the threats had been removed. Thus, one viable approach within the LTEP 

could be to continue stabilizing humpback chub while implementing experiments to further describe how 

the operation of Glen Canyon Dam affects the ability of this recovery unit to stabilize. Further, 

consultation on an LTEP alternative which implemented actions similar to those that resulted in recovery 
Memorandum to TWG from the DFCAHG Page 14 of 26 

November 20, 2007 

should have a low likelihood of resulting in a jeopardy decision. Conclusions reached in the 1994 opinion 

did not consider relevant new scientific information such as the recent population stabilization and the 

2002 goals, and thus, meets the reinitiation requirements under the ESA and the Section 7 Consultation 

Handbook. We expect that reconsultation will occur, and was described in the settlement agreement to 

occur by May 1, 2008 (see agreement August 25, 2006). 

Given that the 2002 Recovery Goals consider a toxic spill upstream in the Little Colorado River to be a 

substantial threat, and s the primary threat to this core population, efforts should be considered which 

reduce this threat (e.g., bridge modifications), and efforts to develop additional spawning populations 

should be critically evaluated in light of these goals, especially those which result in take that does not 

relate directly to achieving the recovery goals. 

Figure 1. Most recent HBC trend estimates through 2005 for the LCR only (from USGS Fact 

Sheet 2006-3109, July 2006). 

Year

Adult Abundance (Age 4+)

19891990199119921993199419951996199719981999200020012002200320042005

0 5000 10000 15000

Variable Mortality

Constant Mortality
Memorandum to TWG from the DFCAHG Page 15 of 26 

November 20, 2007 

Literature Cited 

Allendorf, FW and N. Ryman. 2002. The role of genetics in population viability analysis. 

Pages 50-85 in S. R. Beissinger and D. R. McCullough, eds. Population Viability Analysis. 

University Of Chicago Press. 

Douglas, M.R. and M.E. Douglas. 2007. Genetic structure of Humpback Chub Gila cypha

and Roundtail Chub G. robusta in the Colorado River Ecosystem. Final Report May 2007. GCMRC 

contract 051884. 

Douglas, M.E., and P.C. Marsh. 1996. Population estimates/population movements of Gila 

cypha, an endangered cyprinid fish in the Grand Canyon region of Arizona. Copeia 

1996:15–28. 

Grand Canyon Monitoring and Research Center, USGS workshop on scientific aspects of a long-term 

experimental plan for Glen Canyon Dam, April 10–11, 2007, Flagstaff, Arizona: U.S. Geological Survey 

Scientific Investigations Report 2007–xxx, 60 p. 

McElhany, P., M. Ruckelshaus, M.J. Ford, T. Wainwright, and E. Bjorkstedt. 2000. Viable 

salmonid populations and the recovery of evolutionary significant units. National Marine 

Fisheries Service. Northwest Fisheries Science Center 

Meffe, G.K., and C.R. Carroll. 1994. Principles of conservation biology. Sinauer Associates, 

Inc. Publishers, Sunderland, Massachusetts. 

Reed, D.H., J.J. O’Grady, B.W. Brook, J.D. Ballou, and R. Frankham. 2003. Estimates of minimum viable 

population sizes for vertebrates and factors influencing those estimates. Biol. Cons. 113 (2003) 23-34. 

Rieman, B.E. and F.W. Allendorf. 2001. Effective population size and genetic conservation criteria for 

bull trout. North American Journal of Fisheries Management 21: 756-764. 

U.S. Fish and Wildlife Service. 2002. Humpback chub (Gila cypha) Recovery 

Goals: amendment and supplement to the Colorado Squawfish Recovery Plan. U.S. Fish 

and Wildlife Service, Mountain-Prairie Region (6), Denver, Colorado. 

Valdez, R.A., and R.J. Ryel. 1995. Life history and ecology of the humpback chub (Gila cypha) 

in the Colorado River, Grand Canyon, Arizona. Final Report of Bio/West, Inc., Logan, 

Utah, to U.S. Bureau of Reclamation, Salt Lake City, Utah. 

Valdez, R.A., and R.J. Ryel. 1997. Life history and ecology of the humpback chub in the 

Colorado River in Grand Canyon, Arizona. Pages 3–31 in C. van Riper, III and E.T. 

Deshler (eds.). Proceedings of the Third Biennial Conference of Research on the 

Colorado Plateau. National Park Service Transactions and Proceedings Series 97/12. 

Waples, R.S., G.A. Winans, F.M. Utter, and C. Mahnken. 1990a. Genetic approaches to the management 

of Pacific salmon. Fisheries 15(5):19–25. 
Memorandum to TWG from the DFCAHG Page 16 of 26 

November 20, 2007 

Waples, R.S., G.A. Winans, F.M. Utter, and C. Mahnken. 1990b. Genetic monitoring of Pacific salmon 

hatcheries. Pages 33–37 in Genetics in aquaculture. Proceedings of the 16th U.S.-Japan meeting on 

aquaculture, 20–21 October 1987. U.S. Department of Commerce, Washington D.C. 
Memorandum to TWG from the DFCAHG Page 17 of 26 

November 20, 2007 

Attachment 5: Charge to the DFC Ad Hoc Group from 

the Bureau of Reclamation 

. . . With the assistance of 16 cooperating agencies, Reclamation is now preparing an EIS in 

compliance with the National Environmental Policy Act. Consistent with input from the cooperating 

agencies, we anticipate that some of the alternatives in the EIS may utilize current and desired future 

resource conditions as triggering mechanisms for conducting or modifying specific experimental 

actions. These desired resource conditions are also evidenced in the management objectives 

of the AMP strategic plan, but have never been quantified or finalized. 

Definition of these objective targets could improve future decision making during the term of the 

LTEP experiment, recognizing that the ultimate goal of the LTEP is to better define which 

management actions will lead to achieving these desired future resource conditions. . . . [A]fter 

discussion within DOI, Reclamation would like to request that the TWG dedicate sufficient effort to 

develop a set of technical options for these desired resource condition targets, and present its 

approaches on these targets for consideration by the full AMWG by December 2007. 

These technical options for resource target levels should consider what would be desired over the 

long term and identify what may be achievable within the next 10 years to correspond to the potential 

duration of the LTEP. As these targets are considered, we would encourage that an ecosystem 

perspective be utilized as individual targets are discussed, while recognizing that dam capabilities and 

hydrology may limit actions to achieve these targets. The TWG should consider targets for each 

of the strategic plan management objectives but should initially concentrate on the two main 

resources of focus in the LTEP, i.e., humpback chub and sediment conservation. Ideally, 

options for these targets should be: 

 Easily understandable 

 Measurable 

 Geographically specific 

 Feasible both financially and scientifically 

 Written at a level of detail consistent with current knowledge 

 Compatible with the AMP goals and management objectives 

Maps, photos, graphs, or other materials that would assist the AMWG in understanding the technical 

aspects of the target levels should be included. In addition, the TWG should assess such things as the 

potential effects of such target levels (including effects on other resources). 

Thank you for your dedicated efforts in the AMP. 
Memorandum to TWG from the DFCAHG Page 18 of 26 

November 20, 2007 

Attachment 6: AMP Strategic Plan – Relevant Excerpts 

COMBINED VISION AND MISSION STATEMENT 

The Grand Canyon is a homeland for some, sacred to many, and a national treasure for all. In honor of 

past generations, and on behalf of those of the present and future, we envision an ecosystem where the 

resources and natural processes are in harmony under a stewardship worthy of the Grand Canyon. 

We advise the Secretary of the Interior on how best to protect, mitigate adverse impacts to, and improve 

the integrity of the Colorado River ecosystem affected by Glen Canyon Dam, including natural biological 

diversity (emphasizing native biodiversity), traditional cultural properties’ spiritual values, and cultural, 

physical, and recreational resources through the operation of Glen Canyon Dam and other means. 

We do so in keeping with the federal trust responsibilities to Indian tribes, in compliance with applicable 

federal, state, and tribal laws, including the water delivery obligations of the Law of the River, and with 

due consideration to the economic value of power resources. 

This will be accomplished through our long-term partnership utilizing the best available scientific and 

other information through an adaptive ecosystem management process. 

DEFINITION OF MANAGEMENT OBJECTIVE

“Management Objectives are defined as the desired future condition of a particular resource.” 

DEFINITION OF ECOSYSTEM MANAGEMENT 

“An ecosystem management approach differs from an issue-, species-, or resource-specific 

approach. Ecosystem management is a method for sustaining or restoring ecosystems and their 

functions and values. “It is goal driven, and it is based on a collaboratively developed vision of 

desired future conditions that integrates ecological, economic, and social factors. It is applied within 

a geographic framework defined primarily by ecological boundaries.” (Interagency Ecosystem 

Management Task Force 1995). Ecosystem management is a process that attempts to mimic 

appropriate ecosystem patterns (abundance and distribution of species and habitats) and ecosystem 

processes (drivers of ecosystem patterns). It includes managing for viable populations of all native 

species.” 

PRINCIPLES

The ten principles of the Glen Canyon Dam Adaptive Management Program are: 

1. The goals represent a set of desired outcomes that together will accomplish our vision and achieve the 

purpose of the Grand Canyon Protection Act. Some of the objectives and actions that fall under 

these goals may not be the responsibility of the Adaptive Management Program, and may be funded 

by other sources, but are included here for completeness. 

2. The construction of Glen Canyon Dam and the introduction of non-native species have irreversibly 

changed the Colorado River ecosystem. 

3. Much remains unknown about the Colorado River ecosystem below Glen Canyon Dam and how to 

achieve the Adaptive Management Program goals. 
Memorandum to TWG from the DFCAHG Page 19 of 26 

November 20, 2007 

4. The Colorado River ecosystem is a managed ecosystem. An ecosystem management approach, in lieu 

of an issues, species, or resources approach, will guide our efforts. Management efforts will prevent 

any further human-induced extirpation or extinction of native species. 

5. An adaptive management approach will be used to achieve Adaptive Management Program goals, 

through experimentation and monitoring, to meet the intent of the Grand Canyon Protection Act, 

Glen Canyon Dam Environmental Impact Statement, and the Record of Decision. 

6. Understanding cause and effect relationships is essential for managing the Colorado River ecosystem. 

The adaptive management approach will be geared toward gaining an improved understanding of the 

cause and effect relationships that occur within the Colorado River ecosystem, and their connection, if 

any, to dam operations, while also documenting resource status and trends. 

7. Dam operations and management actions will be tried that attempt to return ecosystem patterns and 

processes to their range of natural variability. When this is not appropriate, experiments will be 

conducted to test other approaches. 

8. Because management actions to achieve a goal may benefit one resource or value and adversely affect 

another, those action alternatives that benefit all resources and values will be pursued first. When this 

is not possible, actions that have a neutral impact, or as a last resort, actions that minimize negative 

impacts on other resources, will be pursued consistent with the Glen Canyon Dam Environmental 

Impact Statement and the Record of Decision. 

9. If the target of a management objective proves to be inappropriate, unrealistic, or unattainable, the 

Adaptive Management Program will reevaluate that target and the methods used to attain it. 

10. Recognizing the diverse perspectives and spiritual values of the stakeholders, the unique aesthetic 

value of the Grand Canyon will be respected and enhanced. 
Memorandum to TWG from the DFCAHG Page 20 of 26 

November 20, 2007 

Attachment 7: Approved AMP Goals and MOs – HBC and 

Sediment 

Goal 2. Maintain or attain viable populations of existing native fish, remove jeopardy for 

humpback chub and razorback sucker, and prevent adverse modification to their critical 

habitats. 

Management Objective Attributes in 

Need of 

Targets 

Original Metric Original Comment (if any) 

Abundance Number of HBC 150 

mm and larger. 

(Length is based on the 

size at which a HBC is 

able to be pit-tagged.) 

The target is viable populations 

and removal of jeopardy. 

Target to be based on 91-96 

population estimate, PVA, & 

Ne. 

M.O. 2.1 Maintain or attain 

humpback chub 

abundance and year-class 

strength in the LCR and 

other aggregations at 

appropriate target levels 

for viable populations and Year-class # of HBC 51 mm to Intended to be an index that to remove jeopardy. strength 150 mm will indicate spawning success. 

Metric is catch per unit The target is viable populations 

effort (CPUE). See and removal of jeopardy. 

Gorman and 

Bramblett.(9) See 

synthesis by Coggins. 

M.O. 2.2 Sustain or Spawning The target is removal of 

establish viable HBC 

spawning aggregations 

outside of the LCR in the 

Colorado River ecosystem 

below Glen Canyon Dam 

to remove jeopardy. 

aggregation jeopardy. 

M.O. 2.3 Maintain HBC Condition 

and other native fish 

condition and 

disease/parasite numbers 

in LCR and other 

aggregations at an 

appropriate target level for 

viable populations and to 

remove jeopardy. 

There should be a minimum 

threshold of condition. 

The target is viable populations 

and removal of jeopardy. PEP 

Disease and should be asked to evaluate the 

method that would be used to other 

calculate condition and the parasites value to be established as the 

threshold. 
Memorandum to TWG from the DFCAHG Page 21 of 26 

November 20, 2007 

Management Objective Attributes in Original Metric Original Comment (if any) 

Need of 

Targets 

M.O. 2.4 Reduce native Mortality due The target is reduction of nonfish mortality due to nonnative fish 

predation/competition as a 

percentage of overall 

mortality in the LCR and 

mainstem to increase 

native fish recruitment. 

to non-native native fish predation so it does 

fish not impinge on native fish 

predation/co viability. Linkages: The native 

mpetition as fish MOs in Goal 2 and Goal 3.

a percentage 

of overall 

mortality 
Memorandum to TWG from the DFCAHG Page 22 of 26 

November 20, 2007 

Goal 8: Maintain or attain levels of sediment storage within the main channel and along 

shorelines to achieve GCDAMP ecosystem goals. 

Management Attributes in Need Original Metric Original Comment (if any) 

Objective of Targets 

Abundance Metric is volume 

(m3) as a rolling 

average. 

Target is current volumes or 

higher (trend), including some 

timeframe based on tributary 

inputs and high flows timing. 

Grain-size Metric is D50 

(median) grain size. 

Also, see 

Kondolf.(16)

Target is current level or finer 

(trend), including some 

timeframe based on reach, 

tributary inputs, and high flows 

timing. 

M.O. 8.1 Maintain or 

attain fine sediment 

abundance, grain-size, 

distribution in the 

main channel below 

5,000 cfs

Distribution Metric is patchiness Target is current level or more 

and area (m2) of areally extensive (trend), 

sand on channel including some timeframe 

bottom. based on tributary inputs and 

high flows timing. 

2 Abundance Metric is area (m ) 

and volume (m3) as 

a rolling average. 

Target includes some timeframe 

based on tributary inputs and 

high flows timing. 

Grain-size Target includes some timeframe 

based on tributary inputs and 

high flows timing. See 

Kondolf. 

M.O. 8.2 Maintain or 

attain fine sediment 

abundance, grain-size, 

and distribution within 

channel margins (not 

eddies) from 5,000 to 

25,000 cfs 

Distribution Metric is number of Target includes some timeframe 

sandbars by reach. based on tributary inputs and 

high flows timing. 

Abundance Metric is volume 

(m3) as a rolling 

average. 

Target includes some timeframe 

based on tributary inputs and 

high flows timing. 

Grain-size Target includes some timeframe 

based on tributary inputs and 

high flows timing. 

M.O. 8.3 Maintain or 

attain fine sediment 

abundance, grain-size, 

and distribution, 

within eddies below 

5,000 cfs 

Distribution Metric is number of Target includes some timeframe 

sandbars by reach. based on tributary inputs and 

high flows timing. 
Memorandum to TWG from the DFCAHG Page 23 of 26 

November 20, 2007 

Management Attributes in Need Original Metric Original Comment (if any) 

Objective of Targets 

2 Abundance Metric is area (m ) Target includes some timeframe 

and volume (m3) as 

a rolling average. 

based on tributary inputs and 

high flows timing. The target 

level should consider spawning 

habitat for trout in Glen Canyon 

and sediment needed for BHBFs.

Grain-size Target includes some timeframe 

based on tributary inputs and 

high flows timing. The target 

level should consider spawning 

habitat for trout in Glen Canyon 

and sediment needed for BHBFs.

M.O. 8.4 Maintain or 

attain fine sediment 

abundance, grain-size, 

and distribution within 

eddies between 5,000 

to 25,000 cfs 

Distribution Metric is number of Target includes some timeframe 

sandbars by reach based on tributary inputs and 

high flows timing. The target 

level should consider spawning 

habitat for trout in Glen Canyon 

and sediment needed for BHBFs. 

2 Abundance Metric is area (m ) 

and volume (m3) as 

a rolling average. 

Grain-size 

M.O. 8.5 Maintain or 

attain fine sediment 

abundance, grain-size, 

and distribution on 

shorelines between 

25,000 cfs and the Distribution Metric is number of 

uppermost effects of sandbars by reach. maximum dam 

releases.* 

Abundance 

Grain-size 

M.O. 8.6 Maintain or 

attain coarse sediment 

(greater than 2 mm) 

abundance, grain-size Distribution 

and distribution 

throughout the 

Colorado River 

Ecosystem needed to 

achieve GCDAMP 

ecosystem goals. 

* This Management Objective is intended to include all shorelines (eddies and channel margins) 

between 25,000 cfs and the highest level of potential dam effects on pre-dam sand bars (about 

125,000 cfs or pre-dam alluvium (pda) terrace of Hereford et al. 1998). The highest level will be 

determined through discussions with sedimentological, cultural, recreational, and riparian 
Memorandum to TWG from the DFCAHG Page 24 of 26 

November 20, 2007 

workers on how best to constrain this boundary and in how many areas it should be 

monitored. 

NOTE: Coarse sediment is important to the ecosystem, as is fine sediment. There is a 

Management Objective on rapids navigability under the recreation goal that indirectly addresses 

debris flows, as well as an MO on trout spawning habitat under the trout goal. 

Information Need: consult with various researchers to determine how best to break out subreaches from the three broader fine sediment reaches as described above. The riparian group 

suggested developing a table that has various resource concerns on the X-axis and various 

processes on the Y-axis. The recreation group suggested developing a table that has river miles 

(-15 to 278) on the X-axis and various resources on the Y-axis (those resource areas impacted 

by sedimentological processes). 
Memorandum to TWG from the DFCAHG Page 25 of 26 

November 20, 2007 

Attachment 8: Statement of Purpose and Decision Rule 

Workshop Purpose and Product 

The product of the Desired Future Conditions Workshop is a recommendation to the TWG on target 

levels for AMWG-approved Management Objectives for Humpback chub and sediment. These will be 

considered by the Technical Work Group (TWG) for use in the LTEP EIS by the Bureau of Reclamation 

(see the BOR charge to the TWG). 

It is anticipated that members of the Desired Future Conditions Ad Hoc Group (DFCAHG) and TWG 

will have different perspectives on targets. In addition, it is consistent with the charge from BOR that a 

range of targets be forwarded to AMWG from TWG. 

It is also anticipated that DFCAHG members can agree that the rationale for a particular target is 

scientifically and technically credible without necessarily agreeing with the assumptions themselves or the 

resulting targets. “Scientifically and technically credible” means that the rationale is based on 

 plausible interpretations of science, 

 rational arguments and methods, and 

 reasonable assumptions, 

and that its conclusions are supported by the available data. 

Therefore, the purpose of this workshop is to review various proposed rationales used to develop target 

levels, and to come to consensus on the question: 

“Is this rationale for developing target levels 

scientifically and technically credible?” 

Those rationales (and the resulting range of targets) for which the group agrees that the answer to 

the question is “yes” will be recommended to TWG. 

Workshop Decision Rule

At the end of the workshop, the Ad Hoc Group members will be asked to approve, by consensus, a 

recommendation to the TWG that will probably consist of several different rationales for 

developing targets, along with the resulting target levels. In order to reach that final 

recommendation, the group will consider individual rationales for developing targets, and develop at 

least provisional consensus on each one. 

During discussion on individual rationales, if there is disagreement on whether the rationale is 

scientifically and technically credible, the Ad Hoc Group sincerely commits to reaching consensus: 

they will discuss the issues with a goal of thoroughly exploring and understanding the areas of 

agreement and disagreement, and try to find ways to reach consensus. This will entail each member 

committing to help others understand his or her point of view, as well as committing to learn from 

others about their points of view. Voting will not be needed or used in this process. 

An example of finding a way to reach consensus might be the addition of text that describes a 

plausible and different interpretation of the science in the proposed rationale, and notes that the 
Memorandum to TWG from the DFCAHG Page 26 of 26 

November 20, 2007 

proposer of the rationale puts greater emphasis on a different interpretation. This allows others to 

better understand the rationale and a potential disagreement. 

 

An example of how the consensus-building process might work is as follows: If someone objects 

to part of a rationale, the facilitator might say something like, “How can the rationale be modified 

so that it is acceptable to you?” If the modification is simple, the facilitator may ask the group, 

“Does anyone have an objection to modifying the rationale so that...?” If there is none, the 

group will have consensus on the modification. If there are objections, or if the modification is 

substantial, they will be thoroughly discussed and worked through. 

If consensus cannot be reached that a particular rationale is scientifically and technically credible, the 

reasons will be recorded in the notes to the workshop, and the rationale and the resultant targets will not 

be included in the recommendation to the TWG. 

Consensus Definition 

In the course of the workshop, consensus on an individual rationale is defined as follows: Each member 

of the DFCAHG understands the proposed rationale for developing targets, and agrees that it is 

scientifically and technically credible. Each member can say that his or her point of view and concerns 

were heard, and, to the extent practicable and necessary, changes were made to accommodate those 

concerns. 

At the end of the workshop, consensus on the recommendation to TWG is defined as follows: Each 

member of the DFCAHG endorses the DFC recommendation being forwarded to the TWG for 

consideration in the LTEP. Each member can say that her or his point of view and concerns were heard, 

and, to the extent practicable and necessary, changes were made to accommodate those concerns. Each 

member supports the rationale behind the target levels, to the extent that it describes the science and the 

assumptions used. 

Participation and Determination of Consensus 

Each agency represented on the Ad Hoc Group may have up to two people present, both of whom may 

freely participate in the workshop discussions. Only they will participate in the determination of 

consensus. If two representatives from an agency are participating in the workshop, a spokesperson who 

will announce whether the agency agrees with a proposed consensus will be identified at the beginning of 

the workshop.